RESUMO
Noroviruses (NoVs) are the major global source of acute gastroenteritis (AGE) outbreaks. To detect NoVs, real-time reverse transcription-quantitative PCR (RT-qPCR) assays have been widely employed since the first decade of the 21st century. We developed a redesigned probe, JJV1PM, for RT-qPCR assay detection of NoV genogroup (G) I strains. The new RT-qPCR assay using the JJV1PM-probe showed broader strain reactivity for 10 NoV GI genotypes, while the old method, using the JJV1PT-probe assay, detected only 7 NoV GI genotypes in a validation panel using human fecal specimens. The improved RT-qPCR assay was also successfully applied to water samples. The JJV1PM-probe assay identified 7 NoV GI genotypes, whereas the JJV1PT-probe assay detected only 2 NoV GI genotypes from water samples. Notably, groundwater-borne NoV GI strains detected by the improved JJV1PM-probe assay were associated with groundwater-borne AGE outbreaks in South Korea. The results of this study underscore the importance of the evaluation of RT-qPCR assays using recently circulating NoV strains prior to field application.
Assuntos
Norovirus/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Genótipo , Microbiologia da ÁguaRESUMO
The genotype distribution of group A rotaviruses (RVAs) circulating in Gyeonggi province, South Korea between 2009 and 2012 was investigated. A total of 2619 stool specimens from sporadic acute gastroenteritis cases and 117 acute gastroenteritis outbreaks were analyzed. Among them, RVAs were detected from 263 (10.0%) sporadic cases and 3 (2.6%) outbreaks. The G4P[6] strains predominated (29.7%), followed by G1P[8] (19.4%), G2P[4] (15.6%), G3P[8] (13.3%) and G9P[8] (6.5%) strain. Especially 96.2% of the genotype G4P[6] strains were isolated from children<1year of age. Phylogenetic analysis revealed that genotype G4P[6] strains were members of sub-lineage Ie(G4) and Ia(P[6]). Intensified monitoring of RVAs, especially G4P[6] strains among young children, is essential to control RVA infections.
Assuntos
Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Rotavirus/classificação , Rotavirus/genética , Proteínas do Capsídeo/genética , Pré-Escolar , Fezes/virologia , Feminino , Gastroenterite/epidemiologia , Gastroenterite/virologia , Genótipo , História do Século XXI , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Epidemiologia Molecular , Filogenia , Vigilância em Saúde Pública , RNA Viral , República da Coreia/epidemiologia , Infecções por Rotavirus/história , Análise de Sequência de DNARESUMO
South Korean isolates of oseltamivir-resistant influenza viruses from 2005-2010 were investigated with a total 491 influenza viruses identified from 1702 specimens. Neuraminidase genes from 342 influenza viruses (71 A/H1N1, 74 pandemic A/H1N1 2009, 117 A/H3N2, and 80 B) were analyzed by RT-PCR with molecular markers for oseltamivir resistance. The H274Y mutation in the NA protein was identified in 100 % (n=40) of A/H1N1 viruses circulating in 2008-2009. Influenza A/H1N1 viruses harboring the H274Y substitution exhibited, on average, a 626-fold reduction in oseltamivir susceptibility and clustered with the A/Norway/1736/2007 strain. Close and timely monitoring for resistance to clinically available influenza antivirals should be consistently performed.