title: GII.4 Sydney_2012 norovirus infection in immunocompromised patients in Beijing and its rapid evolution in vivo.
abstract: To study the epidemiology and evolution of norovirus (NoV) in immunocompromised patients in a tertiary hospital in China. Stool specimens were collected from 131 hospitalized patients presenting with diarrhea from July 1, 2012, to June 30, 2013, and were tested for NoV using RT-PCR. RT-PCR was performed to amplify the complete capsid genome for a series of samples from chronic diarrhea patients, and nucleotide and amino acid changes were analyzed. There were nine NoV-positive patients among 124 immunocompromised patients (7.3%); all nine were infected with GII.4 Sydney_2012 strain. In three chronic diarrhea patients, the GII.4 Sydney_2012 strains accumulated 19, 18, and eight nucleotide mutations within 110, 113, and 22 days, respectively, most were non-synonymous. The greatest number of stable amino acid mutations was 10 in patient 2; eight stable mutations (including three in antigenic sites) occurred while the patient was asymptomatic and shedding the virus. GII.4 Sydney_2012 strain tends to undergo stable mutations during the asymptomatic shedding phase and may generate new variants in chronic diarrhea patients.
authors.affiliation: Department of Infectious Diseases, Peking University Hepatology Institute, Peking University People's Hospital, Beijing, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Mai
authors.affiliation: Department of Infectious Diseases, Peking University Hepatology Institute, Peking University People's Hospital, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Peking University People's Hospital, Peking University Hepatology Institute, Beijing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Cong
authors.affiliation: Department of Clinical Laboratory, Peking University People's Hospital, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Peking University People's Hospital, Beijing, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Peking University People's Hospital, Institute of Hematology, Beijing, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Huang
authors.affiliation: Peking University People's Hospital, Institute of Hematology, Beijing, China.
authors.forename: Lanping
authors.initials: L
authors.lastname: Xu
authors.affiliation: Peking University People's Hospital, Institute of Hematology, Beijing, China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Peking University People's Hospital, Peking University Hepatology Institute, Beijing, China.
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
mesh_terms: D000293:Adolescent; D000368:Aged; D019943:Amino Acid Substitution; D000068476:Beijing / Q000453:epidemiology; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics; D003967:Diarrhea / Q000453:epidemiology* / Q000821:virology; D019143:Evolution, Molecular; D005260:Female; D005838:Genotype; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D020125:Mutation, Missense; D029322:Norovirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D062606:Tertiary Care Centers; D017201:Virus Shedding; D055815:Young Adult
chemical_list: D036022:Capsid Proteins
keywords: GII.4 Sydney_2012; diarrhea; evolution; immunocompromised host; norovirus