The enumeration of coliforms and E. Coli on naturally contaminated beef: a comparison of the petrifilm™ method with the Australian Standard

Petrifilm(TM) PEC was compared to Australian Standard (AS) methods for the enumeration of coliforms and Escherichia coli on 50 naturally contaminated beef samples from three meal works. The standard methods consist of a 3-tube most probable number test or a direct plate count on tryptone bile agar for E. coli, and violet led bile agar and the most probable number test for coliforms (AS 1766.2.12.1984 and AS 1766.2.3.1992)

Virulence Properties and Serotypes of Shiga Toxin-Producing Escherichia coli from Healthy Australian Slaughter-Age Sheep

A group of 1,623 ovine fecal samples recovered from 65 geographically distinct mutton sheep and prime lamb properties across New South Wales, Australia, were screened for the presence of Shiga toxin-producing Escherichia coli (STEC) virulence factors (stx(1), stx(2), eaeA, and ehxA). A subset was cultured for STEC isolates containing associated virulence factors (eaeA and/or ehxA), which were isolated from 17 of 20 (85%) and 19 of 20 (95%) tested prime lamb and mutton sheep properties, respectively. STEC isolates containing stx(1), stx(2), and ehxA were most commonly isolated (19 of 40 flocks; 47.5%), and this profile was observed for 10 different serotypes. Among 90 STEC isolates studied, the most common serotypes were O91:H(−) (22 isolates [24.4%]), O5:H(−) (16 isolates [17.8%]), O128:H2 (11 isolates [12.2%]), O123:H(−) (8 isolates [8.9%]), and O85:H49 (5 isolates [5.6%]). Two isolates (2.2%) were typed as O157:H(−). A total of 78 of 90 STEC isolates (86.7%) expressed Shiga toxin in Vero cell culture and 75 of 84 ehxA-positive isolates (89.3%) expressed enterohemolysin on washed sheep blood agar. eaeA was observed in 11 of 90 (12.2%) ovine STEC isolates, including serotypes O5:H(−), O84:H(−), O85:H49, O123:H(−) O136:H40, and O157:H(−). Although only 2 of 90 isolates were typed as O157:H(−), the predominant serotypes recovered during this study have been recovered from human patients with clinical disease, albeit rarely

Shigatoxigenic Escherichia coli in Australia: a review

Shigatoxigenic Escherichia coli (STEC) belonging to O serogroup O157 are predominantly reported in many parts of the world; this appears not to be the case in Australia, where other serogroups, especially O111, are more common. In this review, the incidence of human STEC infections in Australia from the first reported cases until today is reviewed. In this review, the extensive simultaneous studies on domestic food animals and the incidence of STEC in these animals are discussed in relation to human infections. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.Karl A. Bettelheim, Paul N. Goldwate