Rinsho Biseibutsu Jinsoku Shindan Kenkyukai shi = JARMAM : Journal of the Association for Rapid Method and Automation in Microbiology最新文献

Campylobacter spp. has been the leading cause of bacterial food poisoning in Japan since 2000. The predominant Campylobacter spp. testing method employs selective medium to isolate Campylobacter spp. In the present study, we evaluated the Campylobacter-isolating capacity and clinical utility of BD^TM mCCDA Clear-HT, an agar medium containing a chromogenic substrate, on 230 diarrhea stool samples. After 48 hours incubation, 50 samples (21.7%) were positive with BD^TM mCCDA Clear-HT, while 61 samples (26.5%) were positive using modified Skirrow agar medium. In this study, BD^TM mCCDA Clear-HT had a lower detection rate of Campylobacter jejuni more than Vitalmedia modified Skirrow agar medium.

Man in his 80s. In March 20XX, the level of consciousness decreased at the admission facility, and he was transported as an emergency case. He was diagnosed as aspiration pneumonia, septic shock due to cholecystitis, and DIC, and was hospitalized for medical treatment. During the course of hospitalization, aspiration pneumonia continued to improve and worsen, but in January 20XX＋3, a fever of 38.7°C occurred, and Mucor circinelloides was detected in the blood culture collected at this time. In sputum 7 days before the blood culture was submitted, an image of suspicious zygomycosis was confirmed by Gram stain, so the patient was diagnosed with Mucor disease and started administration of amphotericin B. After that, the condition was temporarily stable, but due to recurrence of aspiration pneumonia and renal damage, he died 19 days after the start of amphotericin B administration. It is difficult to detect Mucor spp. in blood culture, however in this case, it was detected by the blood culture device; Versa TREK (Thermo Fisher Scientific K.K. Tokyo, Japan).

The emergence and dissemination of drug-resistant Gram-negative bacilli have been recognized as a serious health concern in worldwide. The isolation rates of Extended-Spectrum β-lactamases (ESBL) and AmpC β-lactamases (AmpC) producing gram negative rods are increasing in our hospital. In the present study, we evaluate the availability of the antimicrobial resistance testing by the direct disc methods using AmpC/ESBL differential discs. One hundred and ten strains of Enterobacterales were isolated during the observation period, of which 19 strains (17%) were ESBL-positive and 6 strains (5%) were AmpC-positive. The positive and negative coincidence rate between direct disc methods and standard disc methods were 100%. We conclude that the direct disc method is a useful and rapid detection method for ESBL and AmpC from blood culture samples.

Group B Streptococcus (hereinafter GBS) is the main pathogen in neonatal sepsis and meningitis, accounting for approximately one quarter of the cases. 1) Prevention of infection is therefore crucial. The GBS carriage testing of pregnant women is necessary to prevent infections. In this study, we examined the clinical utility of Pourmedia ViGBS agar medium (Eiken Chemical Co., Ltd.) in GBS screening, using a total of 197 vaginal and urine samples. Of these samples, 32 (16.2%) tested GBS positive with Pourmedia ViGBS agar medium, and 29 (14.7%) tested GBS positive with Nissui separated plate sheep blood agar/Drigalski agar medium (Nissui Pharmaceutical Co., Ltd.). These results indicate the usefulness of Pourmedia ViGBS agar medium as a GBS screening selective agar medium.

Making the antibiogram necessary for infectious disease treatment is an important operation of the microbiology laboratory. Antibiogram is required to be up-to-date and to keep up with the annual updates of the Clinical & Laboratory Standards Institute (CLSI). However, these operation and managements require a lot of effort. In addition, even in the surveillance and analysis comparison of multiple facilities, the difference in CLSI base year becomes a barrier, making unified analysis difficult. On the other hand the antibiogram by Japan Nosocomial Infections Surveillance (JANIS) has restrictions on the bacterial species, antibacterial agents, and date range. Accordingly we focused on the fact that the data transmitted to JANIS is in a common format, and attempt construction a system to making the antibiogram based on this. This system uses data transmitted to JANIS, is convenient, can use not only the latest but also past base year CLSI category, has no restrictions on bacterial species, antibacterial agents, date range, works on Microsoft Windows environment, pursuit of compliance with the guidelines, and automatically making the antibiogram.

