Serotypes, Virulence Genes, and Intimin Types of Shiga Toxin (Verotoxin)-Producing Escherichia coli Isolates from Healthy Sheep in Spain

Presence and characteristics of sorbitol-negative Escherichia coli O157 in healthy sheep faeces

“…Although it is generally accepted that the cattle are a primary reservoir of sorbitol-negative E. coli O157, this pathogen has also been isolated from domestic ruminants, especially sheep and goats (Beutin et al, 1993;Kudva et al, 1996Kudva et al, , 1997Heuvelink et al, 1998;Blanco et al, 2003;. However, very little is known about the epidemiology of this organism on sheep farms.…”

“…Recently, a number of PCR-based assays have been developed for detection of sorbitol-negative E. coli O157 (Franck et al, 1998;Hu et al, 1999;Blanco et al, 2003;Kang et al, 2004). Most of these assays are designed for detection of stx and eaeA genes.…”

“…Domestic ruminants, mainly cattle, sheep and goats, have been implicated as the principal reservoir (Beutin et al, 1993;Kudva et al, 1997;Heuvelink et al, 1998). The isolation of sorbitolnegative E. coli O157 from the faeces of healthy sheep supports the epidemiological evidence of a link between human disease and consumption of manure-contaminated products (Heuvelink et al, 1998;Djordjevic et al, 2001;Blanco et al, 2003;Rey et al, 2003).…”

“…In sheep, in contrast to cattle, the number of epidemiological studies carried out on EHEC strains is very limited (Kudva et al, 1996(Kudva et al, , 1997Heuvelink et al, 1998;Blanco et al, 2003;Rey et al, 2003). To our knowledge, there is no study on the genotypic char-acteristics of sorbitol-negative E. coli O157 strains isolated from sheep in Turkey.…”

Anti-microbial Action against VerotoxigenicEscherichia coliO157:H7 of Nitric Oxide Derived from Sodium Nitrite

“…2) Verotoxigenic E. coli produces major two types of verotoxin (VT1 and VT2), enterohemolysin (ehxA) and intimin (eaeA) virulence. 3) Most cases in E. coli O157:H7 infection were associated with the consumption of undercooked, contaminated ground beef and pork, because E. coli O157:H7 is part of the normal bacterial flora in such healthy Artiodactyla as bulls and pigs. 4) In the course of slaughtering these animals, their intestinal contents often contaminate the meat, which subsequently serves as the source of infection unless the meat is well cooked.…”