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Search Results (1,124)

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14 pages, 1351 KiB  
Article
Movement Behaviors and Bone Biomarkers in Young Pediatric Cancer Survivors: A Cross-Sectional Analysis of the iBoneFIT Project
by Jose J. Gil-Cosano, Esther Ubago-Guisado, Francisco J. Llorente-Cantarero, Andres Marmol-Perez, Andrea Rodriguez-Solana, Juan F. Pascual-Gazquez, Maria E. Mateos, Jose R. Molina-Hurtado, Beatriz Garcia-Fontana, Pedro Henrique Narciso, Panagiota Klentrou and Luis Gracia-Marco
Nutrients 2024, 16(22), 3914; https://doi.org/10.3390/nu16223914 (registering DOI) - 16 Nov 2024
Viewed by 270
Abstract
Background/Objectives: This study aims to investigate the association of movement behaviors with irisin, sclerostin, and bone turnover markers in young pediatric cancer survivors. Methods: A total of 116 young pediatric cancer survivors (12.1 ± 3.3 years; 42% female) were recruited. Time spent in [...] Read more.
Background/Objectives: This study aims to investigate the association of movement behaviors with irisin, sclerostin, and bone turnover markers in young pediatric cancer survivors. Methods: A total of 116 young pediatric cancer survivors (12.1 ± 3.3 years; 42% female) were recruited. Time spent in movement behaviors over at least seven consecutive 24 h periods was measured by accelerometers (wGT3x-BT accelerometer, ActiGraph). Blood samples were collected at rest and serum was analyzed for irisin, sclerostin, cross-linked telopeptide of type I collagen (CTX), procollagen type I amino-terminal propeptide (P1NP), total osteocalcin (OC), alkaline phosphatase (ALP), 25-hydroxyvitamin D, parathyroid hormone (PTH), calcium, phosphorous, and magnesium. Results: Irisin and sclerostin were not significantly correlated with bone turnover markers. Sedentary time was negatively correlated with the P1NP (r = −0.411, p = 0.027) and total OC (r = −0.479, p = 0.015) Z-scores, whereas moderate-to-vigorous physical activity was positively correlated with the P1NP (r = 0.418, p = 0.024) and total OC (r = 0.478, p = 0.016) Z-scores. Moreover, total physical activity was positively correlated with the total OC Z-score (r = 0.448, p = 0.025). Finally, the uncoupling index [CTX/P1NP] was positively correlated with sedentary time (r = 0.424, p = 0.012) and negatively correlated with light physical activity (r = −0.352, 0.041). Conclusions: Reducing sedentary time and increasing physical activity may favor bone formation over resorption in young pediatric cancer survivors. Full article
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Figure 1
<p>Flowchart of the study. PA, physical activity; PTH, parathyroid hormone; ALP, alkaline phosphatase; CTX, collagen type I cross-linked C-telopeptide; P1NP, procollagen type I N-terminal propeptide; OC, osteocalcin.</p>
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<p>Bone marker plot with 95% confidence ellipsis from (<b>A</b>) CTX/P1NP and (<b>B</b>) CTX/OC.</p>
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<p>Relationships of circulating sclerostin (panel (<b>A</b>–<b>C</b>)) and irisin (panel (<b>D</b>–<b>F</b>)) with bone turnover markers. CTX, collagen type I cross-linked C-telopeptide; P1NP, procollagen type I N-terminal propeptide; OC, osteocalcin.</p>
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<p>Relationships between movement behaviors and the uncoupling index CTX/P1NP (panel (<b>A</b>–<b>D</b>)) and the uncoupling index CTX/OC (panel (<b>E</b>–<b>H</b>)). SB, sedentary behavior; LPA, light physical activity; MVPA, moderate-to-vigorous physical activity; CTX, collagen type I cross-linked C-telopeptide; P1NP, procollagen type I N-terminal propeptide; OC, osteocalcin. Boldface indicates statistical significance.</p>
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15 pages, 3198 KiB  
Article
Inhalable Anti-EGFR Antibody-Conjugated Osimertinib Liposomes for Non-Small Cell Lung Cancer
by Apoorva Daram, Shruti S. Sawant, Dhwani A. Mehta, Carlos A. Sanhueza and Nitesh K. Kunda
Pharmaceutics 2024, 16(11), 1444; https://doi.org/10.3390/pharmaceutics16111444 - 12 Nov 2024
Viewed by 408
Abstract
Background: Non-small cell lung cancer (NSCLC) is a leading cause of cancer deaths globally. The most extensive treatment is Tyrosine Kinase Inhibitors (TKIs) that target epidermal growth factor receptor (EGFR) overexpression. Osimertinib, a third-generation TKI is approved to target EGFR exon 19 [...] Read more.
Background: Non-small cell lung cancer (NSCLC) is a leading cause of cancer deaths globally. The most extensive treatment is Tyrosine Kinase Inhibitors (TKIs) that target epidermal growth factor receptor (EGFR) overexpression. Osimertinib, a third-generation TKI is approved to target EGFR exon 19 deletions or exon 21 L858R mutations. However, resistance is inevitable due to emergence of triple mutations (sensitizing mutations, T790M and C797S). To overcome this challenge, a combinatorial approach was used wherein Osimertinib liposomes were conjugated with cetuximab (CTX), an anti-EGFR monoclonal antibody, to improve drug efficacy and delivery. Additionally, pulmonary administration was employed to minimize systemic toxicity and achieve high lung concentrations. Methods: Osimertinib liposomes (OB-LPs) were prepared using thin film hydration method and immunoliposomes (CTX-OB-LPs) were prepared by conjugating the OB-LPs surface with CTX. Liposomes were characterized for particle size, zeta-potential, drug loading, antibody conjugation efficiency, in vitro drug release, and aerosolization performance. Further, the in vitro efficacy of immunoliposomes was evaluated in H1975 cell line. Results: Immunoliposomes exhibited a particle size of 150 nm, high antibody conjugation efficiency (87%), efficient drug release, and excellent aerosolization properties with an aerodynamic diameter of 3 μm and fine particle fraction of 88%. Furthermore, in vitro studies in H1975 cells showed enhanced cytotoxicity with CTX-OB-LPs displaying 1.7-fold reduction and 1.2-fold reduction in IC50 compared to Osimertinib and OB-LPs, respectively. The CTX-OB-LPs also significantly reduced tumor cell migration and colonization compared to Osimertinib and OB-LPs. Conclusions: These successful results for EGFR-targeting inhalable immunoliposomes exhibited potential for contributing to greater anti-tumor efficacy for the treatment of non-small cell lung cancer. Full article
(This article belongs to the Section Nanomedicine and Nanotechnology)
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<p>Schematic diagram for liposomal formulation preparation.</p>
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<p>The XRD diffractogram of OB, blank formulation (blank LPs), unconjugated OB liposomes (OB-LPs), and conjugated OB liposomes (CTX-OB-LPs). The crystalline peaks of OB are absent in the XRD diffractogram of OB-LPs and CTX-OB-LPs, indicating drug encapsulation within the liposomes.</p>
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<p>(<b>a</b>) Cumulative release profile for OB from immunoliposomes (CTX-OB-LPs) in phosphate buffer saline (PBS), pH 7.4. Data represents mean ± SD (<span class="html-italic">n</span> = 4). (<b>b</b>) In vitro aerosol deposition profile represented as percentage of drug deposited on each stage of next generation impactor (NGI). Data represents mean ± SD (<span class="html-italic">n</span> = 3).</p>
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<p>Kinetic analysis using SPR for the (<b>a</b>) binding of antibodies (CTX) to the EGFR protein and (<b>b</b>) binding of CTX-OB-LPs to the EGFR protein. Data were fitted using the TraceDrawer software at various concentrations injected at 20 μL/min over EGFR immobilized on the sensor’s surface. Data represents mean ± SD (<span class="html-italic">n</span> = 3).</p>
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<p>Cytotoxicity studies after 72 h treatment, as determined using the MTT assay in the H1975 cell line. (<b>a</b>) Blank liposomes (blank LPs) and CTX-conjugated liposomes (CTX-LPs); (<b>b</b>) OB, unconjugated OB liposomes (OB-LPs), and conjugated OB liposomes (CTX-OB-LPs). Data represents mean ± SD (<span class="html-italic">n</span> = 3).</p>
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<p>Colony-forming ability of H1975 cells under treatment for 72 h, followed by a 10-day incubation in fresh media. (<b>a</b>) Quantitative analysis of the clonogenic nature of the H1975 cells after treatment with OB, unconjugated OB liposomes (OB-LPs), and conjugated OB liposomes (CTX-OB-LPs). (<b>b</b>) Images of the colonies after crystal violet staining. The data are expressed as % colony growth versus the respective treatment. Data represents mean ± SD (<span class="html-italic">n</span> = 3). *** <span class="html-italic">p</span> &lt; 0.0001 and ** <span class="html-italic">p</span> &lt; 0.001; ns—non-significant.</p>
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<p>(<b>a</b>) Scratch assay analysis of the H1975 cell line, shown as % of wound healing over time after treatment with OB, unconjugated OB liposomes (OB-LPs), and conjugated OB liposomes (CTX-OB-LPs). Data represents mean ± SD (<span class="html-italic">n</span> = 3). **** <span class="html-italic">p</span> &lt; 0.0001, ** <span class="html-italic">p</span> &lt; 0.01, and * <span class="html-italic">p</span> &lt; 0.05; ns—non-significant. (<b>b</b>) Effect of OB and liposomal formulations (OB-LPs and CTX-OB-LPs) on the metastatic potential of the H1975 cell line. Representative microscopic images of the scratch after the following treatment times are provided: 0 h, 12 h, 24 h, and 48 h. Scale bar 400 µm.</p>
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<p>Stability data for CTX-OB-LPs when stored at 4 °C. (<b>a</b>) % entrapment efficiency (EE); (<b>b</b>) drug content; (<b>c</b>) particle size; (<b>d</b>) zeta potential.</p>
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25 pages, 3412 KiB  
Article
Is It Time to Start Worrying? A Comprehensive Report on the Three-Year Prevalence of ESBL-Producing Bacteria and Their Trends in Antibiotic Resistance from the Largest University Hospital in Slovakia
by Yashar Jalali, Andrea Kološová, Adriána Liptáková, Ján Kyselovič, Anna Oleárová, Monika Jalali and Juraj Payer
Pharmaceuticals 2024, 17(11), 1517; https://doi.org/10.3390/ph17111517 - 11 Nov 2024
Viewed by 583
Abstract
Background/Objectives: Over the past few decades, extended-spectrum β-lactamase (ESBL)-producing bacteria have become a great concern in healthcare systems worldwide, imposing large burdens by increasing antimicrobial resistance and patient morbidity. Given the high mortality rates and emergence of multidrug-resistant (MDR) strains, monitoring ESBL prevalence [...] Read more.
