ARS | Publication request: Addition of sulfamethoxazole to selective media aids in the recovery of campylobacter spp. from broiler rinses

Submitted to: Journal of Rapid Methods and Automation in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 4, 2007
Publication Date: February 1, 2008
Citation: Line, J.E., Bailey, J.S., Berrang, M.E. 2008. Addition of sulfamethoxazole to selective media aids in the recovery of campylobacter spp. from broiler rinses. Journal of Rapid Methods and Automation in Microbiology. 16(1):2-12.

Interpretive Summary: Campylobacter is one of the leading causes of human bacterial gastroenteritis in the United States and around the world. The association of Campylobacter spp. with raw poultry products has been well established. Efforts have been ongoing to reduce the amount of Campylobacter present in raw poultry and these interventions have been targeted at both the production farm and processing plant environments. In order to evaluate the effect of interventions on Campylobacter populations associated with poultry it is necessary to utilize bacteriological methods which allow numerical estimations of pathogen populations present in the sample to be obtained. Campy-Line agar (CLA) is a recently developed selective culture medium which allows very few non-Campylobacter colonies to grow on the plates and facilitates counting the bacterial colonies. The few contaminants able to grow on CLA were identified and found to be sensitive to the antibiotic sulfamethoxazole (SMX). The purpose of our experiment was to determine the influence of SMX on recovery of C. jejuni from broiler carcass rinse samples when added to Campy-Cefex or Campy-Line agars (CLA). Cefex and CLA were prepared with and without the addition of 25 mg SMX /L media. Broiler carcass rinse samples (post-pick, n=80 and post-chill, n=80) were obtained from eight different commercial processors across the United States and were surface plated on the selective agars. Both Cefex and CLA with and without SMX recovered similar populations of Campylobacter; however, significantly fewer contaminants were observed on the Cefex with added SMX or CLA (with or without SMX) as compared to normal Cefex. The more selective CLA with SMX had no contaminants present from this sample which simplified enumeration. Addition of SMX should be considered for increasing selectivity of Campylobacter specific media. This information will be useful to researchers and microbiological technicians in government, industry and academia.

Technical Abstract: The purpose of our experiment was to determine the influence of sulfamethoxazole (SMX) on recovery of C. jejuni from broiler carcass rinse samples when added to Campy-Cefex or Campy-Line agars (CLA). Cefex and CLA were prepared with and without the addition of 25 mg SMX /L media. Broiler carcass rinse samples (post-pick, n=80 and post-chill, n=80) were obtained from eight different commercial processors across the United States and were maintained at less than 8oC during overnight shipment to our lab. Immediately upon receipt serial dilutions were surface plated on the selective agars and incubated for 48h at 42oC under microaerobic conditions. Following incubation plates were inspected for growth and typical Campylobacter colonies and non-Campylobacter contaminants were differentially enumerated. Both Cefex and CLA with and without SMX recovered similar populations of Campylobacter; however, significantly fewer contaminants were observed on the Cefex with added SMX or CLA (with or without SMX) as compared to normal Cefex. The more selective CLA with SMX had no contaminants present from this sample which simplified enumeration. Addition of SMX should be considered for increasing selectivity of Campylobacter specific media.