Authors : Myeong Ju Chae, Jae Keun Cho and Young Ju Lee
Abstract: Escherichia coli is the most important etiological agent of diarrhea in young piglet. The aim of this research was to investigate the characteristics of serogroups, virulence genes and genetic diversity among E. coli isolated from young pigs with diarrhea in Korea. A total of 105 E. coli strains were isolated from rectal swabs and small intestinal contents of 1-6 weeks old pigs with diarrhea. About 47 (44.8%) of the isolates were one of the 11 serogroups, O2, O9, O11, O15, O103, O112, O121, O125, O139, O142 and O163. The most prevalent serogroup is O139 (10.5%) but 58 (55.2%) isolates were untypable. In pulsed field gel electrophoresis, the isolates were clustered in 40 groups of 50% similarity according to the dice similarity index and the most isolates in the same serogroups were classified differently. About 96 (91.4%) E. coli isolates possessed at least one toxin gene, LT, STa, STb, Stx2e and EAST1. The most prevalent toxin gene was LT (50 isolates) followed by STa (39 isolates) and STb (30 isolates). The 80 (76.2%) E. coli isolates also carried at least one fimbrial gene. The most prevalent fimbrial adhesin was F18 (37 isolates) followed by F6 (33 isolates) and F4 (29 isolates). Most isolates carring genes for fimbrial adhesins also possessed genes for toxin production. The most common associations were LT/STa/Stx2e/F18 (9 isolates), Stx2e/F18 (5 isolates), STa/Stx2e/F18 (4 isolates), LT/EAST1/F4 (4 isolates) and LT/STb/EAST1/F4/F6 (4 isolates). The results indicate the E. coli isolates from piglets with diarrhea in Korea showed a high genetic and phenotypic diversity.
Myeong Ju Chae, Jae Keun Cho and Young Ju Lee, 2012. Virulence Genes of Escherichia coli Isolates from Piglets with Diarrhea in Korea. Journal of Animal and Veterinary Advances, 11: 9-12.