Population Dynamics of Thermotolerant Campylobacter in Broilers Reared on Reused Litter

A study using sentinel broiler chickens was performed to address Campylobacter persistence in litter that was reused for successive flocks. Cloacal swabs, litter, drag swabs, darkling beetles, feed, and drinking water were weekly sampled and analyzed by standard microbiological procedures. Thermotolerant Campylobacter isolated strains were confirmed by polymerase chain reaction and subtyped by pulsed-field gel electrophoresis analysis. Campylobacter was not detected in samples collected immediately after downtime between broiler flocks. However, Campylobacter-positive samples were first detected at 21 d. After Campylobacter was initially isolated from the cloacal swabs, reused litter, drag swabs, or darkling beetles, these samples remained Campylobacter positive in the following weeks until the end of the rearing period. Campylobacter-positive cloacal swabs obtained from sentinel broilers ranged from 97.3% to 100% at 42 d. All isolated strains were identified as Campylobacter jejuni. Among the subtypes identified, an indistinguishable C. jejuni strain was predominant in sentinel broilers and was also detected in the other environmental samples analyzed, suggesting a common and persistent contamination source within the flocks. Sentinel broilers may have contributed to amplify the Campylobacter level, maintaining flock and broiler house contamination until the end of the production cycle.