[Analysis of infection status and pathogenic features of human metapneumovirus among children in Hangzhou between year 2009 and 2011].

Objective: To study the infection status and pathogenic features of human metapneumovirus (hMPV) among children with acute respiratory tract infection in Hangzhou.

Methods: A total of 372 children less than 14 years old with acute respiratory tract infections were recruited as subjects from the pediatric clinic or intensive care unit (ICU) of 3 hospitals in Hangzhou during November 2009 to January 2010, and November 2010 to January 2011. A total of 372 specimens were collected, including 351 respiratory swab, 9 nasopharyngeal aspirate material, 8 endotracheal aspirate material and 4 sputum.

Molecular evolution of HA gene of the influenza A H1N1 pdm09 strain during the consecutive seasons 2009-2011 in Hangzhou, China: several immune-escape variants without positively selected sites.

Background: Even under immune pressure, the highly active influenza A H1N1 pdm09 variants emerged again in December 2010. Did the variability lead to poor vaccine effectiveness?

Objectives: To study the genetic distance and antigenic drift of the influenza A H1N1 pdm09 strains based on the sequence analysis of HA virus gene segments during consecutive seasons 2009-2011 in Hangzhou, China.

Study Design: 39 Clinical samples from influenza-like-illness patients with culture-confirmed influenza A H1N1 pdm09 infections were collected over seasons in routine influenza surveillance.

[Heterozygous genotypes and molecular characteristics of Organophosphorus resistance associated esterase B2 genes of Culex pipiens complex].

Objective: To investigate the heterozygous genotype and molecular characteristics of Organophosphorus resistance associated with heterozygous Estbeta2 of esterase B2 gene from natural population of Culex pipiens complex.

Methods: Genomic DNA was extracted from natural populations of Culex pipiens complex in Hangzhou. The PCR-restriction fragment length polymorphism (PCR-RFLP) assay was applied to type the resistance associated esterase gene.

[Multiplex PCR assay for dissemination and diversity of extended-spectrum beta-lactamase genes in Shigella isolates].

Objective: To develop a rapid and simple multiplex polymerase chain reaction (PCR) method which discriminates extended-spectrum beta-lactamases (ESBLs) genes in sporadic Shigella isolates from 1998 to 2007 in Hangzhou city, China.

Methods: After ESBLs screening according to the Clinical and Laboratory Standards Institute (CLSI) method, CTX-M, TEM, SHV and OXA-1 encoding genes were detected by using a multiplex PCR method, and the results were verified by 8 single gene PCR amplification.

Results: Seventeen isolates harbored ESBLs genes among 195 Shigella isolates (8.

[mRNA expression levels of p53 and DNA damage and repair genes in peripheral blood lymphocytes of benzene-exposed workers].

Objective: To investigate the relationship between the mRNA expression levels of p53-mediating DNA damage and repair genes in the peripheral blood lymphocytes of workers and their exposures to benzene in their working environment.

Methods: The mRNA expression levels of p53 and related genes were determined by SYBR Green I chimeric fluorescence quantitative real-time RT-PCR analysis in peripheral blood lymphocytes of 72 workers, who were classified into group A (46 direct exposure to benzene) and group B (26 indirect exposure to benzene) based on their positions, and 29 controls. The differences of gene expression levels were analyzed by software REST 2005.

[Genotypes, allele frequencies and dynamic distribution on resistance-associated esterase genes of Culex pipiens complex in Hangzhou].

Objective: To investigate the genotypes , allele frequencies and dynamic distribution on resistance associated esterase genes of Culex pipiens complex in Hangzhou.

Methods: The PCR-restriction fragment length polymorphism (PCR-RFLP) assay was applied to type the resistance associated esterase genes, and dynamic surveillance on frequencies of the resistance associated esterase gene of natural population of Culex pipiens complex in Hangzhou during 2003-2005, and phenotype of the resistance associated esterase genes were detected by esterase starch gel electrophoresis technique.

Results: The PCR-RFLP assay of esterase allele genes for three consecutive years disclosed four esterase genotypes, namely, the world-wide highly active homozygous Est beta 1(1) (50%-54%), homozygous Est beta 2 (29%-34%), heterozygous Est beta 1(1)/beta 2 (5%-10%) and Est beta N (3.

[Multiplex real-time PCR detecting Salmonella, Shigella and diarrheagenic Escherichia coli].

Objective: To develop a multiplex real-time PCR for the detection of Salmonella invasion protein A gene (invA), enterotoxigenic Escherichia coli (ETEC) heat-labile I enterotoxin gene (elt), and Shigella or enteroinvasive E. coli (EIEC) invasive plasmid antigen H gene (ipaH).

Methods: Under the optimized reaction conditions of the multiplex real-time PCR, invA, elt, and ipaH were determined in 10-fold series of dilution of DNA extracted from Salmonella enterica serovar Typhimurium, ETEC 44815 strain and Shigella F301 strain.

[PFGE of Shigella flexneri 4c isolates from food-poisoning outbreaks and sporadic diarrhea patients].

Objective: To know the molecular characteristic of Shigella flexneri 4c isolates from patients in two food-poisoning outbreaks and one sporadic diarrhea case in Hangzhou, China.

Methods: S. flexneri isolates from patients in two food-poisoning outbreaks (outbreak 1 and outbreak 2, n = 13 and n = 12, respectively) and one sporadic diarrhea patient (n = 1) in Hangzhou during 2003 and 2005 were serotyped.

[Classification and identification of vibrio cholerae and vibrio parahaemolyticus isolates based on gyrB gene phylogenetic analysis].

In order to validate the usefulness of gyrB genotype for the classification and identification of Vibrio cholerae and Vibrio parahaemolyticus isolates, the phylogenetic analysis of 13 V. cholerae, 8 V. parahaemolyticus, 2 Aeromonas hydrophila and 1 Plesiomonas shigelloides strains was carried out using the partial coding sequence of gyrB, a gene that encodes the B subunit of DNA gyrase (topoisomerase type II ) in bacteria.

[Molecular typing on Vibrio parahaemolyticus isolates from Hangzhou, China, during 2000-2002].

Objective: To study the molecular epidemiology of Vibrio parahaemolyticus isolates from clinical and environmental samples collected in Hangzhou area during 2000 and 2002.

Methods: V. parahaemolyticus isolates from food-poisoning, sporadic diarrhea patients and seafood in market in Hangzhou during 2000 and 2002 were serotyped.