Due to the increase in the number of companion animal breeders in Japan, there are more opportunities for companion animals to come into contact with humans than before. Therefore, we investigated the bacterial flora adhering to the skin of dogs and the bacterial flora was analyzed for the presence of zoonotic bacteria that infect humans from companion animals. With the cooperation of students enrolled in the Department of Medical Technology and Science, Faculty of Fukuoka Health Care, International University of Health and Welfare. 39 samples were collected from the abdomen, back and paws of 13 healthy dogs using sterile swabs by the scraping method. The isolation culture was carried out only for facultative anaerobic bacteria to obligate aerobic bacteria and Bacterial identification was determined by MALDI-TOF MS and 16S rRNA gene analysis. Among the identified strains were Pasteurella canis, Staphylococcus pseudintermedius, Staphylococcus intermedius, which were difficult to detect in humans. The overall ratio of detected bacteria was 35% for coagulasenegative staphylococci, 14% for coagulase-positive staphylococci, 5% for Enterobacteriaceae, and 45% for natural environment. In the future, it is expected that extended-spectrum β-lactamase producing bacteria and drug-resistant bacteria such as Carbapenem-resistant enterobacterales will also be transmitted to humans through contact with companion animals.

There are several problems associated with antimicrobial susceptibility testing (AST) of Haemophilus influenzae. β-Lactamase-negative ampicillin-resistant H. influenzae (BLNAR) isolates with minimum inhibitory concentration (MIC) of ampicillin (ABPC) <4 mg/l will be classified as susceptible according to the MIC breakpoint of the CLSI M100 criteria, in spite of harboring penicillin-binding protein (PBP) mutations that cause ABPC resistance. A total of 103 isolates were collected from clinical materials for analysis. The genotypes of the PBP mutations were analyzed by polymerase chain reaction. The WalkAway 96 Plus (WALKAWAY), dry plate Eiken (DP-EIKEN), and RAISUS S4 systems (RAISUS) were used for AST. HTM broth was used as the culture medium for WALKAWAY, Mueller‒Hinton broth with 5% lysed horse blood for DP-EIKEN, and HTM with 5% horse serum for RAISUS. The MIC concordance rates of ABPC for g-BLNAR, for RAISUS vs. DP-EIKEN, RAISUS vs. WALKAWAY, and DP-EIKEN vs. WALKAWAY were 96.1, 86.4, and 85.4%, respectively. WALKAWAY had a low correlation with the other two systems. Moreover, concordance rates of ABPC MIC ≥4 mg/l, which is considered as resistant, of 69 g-BLNAR isolates for the RAISUS, DP-EIKEN, and WALKAWAY systems were 68.1, 58.0, and 37.7%, respectively. Therefore, in Japan, where the BLNAR strain is isolated at a high frequency, it is necessary to understand the characteristics of the measuring systems to appropriately interpret the test results.

Objective: Mycoplasma hominis usually colonizes the lower urogenital tract and has been occasionally associated with pelvic inflammatory disease, postpartum fever, preterm labor in pregnant females. The aim of this study was to investigate the incidence and antimicrobial susceptibilities of M. hominis isolated from the urogenital tracts of pregnant females.

Methods: Specimens were obtained from the urogenital tract of pregnant females at Department of Obstetrics and Gynecology, Ehime University Hospital, between November 2014 and December 2017. The identification of M. hominis was confirmed by the polymerase chain reaction (PCR) methods. The minimum inhibitory concentrations (MICs) of antibiotics were measured using a broth microdilution assay.

