In this study we evaluated the in vitro variability of flaA in Campylobacter coli strains (Co19 and Co29) isolated from distinct poultry farms. Strains were characterized by flaA PCR-RFLP and subcultured in absence or presence of Salmonella enterica (S. Gallinarum) as a host competitor in poultry. Only transition mutations were detected and no flaA-flaB recombination events were observed. The highest ratio of flaA mutations was detected in the presence of competitor (1x10^-6 and 4.8x10^-6 for Co19 and Co29, respectively). While, transitions in absence of competitor were observed only in the strain Co29 (5.8x10^-7). Data obtained in this investigation represent a preliminary study aimed to evaluate the possible linkage between specific haplotypes and their proneness to acquire point mutations which in turn might help strains to gain a better fitness for survival within and outside hosts.

Key words: Campylobacter coli, Competitive stress,  flaA, Variability