The use of essential oils is increasingly being investigated among new therapeutic approaches based on medicinal plants and their extracts. With the wide use of synthetic and semi-synthetic antimicrobial drugs, the spread of... more
The use of essential oils is increasingly being investigated among new therapeutic approaches based on medicinal plants and their extracts. With the wide use of synthetic and semi-synthetic antimicrobial drugs, the spread of drug-resistant clinical isolates has increased, and research is directed towards natural products, such as essential oils, as useful antimicrobial resources. In the context of a prospective infection, we compared the impact of essential oils and common antimicrobial agents on the microbicidal activity of human phagocytes. Here, we present the results of our decades-long investigation into the effectiveness of thyme red oil (26.52% thymol chemotype), tea tree oil (TTO), and Mentha of Pancalieri [(Mentha x piperita (Huds) var. officinalis (Sole), form rubescens (Camus) (Lamiaceae)] essential oils on human polymorphonuclear leukocytes (PMNs) capacity to kill clinical strains of Candida albicans and C. krusei when compared to three antifungal drugs used to treat can...
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The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to... more
The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, t...
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Over the past 20–30 years, Trichophyton rubrum represented the most widespread dermatophyte with a prevalence accounting for 70% of dermatophytosis. The treatment for cutaneous infections caused by Trichophyton spp. are imidazoles... more
Over the past 20–30 years, Trichophyton rubrum represented the most widespread dermatophyte with a prevalence accounting for 70% of dermatophytosis. The treatment for cutaneous infections caused by Trichophyton spp. are imidazoles (ketoconazole (KTZ)) and triazoles (itraconazole (ITZ)). T. rubrum can develop resistance to azoles after prolonged exposure to subinhibitory concentrations resulting in therapeutic failures and chronic infections. These problems have stimulated the search for therapeutic alternatives, including essential oils, and their potential use in combination with conventional antifungals. The purpose of this study was to evaluate the antifungal activity of tea tree oil (TTO) (Melaleuca alternifolia essential oil) and the main components against T. rubrum and to assess whether TTO in association with KTZ/ITZ as reference drugs improves the antifungal activity of these drugs. We used a terpinen-4-ol chemotype (35.88%) TTO, and its antifungal properties were evaluated...
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The aim of this study was to evaluate the ability of a PIPS (photon-induced photoacoustic streaming) Er:YAG laser to reduce the root canal system bacterial count in vivo in comparison to the traditional irrigation technique. The... more
The aim of this study was to evaluate the ability of a PIPS (photon-induced photoacoustic streaming) Er:YAG laser to reduce the root canal system bacterial count in vivo in comparison to the traditional irrigation technique. The post-operative patients’ quality of life (QoL) after endodontic therapy was evaluated through a questionnaire. Fifty-four patients affected by pulp necrosis with or without apical periodontitis biofilm disease were selected for endodontic treatment and randomly assigned to Group A (n = 27) with traditional irrigation and Group B (n = 27), with PIPS irrigation applied according to the protocol. Shaping was performed with ProGlider and ProTaper Next, and irrigation was performed with 5% NaOCl and 10% EDTA. Intracanal samples for culture tests were collected before and after irrigation. The microbiological analysis was evaluated by the Kolmogorov–Smirnov normality and Mann–Whitney tests (p < 0.05). A self-assessment questionnaire was used to evaluate the QoL...
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Background Hydrolates, complex mixtures containing traces of essential oils (EOs), are inexpensive, easy to make and less toxic than their corresponding EOs. The antibacterial and antifungal activity of the hydrolate of Coridothymus... more
Background Hydrolates, complex mixtures containing traces of essential oils (EOs), are inexpensive, easy to make and less toxic than their corresponding EOs. The antibacterial and antifungal activity of the hydrolate of Coridothymus capitatus (L.) Reichenb. fil. (Lamiaceae) alone and in combination with antimicrobial drugs, such as tetracycline and itraconazole, were evaluated. Methods The chemical composition was analysed by gas-chromatography-mass spectrometry (GC-MS). Standard methods were performed to evaluate the susceptibility of some Gram-positive and Gram-negative bacteria, and Candida spp. to the hydrolate, in comparison with its EO. The hydrolate mechanism of action was assayed by propidium iodide and MitoTracker staining. Checkerboard tests were carried out for combinations studies. Results GC-MS identified 0.14% (v/v) of total EO content into hydrolate and carvacrol as a dominant component. The hydrolate showed a good antimicrobial activity against bacteria and yeasts. I...
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The aim of this study was to evaluate the influence of tea tree oil (TTO) and “Mentha of Pancalieri” essential oil (MPP) on intracellular killing of Candida krusei, often resistant to conventional drugs, by polymorphonuclear leucocytes... more
The aim of this study was to evaluate the influence of tea tree oil (TTO) and “Mentha of Pancalieri” essential oil (MPP) on intracellular killing of Candida krusei, often resistant to conventional drugs, by polymorphonuclear leucocytes (PMNs). Intracellular killing was investigated by incubating yeasts and PMNs with essential oils (EOs) at 1/4 and 1/8 × MIC (Minimal Inhibitory Concentration), in comparison with anidulafungin, used as a reference drug. Killing values were expressed as Survival Index (SI) values. The cytotoxicity of EOs was evaluated by 3-[4,-5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Both EOs were more efficaceous at 1/8 × MIC than 1/4 × MIC, with killing values higher than observed in EO-free systems and in presence of anidulafungin, indicating that the decreasing concentrations did not cause lower candidacidal activity. This better activity at 1/8 × MIC is probably due to the EOs’ toxicity at 1/4 × MIC, suggesting that at higher concentra...
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The promising antimicrobial activity of essential oils (EOs) led researchers to use them in combination with antimicrobial drugs in order to reduce drug toxicity, side effects, and resistance with single agents. In Pancalieri (Turin,... more
The promising antimicrobial activity of essential oils (EOs) led researchers to use them in combination with antimicrobial drugs in order to reduce drug toxicity, side effects, and resistance with single agents. In Pancalieri (Turin, Italy), there is a local production of Mentha x piperita worldwide known as “Mentha of Pancalieri”. The EO from this Mentha is considered as one of the best peppermint EO in the world. In our research, we assessed the antifungal activity of “Mentha of Pancalieri” EO either alone or in combination with azole drugs (fluconazole, itraconazole, ketoconazole) against a wide panel of yeast and dermatophyte clinical isolates. The EO was analyzed by GC-MS and its antifungal properties were evaluated by MIC/MFC parameters, according to the CLSI guidelines, with some modifications. The interaction of peppermint EO with azoles was evaluated through the chequerboard and isobologram methods. Results suggest this EO exerts a fungicidal activity against yeasts, and a ...
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The entry of antibiotics into phagocytes is necessary for activity against intracellular pathogens. The ability of sanfetrinem, the first member of a new class of antibiotics, to penetrate human polymorphonuclear granulocytes and its... more
The entry of antibiotics into phagocytes is necessary for activity against intracellular pathogens. The ability of sanfetrinem, the first member of a new class of antibiotics, to penetrate human polymorphonuclear granulocytes and its consequences upon subsequent phagocytosis and killing of ingested penicillin-resistantStreptococcus pneumoniae have been evaluated. Sanfetrinem penetrated into human polymorphonuclear leukocytes (PMNs) at all concentrations tested, with cellular concentration/extracellular concentration ratios of 6.6 to 5.03 and 4.21 when sanfetrinem was used at 0.25 to 0.5 and 1 μg/ml, respectively, within 30 min of incubation. The uptake was complete within 5 min and was not energy dependent, since it was not affected by cell viability, environmental temperature, or the addition of a metabolic inhibitor. At a concentration of one-half the MIC, sanfetrinem significantly enhanced human PMN phagocytosis and increased intracellular bactericidal activity against penicillin...
