Antimicrobial Resistance, FlaA Sequencing, and Phylogenetic Analysis of Campylobacter Isolates from Broiler Chicken Flocks in Greece.

Human campylobacteriosis caused by thermophilic Campylobacter species is the most commonly reported foodborne zoonosis. Consumption of contaminated poultry meat is regarded as the main source of human infection. This study was undertaken to determine the antimicrobial susceptibility and the molecular epidemiology of 205 Campylobacter isolates derived from Greek flocks slaughtered in three different slaughterhouses over a 14-month period. A total of 98.5% of the isolates were resistant to at least one antimicrobial agent. In terms of multidrug resistance, 11.7% of isolates were resistant to three or more groups of antimicrobials. Extremely high resistance to fluoroquinolones (89%), very high resistance to tetracycline (69%), and low resistance to macrolides (7%) were detected. FlaA sequencing was performed for the subtyping of 64 C. jejuni and 58 C. coli isolates. No prevalence of a specific flaA type was observed, indicating the genetic diversity of the isolates, while some flaA types were found to share similar antimicrobial resistance patterns. Phylogenetic trees were constructed using the neighbor-joining method. Seven clusters of the C. jejuni phylogenetic tree and three clusters of the C. coli tree were considered significant with bootstrap values >75%. Some isolates clustered together were originated from the same or adjacent farms, indicating transmission via personnel or shared equipment. These results are important and help further the understanding of the molecular epidemiology and antimicrobial resistance of Campylobacter spp. derived from poultry in Greece.

Prevalence of and Risk Factors for Campylobacter spp. Colonization of Broiler Chicken Flocks in Greece.

The prevalence and risk factors for Campylobacter spp. colonization of broiler flocks and broiler carcass contamination in Greek slaughterhouses were investigated. Over a 14-month period, a pool of 10 ceca and 5 neck skin samples from chicken carcasses were collected from each of 142 batches of broiler flocks slaughtered in 3 different slaughterhouses. Information on potential risk factors for Campylobacter infection in broilers was collected by an on-farm interview and linked according to the Campylobacter contamination status of broiler flocks and differences in farm characteristics and management practices identified from questionnaires. Campylobacter spp. was isolated from 73.94% and 70.42% of ceca (95% CI 65.92-80.94) and carcasses (95% CI 62.19-77.78), respectively. A significant correlation (p < 0.001) between the presence of Campylobacter spp. in broiler ceca and contamination of carcasses was found, suggesting the spread of the microorganism on the skin of carcasses during the slaughtering procedure. A multiple logistic regression showed the disinfection of the poultry house being conducted by unskilled personnel (odds ratio [OR] » = 3.983) as a significant risk factor (p < 0.05) and the use of straw litter as bedding material (OR » = 0.170) and closure of windows during the intervals of production cycles (OR » = 0.396) as significant protective factors (p < 0.05) for broiler flock contamination. These results are important and help further the understanding of the epidemiology of Campylobacter spp. derived from poultry in Greece.