Survival of Campylobacter jejuni in biofilms isolated from the water system of a chicken house

Survival of C. jejuni in biofilms of gram-positive chicken house isolates (P1, Y1, W1) and a Pseudomonas sp. was determined using a cultural method (modified brucella agar) and direct viable count (DVC). The presence of P1, Y1 and Pseudomonas sp. biofilms enhanced attachment (P < 0.01) of C. jejuni (4.74, 4.62 and 4.78 log cell/cm2, respectively) compared to W1 and controls without preexisting biofilm (4.31 and 4.22 log cell/cm2, respectively). 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) survival of C. jejuni during incubation at 12°C and 23°C over a 7-day period.; Survival of C. jejuni in mixed culture biofilms was determined after treatment with chemical sanitizers including chlorine, quaternary ammonia, peracetic acid, and peracetic acid/peroctanoic acid mixture (PAA/POA). Only 20 CFU/cm2 of C. jejuni were recovered from the untreated control without biofilms compared to 2500 to 5000 CFU/cm 2 in samples with biofilms. Biofilm microflora affected ( P < 0.01) the effectiveness of sanitizers against C. jejuni. Chlorine was the most effective sanitizer for inactivation of C. jejuni in the biofilms, as it completely inactivated the pathogen after treatment at 50 ppm for 45 s.; A confocal scanning laser microscope was used to study the thickness and three-dimensional structure of biofilms. Biofilm isolated from chicken house were different in shapes, sizes, and thickness. The percentages of metabolically reduced cells biofilms varied with the strain used. Metabolic activity in biofilms as determined by reduction of cyanoditolyltetrazolium chloride was associated with enhanced survival of C. jejuni in W1 and Pseudomonas sp. biofilm.