Background/Objectives: Over the past few decades, extended-spectrum β-lactamase (ESBL)-producing bacteria have become a great concern in healthcare systems worldwide, imposing large burdens by increasing antimicrobial resistance and patient morbidity. Given the high mortality rates and emergence of multidrug-resistant (MDR) strains, monitoring ESBL prevalence and resistance patterns is crucial. This study aimed to evaluate ESBL-producing Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae over three years, focusing on phenotypic distribution and resistance profiles. Methods: A total of 1599 ESBL-producing bacterial samples were collected and analysed. A panel of 20 antibiotics was tested to determine resistance traits. Data were recorded on phenotypical distribution, isolation types, changes in antibiotic resistance, and the relation of such changes to antibiotic consumption (defined daily dose) from clinical isolates. Results: Phenotypical analysis revealed the minimal presence of the Cefotaximase from Munich (CTX-M) phenotype in E. coli and K. pneumoniae, creating a distinct epidemiological profile compared to global patterns. Shifts in isolation trends, particularly in P. mirabilis, suggest an expected increase in associated-mortality-rate in the coming years. While resistance trends were not statistically significant, MDR and extensively drug-resistant (XDR) strains were identified across all three bacteria. Only meropenem showed consistent 100% efficacy against E. coli, with other antibiotics displaying only partial effectiveness. Conclusions: These findings highlight the need for ongoing surveillance of ESBL-producing bacteria and underscore challenges in managing antibiotic resistance due to limited efficacy of last-resort treatments. The unique phenotypical distribution observed could impact local resistance management strategies in hospital settings in the coming years. Full article
(This article belongs to the Special Issue Development of Antibacterial Drugs to Combat Drug-Resistant Bacteria)
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<p>Graphical demonstration of the trends in isolation of ESBL-producing bacteria during the study period.</p>
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<p>Graphical presentation of data on the sources of isolated samples during the study period.</p>
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<p>Trends in the numbers of isolated phenotypic variants of ESBL-producing <span class="html-italic">E. coli</span>.</p>
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<p>Three-year changes in the antibiotic resistances of isolated ESBL-producing strains of <span class="html-italic">E. coli</span> (all phenotypes). AMI: amikacin; AMP: ampicillin; CAZ: ceftazidime; CIP: ciprofloxacin; COL: colistin; CTX: cefotaxime; CTC: cefotaxime–sulbactam; CXM: cefuroxime; CZC: ceftazidime–sulbactam; ETP: ertapenem; FEP: cefepime; GEN: gentamicin; MEM: meropenem; SAM: ampicillin–sulbactam; SPZ: sulperazone (cefoperazone–sulbactam); TET: tetracycline; TIG: tigecycline; TMP: trimethoprim–sulfamethoxazole; TOB: tobramycin; TZP: Tazocin (piperacillin–tazobactam).</p>
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<p>Trends in the numbers of isolated phenotypic variants of ESBL-producing <span class="html-italic">P. mirabilis</span>.</p>
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<p>Three-year changes in the antibiotic resistances of isolated ESBL-producing strains of <span class="html-italic">P. mirabilis</span> (all phenotypes). AMI: amikacin; AMP: ampicillin; CAZ: ceftazidime; CIP: ciprofloxacin; COL: colistin; CTX: cefotaxime; CTC: cefotaxime–sulbactam; CXM: cefuroxime; CZC: ceftazidime–sulbactam; ETP: ertapenem; FEP: cefepime; GEN: gentamicin; MEM: meropenem; SAM: ampicillin–sulbactam; SPZ: sulperazone (cefoperazone–sulbactam); TET: tetracycline; TIG: tigecycline; TMP: trimethoprim–sulfamethoxazole; TOB: tobramycin; TZP: Tazocin (piperacillin–tazobactam). Complementary information for better interpretation of the figure is provided in the text following <a href="#pharmaceuticals-17-01517-f004" class="html-fig">Figure 4</a>.</p>
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<p>Trends in the numbers of isolated phenotypic variants of ESBL-producing <span class="html-italic">K. pneumoniae</span>.</p>
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<p>Three-year changes in the antibiotic resistances of isolated ESBL-producing strains of <span class="html-italic">K. pneumoniae</span> (all phenotypes). AMI: amikacin; AMP: ampicillin; CAZ: ceftazidime; CIP: ciprofloxacin; COL: colistin; CTX: cefotaxime; CTC: cefotaxime–sulbactam; CXM: cefuroxime; CZC: ceftazidime–sulbactam; ETP: ertapenem; FEP: cefepime; GEN: gentamicin; MEM: meropenem; SAM: ampicillin–sulbactam; SPZ: sulperazone (cefoperazone–sulbactam); TET: tetracycline; TIG: tigecycline; TMP: trimethoprim–sulfamethoxazole; TOB: tobramycin; TZP: Tazocin (piperacillin–tazobactam). Complementary information for better interpretation of the figure is provided in the text following <a href="#pharmaceuticals-17-01517-f004" class="html-fig">Figure 4</a>.</p>
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<p>Three-year changes in estimated drug consumption based on defined daily dose/patient. AMI: amikacin; AMP: ampicillin; CAZ: ceftazidime; CIP: ciprofloxacin; COL: colistin; cefotaxime; CTC: cefotaxime–sulbactam; CTX: cefotaxime; CXM: cefuroxime; CZC: ceftazidime–sulbactam; DOX: doxycycline; ETP: ertapenem; FEP: cefepime; GEN: gentamicin; MEM: meropenem; SAM: ampicillin–sulbactam; SPZ: sulperazone (cefoperazone–sulbactam); TIG: tigecycline; TMP: trimethoprim–sulfamethoxazole; TOB: tobramycin; TZP: Tazocin (piperacillin–tazobactam).</p>
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10 pages, 263 KiB  
Article
Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Diarrhoeal Faeces from 0 to 5-Year-Old Children Attending Public Hospitals in Franceville, Gabon
by Anicet-Clotaire Dikoumba, Pierre Philippe Mbehang Nguema, Leresche Even Doneilly Oyaba Yinda, Romeo Wenceslas Lendamba, Jean Constan Obague Mbeang, Guy Roger Ndong Atome, Christophe Roland Zinga Koumba, Sylvain Godreuil and Richard Onanga
Antibiotics 2024, 13(11), 1059; https://doi.org/10.3390/antibiotics13111059 - 7 Nov 2024
Viewed by 652
Abstract
Background: In Gabon, studies on the characterization of extended-spectrum beta-lactamase-producing Escherichia coli in young children with diarrhoea are almost nonexistent. The objective was to evaluate the prevalence of antibiotic resistance to extended-spectrum beta-lactamase-producing Escherichia coli in children at public hospitals in Franceville, Gabon. [...] Read more.
Background: In Gabon, studies on the characterization of extended-spectrum beta-lactamase-producing Escherichia coli in young children with diarrhoea are almost nonexistent. The objective was to evaluate the prevalence of antibiotic resistance to extended-spectrum beta-lactamase-producing Escherichia coli in children at public hospitals in Franceville, Gabon. Methods: Seventy diarrhoea faecal samples were collected from children aged 0–5 years. The culture and isolation of colonies were carried out on MacConkey agar. The colonies were identified using VITEK 2. The determination of the extended-spectrum beta-lactamase’s profiles was accomplished using the double disk method. The identification of phylogroups and pathotypes was performed by PCR. Identification of the ESBL genes was performed by sequencing. Results: A total of 26 strains of Escherichia coli (33.0%) were identified from 78 bacterial isolates. Twenty (77.0%) Escherichia coli strains carried extended-spectrum beta-lactamases blaCTX-M-15 and 5.0% carried blaSHV-12 subtypes. Phylogroup D (62.0%) was predominant, followed by B1 (12.0%), B2 (8.0%) and E (4.0%). The bacterial pathogens causing diarrhoea were enterohemorrhagic E. coli (12.0%), typical enteropathogenic Escherichia coli (8.0%), atypical enteropathogenic Escherichia coli (4.0%), Enteroaggregative Escherichia coli (4.0%) and enteroinvasive E. coli (4.0%). Conclusions: This study showed a high prevalence of extended-spectrum beta-lactamase, Escherichia coli of phylogroup D and pathotype enterohemorrhagic Escherichia coli in children under 5 years old in public hospitals in Franceville, most probably due to the misuse or inappropriate consumption of beta-lactams. Full article
(This article belongs to the Section Antibiotic Therapy in Infectious Diseases)
16 pages, 904 KiB  
Article
Emergence of Carbapenem-Resistant Uropathogenic Escherichia coli (ST405 and ST167) Strains Carrying blaCTX-M-15, blaNDM-5 and Diverse Virulence Factors in Hospitalized Patients
by Fatima Mujahid, Muhammad Hidayat Rasool, Muhammad Shafiq, Bilal Aslam and Mohsin Khurshid
Pathogens 2024, 13(11), 964; https://doi.org/10.3390/pathogens13110964 - 5 Nov 2024
Viewed by 497
Abstract
Background: Urinary tract infections (UTIs) are common infectious diseases in hospital settings, and they are frequently caused by uropathogenic Escherichia coli (UPEC). The emergence of carbapenem-resistant (Carb-R) E. coli strains poses a significant threat due to their multidrug resistance and virulence. This study [...] Read more.
