Temperature and nutrient effects on Campylobacter jejuni attachment on multispecies biofilms on stainless steel

Campylobacterjejuni is a thermophilic microaerophilic pathogen that is commonly found in the intestinal tract of chickens. In this study, attachment of C. jejuni 1221gfp in biofilms on stainless steel was assessed at various temperatures and with reduced nutrients. Bacteria collected from a saline rinse of processed broiler chicken carcasses were used to form initial biofilms. The whole carcass rinse (WCR) biofilms were formed by incubation of the bacteria for 16 h at 13, 20, 37, and 42 degrees C on stainless steel coupons in tryptic soy broth (TSB). The resulting biofilms were stained with Hoechst 33258 stain and visualized by epifluorescence microscopy. WCR biofilms formed at 13 degrees C yielded the highest surface area coverage (47.6%), and the lowest coverage (2.1%) was attained at 42 degrees C. C. jejuni transformed to produce green fluorescent protein (gfp) was allowed to attach to the preexisting biofilms (from WCR incubated for 16 h) at each of the four temperatures, and attached cells were enumerated by visualization with an epifluorescence microscope. Attachment of C. jejuni 1221gfp did not significantly differ (P > 0.05) among the four temperatures. C. jejuni 1221gfp was cultured only from coupons with biofilms formed at 13 and 20 degrees C. For nutrient limitation experiments, WCR biofilms were allowed to grow in 10- and 50-fold diluted TSB at 20 and 37 degrees C for 48 h. The WCR biofilm surface area coverage (approximately 2%) was greater at 37 degrees C than at 20 degrees C for both TSB concentrations. C. jejuni 1221gfp was incubated with the WCR biofilm for 48 h at 20 and 37 degrees C, and attached cells were enumerated. Attachment was significantly higher (P < 0.05) only for the treatments with 1:10 TSB at 20 degrees C and 1:50 TSB at 37 degrees C. Under reduced-nutrient conditions, C. jejuni 1221gfp was cultured only from biofilms formed at 20 degrees C. Under the conditions tested, the attachment of C. jejuni 1221gfp on stainless steel and biofilms was affected by a combination of temperature and nutrient availability, but C. jejuni culturability was affected solely by temperature.