Submitted to: National Foundation for Infectious Disease
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2004
Publication Date: 6/28/2004
Citation: Hume, M.E., Lu, L., Burnham, M., Ziprin, R.L., Donskey, C.J. 2004. Vancomycin-resistant Enterococcus faecium microbial ecology in broiler chickens [abstract]. 2004 Conference on Antimicrobial Resistance. p. 40.
Technical Abstract: Broiler chickens are reservoirs for human colonization by vancomycin-resistant Enterococcus (VRE). European broilers given vancomycin-related performance enhancers are sources of VRE, while in the US VRE is nosocomial. Healthy humans colonized by VRE show no clinical effects and eliminate VRE with time. Complications arise with prolonged hospital residence, vancomycin treatment, intensive care unit residence, organ transplant, and blood disease. The objectives of the current study were to examine the effects of performance enhancers on VRE broiler colonization and cecal bacteria populations. Day-of-hatch broilers were inoculated with 10**7 CFU of a human (VREh) or poultry (VREp) isolate. Chicks were given control (Con) feed or feed containing subtherapeutic chlortetracycline (Chl), tylosin (Tyl), or vancomycin (Van). Cecal contents were monitored over a 6-wk grow-out for enterococci, VRE, and denaturing gradient gel electrophoresis (DGGE) profiles. Enterococci at wk-6 averaged 6.29 log10 CFU/g of cecal contents in Con, Chl, and Tyl chicks and 7.29 log10 CFU/g in Van chicks. VREh was not detected at wk-6 in Con, Chl, and Tyl chicks, but was 7.93 log10 CFU/g in Van chicks. VREp was 6.66 log10 CFU/g in Van chicks and 2.59, 0.43, and 0.86 log10 CFU/g in Con, Chl, and Tyl chicks. DGGE analysis resulted in a dendrogram with two main clusters. Van profiles were in one cluster, while the other profiles were in a larger cluster. Results indicate that Van had no affect on enterococcus, while promoting VRE growth. Enterococci and VRE were not affected by Chl and Tyl as reflected by similarities in DGGE profiles.