RESUMO
To investigate the genetic characteristics of poliovirus isolates from environmental sewage surveillance in Shandong province, we collected sewage samples in Jinan and Linyi City. Serotyping and VP1/ 3D sequencing were performed on polioviruses isolated from the concentrated sewage samples, and VP1 mutation and recombination were analyzed. Thirty-two of sewage samples were collected, and polioviruses were detected in 10 of the samples with a positive rate of 31.3%. Eighteen Sabin strains were isolated including three type 1, nine type 2, and six type 3 polioviruses, and the number of nucleotide substitutions in VP1 coding region varied from 0 to 4. Recombination was found in three Sabin 2 and four Sabin 3 polioviruses. Analysis of neurovirulence sites of VP1 revealed that one Sabin 1 vaccine strain had a nucleotide change of A to G at nt 2749, one Sabin 2 strain had a nucleotide change of A to G at nt 2908, three Sabin 2 strains had a nucleotide change of U to C at nt 2909, and all six Sabin 3 strains had a nucleotide change of C to U at nt 2493. Poliovirus vaccine strains could be isolated from environmental sewage with a high rate of gene recombination and back mutation of neuvirulence-associated sites. None of wild-type poliovirus or vaccine-derived poliovirus was detected.
Assuntos
Humanos , Sequência de Aminoácidos , Sequência de Bases , China , Dados de Sequência Molecular , Mutação , Poliomielite , Virologia , Poliovirus , Genética , Vigilância da População , Esgotos , VirologiaRESUMO
<p><b>OBJECTIVE</b>To investigate the pathogen spectrum constitution of HEV related to acute meningitis/encephalitis syndrome (AMES) and to analyze the genetic characterization of the echovirus 30 (Echo30) isolates.</p><p><b>METHODS</b>Cerebrospinal fluid, stool, and/or throat swab specimens from 101 AMES cases were collected for virus isolation with RD and HEp-2 cell lines in Linyi city from April to December, 2010. After typing by neutralization test, the entire VP1 gene of the isolates were amplified by RT-PCR and sequenced. Homologous comparison was carried out and phylogenetic analysis were performed.</p><p><b>RESULTS</b>HEVs were isolated from 47 specimens of 34 patients (4 from cerebrospinal fluid, 18 from throut swab and 25 from stool), with 11 Echo30 isolates identified by microneutralization assay and molecular typing method. In alignment of VP1 sequences with global Echo30 isolates, relative high nucleotide homologies (91.2% - 95.4%) with Taian, Zhangqiu and Jiangsu isolates and high divergences (17.9% -19.6%) with prototype strain were observed. Nucleotide divergences among Linyi isolates were 0 - 10.2%, and 3 lineages were revealed via phylogenetic analysis, reflecting 3 transmission chains of Echo30 co-circulated in Linyi city, 2010.</p><p><b>CONCLUSION</b>Echo30 was the predominant serotype of AMES cases in Linyi city, 2010. These isolates possessed considerable divergence with Echo30 from other countries.</p>