Background: Urinary tract infections (UTIs) are common infectious diseases in hospital settings, and they are frequently caused by uropathogenic Escherichia coli (UPEC). The emergence of carbapenem-resistant (Carb-R) E. coli strains poses a significant threat due to their multidrug resistance and virulence. This study aims to characterize the antimicrobial resistance and virulence profiles of Carb-R UPEC strains isolated from hospitalized patients. Methods: A total of 1100 urine samples were collected from patients in Lahore and Faisalabad, Pakistan, between May 2023 and April 2024. The samples were processed to isolate and identify E. coli using standard microbiological techniques and VITEK®2, followed by amplification of the uidA gene. Antimicrobial susceptibility was evaluated using the Kirby–Bauer disc diffusion method and broth microdilution. Resistance and virulence genes were detected through PCR and DNA sequencing, and sequence typing was performed using MLST. Results: Among the 118 Carb-R UPEC isolates, resistance was most frequently observed against sulfamethoxazole-trimethoprim (96.6%) and doxycycline (96.6%). All of the isolates remained sensitive to colistin and tigecycline. Sequence types ST405 (35.6%) and ST167 (21.2%) were predominant and carried the blaCTX-M-15 and blaNDM-5 genes. The distribution of virulence genes and a variety of antimicrobial resistance genes (ARGs), conferring resistance to aminoglycosides, fluoroquinolones, tetracyclines, and sulfonamides, were observed as specifically linked to certain sequence types. Conclusions: This study provides insights into the molecular epidemiology of carbapenem-resistant Uropathogenic E. coli (Carb-R UPEC) strains and highlights the presence of globally high-risk E. coli clones exhibiting extensive drug resistance phenotypes in Pakistani hospitals. The findings underscore the urgent need for enhanced surveillance and stringent antibiotic stewardship to manage the spread of these highly resistant and virulent strains within hospital settings. Full article
(This article belongs to the Special Issue Hospital-Acquired Infections and Multidrug-Resistant (MDR) Pathogens)
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<p>Antimicrobial resistance patterns of the Carb-R UPEC strains.</p>
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<p>Bubble plots of the minimum inhibitory concentration distribution to various antimicrobial agents against Carb-R UPEC.</p>
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11 pages, 564 KiB  
Review
Bone Mineral Density, C-Terminal Telopeptide of Type I Collagen, and Osteocalcin as Monitoring Parameters of Bone Remodeling in CML Patients Undergoing Imatinib Therapy: A Basic Science and Clinical Review
by Nurita Indarwulan, Merlyna Savitri, Ami Ashariati, Siprianus Ugroseno Yudho Bintoro, Muhammad Noor Diansyah, Putu Niken Ayu Amrita and Pradana Zaky Romadhon
Diseases 2024, 12(11), 275; https://doi.org/10.3390/diseases12110275 - 2 Nov 2024
Viewed by 528
Abstract
Background: Chronic myeloid leukemia (CML) is one of the most commonly found types of myeloproliferative neoplasms, characterized by increased proliferation of granulocytic cells without losing their differentiation ability. Imatinib, a tyrosine kinase inhibitor (TKI), can be effectively used as therapy for CML. However, [...] Read more.
Background: Chronic myeloid leukemia (CML) is one of the most commonly found types of myeloproliferative neoplasms, characterized by increased proliferation of granulocytic cells without losing their differentiation ability. Imatinib, a tyrosine kinase inhibitor (TKI), can be effectively used as therapy for CML. However, Imatinib can affect bone turnover thus having clinical implications on the bones of CML patients undergoing long-term Imatinib therapy. However, parameters that can accurately describe the bone condition in CML patients receiving Imatinib still need further study. A combination of imaging techniques such as bone mineral density (BMD) and bone turnover activity markers such as C-terminal telopeptide of type I collagen (CTX-1) and osteocalcin has the potential to be used as monitoring parameters for bone density abnormalities in CML patients receiving Imatinib. Objectives: This article explains the rationale for using BMD, CTX-1, and osteocalcin as monitoring parameters of bone remodeling in CML patients receiving Imatinib. Results: First, the physiological process of bone turnover will be explained. Then, we describe the role of tyrosine kinase in bone metabolism. Next, the impact of Imatinib on BMD, CTX-1, and osteocalcin will be explained. Conclusion: The assessment of bone health of CML patients on Imatinib should include both BMD tests and bone turnover marker assays such as CTX-1 and osteocalcin. Full article
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<p>Interaction of CTX-1, osteocalcin, and bone mineral density. Osteoclasts produce CTX-1, which is a marker of bone resorption. Osteoblasts produce osteocalcin, which is a marker of bone formation. When the bone formation rate surpasses the bone resorption rate, bone mineral density (BMD) increases. On the other hand, when the bone resorption rate surpasses the bone formation rate, BMD decreases. CTX-1: C-terminal telopeptide of type I collagen. Created in BioRender.</p>
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16 pages, 1458 KiB  
Article
Genetic Insights on Meropenem Resistance Concerning Klebsiella pneumoniae Clinical Isolates
by Fathy M. Elkady, Bahaa M. Badr, Abdel-Aty E. Alfeky, Mohammed S. Abdulrahman, Amr H. Hashem, Abdulaziz A. Al-Askar, Gehad AbdElgayed and Hany R. Hashem
Life 2024, 14(11), 1408; https://doi.org/10.3390/life14111408 - 1 Nov 2024
Viewed by 615
Abstract
The transferable genetic elements are associated with the dissemination of virulence determinants amongst Klebsiella pneumoniae. Thus, we assessed the correlated antimicrobial resistance in carbapenem-resistant Klebsiella pneumoniae clinical isolates. Each isolate’s ability to biosynthesize biofilm, carbapenemase, and extended-spectrum β-lactamase were examined. Genotypically, the [...] Read more.
