ARS | Publication request: Antibiotic resistant bacterial profiles of anaerobic swine lagoon effluent

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 20, 2009
Publication Date: May 18, 2009
Citation: Brooks, J.P., McLaughlin, M.R. 2009. Antibiotic resistant bacterial profiles of anaerobic swine lagoon effluent [abstract). American Society of Microbiology. Paper No. Q-087.

Technical Abstract: Although land application of swine manure lagoon effluent is a common and effective method of disposal, the presence of antibiotic-resistant bacteria, both pathogenic and commensal can complicate already understood issues associated with its safe disposal. To better understand this, more data is needed with regard to the presence of antibiotic resistant bacteria in swine lagoon effluent. The aim of this study was to assess and compare antibiotic resistance between swine lagoon bacteria from sow, nursery, and finisher farms in the southeastern United States. Effluents from 37 lagoons were assayed for the presence of Escherichia coli, Campylobacter, Listeria, Salmonella, and antibiotic resistance genetic determinants. Antibiotic resistance profiles were determined for isolates by the Kirby-Bauer swab method for 12 antibiotics comprising 8 classes, meanwhile resistance genes were quantified via quantitative PCR. Statistical analyses indicated that farm type influenced the amount and type of resistance, with nurseries and sow farms ranking as most influential, probably due to use of more antibiotic treatments. Finisher farms tended to have the least amount of antibiotic class resistance, signaling an overall healthier market pig, and less therapeutic or prophylactic antibiotic use. Many bacterial isolates were resistant to penicillin, cephalosporin, and tetracycline class antibiotics, while nearly all were susceptible to quinolone antibiotics. This is consistent with work which identified tetracycline as a common constituent of antibiotic cocktails administered to swine.