title: Distribution of serotypes and virulence-associated genes in pathogenic Escherichia coli isolated from ducks.
abstract: The objective of the present study was to investigate the serotypes and virulence-associated genes of avian pathogenic Escherichia coli (APEC) isolated from duck colibacillosis cases. Two hundred and fifty-four APEC isolates from duck colibacillosis cases were serotyped and amplified for 12 known virulence-associated genes and the betA gene (encoding choline dehydrogenase) by polymerase chain reaction assays. One hundred and forty-three E. coli isolates from cloacal swabs of healthy ducks were also amplified for the same genes. A total of 53 O-serogroups were found in 254 APEC isolates, among which O93, O78 and O92 were predominant serogroups. Polymerase chain reaction results showed that Shiga-toxin-producing E. coli distributed in only 2.4% of ducks compared with 49.2% of the APEC isolates harbouring the irp2 gene, and 44.9% the fyuA gene, respectively. The ibeA gene was only present in 27 APEC isolates and was not found in healthy ducks. The rfaH gene was detected in 20.5% of APEC isolates, whereas 5.6% was found in healthy ducks. A total 79.5% of APEC isolates harboured the betA gene, which was significantly higher than in healthy ducks (16.1%), suggesting that betA may be associated with virulence.
authors: Southwest University for Nationalities, Chengdu, People's Republic of China.
authors: Ying
authors: Y
authors: Wang
authors: Cheng
authors: C
authors: Tang
authors: Xuehui
authors: X
authors: Yu
authors: Mengyun
authors: M
authors: Xia
authors: Hua
authors: H
authors: Yue
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D004372:Ducks; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000382:microbiology*; D012703:Serotyping / Q000662:veterinary; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers