In vitro assessment of pathogenicity and virulence encoding gene profiles of avian pathogenic
Escherichia coli strains associated with colibacillosis in chickens.
IRANIAN JOURNAL OF VETERINARY RESEARCH 2020;
21:180-187. [PMID:
33178295 PMCID:
PMC7608036]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 07/04/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND
Avian pathogenic Escherichia coli (APEC) strains have been associated with various disease conditions in avian species due to virulence attributes associated with the organism.
AIMS
This study was carried out to determine the in vitro pathogenic characteristics and virulence encoding genes found in E. coli strains associated with colibacillosis in chickens.
METHODS
Fifty-two stock cultures of E. coli strains isolated from chickens diagnosed of colibacillosis were tested for their ability to produce haemolysis on blood agar and take up Congo red dye. Molecular characterization was carried out by polymerase chain reaction (PCR) amplification of virulence encoding genes associated with APEC.
RESULTS
Eleven (22%) and 41 (71%) were positive for haemolysis on 5% sheep red blood agar and Congo red agar, respectively. Nine virulence-associated genes were detected as follows: FimH (96%), csgA (52%), iss (48%), iut (33%), tsh (21%), cva (15%), kpsII (10%), pap (2%), and felA (2%).
CONCLUSION
The APEC strains exhibited virulence properties and harbored virulence encoding genes which could be a threat to the poultry population and public health. The putative virulence genes were diverse and different in almost all isolate implying that pathogenesis was multi-factorial and the infection was multi-faceted which could be a source of concern in the detection and control of APEC infections.
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