WASHINGTON—When compared to conventionally raised beef cattle, organic and natural production systems do not impact antibiotic susceptibility of E. coli O157:H7, according to a new study from researchers from Kansas State University and detailed in the August 2009 issue of the journal Applied and Environmental Microbiology.
“The prevalences of E. coli O157:H7 that we observed in organically and naturally raised beef cattle were similar to the previously reported prevalence in conventionally raised cattle,” they wrote. “No major difference in antibiotic susceptibility patterns among the isolates was observed.”
In the study fecal samples were collected from organically and naturally raised cattle and tested for the presence of E. coli O157:H7. Results showed prevalence rates of 14.8 percent in organically raised and 14.2 percent in naturally raised cattle. The E. coli O157:H7 levels were comparable to those previously identified in conventionally raised cattle. The minimum inhibitory concentration of a variety of antibiotics for E. coli O157:H7 isolates also were analyzed to determine the effects of all three production systems and no significant difference in antibiotic susceptibility was noted.
