No abstract

Aims:  To study the seasonal variation of Shiga toxin‐encoding genes (stx) and to investigate the presence of Shiga toxin‐producing Escherichia coli (STEC) O157 in cattle belonging to five dairy farms from Argentina. Methods and Results:  Rectal swab samples were collected from 360 dairy cows in each season and 115 and 137 calves in autumn and in spring, respectively. The stx were investigated by multiplex PCR and it was used as the indicator for STEC. Samples positives for stx were tested by PCR for eae‐γ1 of E. coli O157 and then subjected to IMS (immunomagnetic separation). In positive animals significant differences in the prevalence of stx between warm and cold seasons were detected. In warm seasons, stx1 + stx2 increased and stx1 decreased, independently of the animal category. The prevalence of STEC O157 in cows and calves were 0·2% and 0·8%, respectively. Conclusions:  This work provides new data about the occurrence of stx and STEC O157 in dairy herds from Argentina and suggests a relationship between the type of stx and season of year. Significance and Impact of Study:  The detection of STEC O157 and the seasonality of stx and its types provide an opportunity to improve control strategies designed to prevent contamination of food products and transmission animal‐person.

In the present study PCR was applied to detect leptospires in human urine. Several

Background: Enterohaemorrhagic Escherichia coli (EHEC) is considered to be common cause of haemorrhagic colitis (HC), thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome (HUS) in humans. In a previous paper, we have demonstrated that EHEC are commonly found in the intestines of livestock. Infections in humans are, in part, a consequence of consumption of undercooked meat or raw milk. Argentina has one of the highest records of HUS (300-400 cases/year; 22/100,000 children under 4 years of age). The aim of this work is to communicate the first isolation of O145:H-from cattle in this country and characterize the virulence cassette, providing useful information to evaluate the risk of foodborne transmission of this emergent non-O157:H7 serotype.