nacltolerance of campylobacter isolates from birds and campylobacter type strains and variation of their serological behaviour growth on media containing 15 nacl is one of the criteria for phenotypical differentiation of campylobacter laridis from other thermophilic campylobacter spp campylobacter isolates from birds and campylobacter type strains could be adapted to growth at 3 nacl within 19 to 72 subsequent passages on nutrient agar with increasing salt contents the acquisition of salttolerance was stable after ten passages on media without salt and did not induce changes in other phenotypical characteristics the results of slide agglutination demonstrate changes in the antigenic pattern of the campylobacter strains after growth in salt heatlabile and heatstable antigens of the salttolerant variants of campylobacter type strains differed from those of the parent strains