20１１ネン カラ ２０１３ネン ノ ヤマガタケン ニ オケル ミッツ ノ コトナル イデンシガタ ノ ハイエン マイコプラズマ ノ チイキテキ ヒロガリ ト マクロライド タイセイ カブ シュツゲン ノ タイミング ニ カンスル ケントウ

Background: We previously revealed that several multiple-locus variable-number tandem-repeat analyses（MLVA）and P1 types of Mycoplasma pneumoniae（M. pneumoniae）cocirculated between 2011 and 2013 in Yamagata, Japan. However, the regional spread of M. pneumoniae infection by genotype is not reported yet. It remains unclear whether there is a difference in the spread of macrolide-resistant M. pneumoniae among genotypes. Methods: Genotypes were labeled according to 4-locus（Mpn 13, 14, 15, and 16）MLVA and P1 types. A total of 208 strains belonging to three major genotypes, i.e., type 4-5-7-2, 1; 4-5-7-3, 1; and 3-5-6-2, 2c, were analyzed by combining with the information of macrolide resistance-associated mutation and the patients’ information including residence. Results and Discussion: The three genotypes were widely distributed over more than four cities and towns in Yamagata Prefecture, cocirculating between late 2011 and early 2013, and there was little difference in the duration of their epidemics. Timing of macrolide-resistant strain appearance during the epidemic period differed between type 4-5-7-2, 1 and type 4-5-7-3, 1, and it did not appear throughout type 3-5-6-2, 2c epidemic. These genotypic differences can account for the variation in the prevalence of macrolide resistance-associated mutations in each of the studied areas

Comparison of virus isolation using the Vero E6 cell line with real-time RT-PCR assay for the detection of human metapneumovirus

Abstract Background The use of cell culture for the diagnosis of human metapneumovirus (hMPV) infection is uncommon at present and molecular method such as reverse-transcription PCR (RT-PCR) has been widely and most commonly used as the preferred test. We aimed to compare the results of virus isolation using Vero E6 cells with real-time RT-PCR for the detection of hMPV, since such a comparison data is not available. Methods Between December 2007 and July 2008, we obtained 224 nasopharyngeal swab specimens from patients with acute respiratory infection and tested by the two methods. Results Forty-three (19.2%) were found positive by cell culture and 62 (27.7%) by real-time RT-PCR. Cell cultures were positive for 42 of 62 specimens found positive by real-time RT-PCR (67.7% sensitivity) and for 1 of 162 specimens found negative by real-time RT-PCR (99.4% specificity), respectively. The sensitivity of the cell culture was 76.2-87.5% (mean 81.8%) when specimens were collected within 3 days after the onset of symptoms, and the sensitivity decreased to 50% or less thereafter. Among specimens collected within 3 days after symptom onset, all of the real-time RT-PCR positive specimens having a viral load of more than 1.25×105 copies/ml were found positive by cell culture. Conclusions Cell culture using Vero E6 cell line has 81.8% sensitivity compared with the real-time RT-PCR method, when specimens are collected within 3 days after the onset of symptoms. Thus, this method is a useful method for epidemiological and virological research even in facilities with minimal laboratory resources.</p

Evaluation of a New Rapid Antigen Test Using Immunochromatography for Detection of Human Metapneumovirus in Comparison with Real-Time PCR Assay▿

A new rapid human metapneumovirus (hMPV) detection kit using immunochromatography (SAS hMPV test) was compared to real-time PCR for 224 nasal swab specimens, 96.4% of which were obtained from children of <15 years of age. The overall sensitivity and specificity were 82.3% and 93.8%, respectively, suggesting that this test is useful for pediatricians to diagnose hMPV infection in a clinical setting