Author
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Line, John |
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Submitted to: Journal of Rapid Methods and Automation in Microbiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/9/2006 Publication Date: 3/1/2006 Citation: Line, J.E. 2006. Comparison of enrichment vessels for recovery of campylobacter spp. from broiler rinse samples. Journal of Rapid Methods and Automation in Microbiology. 14:110-117. Interpretive Summary: Campylobacter spp. are import foodborne pathogens frequently associated with raw poultry. To date there are no universally accepted methods for isolation of campylobacters from a wide range of sample types and optimization of recovery methodology is needed. For most Campylobacter selective enrichment methods, little concern has been given to the actual culture vessel used to hold the sample during the incubation period. The upper surface area of a culture medium that is exposed to the gaseous headspace in a container could be important to ensure adequate gas exchange when attempting to recover organisms such as Campylobacter which require a modified atmosphere (less oxygen and more carbon dioxide than room air normally contains) for growth. The purpose of this study was to determine if the type of culture vessel used during incubation of an enrichment medium would affect recovery of Campylobacter spp. from processed broiler rinse samples. Freshly processed broiler carcasses were rinsed and the rinses serially diluted. The diluted rinses were mixed with an equal volume of 2x Bolton enrichment broth (BEB; with or without blood) and placed in a variety of different container types for incubation and recovery of Campylobacter. Differences were observed in recovery of Campylobacter spp. from samples incubated in different vessels. BEB in vented tissue culture flasks recovered campylobacters from significantly more samples at higher dilutions than did BEB in resealable plastic bags (P<0.05) likely due to gas permeability of the bags and greater media surface area in the flasks. Blood-free BEB in vented tissue culture flasks was found to give an equivalent rate of Campylobacter recovery as BEB and is suggested for use in recovering Campylobacter from this sample type. This information will be of use to scientists in academia, government and commercial analytical laboratories to improve recovery of campylobacters. Technical Abstract: Campylobacter spp. are import foodborne pathogens frequently associated with raw poultry. To date there are no universally accepted methods for isolation of campylobacters from a wide range of sample types and optimization of recovery methodology is needed. For most Campylobacter selective enrichment methods, little concern has been given to the actual culture vessel utilized during the incubation period. The upper surface area of a culture medium that is exposed to the gaseous headspace in a container could be important for adequate gas exchange when attempting to recover organisms such as Campylobacter requiring a modified atmosphere for growth. The purpose of this study was to determine if the type of culture vessel used during incubation of an enrichment medium would affect recovery of Campylobacter spp. from processed broiler rinse samples. Freshly processed broiler carcasses were rinsed and the rinses serially diluted. The diluted rinses were mixed with an equal volume of 2x Bolton enrichment broth (BEB; with or without blood) and placed in a variety of different container types for incubation and recovery of Campylobacter. Differences were observed in recovery of Campylobacter spp. from samples incubated in different vessels. BEB in tissue culture flasks recovered campylobacter from significantly more samples at higher dilutions than did BEB in resealable plastic bags (P<0.05) likely due to gas permeability of the bags and greater media surface area in the flasks. Blood-free BEB in vented tissue culture flasks was found to give an equivalent rate of Campylobacter recovery as BEB for this sample type. |
