Serological and virulence factors analysis of Escherichia coli isolates causing post-weaning diarrhea in intensive pig farms
In order to determine the prevalent serotypes and virulence factors of pathogenic Escherichia coli isolates from piglets with post-weaning diarrhea (PWD) in intensive pig farms of Zhejiang Province, rectum swabs from piglets with PWD in intensive pig farms were collected for isolations of pathogenic...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Zhejiang University Press
2006-09-01
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| Series: | 浙江大学学报. 农业与生命科学版 |
| Subjects: | |
| Online Access: | https://www.academax.com/doi/10.3785/1008-9209.2006.05.0520 |
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| Summary: | In order to determine the prevalent serotypes and virulence factors of pathogenic Escherichia coli isolates from piglets with post-weaning diarrhea (PWD) in intensive pig farms of Zhejiang Province, rectum swabs from piglets with PWD in intensive pig farms were collected for isolations of pathogenic Escherichia coli. The isolations were identified by gram stain, biochemical reactions and pathogenicity tests in mice. The O serotyping and pili typing were conducted by slide agglutination with antiserum against 11 commonly seen swine Escherichia coli O antigens and anti-K88 and anti-F18 monoclonal antibodies, respectively. The types of adhesins and enterotoxins were further verified by Polymerase chain reactions (PCR) with specific primer pairs. Among 56 Escherichia coli isolates, 33 were typable and distributed in 11 serotypes. The prevalent serotypes included O<sub>149</sub>, O<sub>139</sub> and O<sub>8</sub>, amounted to 51.5% (17/33) of the total typable ones. Slide agglutination tests and PCR analysis showed that the enterotoxigenic Escherichia coli accounted for 67.92% (36/53), of which harbored the genes for enterotoxin STa, STb, STa+STb, LT and SLT-2e amounted to 30.19% (16/53), 35.85% (19/53), 18.9% (10/53), 1.89% (1/53) and 9.43% (5/53), respectively. Isolations with F18 and K88 adhesins contributed 28.30% (15/53), 24.53% (13/53), respectively. It is concluded that pathogenic Escherichia colt isolates collected from piglets with PWD of Zhejiang Province covered at least 11 O serotypes and the predominant serotypes are O<sub>149</sub>, O<sub>139</sub>, and O<sub>8</sub>. Escherichia coli causing PWD are mostly enterotoxigenic, with the predominant enterotoxins STa, STb, SLT-2e. The toxins and adhesins F18 and K88 are the most important virulence factors involved. |
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| ISSN: | 1008-9209 2097-5155 |