Location: Poultry Microbiological Safety and Processing Research UnitTitle: Antibiotic profiles of bacteria isolated on selective campylobacter media
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/14/2018
Publication Date: 7/23/2018
Citation: Hinton Jr, A., Rothrock Jr, M.J., Cosby, D.E., Ingram, K.D., Cox Jr, N.A. 2018. Antibiotic profiles of bacteria isolated on selective campylobacter media [abstract]. Poultry Science Association Meeting Abstract. 97(E-Suppl.1):207.
Interpretive Summary: none
Technical Abstract: The objective of this study was to determine antibiotic profiles of non-Campylobacter bacteria recovered on selective Campylobacter media. Broiler carcasses were obtained from a processing facility, and whole-carcass rinses were performed by shaking carcasses in plastic bags with 200 mL of distilled water for 2 min. Rinsates were decanted, and serial dilutions were prepared. Selective Campylobacter agar supplemented with Blaser-Wang antibiotic mixture and selective Campylobacter aerobic (CAE) broth supplemented with Bolton’s antibiotic mixture were inoculated with serial dilutions of the rinsates. Agar plates were incubated microaerobically in GasPak jars and CAE was incubated aerobically for 48 h at 37oC. After CAE incubation, serial dilutions of the media were also spread-plated on selective Campylobacter agar and incubated microaerobically for 48 h at 37oC to isolate bacteria that could grow on both media. Colonies were selected from agar plates and identified using the Biolog Bacterial Identification System. Antimicrobial profiles of the isolates were determined using Sensititre™ Antimicrobial Susceptibility Testing Plates containing the antibiotic series and concentrations of the CDC National Antimicrobial Resistance Monitoring System for enteric bacteria. Isolates recovered from direct plating of rinsates onto selective agar included Acinetobacter spp., Ochrobactrum spp., Pseudomonas spp., Rhizobium radiobacter, and Stenotrophomonas maltophilia. Ochrobactrum spp. and Pseudomonas fulva were recovered from selective CAE plated on selective agar. All isolates were susceptible to azithromycin, ciprofloxacin, ceftriaxone, and gentamicin; and resistant to cefoxitin. Only Ochrobactrum anthropi was resistant to streptomycin and only R. radiobacter was resistant to tetracycline. Pseudomonads were resistant to nalidixic acid and sulfisoxazole, while pseudomonads and S. maltophilia were resistant to ampicillin. Pseudomonads and Acinetobacter spp. showed the highest resistance to chloramphenicol. Additionally pseudomonads, O. anthropi, and S. maltophilia were resistant to amoxicillin-clavulanate; while these isolates and A. guillouiae showed resistance to ampicillin. Statistical analysis of data was performed to compare the efficacy of each antibiotic to inhibit growth of each isolate. Conclusions indicate that further studies should be conducted to determine if supplementing selective Campylobacter media with additional antibiotics will improve the ability of the media to inhibit the growth of bacterial contaminants on the medium. Findings may be used to formulate improved supplements to reduce growth of contaminants on selective Campylobacter media.