|Cox, Nelson - Nac|
|Meinersmann, Richard - Rick|
|OAKLEY, BRIAN - Former ARS Employee|
|Line, John - Eric|
Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2015
Publication Date: 5/5/2015
Citation: Berrang, M.E., Cox Jr, N.A., Meinersmann, R.J., Oakley, B., Line, J.E. 2015. Detection of Campylobacter in 100 commercial flocks - evaluation of plating media and filtration method. Journal of Applied Poultry Research. 24(2):240-245.
Interpretive Summary: Campylobacter is a human pathogen that has been associated with broiler chickens. This organism is a natural component of the broiler gut microflora and as such can contaminate meat during processing. It is useful for a commercial processor to know the status of a flock during or prior to processing. However, due to extraneous growth on bacterial growth media, it can be very difficult to detect Campylobacter from a complex sample such as gut contents or feces. We examined gut tissue from 100 different broiler flocks 50 of which we also examined carcass samples. We tested three different plating media with and without the extra selection of a filtration method. We found that 52% of flocks tested were positive for Campylobacter. In general, the Campylobacter status of gut contents was predictive of the status of a corresponding carcass rinse sample. We found that all media suffered to some degree from the growth of extraneous bacteria, making it very difficult to see Campylobacter colonies. In all cases, this was solved by using a filter with 0.45µm pores laid on top of the agar prior to placement of the diluted sample. This filter method is very effective to improve the detection and isolation of Campylobacter from highly contaminated samples. This information will be useful to poultry researchers and commercial processors as they attempt to determine the Campylobacter status of broilers.
Technical Abstract: Campylobacter is a natural member of the gut microflora in many commercial broilers and as such can become a contaminant on edible surfaces during processing. Culturing gut contents or feces can be a means to determine flock status prior to live-haul. The wide variety of non-Campylobacter background bacteria in these complex samples contaminates growth media and can make it very difficult to isolate Campylobacter. Over the course of 17 months, we cultured cecal contents from 100 different broiler flocks. For the last 50 flocks, we tested three selective plating media with and without the additional selection of a 0.45 µm pore filter for detection of Campylobacter from cecal contents. Furthermore, from the last 50 flocks we also collected and cultured carcass rinse samples. Growth media tested included: Campy-Cefex Agar, Campy-Line Agar and RF-Campylobacter jejuni/coli agar. About half (52%) of the 100 tested flocks were positive for Campylobacter; positive flocks were detected during each month of the year. Overall, the Campylobacter status of cecal contents from one carcass was predictive of the status of a carcass rinse from the same flock. Placing a complex sample such as cecal contents onto a 0.45 µm filter laid on top of the plating medium improved the detection of Campylobacter by eliminating non-Campylobacter background colonies. All media allowed for detection of Campylobacter from less complex carcass rinse samples without filtering. However, Campy-cefex agar had higher numbers of competing bacterial colonies than did Campy-Line agar or RF-Campylobacter jejuni/coli agar.