Prevalence of Asymptomatic Carriers of Shiga Toxin-Producing Escherichia Coli (STEC) in Dairy Cattle Farms in the Governorate of Blida (Algeria)

We investigated whether dairy beef cattle raised in Algeria are Shiga toxin-producing Escherichia coli (STEC) carriers. Stx1 and stx2 genes were analysed in DNA isolated from 200 faecal samples collected from adult dairy cows from 27 randomly selected farms in Blida, North Algeria, after amplification by PCR. Samples from 61 (30.5%) animals out of the 200 were positive and were located in 18 farms with a prevalence of 66.7%. Interestingly, no sample from any cow was positive for only the stx2 gene, while in contrast, samples from 51 cows were positive for the stx1 gene alone (83.6%) and those from 10 other cows were positive for both stx1 and stx2 genes (16.4%). It should be noted that the faecal samples infected with pathogens carrying the two genes originated from 4 out of the 18 farms that were found to be positive, with a rate of 22.2%.