Survival of Campylobacter jejuni in biofilms isolated from chicken houses.
Campylobacter jejuni is a thermophilic and microaerophilic enteric pathogen associated with poultry. Biofilms may be a source of C. jejuni in poultry house water systems since they can protect constituent microorganisms from environmental stress. In this study, the viability of C. jejuni in biofilms of gram-positive chicken house isolates (P1, Y1, and W1) and a Pseudomonas sp. was determined using a cultural method (modified brucella agar) and direct viable count (DVC). Two-day biofilms grown on polyvinyl chloride (PVC) coupons in R2A broth at 12 and 23 degrees C were incubated with C. jejuni for a 6-h attachment period. Media were then refreshed every 24 h for 7 days to allow biofilm growth. Two-day biofilms of P1, Y1, and Pseudomonas spp. enhanced attachment (P < 0.01) of C. jejuni (4.74, 4.62, and 4.78 log cells/cm2, respectively) compared to W1 and controls without preexisting biofilm (4.31 and 4.22 log cells/cm2, respectively). On day 7, isolates P1 and Y1 and Pseudomonas biofilms covered 5.4, 7.0, and 21.5% of the surface, respectively, compared to 4.9% by W1. Viable C. jejuni on the surface decreased (P < 0.05) with time, with the greatest reduction occurring on surfaces without a preexisting biofilm. The number of viable C. jejuni determined by DVC was greater than that determined by the cultural method, indicating that C. jejuni may form a viable but nonculturable state within the biofilm. Both DVC and the cultural method indicate that biofilms enhance (P < 0.01) the survival of C. jejuni during incubation at 12 and 23 degrees C over a 7-day period.
Trachoo
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Center for Food Safety, Department of Food Science and Technology, University of Georgia, Athens 30605-2106, USA.
Frank
J F
JF
Stern
N J
NJ
D000818:Animals; D018441:Biofilms / Q000254:growth & development*; D016123:Campylobacter jejuni / Q000254:growth & development / Q000502:physiology*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D005516:Food Microbiology; D006799:Housing, Animal; D011549:Pseudomonas / Q000254:growth & development / Q000502:physiology*; D013696:Temperature; D013997:Time Factors; D014871:Water Microbiology