The transferable genetic elements are associated with the dissemination of virulence determinants amongst Klebsiella pneumoniae. Thus, we assessed the correlated antimicrobial resistance in carbapenem-resistant Klebsiella pneumoniae clinical isolates. Each isolate’s ability to biosynthesize biofilm, carbapenemase, and extended-spectrum β-lactamase were examined. Genotypically, the biofilm-, outer membrane porin-, and some plasmid-correlated antimicrobial resistance genes were screened. About 50% of the isolates were multidrug-resistant while 98.4% were extended-spectrum β-lactamase producers and 89.3% were carbapenem-resistant. Unfortunately, 93.1% of the multidrug-resistant isolates produced different biofilm levels. Additionally, fimD and mrkD genes encoding adhesins were detected in 100% and 55.2% of the tested isolates, respectively. Also, the blaKPC, blaOXA-48-like, and blaNDM-encoding carbapenemases were observed in 16.1%, 53.6%, and 55.4% of the tested isolates, respectively. Moreover, the blaSHV and blaCTX-M extended-spectrum β-lactamase-associated genes were detected at 95.2% and 61.3%, respectively. Furthermore, aac(3)IIa, qnrB, and tetB resistance-correlated genes were observed in 38.1%, 46%, and 7.9% of the tested isolates, respectively. Certainly, the tested antimicrobial resistance-encoding genes were concurrently observed in 3.2% of the tested isolates. These findings confirmed the elevated prevalence of various antimicrobial resistance-associated genes in Klebsiella pneumoniae. The concurrent transferring of plasmid-encoding antimicrobial resistance-related genes could be associated with the possible acquisition of multidrug-resistant Klebsiella pneumoniae phenotypes. Full article
(This article belongs to the Special Issue Infection, Colonization, and Spread of Drug-Resistant Bacteria)
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<p>ESβL-positive (<b>A</b>) and -negative (<b>B</b>) phenotypes. CTX: cefotaxime and CEC: cefotaxime/clavulanic acid. Phenotypic carbapenemase activity (<b>C</b>). P: positive phenotype and N<sub>1</sub> and N<sub>2</sub>: negative phenotypes of <span class="html-italic">K. pneumoniae</span> isolates.</p>
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<p>Biofilm formation ability of <span class="html-italic">K. pneumoniae</span> isolates regarding each type of clinical specimen.</p>
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<p>Agarose gel electrophoresis showing gene-specific PCR products from the <span class="html-italic">K. pneumoniae</span> isolates. (<b>A</b>) The 16S–23S rDNA. Lanes from 1 to 6: species-specific positive amplicon results for representative tested isolates; Lanes 7 and 8: positive control using DNA from <span class="html-italic">K. pneumoniae</span> ATCC 13,882 standard strain according to the presence of F/R<sub>1</sub> (130 bp) and F/R<sub>2</sub> (260 bp), respectively. (<b>B</b>) Biofilm-related genes, <span class="html-italic">fim</span>D (1114 bp) and <span class="html-italic">mrk</span>D (880 bp). Lanes from 1 to 6: positive biofilm-forming <span class="html-italic">K. pneumoniae</span> isolates. (<b>C</b>) The outer membrane porins (OMPs) and carbapenemase-encoding genes. Lanes from 1 to 5: specific bands of <span class="html-italic">omp</span>K35 (684 bp), <span class="html-italic">omp</span>K36 (1076 bp), <span class="html-italic">bla</span><sub>NDM</sub> (782 bp), <span class="html-italic">bla</span><sub>OXA-48-like</sub> (438 bp), and <span class="html-italic">bla<sub>KPC</sub></span> (798 bp) in carbapenemase-producing <span class="html-italic">K. pneumoniae</span> isolates. (<b>D</b>) The ESβLs [<span class="html-italic">bla</span><sub>SHV</sub> (104 bp) and <span class="html-italic">bla</span><sub>CTX-M</sub> (909 bp)], <span class="html-italic">qnr</span>B (469 bp), <span class="html-italic">aac(3)IIa</span> (877 bp), and <span class="html-italic">tet</span>B (571 bp) genes. Lanes from 1 to 5: specific bands of <span class="html-italic">bla</span><sub>SHV</sub>, <span class="html-italic">bla</span><sub>CTX-M</sub>, <span class="html-italic">qnr</span>B, <span class="html-italic">aac(3)IIa</span>, and <span class="html-italic">tet</span>B in representative MDR <span class="html-italic">K. pneumoniae</span> isolates. bp, base pair; Lane M, 100 bp DNA ladder; Lane N, negative control.</p>
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14 pages, 1510 KiB  
Article
First Detection of High-Level Aminoglycoside-Resistant Klebsiella pneumoniae and Enterobacter cloacae Isolates Due to 16S rRNA Methyltransferases with and Without blaNDM in Uruguay
by Romina Papa-Ezdra, Nicolás F. Cordeiro, Federica Ferreira, Virginia García-Fulgueiras, Lucía Araújo, María Inés Mota, Matilde Outeda, Verónica Seija, Rafael Vignoli and Inés Bado
Antibiotics 2024, 13(11), 1029; https://doi.org/10.3390/antibiotics13111029 - 31 Oct 2024
Viewed by 888
Abstract
Background: The increase in antimicrobial resistance includes emerging mechanisms such as 16S ribosomal RNA methylases, which confer high-level resistance to aminoglycosides. In this regard, the most predominant genes observed worldwide are rmtB and armA, but their presence in Uruguay is unknown. Objectives: [...] Read more.
Background: The increase in antimicrobial resistance includes emerging mechanisms such as 16S ribosomal RNA methylases, which confer high-level resistance to aminoglycosides. In this regard, the most predominant genes observed worldwide are rmtB and armA, but their presence in Uruguay is unknown. Objectives: We describe the genomic characterization of isolates carrying rmtB and rmtC, together with blaNDM-5 and blaNDM-1, respectively, and rmtD in our country. Methology: Five isolates from patients admitted to three hospitals were studied. Identification and antibiotic susceptibility testing were performed using the Vitek2 System. Whole Genome Sequencing was conducted, and hybrid assembly was performed with Unicycler. In silico analysis using the Center for Genomic Epidemiology’s tools was undertaken to predict antibiotic resistance determinants, plasmid incompatibility groups, and sequence types. Results: We report three K. pneumoniae ST307 isolates with an IncR plasmid carrying blaNDM-5/blaCTX-M-15/blaTEM-1B/rmtB/dfrA14/dfrA12/sul1/qacEΔ1/ermB/mphA, one K. pneumoniae ST258 harboring an IncC plasmid containing rmtC/blaNDM-1/blaCMY-6/aac(6′)-Ib/sul1, and one E. cloacae ST88 isolate with an IncFIB/II plasmid hosting rmtD, within a novel Tn21-like transposon named Tn7825, alongside blaOXA-101/sul1/tet(G)/floR, and a new variant of blaTEM assigned as blaTEM-258. One of the strains, named UH_B2, also carried an IncM1 plasmid encoding qnrE1/blaTEM-1/blaCTX-M-8 associated with ISEcp1. Conclusions: This is the first description of plasmids harboring 16S rRNA methyltransferases in Uruguay. The association and dissemination of diverse antibiotic-resistant genes underpin the health threat they represent, highlighting the lack of available antibiotics effective against multidrug-resistant microorganisms. Full article
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Figure 1
<p>Linear representation of the <span class="html-italic">rmtB1</span>-harboring plasmids. (<b>a</b>) Linear map of UH_B1 plasmid; (<b>b</b>) sequence comparison of the <span class="html-italic">rmtB1</span>-harboring plasmids of the <span class="html-italic">K. pneumoniae</span> ST307 strains UH_B1 (acc. No. PQ203016), <span class="html-italic">K. pneumoniae</span> ST307 UH_B2 (acc. No. PQ212749), and <span class="html-italic">K. pneumoniae</span> ST307 UH_B3 (PQ203988), against database retrieved complete (p_3575_NDM-5) or partial (p_b199b_NDM5, p_dm8036_NDM) plasmid sequences. Genes are represented by bars or arrows and colored according to their function or location in the plasmids. Regions were defined for a better understanding of the scheme.</p>
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<p>Linear map of Tn<span class="html-italic">7825</span> (<span class="html-italic">E. cloacae</span> ST88 strain UD_D1) and BLAST comparison results within GenBank available sequences: <span class="html-italic">C. freundii</span> Q1174 (acc. No. HQ401567.1), <span class="html-italic">E. aerogenes</span> (acc. No. HQ401565.1), and <span class="html-italic">K. pneumoniae</span> pKPN-431cz (acc. No. KY020154.1). Genes are represented by arrows and colored according to their function.</p>
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23 pages, 4300 KiB  
Article
Immunostimulation Signaling via Toll-like Receptor 2 Activation: A Molecular Mechanism of Lactococcus lactis OTG1204 In Vitro and In Vivo
by Hyeon-A Song, Seo-Yun Jang, Min-Ji Park, Seung Wook Kim, Choon Gil Kang, Joo Hyun Lee, Hye-Jin Kim, Jiheon Kim, Jong Kil Lee, Kyung-Sook Chung and Kyung-Tae Lee
Nutrients 2024, 16(21), 3629; https://doi.org/10.3390/nu16213629 - 25 Oct 2024
Viewed by 464
Abstract
Introduction: The immune system’s defense against pathogens involves innate and adaptive responses, crucial in maintaining overall health. Immunosuppressed states render individuals more susceptible to potential diseases, indicating the need for effective strategies to bolster immune functions. Objectives: Although the immunostimulatory effects of various [...] Read more.