Research Interests: Microbiology, Medical Microbiology, Biology, Medicine, Streptococcus pneumoniae, and 15 moreHumans, Bacteria, Cell Viability, Antibiotics, Phagocytosis, Environmental Temperature, Permeation, Extracellular, Penicillin, Bactericidal Activity, Intracellular, lactams, Streptococci, Pharmacology and pharmaceutical sciences, and Minimum Inhibitory Concentration
The physico–chemical and biological properties of nanostructured ZnO are combined with the non-toxic and eco-friendly features of the scCO2-mediated drug loading technique to develop a multifunctional antimicrobial drug delivery system... more
The physico–chemical and biological properties of nanostructured ZnO are combined with the non-toxic and eco-friendly features of the scCO2-mediated drug loading technique to develop a multifunctional antimicrobial drug delivery system for potential applications in wound healing. Two nanostructured ZnO (NsZnO) with different morphologies were prepared through wet organic-solvent-free processes and characterized by means of powder X-ray diffraction, field emission scanning electron microscopy (FESEM), and nitrogen adsorption analysis. The antimicrobial activity of the two samples against different microbial strains was investigated together with the in vitro Zn2+ release. The results indicated that the two ZnO nanostructures exhibited the following activity: S. aureus > C. albicans > K. pneumoniae. A correlation between the antimicrobial activity, the physico–chemical properties (specific surface area and crystal size) and the Zn2+ ion release was found. Ibuprofen was, for the ...
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Cryptococcal infections, besides being a problem for immunocompromised patients, are occasionally being a problem for immunocompetent patients. In addition, the lower susceptibility of this yeast to azoles is a growing problem in health... more
Cryptococcal infections, besides being a problem for immunocompromised patients, are occasionally being a problem for immunocompetent patients. In addition, the lower susceptibility of this yeast to azoles is a growing problem in health care. To date, there are very few molecules with any activity towards Cryptococcus neoformans, leading to heightened interest in finding new alternatives or adjuvants to conventional drugs for the treatment of mycosis caused by this yeast. Since the essential oils (EOs) are considered as a potential rich source of bioactive antimicrobial compounds, we evaluated the antifungal activity of Origanum vulgare (oregano), Pinus sylvestris (pine), and Thymus vulgaris (thyme red) EOs, and their components (α-pinene, carvacrol, thymol) compared with fluconazole, itraconazole, and voriconazole, against C.neoformans clinical strains. Then, we investigated the effect of EOs and components in combination with itraconazole. EO composition was analysed by Gas chroma...
Research Interests: Chemistry, Complementary and Alternative Medicine, Kinetics, Biology, Medicine, and 15 moreEssential Oil, Lamiaceae, Cryptococcus Neoformans, Fluconazole, Voriconazole, Pinus sylvestris, Antifungal Agents, Itraconazole, Microbial Viability, Origanum, Thymol, Carvacrol, Drug synergism, Thymus Plant, and Broth Microdilution
Despite ongoing global efforts, antimicrobial resistance continues to threaten the treatment of an ever-increasing range of bacterial infections. Substantial evidence has shown that public education programs that foster microbial literacy... more
Despite ongoing global efforts, antimicrobial resistance continues to threaten the treatment of an ever-increasing range of bacterial infections. Substantial evidence has shown that public education programs that foster microbial literacy amongst young school audiences may improve correct knowledge of specific health issues, such as prevention of microbial infections and responsible use of antibiotics. The aim of the Microbiological@mind project was to engage primary school students with the subject of microbiology, to promote both scientific interest and awareness towards correct behaviors that may ensure a safer lifestyle. Interactive workshops based on a full ''hands on'' approach were carried out at primary schools of Turin by an expert team from the University of Turin to over 1200 children aged 9-11 years. A questionnaire (pre- and post-activity test) on the main topic (i.e.antibiotics) was used to assess project effectiveness. The workshops provided a useful m...
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A prospective international multicentre surveillance study was conducted to investigate the prevalence and amphotericin B (AMB) susceptibility of Aspergillus terreus species complex infections. Three hundred seventy cases from 21... more
A prospective international multicentre surveillance study was conducted to investigate the prevalence and amphotericin B (AMB) susceptibility of Aspergillus terreus species complex infections. Three hundred seventy cases from 21 countries were evaluated. The overall prevalence of A. terreus species complex among patients investigated and with mold positive cultures was 5.2% (370/7116). AMB MICs were ranging from 0.125 to 32 mg/L, (median 8mg/L). A. terreus species complex infections cause a wide spectrum of aspergillosis and the majority of cryptic species display high AMB MICs.
