ABSTRACT
Objective@#To understand the infection status and genetic characteristics of Norovirus from foodborne diseases in sentinel hospital of Ma′anshan city.@*Methods@#The 911 stool samples and epidemiological data of the patients with foodborne disease were collected from three hospitals of Ma′anshan city during January 2015 to June 2018. The G Ⅰ and G Ⅱ Norovirus were detected by real-time reverse transcription PCR. Some of the positive specimens were amplified by conventional reverse transcription PCR, and the PCR products were sequenced for sequence alignment and phylogenetic analysis.@*Results@#The positive rate of Norovirus was 14.7% (134/911), in which 7 strains were G Ⅰ, 124 strains were G Ⅱ and 3 strains were mixed infection. Norovirus can be detected throughout the year, with high positive rate from December to April of the next year [24.4%(20/82)-45.3%(24/53)]. The 78 males (15.5%) and 55 females (13.7%) were positive for Norovirus (χ2=0.58,P=0.448). There was no significant difference in different age groups (χ2=9.55, P=0.089). A total of 79 strains were successfully sequenced, 4 strains were G Ⅰ group(5.1%), 75 strains were G Ⅱ group (94.9%). The predominant strains were GⅡ.17 and GⅡ.4, aud the number were 35 and 15 respectively. The predominant strains were different in different years. The main strain was GⅡ.17 in 2015 (30, 68.2%),GⅡ.4 in 2016 (5/9) and 2017 (8/16), but GⅡ.3 in 2018 (3/6).@*Conclusion@#Norovirus diarrhea was popular in Ma′anshan city throughout the year,especially in winter and spring. The prevalent strain was GⅡ,genotypes were diversified distribution,the dominant strains were GⅡ.17 and GⅡ.4. The predominant strains were different in different years.
ABSTRACT
Objective@#To analyze the genotype diversity and phylogenetic characterization of norovirus(NoV) in patients with diarrhea from Anhui province.@*Methods@#NoV positive fecal specimens from sentinel hospitals were collected from January, 2016 to December, 2017. The samples were detected by Real-time fluorescent quantitative PCR. Positive samples were of randomly selected and amplified by RT-PCR and the products were sequenced. Phylogenetic tree was constructed by the Neighbor-Joining method based on partial VP1 gene regions of NoV to perform phylogenetic analysis.@*Results@#A total of 263 NoV positive samples were genotyped, of which 239 belonged to genogroup II, 24 belonged to genogroup I. Fifty-five positive samples were successfully sequenced. There were 6 NoV GII genotypes, which included GII.2, 3, 4/Sydney_2012, 13, 17 and 21, while NV GII.17 and GII.4 were the dominant genotypes from 2016 to 2017. The predominant genotype was GII.4/Sydney 2012 (47.27%, 26/55), followed by GII.17 (23.64%, 13/55) and GII.2 (14.55%, 8/55). Phylogenetic tree showed that 26 strains belonged to genotype GII.4/Sydney 2012, NoV. The nucleotide homology among the 26 VP1 genes was 97.8% to 100%. Analysis of the partial VP1 genes of 26 strains showed that it shared the highest homology of 98.9% with the strain of GII.4Sydney2012 (GenBank ID: KU720515). However, the prevailing genotype in the Anhui province has shifted on two separate occasions, the GII.17 strain was dominant in 2016, and the GII.4/Sydney 2012 strain was dominant in 2017.@*Conclusions@#NoV GII was the major pathogen causing sporadic diarrhea in Anhui province during from 2016 to 2017, the genotypes are widely distributed, and shifted into the two predominant strains.
ABSTRACT
To study on the phylogenetic characterization of the VP1 genes of coxsackievirus A16 (CVA16) causing hand-food-mouth disease (HFMD) isolated from Anhui province in 2014. A total of 413 throat swab specimens from HFMD patients were collected during January to November, 2014 for the isolation and identification of enteroviruses using real-time RT-PCR assays. The VP1 regions of CVA16 isolates were amplified using RT-PCR and sequenced. And the phylogenetic tree was constructed among the VP1 regions of those isolates, the different genotypes and sub-genotypes of CVA16 strains. A total of 97 enteroviruses were isolated from 413 samples, the positive rate was 23.49% (97/413), including seventeen CVA16, seventy six HEV71 and four other enteroviruses. The results of the phylogenetic tree showed that 17.CVA16 strains isolated from Anhui in 2014 clustered within B1b evolution branch of B1 genotype. The nucleotide and amino acid sequence identities were 95.30%-100% and 98.70%-100% among the isolates, respectively, but within B1b branch of 17 strains formed several small transmission chains. The nucleotide acid of 17 CVA16 isolates in Anhui province were closed to the strains isolated from Yunnan, Hunan, Guangdong, Tibet and Jiangsu, especially from Hunan in 2013 and from Shenzhen of Guangdong in 2014, the identity were 96.40%-99.70%. The CVA16 strains isolated from Anhui in 2014 were all belong to genetic subtype B1b of B1 genotype was dominant, and among those isolates, several small virus transmission chains had formed with co-circulating and evolution.