The increasing rate of development of bacterial resistance to antibiotics has been well-documented, and this has major consequences for human and animal health. There is a considerable lack of data regarding the ecologic and epidemiologic forces that drive the spread and persistence of antibiotic resistance genes in agricultural settings.
Therefore, through a 3-year prospective study in 6 Illinois dairies, we have the following specific objectives:
<li> To evaluate antibiotic resistance profiles of commensal and pathogenic bacteria over time in order to assess factors that influence changes in antimicrobial susceptibility;</li>
<li> To study the bacterial genes that confer antimicrobial resistance in order to elucidate the ecology of these genes in the natural environment;and </li>
<li> To develop and validate quantitative sampling methods for monitoring antimicrobial resistance and to build mathematical models that predict the spread and persistence of resistance genes on the dairy. </li></ol>
Feces from all cows in the study will be cultured for bacterial organisms in the genera E. coli, Salmonella, Enterococcus, and Prevotella. Milk samples will also be cultured. </p>
The results of this study, descriptive and analytical,will greatly increase our understanding of the epidemiology and ecology of antibiotic resistance. On the dairy farm, critical points for controlling resistance will be identified. Efficient monitoring and sampling strategies will be identified. The risk of gene transfer between commensal and pathogenic bacteria will be estimated.</p>