Introduction: The immune system’s defense against pathogens involves innate and adaptive responses, crucial in maintaining overall health. Immunosuppressed states render individuals more susceptible to potential diseases, indicating the need for effective strategies to bolster immune functions. Objectives: Although the immunostimulatory effects of various probiotics have been studied, the specific effects and molecular mechanisms of Lactococcus lactis OTG1204 (OTG1204) remain unknown. In this study, the aim was to investigate the molecular mechanisms of OTG1204 in RAW 264.7 macrophages, the key effector cells of the innate immune system involved in host defense and inflammatory responses. Additionally, in this study, the effects of OTG1204 on cyclophosphamide (CTX)-induced immunosuppression states were investigated, thereby demonstrating its potential as an immune stimulant. Methods: To assess the macrophage activation ability and underlying mechanisms of OTG1204, RAW 264.7 cells were utilized with transfection, enzyme-linked immunosorbent assay, and quantitative real-time PCR analyses. Furthermore, to evaluate the immunostimulatory effects under immunosuppressed conditions, CTX-induced immunosuppression mice model was employed, and analyses were performed using hematoxylin and eosin staining, flow cytometry, and microbiota examination. Results: OTG1204 activated RAW 264.7 macrophages, leading to increased production of nitric oxide, prostaglandin E2, and cytokines. This immune activation was mediated through the upregulation of toll-like receptor 2, which subsequently activated the nuclear factor-κB (NF-kB) and mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) pathways, thereby stimulating the immune response. In CTX-treated mice, OTG1204 recovered body weight, spleen, and mesenteric lymph node indices, and natural killer cell activity. It re-established populations of innate and adaptive immune cells and activated T cells to secrete cytokines. We also examined the gut barrier integrity and microbiota composition to assess OTG1204’s impact on intestinal health, as these factors play a significant role in immune enhancement. OTG1204 enhanced gut barrier integrity by upregulating mucin 2 and tight junction proteins and modulated the gut microbiota by restoring the Firmicutes/Bacteroidetes balance and reducing the abundance of Actinobacteria and Tenericutes. Conclusion: These results suggest that OTG1204 may serve as an effective probiotic for immune enhancement and gut health management by targeting the NF-κB and MAPK/AP-1 pathways, with minimal side effects. Full article
(This article belongs to the Special Issue Functional Foods and Health Promotion)
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<p>Scheme of the in vivo study.</p>
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<p>The immunostimulatory activities of OTG1204 in RAW264.7 macrophages. (<b>A</b>,<b>B</b>) The cell viability of OTG1204 was analyzed by MTT and NO production was detected by Griess reaction. LPS (5 ng/mL) was used as the positive control. For endotoxin contamination tests, cells were pretreated with or without Polymyxin B (80 ng/mL) for 1 h and then treated with OTG1204 for 24 h. (<b>C</b>) The PGE<sub>2</sub> production was measured by ELISA kits. (<b>D</b>) The protein expressions of iNOS and COX-2 were detected by Western blot analysis. β-actin was used as the internal control. (<b>E</b>,<b>F</b>) The mRNA expressions of iNOS and COX-2 were detected by qRT-PCR analysis. (<b>G</b>–<b>I</b>) The production and (<b>J</b>–<b>L</b>) mRNA expression of IL-1β, IL-6, and TNF-α were measured by ELISA kits and qRT-PCR, respectively. Data are expressed as means ± SD. * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. Control. <sup><span>$</span><span>$</span><span>$</span></sup> <span class="html-italic">p</span> &lt; 0.001 vs. LPS treatment. n.s.: not significant.</p>
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<p>Effects of OTG1204 on NF-κB, AP-1, MAPK, and TLR2 signaling pathways in RAW 264.7 macrophages. (<b>A</b>) NF-κB activity was determined by luciferase assay as described in the <a href="#sec2-nutrients-16-03629" class="html-sec">Section 2</a>. (<b>B</b>,<b>C</b>) Cells were treated with OTG1204 (0.5 × 10<sup>6</sup>, 1 × 10<sup>6</sup>, or 2 × 10<sup>6</sup> cfu/mL) for 1 h (p-p65, p65), 30 min (p-IkBα, IkBα) or 15 min (p-IKKα/β, IKKα, IKKβ), and expression levels of proteins were detected by Western blot analysis. LPS (5 ng/mL) was used as the positive control. (<b>D</b>) AP-1 activity was determined by luciferase assay as described in the <a href="#sec2-nutrients-16-03629" class="html-sec">Section 2</a>. (<b>E</b>,<b>F</b>) Cells were treated with OTG1204 (0.5 × 10<sup>6</sup>, 1 × 10<sup>6</sup>, or 2 × 10<sup>6</sup> cfu/mL) for 1 h (AP-1) or 20 min (MAPKs), and expression levels of proteins were detected by Western blot analysis. (<b>G</b>,<b>H</b>) Cells were treated with OTG1204 (0.5 × 10<sup>6</sup>, 1 × 10<sup>6</sup>, or 2 × 10<sup>6</sup> cfu/mL) for 1 h, the mRNA expressions of TLR2 and Myd88 were determined by qRT-PCR. LPS (5 ng/mL) was used as the positive control. (<b>I</b>) Cells were treated with OTG1204 for 2 h (TRAF6) or 30 min (p-TAK1 and TAK1), and then the expression levels of proteins were detected by Western blot analysis. β-actin was used as the internal control. (<b>J</b>) After pretreatment with isotype antibody or anti-TLR2 antibody (20 μg/mL) for 1 h, cells were exposed to peptidoglycan (PGN) (1 μg/mL) or OTG1204 (2 × 10<sup>6</sup> cfu/mL) for 24 h. NO production was measured by Griess reaction, as described in the <a href="#sec2-nutrients-16-03629" class="html-sec">Section 2</a>. β-actin and Histone H3 were used as the internal control. N—nuclear fraction; C—cytosolic fraction. Data were expressed as means ± SD. * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. Control; <sup>###</sup> <span class="html-italic">p</span> &lt; 0.001 vs. anti-TLR2 Ab treatment; <sup>&amp;&amp;&amp;</sup> <span class="html-italic">p</span> &lt; 0.001 vs. PGN and anti-TLR2 Ab treatment.</p>
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<p>Effects of OTG1204 on body weight, immune organ indices, and NK cell activity in cyclophosphamide (CTX)-induced mice. (<b>A</b>) The mice body weights and indices of (<b>B</b>) spleen and (<b>C</b>) MLN were estimated at the end of the experiments. (<b>D</b>) NK cell activity was determined by LDH assay, as described in the <a href="#sec2-nutrients-16-03629" class="html-sec">Section 2</a>. Data are presented as the mean ± SEM. <sup>#</sup> <span class="html-italic">p</span> &lt; 0.05 vs. CON group; *** <span class="html-italic">p</span> &lt; 0.001 vs. CTX group.</p>
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<p>Effects of OTG1204 on innate immune cells in splenocytes of CTX-induced mice. To identify innate immune cells, the isolated splenocytes were stained with fluorescent antibodies indicating marker proteins, as follows: (<b>A</b>) CD3<sup>−</sup>/NK1.1<sup>+</sup>; NK cell; (<b>B</b>) CD11b<sup>+</sup>/Ly6C<sup>+</sup>/F4/80<sup>+</sup>; macrophage; (<b>C</b>) CD11b<sup>+</sup>/Ly6C<sup>+</sup>; monocyte; (<b>D</b>) CD11b<sup>+</sup>/Ly6G<sup>+</sup>; neutrophil; (<b>E</b>) CD11C<sup>+</sup>/MHCII<sup>+</sup>; dendritic cell and immune cell populations were analyzed by flow cytometry. Data are presented as the mean ± SEM. <sup>#</sup> <span class="html-italic">p</span> &lt; 0.05 vs. CON group; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. CTX group.</p>
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<p>Effects of OTG1204 on adaptive immune cells in splenocytes of CTX-induced mice. To identify adaptive immune cells, the isolated splenocytes were stained with fluorescent antibodies indicating marker proteins, as follows: (<b>A</b>) B220<sup>+</sup>/CD19<sup>+</sup>; B cell; (<b>B</b>) CD3<sup>+</sup>; T cell; (<b>C</b>) CD3<sup>+</sup>/CD4<sup>+</sup>; Th cell; (<b>D</b>) CD3<sup>+</sup>/CD4<sup>+</sup>/IFN-γ<sup>+</sup>; Th1 cell; (<b>E</b>) CD3<sup>+</sup>/CD4<sup>+</sup>/IL-4<sup>+</sup>; Th2 cell and immune cell populations were analyzed by flow cytometry. Data are presented as the mean ± SEM. <sup>#</sup> <span class="html-italic">p</span> &lt; 0.05 vs. CON group; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. CTX group.</p>
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<p>Effects of OTG1204 on the production and mRNA expression of cytokines in splenocytes of CTX-induced mice. For T cell activation, isolated splenocytes were stimulated with ConA (5 μg/mL) for 48 h. Isolated splenocytes were stimulated with ConA (5 μg/mL) for 48 h. (<b>A</b>–<b>C</b>,<b>G</b>,<b>H</b>) the cytokine production and (<b>D</b>–<b>F</b>,<b>I</b>,<b>J</b>) mRNA expression were measured by ELISA kits and qRT-PCR, respectively. Data are presented as the mean ± SEM. <sup>#</sup> <span class="html-italic">p</span> &lt; 0.05 vs. CON group; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. CTX group.</p>
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<p>Effect of OTG1204 on gut barrier disruption in CTX-induced mice. (<b>A</b>) H&amp;E staining of colon tissue; scale bars, 500 μm and 200 μm. (<b>B</b>) Crypt length. (<b>C</b>) The protein and (<b>D</b>) mRNA expressions of MUC2 were detected by Western blot analysis and qRT-PCR, respectively. (<b>E</b>) The protein and (<b>F</b>–<b>H</b>) mRNA expressions of tight junction-related markers were detected by Western blot analysis and qRT-PCR, respectively. Data are presented as the mean ± SEM. <sup>#</sup> <span class="html-italic">p</span> &lt; 0.05 vs. CON group; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. CTX group.</p>
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<p>Effect of OTG1204 on gut microbiota composition in CTX-induced mice. (<b>A</b>) β-diversity was presented by principal coordinate analysis (PCoA). (<b>B</b>) Bacterial taxonomic profiling at the phylum level. Abundance of (<b>C</b>) <span class="html-italic">Firmicutes</span> and (<b>D</b>) <span class="html-italic">Bacteroidetes</span> at the phylum level. (<b>E</b>) Ratio of <span class="html-italic">Firmicutes/Bacteroidetes</span>. Abundance of (<b>F</b>) <span class="html-italic">Actinobacteria</span> and (<b>G</b>) <span class="html-italic">Tenericutes</span> at the phylum level. Network analyses of interactions between (<b>H</b>) the gut microbiota and various immune cells and cytokines, and (<b>I</b>) the gut microbiota and tight junction proteins, assessed by the Spearman coefficient test. Data are presented as the mean ± SEM. <sup>#</sup> <span class="html-italic">p</span> &lt; 0.05 vs. CON group; ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 vs. CTX group.</p>
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15 pages, 486 KiB  
Article
Antimicrobial Resistance and Pathotypes of Escherichia coli Isolates from Yellow-Legged Seagulls (Larus michahellis) in Central Italy
by Giulia Cagnoli, Fabrizio Bertelloni, Renato Ceccherelli and Valentina Virginia Ebani
Animals 2024, 14(21), 3048; https://doi.org/10.3390/ani14213048 - 22 Oct 2024
Viewed by 625
Abstract
Seagulls are synanthropic wild birds that can contaminate, through their droppings, beaches, urban and peri-urban environments. This concern is more serious when seagulls eliminate antimicrobial-resistant pathogenic bacteria. This study analyzed the fecal samples from 137 yellow-legged seagulls (Larus michahellis) from Central [...] Read more.
