Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/17/2002
Publication Date: 6/30/2002
Citation: Byrne, C., Call, J.E., Wallace, F.M., Luchansky, J.B., Erol, I., Cray, P.J., Kaspar, C.W., Ball, T.A. 2002. Genotypic variability and antibiotic resistance profiles of escherichia coli 0157:h7 isolates from downer and healthy dairy cattle. International Association of Food Protection. Abstract #P136, p. 92. Interpretive Summary:
Technical Abstract: While cattle have been identified as a reservoir of Escherichia coli O157:H7, there is limited data regarding the prevalence and clonality of this pathogen in downer dairy cattle and the contribution of this source of ground beef to human health. A study conducted in a mid-western state between April and October of 2001 established a three-fold higher prevalence of E. coli O157:H7 in fecal samples obtained aseptically from intact colons of downer (12/201, 6.0 percent) than in healthy (4/200, 2.0 percent) dairy cattle. Analyses of 67 isolates, representing these 16 positive samples (1 to 5 isolates per sample), by PFGE revealed 17 distinct XbaI profiles. Isolates from different animals displayed distinct profiles. However, in one sample, three different, but related, XbaI profiles were displayed by the isolates recovered. In the remaining samples, the isolates from the same fecal/colon sample displayed indistinguishable profiles. Moreover, at least 15 of 67 isolates from 3 ( downer and 2 healthy animals) of the 16 positive samples contained isolates that were resistant to at least 3 of the 18 antibiotics tested. Also, isolates with the same PFGE profile displayed the same antibiotic resistance profile. It was not possible to distinguish between isolates recovered from downer or healthy cattle based on their XbaI or antibiotic resistance profiles. However, the results establish that downer cattle had a greater prevalence of E. coli O157:H7 than healthy cattle within the time frame and geographic scope of this study.