Campylobacter spp. in Eggs and Laying Hens in the North-East of Tunisia: High Prevalence and Multidrug-Resistance Phenotypes

Despite the importance of eggs in the human diet, and unlike other products, for which food safety risks are widely investigated, information on the occurrence of Campylobacter and antimicrobial resistance in eggs and layer hen flocks is lacking in Tunisia. This study was conducted to determine the occurrence of Campylobacter and the antimicrobial resistance in layer hens and on eggshells. Thus, 366 cloacal swabs and 86 eggshell smear samples were collected from five layer hen farms in the North-East of Tunisia. The occurrence of Campylobacter infection, and the antimicrobial resistance rates and patterns, were analyzed. The occurrence rates of Campylobacter infection in laying hens and eggshells were 42.3% and 25.6%, respectively, with a predominance of C. jejuni (68.4%, 81.9%), followed by C. coli (31.6%, 18.2%). The antimicrobial susceptibility testing revealed high resistance rates against macrolides, tetracycline, quinolones, β-lactams, and chloramphenicol, with percentages ranging from 35.5% to 100%. All isolates were multidrug resistant (MDR) and five resistance patterns were observed. These results emphasized the risk to consumer health and the need to establish a surveillance strategy to control and prevent the emergence and the spread of resistant strains of Campylobacter in poultry and humans.