Hand-foot-mouth disease pathogen separation and EV71 VP1 gene analysis in Sanmenxia City, Henan Province, China / 病毒学报

The aim of this study was to understand the enterovirus types and biological features of pediatric cases of HFMD in Sanmenxia City during 2011, and compare the latter to a cohort of healthy children. Stool samples of 55 cases of HFMD and 60 healthy children were collected for the isolation and identification of enteroviruses using RNA extraction and real-time RT-PCR assays. EV71 and CA16 were identified by nucleotide sequencing using virus-specific VP1 primers; for the other enteroviruses, 012/011 and 008/013 primers were used for amplification and sequencing. The results were analysed by sequence alignment with known sequences, and the characteristics of the EV71 VP1 gene were also analyzed. The detection rates for enteroviruses in cases of HFMD and healthy children were 52.73% (29/55) and 18.33% (11/60), respectively. Among these, there were 22 cases of EV71, four cases of CA16 and three cases of other enteroviruses in the cases with HFMD. Eleven healthy children had intestinal viruses, of which nine were Coxsackie B virus strains (81.82%, 9/11). Gene sequencing of the 19 EV71 strains illustrated that they were all subgenotype C4a, but the evolutionary tree showed an obvious clustering between cases from Lingbao City and Lushi County. This study demonstrates that the EV71 subgenotype C4a and CA16 strains were the most common cause of HFMD in Sanmenxia City in 2011, and that Coxsackie B strains were prevalent in healthy children. This finding may indicate that there is a widespread source of recessive infection in the community.

Genomic characteristics of coxsakievirus A16 isolated in Henan Province / 病毒学报

To reveal the genomic sequence characteristics of coxsackievirus A16 (CoxA16) strain isolated from patients with hand-foot-mouth disease (HFMD) in Henan province. A total of 406 samples were detected by reverse-transcription polymerase chain reaction (RT-PCR) and cell-culture-based isolation of coxsackievirus A16. The whole genome of CoxA16 isolate was amplified using 10 pairs of primers, the sequences were analyzed and phylogenetic tree was generated by bioinformatics software. The full length of HN1162/HN/CHN/2010 genome was 7411bp. Compared with the other CoxA16 strains released in GenBank, the nucleotide similarities were 87.0-97.9%, 77.0%-95.4%, 80.3%-96.9%, 77.9% 96.2%, 80.5-100% in 5'UTR, P1, P2, P3, 3'UTR region, respectively; The similarities of nucleotide and amino acid sequences in VP1 region were 91.4%-96.4% and 99.3%-99.7%, respectively. Phylogenetic tree analysis showed that CoxA16 strains isolated from Henan, Shenzhen, Guangzhou and Fujian belonged to the same cluster. The newly isolated CoxA16 from Henan province belonged to subgenotype C2/B-2. These results will have great significance in monitoring CoxA16 and for prevention and control of hand-foot-mouth disease.