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

Identification of bacteria of sepsis or bacteremia is a useful result for treatment policy. In recent years, bacterial identification has become possible from blood culture bottles by MALDI‒TOF, but it is not as accurate as bacterial identification from agar colonies. Blood culture pretreatment kit (MALDI Sepcityper Kit) is currently on sale from Bruker. However, the current situation has not reached good accuracy. This time, a new blood culture pretreatment kit appeared, so I studied. Up to now, the blood culture pretreatment kit was only MALDI Sepcityper Kit using enzyme digestion method. Rapid BAC pro (Nittobo) is a pretreatment kit using nanomaterials. This time, comparison examination (total number 40 samples) was done. Among them, 33 specimens were identified by MALDI Sepcityper Kit. There were 21 specimens that could be identified by rapid BAC pro. In this study, rapid BAC pro did not show superior results over MALDI Sepcityper Kit.

Urinary antigen test is frequently used as a routine laboratory test for early diagnosis of Legionella infection, which is especially suitable for ordinary Legionella pneumophila serogroup 1, but not for other types of Legionella. We report a case of severe pneumonia caused by Legionella longbeachae, where a method of loop-mediated isothermal amplification (LAMP) assay contributed an important role for the early detection. This case involved an 83-year-old man who developed fever, dyspnea, and productive cough. Since the medication of prescribed ceftriaxone had not been effective, he visited the emergency room of our hospital, where an X-ray revealed a severe pneumonia harboring a consolidation with air bronchogram in his right lower lung. His sputum and urine were subjected to the routine bacterial culture or the urinary antigen test for Legionella, which initially brought negative results. However, a positive result of LAMP assay enabled early diagnosis of Legionella pneumonia. Later, the bacterial cultures of sputum made some progress and 16S rRNA sequencing provided a proof of L. longbeachae. This LAMP assay may bring a benefit for the patients with Legionella pneumonia by enabling early detection of not only specific L. pneumophila serogroup 1, but also of the other Legionella species.

We have evaluated a new immunochromatographic kit, "KBM LineCheck Flu AB", which had been developed for enhanced detection of influenza B viruses. Five strains of influenza A and B viruses were tested for reactivity and detection limits of the kit. Compared with the detection limits of commercially available kit of QuickNavi-Flu, "KBM LineCheck Flu AB" showed a nearly equal reactivity to influenza A viruses, but quadruple reactivity to 2 influenza B viruses. Also, "KBM LineCheck Flu AB" exhibited high specificity when tested in 130 influenza-negative culture specimens derived from 24 adult volunteers. Furthermore, "KBM LineCheck Flu AB" was clinically evaluated by using 866 specimens, including 190 nasal swabs, 201 nasal aspirations, 262 self-blown nasal discharges, and 213 pharyngeal swabs. Compared with the results of QuickNavi-Flu for influenza A, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs were calculated to be 95.8%, 92.0%, 95.0%, and 94.8%, respectively. Whereas, as to influenza B, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs was calculated to be 96.3%, 98.5%, 96.2%, and 93.4%, respectively. Similarly, compared with the results of influenza A viral culture, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs was calculated to be 95.3%, 91.0%, 93.9%, and 92.5%, respectively. Regarding influenza B culture, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs were calculated to be 95.8%, 97.5%, 95.1%, 91.5%, respectively. Overall, we concluded that the "KBM LineCheck Flu AB" is useful and suitable for diagnosis of influenza A and especially influenza B.

The 2-step method is an algorithm to detect toxigenic Clostridium difficile. We herein compared the sensitivities and specificities of an enzyme immunoassay (toxin A/B-EIA), toxigenic culture (TC-EIA), Loop-Mediated Isothermal Amplification assay (LAMP), and Xpert C. difficile (Xpert) with the detection of the toxin B gene by a polymerase chain reaction (PCR). The results obtained showed that the sensitivities and specificities of toxin A/B-EIA, Xpert, TC-EIA, and LAMP were 30 and 100%, 87.2 and 100%, 97.5 and 89.7%, and 95 and 100%, respectively. We also evaluated the turnaround time (TAT) and cost of toxigenic C. difficile detection. Our hospital TAT for toxin A/B-EIA and TC-EIA are 37 min and 5 days, respectively. We estimated the TAT of Xpert, LAMP, and PCR to be 105 min, 5 days, and 6 days, respectively. On the other hand, the cost to detect toxigenic C. difficile increased in the order of TC-EIA, LAMP, Xpert, and PCR. We have never experienced outbreak of Clostridium difficile infection (CDI) in our hospital, and there is less the number of CDI than other place. So we selected TC-EIA that is good sensitivity and low cost per specimen. Hereafter it'll be necessary to solve a problem it takes time, because we have to respond to outbreak of CDI quickly if it happens.

