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

According to aging of population and medical progress, the risk and mortality rate of pneumonia have been increased. In the causative organism inspection, smear-culture examination of sputum is the gold standard. When it is difficult to obtain high quality sputum and to culture the causative organism, or when antibiotics are previously administered, we have no choice but to start the treatment with pathogenic bacteria unknown. In these cases, it is necessary to select an appropriate test method for expecting pathogen. If bacteria are detected in laboratory culture, it is difficult to distinguish whether it is a causative or colonizers. Future development is expected in rapid diagnostic methods.

We have evaluated our new Norovirus rapid detection kit "QuickNavi™-Norovirus2" (Denka Seiken Co., Ltd.). The kit is based on Immunochromatographic method using colored latex particles. In addition to simple preparations giving quick (15 min) results, our newly developed kit enables specimen collection directly from rectum and can also be used with neonatal stool samples, both of which cannot be used with the current version of the kit, "QuickNavi™-Norovirus." Clinical study (stool samples, n=172) shows sensitivity, specificity and accuracy of the test compared to RT-PCR are 92.0%, 98.3%, and 94.2%, respectively. The result also showed good correlation with QuickNavi™-Norovirus. In this study, the new Norovirus rapid detection kit has shown sufficient sensitivity and specificity. Their performance, simple preparation enabling rectal swab samples, and quick results can be useful for day to day clinical practice when diagnosing Norovirus infection.

Because it is not easy to differentiate Influenza virus (Flu) from RS virus (RSV) just by clinical symptoms, to accurately diagnose those viruses in conjunction with patient's clinical symptoms, rapid diagnostic kits has been used separately for each of those viruses. In our new study, we have developed a new rapid diagnostic kit, QuickNavi™-Flu+RSV. The kit can detect Flu A, Flu B, and RSV antigens with a single sample collection and an assay. Total of 2,873 cases (including nasopharyngeal swabs and nasopharyngeal aspirates specimens) in 2010/2011 and 2011/2012 seasons were evaluated with QuickNavi™-Flu+RSV and a commercially available kit. Sensitivity, specificity, and accuracy of Flu type A, type B, and RSV were above 95% when compared to commercially available kits (QuickNavi™-Flu and QuickNavi™-RSV) and considered to be equivalent to the commercially available kits. In 2011/2012 season, RSV infections increased prior to Flu season and continued during the peak of the Flu season. The kit can contribute to accurate diagnosis of Flu and RSV infections since co-infection cases have also been reported during the 2011/2012 season. QuickNavi™-Flu+RSV is useful for differential diagnosis of respiratory infectious diseases since it can detect Flu type A, type B, and RSV virus antigens with a single sample collection.

It was developed that an anti-norovirus single-chain Fv (scFv) antibody for immunochromathographic test kit by using the phage displayed technique and biopanning. To obtain the scFv having wide reactivity for several norovirus genotypes, a mixture of recombinant norovirus capsid proteins, including 11 norovirus genotypes, was used for biopanning. Then, one anti-norovirus scFv antibody that recognized both of norovirus genogroups GI and GII was identified. An immunochromatographic test strip was constructed by using the scFv and demonstrated it to detect norovirus in stool samples. The immunochromatographic strip showed similar sensitivity to a commercially available one on which several monoclonal antibodies are included.

Reports of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have recently increased in Japan. To determine the status of MRSA infections in our hospital, we investigated their Staphylococcal cassette chromosome mec (SCCmec) types and prevalence of Panton-Valentine leukocidin (PVL). In addition, we investigated the relation between their SCCmec and antimicrobial susceptibility. The 191 strains were isolated from January to July in 2011 and were classified as SCCmec type I (2, 1.0％), type II (136, 71.2％), type IV (36, 18.8％), type V (4, 2.1％) and type VIII (2, 1.0％). Eleven isolates (5.8％) were designated as nontypable. No isolates were PVL-positive in this study. The SCCmec type IV strains were more susceptible to imipenem (MIC90, 0.25 μg/ml) than SCCmec type II strains (MIC90, >16 μg/ml). This difference was also observed between SCCmec type IV and SCCmec type II in susceptibility levels to clarithromycin, clindamycin, minocycline, and levofloxacin, but not to gentamicin. In particular, SCCmec type IV strains were susceptible to imipenem and minocycline. The result indicates these susceptibility is useful to discriminate CA-MRSA from Hospital-associated MRSA (HA-MRSA).