Seagulls are synanthropic wild birds that can contaminate, through their droppings, beaches, urban and peri-urban environments. This concern is more serious when seagulls eliminate antimicrobial-resistant pathogenic bacteria. This study analyzed the fecal samples from 137 yellow-legged seagulls (Larus michahellis) from Central Italy. A total of 218 Escherichia coli strains were isolated and analyzed for phenotypic and genotypic antimicrobial resistance and to identify the virulence genes characterizing different pathotypes. The disk diffusion method on all isolates found relevant resistance rates to ampicillin (38.99%), tetracycline (23.85%), and enrofloxacin (21.10%). On the basis of all results obtained with this test, 62 (28.44%) isolates were classified as multidrug-resistant (MDR) and 6 (2.75%) as extensive drug-resistant (XDR). Molecular analyses conducted on the strains phenotypically resistant to carbapenems, cephalosporins, and penicillins found 9/37 (24.32%) strains positive for blaOXA-48, 52/103 (50.49%) for blaTEM, 12/103 (11.65%) for blaCMY2, 3/103 (2.91%) for blaCTX, and 1/103 (0.97%,) for blaSHV. PCR to detect virulence genes characterizing different pathotypes found that 40 (18.35%) isolates had the astA gene, indicative of the enteroaggregative (EAEC) pathotype, 2 (0.92%) had cnf1, 2 (0.92%) had cnf2, and 1 (0.46%) had cdt-IV. All five (2.29%) strains were reportable as necrotoxigenic (NTEC), while 4 (1.83%) had both eaeA and escV, reportable as enteropathogenic (EPEC). Measures to limit seagulls’ access where humans and other animals reside are pivotal to reduce the risk of infection with antimicrobial-resistant and pathogenetic E. coli strains. Full article
(This article belongs to the Section Wildlife)
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<p>Antimicrobial resistance profile of <span class="html-italic">Escherichia coli</span> isolates (n.218) from seagulls. Legend: AMP: ampicillin; AMC: amoxicillin-clavulanate; FOX: cefoxitin; CTX: cefotaxime; EFT: ceftiofur; IMP: imipenem; ETP: ertapenem; AZM: aztreonam; C: chloramphenicol; TE: tetracycline; ENR: enrofloxacin; CIP: ciprofloxacin; CN: gentamicin; AK: amikacin; SXT: trimethoprim-sulfamethoxazole; PEN: penicillins; CEPH: cephalosporins; CARB: carbapenems; MONO: monobactams; PHEN: phenicols; TET: tetracyclines; FLU: fluoroquinolones; AMIN: aminoglycosides.</p>
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15 pages, 5949 KiB  
Article
Immunomodulatory Effects of a Prebiotic Formula with 2′-Fucosyllactose and Galacto- and Fructo-Oligosaccharides on Cyclophosphamide (CTX)-Induced Immunosuppressed BALB/c Mice via the Gut–Immune Axis
by Wanyun Ye, Hanxu Shi, Wentao Qian, Liping Meng, Meihua Wang, Yalin Zhou, Zhang Wen, Muke Han, Yile Peng, Hongliang Li and Yajun Xu
Nutrients 2024, 16(20), 3552; https://doi.org/10.3390/nu16203552 - 19 Oct 2024
Viewed by 1115
Abstract
Obejectives: This study explored the immunomodulatory effects of a prebiotic formula consisting of 2′-fucosyllactose (2′-FL), galacto-oligosaccharides (GOSs), and fructo-oligosaccharides (FOSs) (hereinafter referred to as 2FGF) in cyclophosphamide (CTX)-induced immunosuppressed BALB/c mice and its underlying mechanisms. Methods: Sixty healthy female BALB/c mice were randomly [...] Read more.
Obejectives: This study explored the immunomodulatory effects of a prebiotic formula consisting of 2′-fucosyllactose (2′-FL), galacto-oligosaccharides (GOSs), and fructo-oligosaccharides (FOSs) (hereinafter referred to as 2FGF) in cyclophosphamide (CTX)-induced immunosuppressed BALB/c mice and its underlying mechanisms. Methods: Sixty healthy female BALB/c mice were randomly divided into the following groups: normal control (NC) group; CTX treatment (CTX) group; 2FGF low-dose (2FGF-L) group; 2FGF medium-dose (2FGF-M) group; and 2FGF high-dose (2FGF-H) group. An immunosuppressed model was established in the 2FGF-H group by intraperitoneal injection of 80 mg/kg CTX. After 30 days of 2FGF intervention, peripheral blood, spleen tissue, thymus tissue, and intestinal tissue from the mice were collected and analyzed. The changes in weight and food intake of the mice were recorded weekly. Hematoxylin-eosin (HE) staining was used to observe the histological change of the spleen tissue. Enzyme-linked immunosorbent assay (ELISA) was employed to detect cytokine levels in peripheral blood. Flow cytometry was used to analyze T lymphocyte subgroup ratio of splenic lymphocytes. Western blot analysis was conducted on intestinal tissues to assess the expression of proteins involved in the tight junction, toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathways. Additionally, molecular techniques were used to analyze the intestinal microbiota. Results: The results showed that 2FGF restored CTX-induced splenic injury, increased the number of splenic T lymphocytes, and elevated serum cytokines such as interleukin-4 (IL-4) and IL-10. In the intestine, 2FGF upregulated the expression of intestinal epithelial tight junction proteins such as Claudin-1 and zonula occludens 1 (ZO-1), thereby enhancing intestinal barrier function and activating the MAPK and NF-κB pathways via TLR4. Furthermore, 2FGF elevated the α-diversity (Shannon and Simpson indices) of the gut microbiota in CTX-induced immunosuppressed mice, enriching bacteria species positively correlated with anti-inflammatory cytokines (e.g., IL-4) such as g_Streptomyces and g_Bacillus and negatively correlated with pro-inflammatory cytokines (e.g., IL-1β) such as g_Saccharomyces. The results suggest that 2FGF may enhance immunity via the gut–immune axis. Conclusions: The 2FGF prebiotic formula showed an immunomodulatory effect in CTX-induced immunosuppressed mice, and the mechanism of which might involve optimizing the gut flora, enhancing intestinal homeostasis, strengthening the intestinal barrier, and promoting the expression of immune factors by regulating the TLR-4/MAPK/NF-κB pathway. Full article
(This article belongs to the Section Nutritional Immunology)
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<p>The effect of 2FGF on body weight (<b>A</b>), food intake (<b>B</b>), immune organ indices (<b>C</b>), histological observation of the spleen (original magnification: ×40) (<b>D</b>), and splenic T lymphocyte subgroups in CTX-induced immunosuppressed mice (<b>E</b>). NC, normal control group; CTX, CTX-induced immunosuppressed model group; 2FGF-L, 2FGF (2′-FL/GOS/FOS = 1:3:3) administered at 1 g/kg bw; 2FGF-M, 2FGF administered at 2 g/kg bw; 2FGF-H, 2FGF administered at 4 g/kg bw. The yellow arrows in (<b>D</b>) indicate the boundaries of the red and white pulp of the spleen. Data are presented as means ± standard deviations (n = 12). Significant differences compared to the NC group are indicated by * (<span class="html-italic">p</span> &lt; 0.05), and significant differences compared to the CTX group are indicated by # (<span class="html-italic">p</span> &lt; 0.05).</p>
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<p>The effect of 2FGF on the protein expression of Claudin-1 and ZO-1 (<b>A</b>), TLR-4, <span class="html-italic">p</span>-p38, p38, <span class="html-italic">p</span>-ERK, ERK, <span class="html-italic">p</span>-JNK, JNK, <span class="html-italic">p</span>-p65, and p65 in the large intestines (ascending colon) of CTX-induced immunosuppressed mice (<b>B</b>), with representative Western blot images (<b>C</b>). Data are presented as means ± standard deviations (n = 3). Significant differences compared to the NC group are indicated by * (<span class="html-italic">p</span> &lt; 0.05) and ** (<span class="html-italic">p</span> &lt; 0.01), and significant differences compared to the CTX group are indicated by # (<span class="html-italic">p</span> &lt; 0.05) and ## (<span class="html-italic">p</span> &lt; 0.01).</p>
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<p>The effect of 2FGF on the Shannon index (<b>A</b>), Simpson index (<b>B</b>), PCoA analysis (<b>C</b>), phylum-level relative abundance (<b>D</b>), and species-level relative abundance (<b>E</b>) of the gut microbiota in CTX-induced immunosuppressed mice. Data are presented as means ± standard deviations (n = 8). Significant differences compared to the NC group are indicated by * (<span class="html-italic">p</span> &lt; 0.05) and ** (<span class="html-italic">p</span> &lt; 0.01).</p>
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<p>Histogram of LDA scores (<b>A</b>). Correlation analysis between differential genera and cytokines (<b>B</b>). Red indicates a positive correlation, and blue indicates a negative correlation. Significant differences are indicated by * (<span class="html-italic">p</span> &lt; 0.05) and ** (<span class="html-italic">p</span> &lt; 0.01).</p>
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<p>Histogram of LDA scores (<b>A</b>). Correlation analysis between differential genera and cytokines (<b>B</b>). Red indicates a positive correlation, and blue indicates a negative correlation. Significant differences are indicated by * (<span class="html-italic">p</span> &lt; 0.05) and ** (<span class="html-italic">p</span> &lt; 0.01).</p>
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<p>Possible immunomodulatory mechanism of the 2FGF prebiotic formula in CTX-induced immunosuppressed mice.</p>
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19 pages, 2026 KiB  
Article
Effect of Interrupting the Daily Scotophase Period on Laying Hen Performance, Bone Health, Behavior, and Welfare; Part I: Bone Health
by Alexis J. Clark, Cerano Harrison, Ari J. Bragg, Gabrielle M. House, Aaron B. Stephan, Mireille Arguelles-Ramos and Ahmed Ali
Poultry 2024, 3(4), 364-382; https://doi.org/10.3390/poultry3040028 - 14 Oct 2024
Viewed by 456
Abstract
Laying hens usually have 16 h of light and 8 h of darkness during egg laying, with eggshell formation primarily occurring during darkness when dietary calcium is lacking, leading to bone calcium resorption and osteoporosis. This study examined how interrupting the dark phase [...] Read more.