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Allergic rhinitis is known to be one of the most common chronic diseases in the industrialized world. According to the concept that allergic rhinitis patients generally suffer from an immune deficit, in order to stimulate specifically or... more
Allergic rhinitis is known to be one of the most common chronic diseases in the industrialized world. According to the concept that allergic rhinitis patients generally suffer from an immune deficit, in order to stimulate specifically or aspecifically their immune system, immunomodulating agents from various sources, such as synthetic compounds, tissue extracts or a mixture of bacterial extracts, have been used. The aim of the present trial is to evaluate the efficacy of the treatment with an immunostimulating vaccine consisting of a polyvalent mechanical bacterial lysate (PMBL) in the prophylaxis of allergic rhinitis and subsequently to analyze its in vivo effects on immune responses. 41 allergic rhinitis patients were enrolled: 26 patients were randomly assigned to the group for PMBL sublingual treatment and 15 others to the group for placebo treatment. For all 26 patients blood samples were drawn just before (T0) and after 3 months of PMBL treatment (T3) to evaluate plasma IgE le...
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Research Interests: Chemistry, Drug delivery, Medicine, Pharmaceutics, Drug, and 15 moreCell line, Humans, Animals, Nanostructures, Drug Delivery Systems, Skin, Bioavailability, Antibiotics, Drug Compounding, Drug Stability, Cell Survival, Methicillin Resistant Staphylococcus Aureus, Nanocarriers, Pharmacology and pharmaceutical sciences, and In Vitro Techniques
Research Interests: Pharmacology, Chemistry, Kinetics, Pharmacokinetics, Drug delivery, and 15 moreNanoparticles, Medicine, Lipids, Animals, Male, Drug Delivery Systems, Bioavailability, Pseudomonas aeruginosa, Neutrophils, Particle Size, Pseudomonas Aeruginosa, Drug Carriers, Eye Diseases, Dispersity, and Pharmacology and pharmaceutical sciences
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Lactobacilli have the potential to act as reservoirs of antibiotic resistance genes similar to those found in human pathogens, with the risk of transferring these genes to many pathogenic bacteria. In this study, we investigated the role... more
Lactobacilli have the potential to act as reservoirs of antibiotic resistance genes similar to those found in human pathogens, with the risk of transferring these genes to many pathogenic bacteria. In this study, we investigated the role of human polymorphonuclear cells (PMNs) against Lactobacillus spp. both resistant and susceptible to ciprofloxacin (a fluoroquinolone) and the effect of ciprofloxacin on the interaction between PMNs and three Lactobacillus spp. with different patterns of susceptibility to this drug. Hence, the primary functions of PMNs, such as phagocytosis and bacterial intracellular killing, against lactobacilli were investigated. The rate of PMN phagocytosis was high for ciprofloxacin-sensitive and ciprofloxacin-resistant strains. The patterns of intracellular killing of ciprofloxacin-sensitive and ciprofloxacin-resistant strains by PMNs underline that PMNs alone were able to kill lactobacilli. The addition of ciprofloxacin to PMNs did not result in a significant...
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The risk of opportunistic infections caused by non-Candida yeasts and yeast-like fungi is increasingly common, mainly in immunocompromised patients. Appropriate first-line therapy has not been defined and standardized, mainly due to the... more
The risk of opportunistic infections caused by non-Candida yeasts and yeast-like fungi is increasingly common, mainly in immunocompromised patients. Appropriate first-line therapy has not been defined and standardized, mainly due to the low number of cases reported. To improve empirical treatment guidelines, we describe the susceptibility profile to fluconazole and voriconazole of 176 non-Candida yeasts and yeast-like fungi collected from hospitals in Piedmont, North West Italy from January 2009 to December 2013. The results showed that most isolates are susceptible to voriconazole (94%), but less susceptible to fluconazole (78%), suggesting that voriconazole could be used as first-line therapy in infections caused by these fungi.
