Emiko Rimbara

A 56-year-old previously healthy man was hospitalized due to a 10-day history of neck pain and an elevated C-reactive protein level. Gram-negative spiral bacilli were isolated from his blood, and Helicobacter cinaedi was confirmed using 16S rRNA sequencing. The infectious focus was not identified by initial cervical magnetic resonance imaging (MRI); however, repeated MRI demonstrated prominent high signal intensity in the entire region of the C6-C7 vertebrae and C6/C7 disc space. Furthermore, fluorodeoxyglucose-positron emission tomography/computed tomography showed no significant uptake, other than in the C6-C7 region. The patient was successfully treated with ceftriaxone for six weeks without sequelae.

A 43-year-old man was referred to our hospital for an acute-onset fever and left flank pain. He had been previously diagnosed with lymphangioma, and abdominal computed tomography showed pararenal cysts with fat stranding around the left kidney, of which infection was subsequently confirmed on magnetic resonance imaging. Gram-negative spiral bacilli were isolated from two sets of blood cultures, and Helicobacter cinaedi was identified using 16S rRNA sequencing. The patient was successfully treated with ceftriaxone therapy without recurrence. A multilocus sequence typing analysis indicated the current H. cinaedi strain differed from previous strains isolated in Japan.

Despite the fact that sequential therapy has been evaluated in more than 2500 patients and has been shown to on average provide Helicobacter pylori eradication in 90% to 94%, some authorities still question whether it should be a first-line anti-H. pylori regimen. Here, we discuss H. pylori eradication using experience and expectations with other common bacterial infections as a frame of reference. H. pylori is no exception and near 100% success is expected for optimized regimens treating susceptible infections. As such, the proper comparator would be the relation to 100% eradication. Superiority to another, often proven inferior, therapy per se provides little or no useful information. Treatment failures in infectious diseases are typically easily explainable and most often relate to the presence of antimicrobial resistance or failure to take the drugs. We provide a model for predicting the results of H. pylori combination therapies in relation to the pattern and prevalence of resistance. The results are consistent with clinical practice and explain why sequential is typically superior and essentially never inferior to triple therapy. We also show when meta-analysis is an inappropriate technique for the analysis of H. pylori clinical trials and discuss how to appropriately use the technique. Finally, we discuss why the location of studies (eg, Italy), is unimportant and explain why, from the standpoint of a therapy for an infectious disease, sequential therapy is a significant advance and should be considered one of the replacements for the outdated legacy triple therapy (proton pump inhibitor--clarithromycin--amoxicillin).

The aim of this study was to discuss subject selection and the evaluation method for an objective structured clinical examination (OSCE) in pharmaceutical sciences. We designed the OSCE to assess pharmaceutical students' clinical ability. In this trial, there are three stations (ST1 in circle: dispensing powdered medicine, ST2 in circle: patient reception, ST3 in circle: drug counseling), and 25 students and six instructors participated. Each student took an examination at two stations, and evaluated other students at the other station. Each instructor evaluated the student at two stations. Before the evaluation, we developed a checklist that contained the items "evaluation of the quantity" of the action, "evaluation of the quality" of the skill and the attitude, and "overall evaluation" to ensure the standardization of scoring. After the OSCE trial, we calculated and analyzed each examinee's evaluation score. In ST1 in circle and ST3 in circle, the average time for performance exceeded the time limit (5 min). There was no significant relationship between the each examinee's evaluation score and the time at all stations. The evaluation point "evaluation of the quantity" did not differ among evaluators, but a difference was seen in the "evaluation of the quality." In addition, in the quantitative evaluation, there was a difference in the evaluation of the item for which the evaluator's judgment was necessary. Instructors' evaluations were more severer than students'. In the "overall evaluation," there was no significant relation between the quantitative evaluation score and the score of the overall impression. However, there was a significant relationship with the qualitative evaluation. From these results, for assignment making, it is necessary for examinees to finish the work within the time limit, and that the evaluation not affect the performance time. Additionally, it is necessary to standardize the evaluation to reduce differences among evaluators, who should be trained. Moreover, it was suggested that the selection of an appropriate evaluation system for each evaluation item is important in OSCE stations.