Laying hens usually have 16 h of light and 8 h of darkness during egg laying, with eggshell formation primarily occurring during darkness when dietary calcium is lacking, leading to bone calcium resorption and osteoporosis. This study examined how interrupting the dark phase affects bone health in 396 Hy-line W36 hens assigned to control (C) or treatment groups (W1 and W2). All hens received 16 h of light and 8 h of darkness daily in different variations of scotophase interruption. Blood samples were taken at weeks 20, 30, 50, and 70, serum calcium was measured during darkness at two timepoints (SRT and END), and bone demineralization markers were examined using enzyme concentrations (TRACP-5b and CTX-I). Across weeks, tibias were CT-scanned for density (mg/cm3) and area (mm2), then used for breakage strength analysis (N) and ash%. No SRT Ca level differences emerged, but C hens had lower END Ca levels compared to W1 and W2 hens across all weeks, while W1 and W2 hens showed no significant differences. C hens displayed higher TRACP-5b and CTX-I concentrations across all weeks compared to W1 and W2 (all p ≤ 0.05). At week 70, C hens had the lowest cortical bone cross-sectional area and mineral density compared to W1 and W2 (all p ≤ 0.05). Tibiotarsi bone breakage strength was lower in C hens compared to W1 and W2. C hens had significantly lower ash% than treatment birds. Interrupting the scotophase period improved overall bone health in Hy-line W36 laying hens. Full article
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<p>Light schedules applied during the experiment. C: birds received 16 h of continuous light (photophase) and 8 h of continuous darkness (scotophase). W1: birds received 15 h of continuous photophase, 4 h of scotophase, 1 h of photophase, then 4 h of scotophase; W2: birds received 14 h of continuous photophase, 4 h of scotophase, 2 h of photophase, then 4 h of scotophase.</p>
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<p>Image examples of CT analysis of the tibiotarsal region. (<b>a</b>) Determination of proximal, middle, and distal points of interest of the tibiotarsus, (<b>b</b>) orientation of tracing regions of interest for analysis, and (<b>c</b>) orientation of tracing regions of interest for the hydroxyapatite rods in the phantom.</p>
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<p>Mean serum concentrations of tartrate-resistant acid phosphatase 5b (TRACP-5b; U/L) in laying hens at 20, 30, 50, and 70 weeks of age (n = 54/week), with treatments consisting of no scotophase interruption (C), 1 h of scotophase interruption (W1), and 2 h of scotophase interruption (W2). <sup>a,b</sup> Means with differing superscripts indicate statistically significant differences across treatments of the same week at <span class="html-italic">p</span> &lt; 0.05. <sup>A–C</sup> Means with differing superscripts indicate statistically significant differences within treatments across weeks at <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>Mean serum concentrations of C-terminal telopeptide of type I collagen (CTX-I; ng/L) in laying hens at 20, 30, 50, and 70 weeks of age (n = 54/week), with treatments consisting of no scotophase interruption (C), 1 h of scotophase interruption (W1), and 2 h of scotophase interruption (W2). <sup>a,b</sup> Means with differing superscripts indicate statistically significant differences across treatments of the same week at <span class="html-italic">p</span> &lt; 0.05. <sup>A–C</sup> Means with differing superscripts indicate statistically significant differences within treatments across weeks at <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>Mean tibia ash percentage (%) of laying hens at 70 weeks of age (n = 54) with treatments consisting of no scotophase interruption (C), 1 h of scotophase interruption (W1), and 2 h of scotophase interruption (W2). <sup>a,b</sup> Means with differing superscripts indicate statistically significant differences between treatments at <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>Mean tibia breaking strength (N) and stiffness (N/mm) of laying hens at 70 weeks of age (n = 54), with treatments consisting of no scotophase interruption (C), 1 h of scotophase interruption (W1), and 2 h of scotophase interruption (W2). <sup>a,b</sup> Means with differing superscripts indicate statistically significant differences between treatments within a parameter at <span class="html-italic">p</span> &lt; 0.05.</p>
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17 pages, 3012 KiB  
Article
Genotypic Characterisation and Antimicrobial Resistance of Extended-Spectrum β-Lactamase-Producing Escherichia coli in Humans, Animals, and the Environment from Lusaka, Zambia: Public Health Implications and One Health Surveillance
by Maisa Kasanga, Márió Gajdács, Walter Muleya, Odion O. Ikhimiukor, Steward Mudenda, Maika Kasanga, Joseph Chizimu, Doreen Mainza Shempela, Benjamin Bisesa Solochi, Mark John Mwikisa, Kaunda Yamba, Cheryl P. Andam, Raphael Chanda, Duncan Chanda and Geoffrey Kwenda
Antibiotics 2024, 13(10), 951; https://doi.org/10.3390/antibiotics13100951 - 10 Oct 2024
Viewed by 1467
Abstract
Background: Extended-spectrum β-lactamases (ESBL) in Escherichia coli are a serious concern due to their role in developing multidrug resistance (MDR) and difficult-to-treat infections. Objective: This study aimed to identify ESBL-carrying E. coli strains from both clinical and environmental sources in Lusaka District, Zambia. [...] Read more.
Background: Extended-spectrum β-lactamases (ESBL) in Escherichia coli are a serious concern due to their role in developing multidrug resistance (MDR) and difficult-to-treat infections. Objective: This study aimed to identify ESBL-carrying E. coli strains from both clinical and environmental sources in Lusaka District, Zambia. Methods: This cross-sectional study included 58 ESBL-producing E. coli strains from hospital inpatients, outpatients, and non-hospital environments. Antimicrobial susceptibility was assessed using the Kirby–Bauer disk diffusion method and the VITEK® 2 Compact System, while genotypic analyses utilised the Illumina NextSeq 2000 sequencing platform. Results: Among the strains isolated strains, phylogroup B2 was the most common, with resistant MLST sequence types including ST131, ST167, ST156, and ST69. ESBL genes such as blaTEM-1B, blaCTX-M,blaOXA-1, blaNDM-5, and blaCMY were identified, with ST131 and ST410 being the most common. ST131 exhibited a high prevalence of blaCTX-M-15 and resistance to fluoroquinolones. Clinical and environmental isolates carried blaNDM-5 (3.4%), with clinical isolates showing a higher risk of carbapenemase resistance genes and the frequent occurrence of blaCTX-M and blaTEM variants, especially blaCTX-M-15 in ST131. Conclusions: This study underscores the public health risks of blaCTX-M-15- and blaNDM-5-carrying E. coli. The strengthening antimicrobial stewardship programmes and the continuous surveillance of AMR in clinical and environmental settings are recommended to mitigate the spread of resistant pathogens. Full article
(This article belongs to the Special Issue Antibiotic Resistance: From the Bench to Patients, 2nd Edition)
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<p>Matrix for antimicrobial susceptibility of <span class="html-italic">E. coli</span> genomes. The top row annotation shows the source, ST, and ESBL producers. The left row annotation refers to the antibiotic classes of antimicrobials. Columns are clustered using the Euclidean method.</p>
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<p>Heat map indicating the abundance of phenotypically resistant AMR genes and β-lactamase production in ESBL-producing <span class="html-italic">E. coli</span> strains from clinical and environmental isolates. Darker colours indicate stronger correlations, while lighter colours represent weaker correlations. Key: AMP (ampicillin); AMC (amoxicillin-clavulanic acid); CXM (cefuroxime); NAL (nalidixic acid); CHL (chloramphenicol); CRO (ceftriaxone); CIP (ciprofloxacin); SXT (trimethoprim-sulfamethoxazole); CN (gentamicin); MEM (meropenem); IMP (imipenem).</p>
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<p>Distribution of AMR genes in antibiotic classes in ESBL-producing <span class="html-italic">E. coli</span> obtained from clinical and environmental sources.</p>
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<p>The distribution of phylogroups amongst environmental and clinical isolates of <span class="html-italic">E. coli</span>.</p>
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<p>The diversity of phylogroups and sequence types in ESBL <span class="html-italic">E. coli</span> isolates.</p>
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19 pages, 2287 KiB  
Article
Genomic Characterization of 16S rRNA Methyltransferase-Producing Enterobacterales Reveals the Emergence of Klebsiella pneumoniae ST6260 Harboring rmtF, rmtB, blaNDM-5, blaOXA-232 and blaSFO-1 Genes in a Cancer Hospital in Bulgaria
by Stefana Sabtcheva, Ivan Stoikov, Sylvia Georgieva, Deyan Donchev, Yordan Hodzhev, Elina Dobreva, Iva Christova and Ivan N. Ivanov
Antibiotics 2024, 13(10), 950; https://doi.org/10.3390/antibiotics13100950 - 10 Oct 2024
Viewed by 865
Abstract
Background: Acquired 16S rRNA methyltransferases (16S-RMTases) confer high-level resistance to aminoglycosides and are often associated with β-lactam and quinolone resistance determinants. Methods: Using PCR, whole-genome sequencing and conjugation experiments, we conducted a retrospective genomic surveillance study of 16S-RMTase-producing Enterobacterales, collected between 2006 [...] Read more.
