The emergence of fluoroquinolone-resistant Campylobacter in the United States suggests an association between use of antibiotics in food animals and occurrence of drug-resistant pathogens affecting human beings. Our long-range goal is to understand the processes underlying the spread of antibiotic resistance among major food-borne pathogens so as to devise measures to reduce or eliminate this problem.<P> The objective of this proposal is to assess the role of antimicrobial usage in poultry in the emergence of drug resistance in Campylobacter. The central hypothesis for the proposed research is that the normal flora is a reservoir of drug resistance genes for important veterinary and human pathogens such as Campylobacter.
Specific Aim 1. Identify the integron classes and drug resistance genes present within the total bacterial flora of poultry, and determine if: the presence of these resistance factors in broiler flocks are related to the recent use of antibiotics and; if these genes, detected in the total bacteria flora, are also present in individual campylobacter species present in poultry houses.<P> Specific Aim 2. Experimentally determine the effect of oral antibiotic administration on the antibiotic resistance of Campylobacter and resident microflora of broiler chickens raised in research colony houses. <P> Our intent is to develop a model system, based on broiler chicken production, to provide a means with which to identify risk factors associated with the use of antibiotics in food animals and the potential to develop antibiotic resistance associated with specific genetic elements. Chickens are the ideal food animal model for such work. They reach maturity faster than other food animals and more of them can be reared for less cost than for beef cattle or pigs. Such a system could provide a cost efficient and rapid method to experimentally investigate this important and multifactorial issue under controlled conditions. Knowing how resistance actually disseminates in these ecosystems will foster development of best practice guidelines for judicious use of existing antibiotics.