Determination of the genetic similarities of fingerprints from Escherichia coli O157:H7 isolated from different sources in the North West Province, South Africa using ISR, BOXAIR and REP-PCR analysis

Abstract

The aim of this study was to determine the genetic relationships of Escherichia coli O157:H7 isolated from pigs, cattle, pork, beef, humans and water samples using REP, ISR and BOXAIR PCR analysis. A total of 94 isolates were subjected to the REP-PCR analysis while 95 were screened for ISR and BOXAIR PCR fingerprints. The band sizes for amplicons from the ISR-PCR analysis ranged from 0.173kb to 0.878kb. However, a large proportion of the isolates had four bands ranging from 0.447kb to 0.878kb. Cluster analysis of the BOXAIR PCR profiles based on banding patterns revealed seven main clusters. It was identified in the clusters III, IV and VII in the BOXAIR PCR that 17.9%, 16.8% and 18.9%, of E. coli O157:H7 isolates respectively were present from all the animal species, meat and water samples. REP-PCR analysis produced 9 different patterns with bands ranging from 0 to 12 per isolate. The band sizes ranged from 200bp to 8000bp. Nine major clusters (I-IX) were identified. From the three different species sampled cluster eight was the largest and a mixed cluster with 23.4% (22/94) of the E. coli O157:H7 isolates. These indicate that food products obtained from supermarkets in the study area are contaminated with E. coli O157:H7.