Molecular screening and characterization of shiga toxin-producing escherichia coli by multiplex pcr assays for stx1, stx2, eaea, h7 in raw milk

Abstract

The presence of Shiga-toxin producing Escherichia coli (STEC) was evaluated in bulk milk from dairy cattle farms in Bulgaria. From 20 regional farms only 4 were selected as a source for milk sampling on the basis of their annual STEC shedding in feces. All the samples were PCR analyzed after selective enrichment. Positive samples were detected in subsequent molecular testing as: two of samples (9.08%) were positive for stx1, one sample (4.54%) for stx2, 10 samples (45.54%) for eae and 12 (54.54%) for H7 coding genes.

Keywords

• escherichia coli o157: н7
• dairy farms
• bulk milk
• enrichment
• pcr