Multiple-antibiotic resistance of Enterococcus spp. isolated from commercial poultry production environments

• Published in: Applied and Environmental Microbiology 2004-10, Vol.70 (10), p.6005-6011
• Main Authors: Hayes, J.R, English, L.L, Carr, L.E, Wagner, D.D, Joseph, S.W
• Format: Article
• Language: English
• Subjects: aminoglycosides; Animal Husbandry; animal transport; Animals; antibiotic resistance; Antibiotics; antimicrobial agents; Bacteria; Bacteriology; Biological and medical sciences; cages; Chickens - microbiology; Drug resistance; Drug Resistance, Multiple, Bacterial; Enterococcus - drug effects; Enterococcus - isolation & purification; Enterococcus - pathogenicity; Enterococcus faecalis; Enterococcus faecalis - drug effects; Enterococcus faecalis - isolation & purification; Enterococcus faecalis - pathogenicity; Enterococcus faecium; Enterococcus faecium - drug effects; Enterococcus faecium - isolation & purification; Enterococcus faecium - pathogenicity; Food Microbiology; Fundamental and applied biological sciences. Psychology; human food chain; Humans; isolation; Microbial Sensitivity Tests; Microbiology; multiple drug resistance; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phenotype; Poultry; poultry housing; poultry manure; Public Health Microbiology; Species Specificity
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.70.10.6005-6011.2004

The potential impact of food animals in the production environment on the bacterial population as a result of antimicrobial drug use for growth enhancement continues to be a cause for concern. Enterococci from 82 farms within a poultry production region on the eastern seaboard were isolated to establish a baseline of susceptibility profiles for a number of antimicrobials used in production as well as clinical environments. Of the 541 isolates recovered, Enterococcus faecalis (53%) and E. faecium (31%) were the predominant species, while multiresistant antimicrobial phenotypes were observed among all species. The prevalence of resistance among isolates of E. faecalis was comparatively higher among lincosamide, macrolide, and tetracycline antimicrobials, while isolates of E. faecium were observed to be more frequently resistant to fluoroquinolones and penicillins. Notably, 63% of the E. faecium isolates were resistant to the streptogramin quinupristin-dalfopristin, while high-level gentamicin resistance was observed only among the E. faecalis population, of which 7% of the isolates were resistant. The primary observations are that enterococci can be frequently isolated from the poultry production environment and can be multiresistant to antimicrobials used in human medicine. The high frequency with which resistant enterococci are isolated from this environment suggests that these organisms might be useful as sentinels to monitor the development of resistance resulting from the usage of antimicrobial agents in animal production.