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Clavulanic acid is an effective inhibitor of a broad range of clinically important beta-lactamases and its combination with some beta-lactam antibiotics such as ticarcillin has been shown to extend the inhibition spectrum of the... more
Clavulanic acid is an effective inhibitor of a broad range of clinically important beta-lactamases and its combination with some beta-lactam antibiotics such as ticarcillin has been shown to extend the inhibition spectrum of the beta-lactams. The activity of ticarcillin, both alone and in combination with clavulanic acid, upon PMN phagocytosis and bactericidal activity towards Klebsiella pneumoniae was investigated. The results indicate that a combination of ticarcillin with clavulanic acid is more active than ticarcillin alone against a beta-lactamase-producing strain of K. pneumoniae, and hence may significantly increase the bacterial vulnerability to phagocyte functions.
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The use of broad spectrum beta-lactamase inhibitors in association with beta-lactam agents provides one strategy to overcome the enzymatic resistance. Clavulanic acid is a potent inhibitor of a wide range of bacterial beta-lactamases and... more
The use of broad spectrum beta-lactamase inhibitors in association with beta-lactam agents provides one strategy to overcome the enzymatic resistance. Clavulanic acid is a potent inhibitor of a wide range of bacterial beta-lactamases and its potentiating effect on amoxycillin has been established both in vitro and in clinical trials. Since the efficacy of an antimicrobial agent in the therapy of infections depends on the interaction of bacteria, antibiotic and phagocytes, we investigated the effect of amoxycillin/clavulanic acid on the in vitro interaction between human polymorphonuclear cells (PMNs) and beta-lactamase producing strains of Klebsiella pneumoniae and Staphylococcus aureus. Clavulanic acid did not have any significant influence upon the PMN phagocytosis and killing against intracellular bacteria. Interestingly, the presence of the suicide inhibitor, with its beta-lactamase inhibitory properties, potentiated the activity of amoxycillin against the beta-lactamase produci...
Research Interests: Microbiology, Biology, Drug interactions, Enzyme Inhibitors, Medicine, and 15 moreHumans, Pubmed, Bacteria, Staphylococcus aureus, Antimicrobial, Antibiotics, Neutrophils, Anti-Bacterial Agents, Phagocytosis, Amoxicillin, Antibacterial Agent, Klebsiella pneumoniae, Clavulanic Acid, Pharmacology and pharmaceutical sciences, and Penicillins
Many antibiotics in addition to their direct effect on bacteria can modulate host defence in different ways. The influence of cefotaxime on the phagocytic and bactericidal activity of mouse peritoneal macrophages was investigated. At... more
Many antibiotics in addition to their direct effect on bacteria can modulate host defence in different ways. The influence of cefotaxime on the phagocytic and bactericidal activity of mouse peritoneal macrophages was investigated. At concentrations of half the MIC the antibiotic caused macrophages to kill intracellular Staphylococcus aureus at a higher level than did macrophages without drug. Bacteria pretreated with cefotaxime became more sensitive to macrophage phagocytic and bactericidal activity. Macrophages taken from mice receiving intravenous cefotaxime showed greater phagocytic capacity than those from control mice.
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The goal of antimicrobial therapy is to eliminate invading bacteria both in the extracellular and intracellular environment. Thus, recent work has focused on the ability of various antibiotics to enter phagocytic cells and kill... more
The goal of antimicrobial therapy is to eliminate invading bacteria both in the extracellular and intracellular environment. Thus, recent work has focused on the ability of various antibiotics to enter phagocytic cells and kill intracellular pathogens, since bacteria which survive within phagocytes may often produce prolonged or recurrent infections. In the last ten years the antibiotic modulation of phagocytic cell functions has become the subject of our major investigational activity. Taking into account that entry of antibiotics into phagocytes is necessary for activity against intracellular organisms, we examined the uptake of 11 radiolabelled antibiotics by macrophages. Penicillins and cephalosporins were taken up poorly by phagocytes. Teicoplanin was efficiently concentrated by macrophages, achieving intracellular concentrations higher than those in the surrounding extracellular medium. Roxithromycin was more markedly accumulated within phagocytes than was erythromycin, depend...