Background: Acquired 16S rRNA methyltransferases (16S-RMTases) confer high-level resistance to aminoglycosides and are often associated with β-lactam and quinolone resistance determinants. Methods: Using PCR, whole-genome sequencing and conjugation experiments, we conducted a retrospective genomic surveillance study of 16S-RMTase-producing Enterobacterales, collected between 2006 and 2023, to explore transmission dynamics of methyltransferase and associated antibiotic resistance genes. Results: Among the 10,731 consecutive isolates, 150 (1.4%) from 13 species carried armA (92.7%), rmtB (4.7%), and rmtF + rmtB (2.7%) methyltransferase genes. The coexistence of extended-spectrum β-lactamase (blaCTX-M-3/15, blaSHV-12, blaSFO-1), carbapenemase (blaNDM-1/5, blaVIM-1/4/86, blaOXA-48), acquired AmpC (blaCMY-2/4/99, blaDHA-1, blaAAC-1), and plasmid-mediated quinolone resistance (qnrB, qnrS, aac(6′)-Ib-cr) genes within these isolates was also detected. Methyltransferase genes were carried by different plasmids (IncL/M, IncA/C, IncR, IncFIB, and IncFII), suggesting diverse origins and sources of acquisition. armA was co-transferred with blaCTX-M-3/15, blaNDM-1, blaVIM-4/86, blaOXA-48, blaCMY-4, aac(6′)-Ib-cr, qnrB, and qnrS, while rmtF1 was co-transferred with blaSFO-1, highlighting the multidrug-resistant nature of these plasmids. Long-read sequencing of ST6260 K. pneumoniae isolates revealed a novel resistance association, with rmtB1 and blaNDM-5 on the chromosome, blaOXA-232 on a conjugative ColKP3 plasmid, and rmtF1 with blaSFO-1 on self-transmissible IncFIB and IncFII plasmids. Conclusions: The genetic plasticity of plasmids carrying methyltransferase genes suggests their potential to acquire additional resistance genes, turning 16S-RMTase-producing Enterobacterales into a persistent public health threat. Full article
(This article belongs to the Special Issue Genomic Analysis of Antimicrobial Drug-Resistant Bacteria)
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<p>Prevalence of 16S rRNA methyltransferase genes and their distribution among 16S-RMTase-producing isolates. (<b>a</b>) The first chart shows the prevalence rate of ArmA, RmtB and RmtF methyltransferases among the 150 bacterial isolates. (<b>b</b>) The second chart depicts the distribution of 16S-RMTase-producing isolates across the studied bacterial species.</p>
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<p>Heatmap representation of the acquired antimicrobial resistance genes of (<b>a</b>) <span class="html-italic">Klebsiella pneumoniae</span>; (<b>b</b>) <span class="html-italic">Enterobacter cloacae</span> complex; (<b>c</b>) <span class="html-italic">Serratia marcescens</span>. Phylogenetic trees were constructed based on SNP analysis for (<b>b</b>,<b>c</b>) with PhaME v1.0.4, while for (<b>a</b>), MLVA types were used for phylogenetic tree construction according to Grissa et al. [<a href="#B18-antibiotics-13-00950" class="html-bibr">18</a>] (see <a href="#sec4dot7-antibiotics-13-00950" class="html-sec">Section 4.7</a>). For (<b>a</b>) strains marked with an asterisk (*), resistance data were obtained from PCR and for the remaining strains from WGS. Drug classes are colored consistently, as shown in the legend (right). The only exception from the legend is <span class="html-italic">aac(6′)-Ib-cr5</span>, colored in pale green to indicate dual resistance. Both dendrograms and heatmaps were annotated with iTOL v6.8.1 (<a href="https://itol.embl.de/about.cgi" target="_blank">https://itol.embl.de/about.cgi</a>, accessed on 20 August 2024). Sequence type (ST) was derived for the species with available MLST schemes. ND, not determined either due to missing alleles or imperfect match. KP, <span class="html-italic">Klebsiella pneumoniae</span>; EA, <span class="html-italic">Enterobacter asburiae</span>; EH, <span class="html-italic">Enterobacter hormaechei</span>; SM, <span class="html-italic">Serratia marcescens</span>.</p>
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<p>Heatmap representation of the acquired antimicrobial resistance genes of (<b>a</b>) <span class="html-italic">Escherichia coli</span>; (<b>b</b>) <span class="html-italic">Citrobacter freundii</span> complex; (<b>c</b>) <span class="html-italic">Klebsiella oxytoca</span> complex; (<b>d</b>) <span class="html-italic">Morganella morganii</span>; (<b>e</b>) <span class="html-italic">Klebsiella aerogenes</span>. Phylogenetic trees were constructed based on SNP analysis for (<b>a</b>–<b>e</b>) with PhaME v1.0.4 (see <a href="#sec4dot7-antibiotics-13-00950" class="html-sec">Section 4.7</a>). Drug classes are colored consistently, as shown in the legend (right). The only exception from the legend is <span class="html-italic">aac(6′)-Ib-cr5</span>, colored in pale green to indicate dual resistance. Both dendrograms and heatmaps were annotated with iTOL v6.8.1 (<a href="https://itol.embl.de/about.cgi" target="_blank">https://itol.embl.de/about.cgi</a>, accessed on 20 August 2024). Sequence type (ST) was derived for the species with available MLST schemes. ND, not determined either due to missing alleles or imperfect match. EC, <span class="html-italic">Escherichia coli</span>; CF, <span class="html-italic">Citrobacter freundii</span>; CP, <span class="html-italic">Citrobacter portucalensis</span>; KO, <span class="html-italic">Klebsiella oxytoca</span>; KM, <span class="html-italic">Klebsiella michiganensis</span>; MM, <span class="html-italic">Morganella morganii</span>; KA, <span class="html-italic">Klebsiella aerogenes</span>.</p>
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30 pages, 3799 KiB  
Article
Determinants of Antibiotic Resistance and Virulence Factors in the Genome of Escherichia coli APEC 36 Strain Isolated from a Broiler Chicken with Generalized Colibacillosis
by Dmitry S. Karpov, Elizaveta M. Kazakova, Maxim A. Kovalev, Mikhail S. Shumkov, Tomiris Kusainova, Irina A. Tarasova, Pamila J. Osipova, Svetlana V. Poddubko, Vladimir A. Mitkevich, Marina V. Kuznetsova and Anna V. Goncharenko
Antibiotics 2024, 13(10), 945; https://doi.org/10.3390/antibiotics13100945 - 9 Oct 2024
Viewed by 1095
Abstract
Objective: Multidrug-resistant, highly pathogenic Escherichia coli strains are the primary causative agents of intestinal and extraintestinal human diseases. The extensive utilization of antibiotics for farm animals has been identified as a contributing factor to the emergence and dissemination of E. coli strains that [...] Read more.
Objective: Multidrug-resistant, highly pathogenic Escherichia coli strains are the primary causative agents of intestinal and extraintestinal human diseases. The extensive utilization of antibiotics for farm animals has been identified as a contributing factor to the emergence and dissemination of E. coli strains that exhibit multidrug resistance and possess high pathogenic potential. Consequently, a significant research objective is to examine the genetic diversity of pathogenic E. coli strains and to identify those that may pose a threat to human health. Methods: In this study, we present the results of genome sequencing and analysis, as well as the physiological characterization of E. coli strain APEC 36, which was isolated from the liver of a broiler chicken with generalized colibacillosis. Results: We found that APEC 36 possess a number of mechanisms of antibiotic resistance, including antibiotic efflux, antibiotic inactivation, and antibiotic target alteration/replacement/protection. The most widely represented group among these mechanisms was that of antibiotic efflux. This finding is consistent with the strain’s documented resistance to multiple antibiotics. APEC 36 has an extremely rare variant of the beta-lactamase CTX-M-169. Notwithstanding the multitude of systems for interfering with foreign DNA present in the strain, seven plasmids have been identified, three of which may possess novel replication origins. Additionally, qnrS1, which confers resistance to fluoroquinolones, was found to be encoded in the genome rather than in the plasmid. This suggests that the determinants of antibiotic resistance may be captured in the genome and stably transmitted from generation to generation. Conclusions: The APEC 36 strain has genes for toxins, adhesins, protectins, and an iron uptake system. The obtained set of genetic and physiological characteristics allowed us to assume that this strain has a high pathogenic potential for humans. Full article
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<p>Human pathogenic strains close to <span class="html-italic">E. coli</span> APEC 36 according to the BV-BRC database.</p>
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<p>The antibiotic resistance mechanisms proposed for the <span class="html-italic">E. coli</span> APEC 36 strain, based on the analysis of its sequenced genome.</p>
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<p>Assessment of pathogenicity of <span class="html-italic">E. coli</span> strain APEC 36. (<b>A</b>). An example of specific adhesion of <span class="html-italic">E. coli</span> APEC 36 on chicken red blood cells (arrow), 30 min, staining with gentian violet, 1000×. (<b>B</b>). An example of <span class="html-italic">E. coli</span> growth on chicken blood agar: viewed with incident light–obvious hemolysis. (<b>C</b>). Assessment of the siderophore production level.</p>
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<p>APEC 36 strain does not contain lysogenic prophages. (<b>A</b>) <span class="html-italic">E. coli</span> APEC 36; (<b>B</b>) control lysogenic prophage-carrying strain.</p>
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