The laboratory culture methods for isolating drug-resistant pathogens has been the gold standard in medical microbiology, and play pivotal roles in the overall management of infectious diseases. Recently, several reports have emphasized the development of antibiotics-resistance among anaerobic gram-negative rods, especially Genus Bacteroides and Prevotella. Therefore, a selective culture method to detect these pathogens is needed. We developed here the new selective culture medium, termed "KBM Anaero RS-GNR," for detecting anaerobic Gram-negative rods. Growth capability and selectivity of the agar medium were assessed by using the pure culture suspensions of more than 100 bacterial strains as well as the 13 samples experimentally contaminated with these bacterial strains. This new medium, "KBM Anaero RS-GNR," successfully showed the selective isolation of anaerobic Gram-negative rods. Compared with commercially available medium, "PV Brucella HK Agar, " which is also designed to detect anaerobic Gram-negative rods, there was no significant difference of the overall detection efficiency between two media. However, "KBM Anaero RS-GNR" showed superior to selectivity for anaerobic Gram-negative rods, especially from the samples contaminated with Candida species. Thus, the culture method using KBM Anaero RS-GNR is relevant for isolation of anaerobic Gram-negative rods especially from clinical specimens.

Recently, many laboratories use fluorescence microscopy for rapid screening of clinical specimens for detection of Genus Mycobacterium. The success of the stain depends on the staining temperature at which the fluorescent dye could uniformly penetrate the cell wall through waxy lipid barrier of the mycobacterial organism. Therefore, this process requires a precise heating control. In this study, to control the temperature during fluorescent auramine- rhodamine staining, we explored the potential use of microwave. The efficiency of microwave irradiation during the staining process was evaluated by using a Mycobacterium avium-containing sputum of which the smear slide was irradiated with several different conditions in combination of time and wattage. As a result, 1) the liquid temperature of the stain correlated well with wattage of microwave irradiation. 2) The tubercle bacilli were easily visualized as brilliant fluorescent bacilli in an orange color when it was set at the best condition of 600 W and 10 sec irradiation. 3) The sensitivity of microscopy with this staining method (MW method) was higher than those of conventional staining methods such as Ziehl-Neelsen staining and standard auramine-rhodamine staining, demonstrating that MW method can be applicable to the sputum slides which contained a few bacilli. Thus, we established the new staining method that is rapid and easy to perform in clinical laboratories. Since the MW method has not yet been utilized in order to conduct fluorescence microscopy for sputum smears, advancement on this method will make a vast change in testing of acid fast bacilli.

Procalcitonin (PCT) was first described as a sepsis-associated protein in 1993. PCT is increased in the blood at the time of infection by bacteria. Therefore, it is used as an auxiliary indicator of sepsis diagnosis. In addition, PCT is reduced quickly by antibiotics. And use as a stop or change marker is also expected. We have investigated the antimicrobial use and microbial testing of measurement patient and PCT running performance. Number of requests was 3,387 cases (inpatient 2,649 and outpatient 742 cases) for one year. It was subject to the 820 cases that had inspection request to July to October 2012. In 820 cases, 57 cases had exhibited a PCT >0.5 ng/ml and diagnosed with infectious diseases. In 57 cases, 44 cases (77%) were performed microbiology and blood culture. And only blood culture performed in 8 (14%), blood culture and microbiology is not performed for 5 cases (9%), In 21 (40%) cases of 52 cases performed the blood culture shown positive. Detecting bacteria accounted for more than half in 17 cases of Gram-negative bacilli. Also, it had exhibited a systemic inflammatory response syndrome (SIRS) in 18 cases. Antibiotics have been used in all cases regardless of implementation of the microbiology test. If sepsis is suspected, it is necessary for diagnosis is done correctly and quickly. Therefore, PCT has been suggested high usefulness by examining in the hospital. It is required that the reference identification and drug susceptibility results of the pathogenic bacterium combination of microbiology test and the PCT. We considered useful to PCT monitoring that as an indicator of antimicrobial agents change or shorten of antibiotic use period. Future, proactive use of clinical practice is expected.

Group B Streptococcus (GBS) are normal flora of the vagina and intestinal, but if the pregnant woman was infected with GBS in the vagina, miscarriage or premature would occur or the newborn would be developed to severe GBS infection. It is recommended that the inspection of GBS on all pregnant women by Japan Society of Obstetrics and Gynecology (JSOG) and Center for Disease Control and Prevention (CDC). We examined the comparison of detection rate between Pourmedia GBS agar (Eiken Chemical Co., Ltd.) and Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium (Nissui Pharmaceutical Co., Ltd.) on 112 sample. The positive rate of Pourmedia GBS agar was 21.4% (24/112 samples), Whereas Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium was 17.8% (20/112 samples). It was found that the detection rate was improved by using Pourmedia GBS agar on GBS screening test of vaginal swab.