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Objective@#To understand the status and genotype of norovirus in Wuhu, and provide the basic molecular epidemiological data for norovirus infection control and prevention, 2017.@*Methods@#Anal swab and vomit specimens were collected during outbreaks from patients, primarily using fluorescence quantitative PCR to preliminarily identify the genotype of norovirus; according to preliminary result , through their respective specific primer, RT-PCR was applied, and sequencing was done to identify virus genotypes. Sequence alignment and phylogenetic analysis of norovirus was performed by using biological software.@*Results@#Seventeen norovirus epidemics were observed in Wuhu area, a total of 137 specimens were collected. Real-time fluorescent quantitative PCR result showed that 77 specimens were norovirus nucleic acid testing positive, and all were GⅡ genotype. Through specific primers amplification, sequencing analysis showed that the 2017 outbreaks in Wuhu were caused only by two genotypes, GⅡ.3 and GⅡ. 2, including one case of GⅡ. 3, Six cases of GⅡ.2, and 10 epidemic aggregations, 8 cases of GⅡ. 2, and there were two cases of G Ⅱ. 4 Sydney 2012.@*Conclusions@#Norovirus GⅡ.2 genotype was dominant in norovirus outbreaks and the aggregation epidemics, other genotypes were occasionally seen in Wuhu, 2017.
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To determine the lysis spectrum of Yersinia enterocolitica bacteriophage phiYe-F10 and to analyze the relationship between the lysis ability of phiYe-F10 and the virulence gene of Yersinia enterocolitica. To observe the lysis ability of the phage phiYe-F10 to the different Yersinia strains with the double-layer technique. The strains used in this study including 213 of Yersinia enterocolitica and 36 of Yersinia pseudotuberculosis and 1 of Yersinia pestis. The virulence genes of these Yersinia enterocolitica (attachment invasion locus (ail) and enterotoxin (ystA, ystB) and yersinia adhesin A (yadA), virulence factor (virF), specific gene for lipopolysaccharide O-side chain of serotype O : 3 (rfbc) were all detected. Among the 213 Yersinia enterocolitica, 84 strains were O : 3 serotype (78 strains with rfbc gene), 10 were serotype O : 5, 13 were serotype O : 8, 34 were serotype O : 9 and 72 were other serotypes. Of these, 77 were typical pathogenic Yersinia enterocolitica harboring with virulence plasmid (ail+, ystA+, ystB-, yadA+, virF+), and 15 were pathogenic bacterial strains deficiency virulence plasmid (ail+, ystA+, ystB-, yadA-, virF-) and the rest 121 were non pathogenic genotype strains. PhiYe-F10 lysed the 71 serotype O : 3 Yersinia enterocolitica strains which were all carried with rfbc+, including 52 pathogenic Yersinia enterocolitica, 19 nonpathogenic Y. enterocolitica. The phiYe-F10 can not lysed serotype O : 5, O : 9 and other serotype Y. enterocolitica, the lysis rate of serotype O : 3 was as high as 84.5%. The phiYe-F10 can not lysed Yersinia pseudotuberculosis and Yersinia pestis. Yersinia phage phiYe-F10 is highly specific for serotype O : 3 Yersinia enterocolitic at 25 degrees C, which showed a typical narrow lysis spectrum. Phage phiYe-F10 can lysed much more pathogenic Y. enterocolitica than nonpathogenic Y. enterocolitica.