In the past year, a substantial number of (putative) novel Helicobacter species have been described, including Helicobacter himalayensis colonizing the Himalayan marmot and Helicobacter apodemus, colonizing the Korean striped field mouse. In addition, a putative novel gastric Helicobacter species was identified in wild gorillas and chimpanzees, for which the name "Candidatus H. homininae" was proposed. A high incidence of gastric non-H. pylori Helicobacter infection was described in China and multiple case reports have described the involvement of enterohepatic Helicobacter species, especially Helicobacter cinaedi, in a wide range of diseases. Several studies in rodent models further elucidated the mechanisms underlying the development of gastric mucosa-associated lymphoid tissue lymphoma during infection with gastric non-H. pylori Helicobacters. The effects of infection with gastric Helicobacters on the development of neuroinflammation were investigated and several enterohepatic Helicobacter species were shown to affect the composition of the gut microbiota, to influence vaccine efficiency as well as the progression of cancer in distant sites of the body.

... Kohei Kawakami1, Takashi Kawai2,*, Mikinori Kataoka2, Kazuo Takei2, Satoru Taira1, Takao Itoi1, Fuminori Moriyasu1, Yuu Takagi3, Tatsuya Aoki3, Jun Matsubayasiu4, Kiyoshi Mukai4, Emiko Rimbara5, Norihisa Noguchi5, and ... [12] Leung, WK, Ng, EK, Chan, FK, Chung, SC ...

... Takashi Kawai1,*, Kohei Kawakami1, Mikinori Kataoka1, Kazuo Takei1, Satoru Taira2, Takao Itoi2, Fuminori Moriyasu2, Yuu Takagi3, Tatsuya Aoki3, Jun Matsubayasiu4, Kiyoshi Mukai4, Emiko Rimbara5, Norihisa Noguchi5, and Masanori Sasatsu5 ... [10] Kamada, T., Haruma, K ...

We recently demonstrated that the Rv2613c protein from Mycobacterium tuberculosis H37Rv is a novel diadenosine 5',5‴-P(1),P(4)-tetraphosphate (Ap4A) phosphorylase (MtAPA) that forms a tetramer. Mycobacterium avium and Mycobacterium smegmatis express proteins named MAV_3489 and MSMEG_2932, respectively, that are homologous to MtAPA. Here we showed that the MAV_3489 and MSMEG_2932 proteins possess Ap4A phosphorylase activity and enzymatic properties similar to those of MtAPA. Furthermore, gel-filtration column chromatography revealed that MAV_3489 and MSMEG_2932 assembled into homotetramers in solution, indicating that they may also form unique Ap4A-binding sites composed of tetramers.

In Japan, eradication regimens consisting of a proton pump inhibitor (PPI) + amoxicillin (AMPC) + clarithromycin (CAM) (PPI/AC) for 1 week have been conducted. In the present study, we assessed the eradication rates following treatment with low doses of various PPIs. 135 patients were divided randomly into one of three 7-day regimens: (i) omeprazole (OPZ) 20 mg/day + AMPC 1500 mg/day + CAM 600 mg/day (OAC); (ii) lansoprazole (LPZ) 30 mg + AMPC 1500 mg/day + CAM 600 mg/day (LAC); and (iii) rabeprazole (RPZ) 10mg/day + AMPC 1500 mg/ day + CAM 600 mg/day (RAC). The genetic polymorphism of CYP2C19 was also examined. The eradication rates according to the treatment regimen were as follows: 69.9% (31/45) for OAC, 62.2% (28/45) for LAC, and 71.1% (32/45) for RPZ. No significant differences were found among the regimens. Moreover, eradication rates, according to CYP2C19 phenotype (homozygous extensive metabolizer (EM), heterozygous EM, and poor metabolizer) were: 68.6% (35/51), 77.4% (41/53...

To investigate the mechanisms underlying glucocorticoid (GC) resistance in rheumatoid arthritis (RA), we evaluated the suppressive effects of prednisolone (PSL) or methylprednisolone (MPSL) on the blastogenesis of peripheral blood mononuclear cells (PBMC). We also measured the expression of mRNA for transcription factors [GC receptor-alpha (GRalpha) and activator protein-1] known to be involved in the exertion of GC effects. Twenty-six patients with RA and 17 healthy subjects were studied. IC50 of PSL and MPSL on the blastogenesis of PBMC stimulated with concanavalin A in vitro was estimated. Transcripts for GRalpha, c-fos, c-jun, and GAPDH genes in PBMC were quantitatively determined by real-time RT-PCR procedures. The amount of c-fos transcript in PBMC from RA patients was significantly high compared to the healthy subjects (p = 0.001). However, no difference was found in the amounts of mRNA of other transcription factors between the patients and healthy subjects. When PSL or MPSL...