Research Interests: Microbiology, Chemistry, Biology, Chemotherapy, Macrophages, and 15 moreMedicine, Humans, Macrophage, Pubmed, Bacteria, Chemotaxis, Antibiotics, Anti-Bacterial Agents, Phagocytosis, Bacterial infections, Extracellular, Phagocytes, Intracellular, Roxithromycin, and Pharmacology and pharmaceutical sciences
Teicoplanin, a glycopeptide antibiotic chemically related to the vancomycin-ristocetin group of antibiotics, has been shown to be active against gram-positive bacteria. Binding of teicoplanin by actively growing bacteria leads to... more
Teicoplanin, a glycopeptide antibiotic chemically related to the vancomycin-ristocetin group of antibiotics, has been shown to be active against gram-positive bacteria. Binding of teicoplanin by actively growing bacteria leads to morphological damage to the cell surface in staphylococci, as largely shown by transmission and scanning microscopy results.
Research Interests: Microbiology, Chemistry, Glycopeptide Research, Chemotherapy, Scanning Electron Microscopy, and 12 moreTransmission Electron Microscopy, Medicine, Vancomycin, Pubmed, Bacteria, Staphylococcus aureus, Ultrastructure, Antibiotics, Anti-Bacterial Agents, Cell Wall, Teicoplanin, and Pharmacology and pharmaceutical sciences
The in-vitro activities of two new miconazole and econazole salts (sulfosalicylic acid formulation) against 98 clinical isolates of dermatophytes were evaluated, in comparison to those of miconazole, miconazole nitrate, econazole and... more
The in-vitro activities of two new miconazole and econazole salts (sulfosalicylic acid formulation) against 98 clinical isolates of dermatophytes were evaluated, in comparison to those of miconazole, miconazole nitrate, econazole and econazole nitrate. Miconazole sulfosalicylate and econazole sulfosalicylate exhibited good activity towards all the dermatophytes tested, although econazole and its derivatives were more efficacious than miconazole and its salts. The new imidazoles were equally effective in inhibiting the fungal growth with respect to miconazole, miconazole nitrate, econazole and econazole nitrate.
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During acute bacterial infections, antibiotics only assist the phagocytic system in eradicating the invading organism. In this regard, the effect of ampicillin and its prodrug bacampicillin on the phagocytosis and killing of... more
During acute bacterial infections, antibiotics only assist the phagocytic system in eradicating the invading organism. In this regard, the effect of ampicillin and its prodrug bacampicillin on the phagocytosis and killing of Staphylococcus aureus by human macrophages was compared. Bacterial phagocytosis was enhanced after pre-incubation of staphylococci with bacampicillin. At a concentration of half the MIC bacampicillin showed a much more impressive killing capacity on macrophage-ingested live bacteria than did ampicillin, under all the experimental conditions tested.
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The entry of an antibiotic into phagocytes is a prerequisite for its intracellular bioactivity against susceptible facultative or obligatory intracellular microorganisms. AF 3013 is a new fluoroquinolone, and its uptake into and... more
The entry of an antibiotic into phagocytes is a prerequisite for its intracellular bioactivity against susceptible facultative or obligatory intracellular microorganisms. AF 3013 is a new fluoroquinolone, and its uptake into and elimination from mouse peritoneal macrophages, together with its effects on phagocytic and antimicrobial mechanisms against Klebsiella pneumoniae, were investigated. AF 3013 efficiently penetrated into phagocytic cells at all concentrations tested. The uptake proceeded rapidly and was energy independent, since it was not affected by cell viability, environmental temperature or the addition of a metabolic inhibitor. Therefore, a possible passive transmembrane diffusion mechanism might be proposed. The elution of AF 3013 from macrophages occurred relatively slowly; in fact, 60 min after the removal of extracellular AF 3013, nearly 40% of the drug still remained in the phagocytes. Exposure to 1 MIC of AF 3013 significantly enhanced macrophages phagocytosis and ...