Results: Of the 1074 specimens tested, 63 (5.9%) were positive for M. hominis. The M. hominis-positive rate was highest at 21.3% between 18 and 24 years old. The 21 (25.6%) of 82 patients with bacterial vaginosis were positive for M. hominis. The 17 (40.5%) of 42 patients delivered by cesarean section that occurred infections including of intrauterine infection and pelvic abscess were positive for M. hominis. They were all administered β-lactam antibiotics before and after cesarean section. All patients recovered immediately following administration of clindamycin (CLDM). β-lactam antibiotics, macrolides and fosfomycin (FOM) were all resistant against M. hominis strains. In contrast, M. hominis strains were susceptible to CLDM, minocycline (MINO) and quinolones.

Conclusions: Our data suggests that the prevalence of genital M. hominis in pregnant females is high at younger age, bacterial vaginosis and infections after cesarean section with β-lactam antibiotics administration. CLDM, MINO and quinolones may be recommended against M. hominis infection. Especially, CLDM can be used as the adequate agent for pregnant females because tetracycline and quinolones are undesirable during pregnancy and lactation.

There is a report that an infection by medicine resistant bacteria will be the number one cause of death in 2050 according to the recommendation of WHO, and the CPE (carbapenem-producing Enterobacteriaceae) infection is regarded as a problem in particular. When detecting CPE, it is important how to detect stealth type CPE sensitive to carbapenem series medicines. So we used the 2 types of screening culture medium, "KBM" CRE-JU culture medium ‹KOJINBAIO› (CRE-JU culture medium) and the FRPM culture medium, and tried to detect drug-resistant gram-negative bacilli such as CPE, stealth type CPE, ESBL-producing bacteria, and excess AmpC-producing bacteria (AmpC-producing bacteria), etc. in combination of this culture mediums. As a result, CRE-JU culture medium showed a difference in the growth of CPE depending on the amount of inoculated bacteria while β-lactamase non-producing strain and other strains except for high concentration ESBL-producing bacteria and AmpC-producing bacteria were un-growing. Most of the CRE, stealth type CPE, ESBL-producing bacteria and AmpC-producing bacteria grew in the FRPM culture medium while most of the β-lactamase non-producing strains with a MIC value of meropenem (MEPM) of 2 µg/mL or less were un-growing. From these results, it was suggested that when a strain grown on CRE-JU and FRPM culture mediums, it could be distinguished as CPE, and when strains grown on FRPM culture medium which were un-grown on CRE-JU culture medium, it could be distinguished as drug-resistant bacteria such as stealth type CPE, ESBL-producing bacteria, and AmpC-producing bacteria. When strains not grown on CRE-JU and FRPM culture mediums, it could be distinguished as sensitive.

The PCR-based open reading frame typing (POT) is an important method for analyzing outbreak information. Many institutions use POT as a molecular epidemiological method for analyzing horizontal transmission in methicillin-resistant Staphylococcus aureus (MRSA). However, typing and analyzing MRSA only based on POT, with high detection frequency, has some limitations. In this study, we analyzed 62 strains of MRSA, isolated at Ehime University Hospital between January 2018 to December 2018 based on six POT types, toxin type, and antimicrobial susceptibility. Types of POT and strains used were as follows: 106-183-37 (28 strains), 106-137-80 (7 strains), 106-77-113 (7 strains), 106-9-80 (7 strains), 70-18-81 (7 strains), 106-247-33 (6 strains). Based on antimicrobial susceptibility patterns, 5 types of MRSA were detected, including types susceptible to gentamicin (GM), clarithromycin (CAM), and levofloxacin (LVFX). Strains belonging to the same POT type, showed differential antimicrobial susceptibility patterns and had different toxin productivity. These findings suggest that the combination of POT method with antimicrobial susceptibility patterns and toxin type may be a useful technique for MRSA typing.