Quinolinic acid phosphoribosyltransferase (QAPRTase, EC 2.4.2.19) is a key enzyme in the de novo pathway of nicotinamide adenine dinucleotide (NAD) biosynthesis and a target for the development of new anti-tuberculosis drugs. QAPRTase catalyzes the synthesis of nicotinic acid mononucleotide from quinolinic acid (QA) and 5-phosphoribosyl-1-pyrophosphate (PRPP) through a phosphoribosyl transfer reaction followed by decarboxylation. The crystal structure of QAPRTase from Mycobacterium tuberculosis H37Rv (MtQAPRTase) has been determined; however, a detailed functional analysis of MtQAPRTase has not been published. Here, we analyzed the enzymatic activities of MtQAPRTase and determined the effect on catalysis of the anti-tuberculosis drug pyrazinamide (PZA). The optimum temperature and pH for MtQAPRTase activity were 60°C and pH 9.2. MtQAPRTase required bivalent metal ions and its activity was highest in the presence of Mg2+. Kinetic analyses revealed that the Km values for QA and PRPP w...

Helicobacter pylori is an important pathogen whose primary niche is the human stomach. H. pylori is etiologically associated with gastric inflammation (gastritis), peptic ulcer disease, and gastric cancer. Both noninvasive (e.g., urea breath and stool antigen tests) and invasive (gastric biopsy for histology, culture, or PCR) tests are used for diagnosis. PCR detection of H. pylori has been reported using a variety of clinical samples including gastric biopsy, gastric juice, saliva, dental plaque, and stools as well as environmental samples. Whenever possibly, noninvasive tests are preferred over invasive tests. H. pylori are excreted in the stool. Culture from stool is variable whereas stool antigen testing is widely used. Stool consists of a complicated mixture of commensal bacteria and chemicals and often includes inhibitors of PCR. Nevertheless, simple extraction methods are available to efficiently extract DNA from human stools and nested-PCR targeting the 23S rRNA gene have pr...

Although Helicobacter pylori infection is both a common and a serious bacterial infection, antimicrobial therapies have rarely been optimized, are prescribed empirically, and provide inferior results compared with antimicrobial therapies for other common infectious diseases. The effectiveness of many of the frequently recommended H. pylori infection treatment regimens has been increasingly compromised by antimicrobial resistance. Regional data on the susceptibility of strains of H. pylori to available antimicrobials are sorely needed. Noninvasive molecular methods are possible to assess clarithromycin susceptibility in isolates obtained from stool specimens. As a general rule, clinicians should prescribe therapeutic regimens that have a ≥90% or, preferably, ≥95% eradication rate locally. If no available regimen can achieve a ≥90% eradication rate, clinicians should use the most effective regimen(s) available locally. Eradication of infection should always be confirmed after treatmen...

Molecular testing can rapidly detect Helicobacter pylori susceptibility using gastric biopsies. Allele-specific polymerase chain reaction (ASP-PCR) was used to identify H. pylori 23S rRNA and gyrA mutation using gastric biopsies from Colombian patients and confirmed by PCR and sequencing of the 23S rRNA and gyrA genes. The sensitivity and specificity of ASP-PCR were compared with susceptibilities measured by agar dilution. Samples included gastric biopsies from 107 biopsies with H. pylori infections and 20 H. pylori negative. The sensitivity and specificity of ASP-PCR for the 23S rRNA gene were both 100%. The sensitivity and specificity of ASP-PCR for the gyrA gene, published in 2007 by Nishizawa et al., were 52% and 92.7%, respectively; the lower sensitivity was due to the presence of mutation N87I in our samples, which were not detected by the test. In this study, we designed new primers to detect the mutation N87I in GyrA. The ASP-PCR was performed with the original primers plus the new primers. The molecular test with the new primers improved the sensitivity to 100%. In conclusion, ASP-PCR provides a specific and rapid means of predicting resistance to clarithromycin and levofloxacin in gastric biopsies.

