tailieunhanh - Antibiotic resistant enterococci and staphylococci isolated from flies collected near confined poultry feeding operations

Ducklings may be reared in intensive, semi-intensive or range system. Under intensive system, allow a floor space of (3 .) up to 16 weeks of age. Under semi-intensive system, a floor space of to (21/2 to 3 ) per bird is allowed in night shelter and to m2 (10 to 15 .) as outside run per bird upto the age of 16 weeks. Usually ducklings are allowed to move to runs at the end of 3 to 4 weeks of age depending upon weather. Water in the drinkers should be to 15 cm (5”. | STOTEN-11054 No of Pages 10 ARTICLE IN PRESS SCIENCE OF THE TOTAL ENVIRONMENT XX 2009 XXX - XXX available at ScienceDirect locate scitotenv Antibiotic resistant enterococci and staphylococci isolated from flies collected near confined poultry feeding operations Jay P. Graham Lance B. Price Sean L. Evans Thaddeus K. Graczyk Ellen K. Silbergeld Johns Hopkins Bloomberg School of Public Health Department of Environmental Health Sciences Division of Environmental Health Engineering Baltimore MD 21205 USA ARTICLE DATA ABSTRACT Article history Received 29 July 2008 Received in revised form 17 November 2008 Accepted 25 November 2008 Keywords Antibiotic resistance Enterococci Flies Poultry litter Staphylococci Use of antibiotics as feed additives in poultry production has been linked to the presence of antibiotic resistant bacteria in farm workers consumer poultry products and the environs of confined poultry operations. There are concerns that these resistant bacteria may be transferred to communities near these operations however environmental pathways of exposure are not well documented. We assessed the prevalence of antibiotic resistant enterococci and staphylococci in stored poultry litter and flies collected near broiler chicken houses. Drug resistant enterococci and staphylococci were isolated from flies caught near confined poultry feeding operations in the summer of 2006. Susceptibility testing was conducted on isolates using antibiotics selected on the basis of their importance to human medicine and use in poultry production. Resistant isolates were then screened for genetic determinants of antibiotic resistance. A total of 142 enterococcal isolates and 144 staphylococcal isolates from both fly and poultry litter samples were identified. Resistance genes erm B erm A msr C msr A B and mobile genetic elements associated with the conjugative transposon Tn916 were found in isolates recovered from both poultry litter and flies. .