Prevalence of virulence genes in Escherichia coli strains recently isolated from young pigs with diarrhea in the US

Prevalence of virulence genes in Escherichia coli strains isolated from piglets in the suckling and weaning period in Mexico

“…The gene that encodes F4 adhesin is one of the most frequently found genes in E. coli isolates from suckling and weaning piglets from different countries (Frydendahl, 2002;Vu-Khac et al, 2006;Zhang et al, 2007). Contrary to these results, we found that only 1 and 2 % of isolates from piglets with diarrhoea contained this virotype.…”

“…These fimbriae are highly associated with ETEC diarrhoea in piglets in experimental animals and in the field (Vu-Khac et al, 2006). The F41 adhesin gene is not as prevalent in countries such as Slovakia, Korea, USA and Vietnam (VuKhac et al, 2006;Do et al, 2006;Zhang et al, 2007;Lee et al, 2008). In our study, the F41 adhesin gene was strongly associated with the population of piglets, since on average 36 % of the isolates from piglets with diarrhoea were positive, regardless of the suckling or weaning stage.…”

“…Diarrhoea remains an important cause of morbidity and mortality in livestock and is one of the most common diseases of suckling and weaning piglets worldwide. These diseases have negative economic effects in the pork industry due to high mortality and reduced growth rate (Vu-Khac et al, 2004;Zhang et al, 2007;Madoroba et al, 2009). In neonatal and weaning piglets, E. coli induces acute and watery diarrhoea that may be followed by terminal septicaemia, an important cause of economic loss for swine producers (Lee et al, 2008).…”

“…The astA gene encoding EAST1 has also been detected in E. coli of different pathogenic strains, such as ETEC, enteropathogenic E. coli (EPEC) and STEC from humans and animals (Frydendahl, 2002;Ngeleka et al, 2003;Osek, 2003;VuKhac et al, 2007;Zhang et al, 2007). Through PCR tests, Choi et al (2001) found that 31 % of E. coli strains isolated from weaning piglets with diarrhoea or oedema disease had the EAST1 gene.…”

“…These attaching and effacing E. coli strains carry the eae gene encoding the outer-membrane protein known as intimin, which is involved in the attachment of the bacteria to the surface of epithelial cells in the gastrointestinal tract. This gene is a marker for porcine EPEC; however, the pathogenic significance of porcine eae strains in weaning pigs is unclear because some eae-positive isolates may also be found in healthy pigs (Fairbrother et al, 2005;Malik et al, 2006;Cheng et al, 2006;Zhang et al, 2007).…”