Helicobacter fennelliae, a human enterohepatic pathogen, causes bacteremia and colitis. We isolated H. fennelliae strain MRY12-0050 from a female patient; this strain was isolated from 2 other patients from the same hospital during the same period, suggesting human-to-human transmission. This is the first report of an H. fennelliae genome sequence.

γ-Glutamyltranspeptidase and asparaginase have been shown to play important roles in Helicobacter pylori colonization and cell death induced by H. pylori infection. In this study, the association of γ-glutamyltranspeptidase and asparaginase was elucidated by comparing activities of both deamidases in H. pylori strains from patients with chronic gastritis, gastric and duodenal ulcers, and gastric cancer. γ-Glutamyltranspeptidase activities in H. pylori strains from patients with gastric cancer were significantly higher than in those from patients with chronic gastritis or gastric ulcers. There was a wide range of asparaginase activities in H. pylori strains from patients with gastric cancer and these were not significantly than those from patients with other diseases. To identify the contributions of γ-glutamyltranspeptidase and asparaginase to gastric cell inflammation, human gastric epithelial cells (AGS line) were infected with H. pylori wild-type and knockout strains and inflammatory responses evaluated by induction of interleukin-8 (IL-8). IL-8 response was significantly decreased by knockout of the γ-glutamyltranspeptidase-encoding gene but not by knockout of the asparaginase-encoding gene. Additionally, IL-8 induction by infection with the H. pylori wild-type strain was significantly decreased by adding glutamine during infection. These findings indicate that IL-8 induction caused by γ-glutamyltranspeptidase activity in H. pylori is mainly attributable to depletion of glutamine. These data suggest that γ-glutamyltranspeptidase plays a significant role in the chronic inflammation caused by H. pylori infection.

Pharmaceutical Microbiology in its seventh edition is a considerably updated and comprehensive textbook covering the broad and exciting area of a key pharmaceutical science. The topics covered range from the fundamental aspects of pathogens of pharmaceutical significance through ...

Gastric infection of clarithromycin (CAM)-resistant Helicobacter pylori is one of the major causes of failure to eradicate this organism. A noninvasive and useful method for the detection of CAM-resistant H. pylori from human feces by restriction fragment length polymorphism (RFLP)-nested polymerase chain reaction (PCR) targeting the mutation of the 23S rRNA gene that confers CAM-resistance in H. pylori was developed in this study. Our nested PCR method detected DNA of H. pylori in feces with high sensitivity and specificity compared with both an enzyme-linked immunoadsorbent assay (ELISA) of H. pylori in feces and the isolation of H. pylori from gastric biopsy. Furthermore, the results of mutation analysis of the H. pylori 23S rRNA gene amplified from feces completely correlated with both that of the H. pylori 23S rRNA gene amplified from the isolates of gastric biopsy and the susceptibility of H. pylori isolates to CAM. Therefore, our results show that this RFLP/nested PCR method is useful for the accurate diagnosis of CAM-resistant H. pylori infection from feces.

The aim of this study was to determine the susceptibilities to clarithromycin, amoxycillin and metronidazole of Helicobacter pylori isolates from the antrum and corpus of Japanese patients examined during the period 1995-2001. There was an increase, from 6.2% in 1995 to 22.1% in 2000-2001, in the proportion of patients infected with clarithromycin-resistant H. pylori. Of patients infected with clarithromycin-resistant H. pylori, 39.1% were infected with both clarithromycin-susceptible and -resistant H. pylori. Furthermore, the MIC90 of clarithromycin for H. pylori rose from < 1 mg/L in 1995-1998 to 8 mg/L in 1999. In contrast, the MIC90s of amoxycillin and metronidazole were < or = 0.125 and 4 mg/L, respectively, throughout the study period. The results showed that, while most H. pylori isolates were susceptible to amoxycillin and metronidazole, resistance to clarithromycin among H. pylori isolates increased markedly in Japan during 1995-2001. The results also indicated a need to test the susceptibility of H. pylori isolates from more than two samples obtained from two different sites in the stomach of a single patient in order to diagnose the presence of clarithromycin-resistant H. pylori correctly.