Campylobacter spp. at different stages of the poultry slaughtering line in Algeria: Evaluation of direct and indirect modified ISO 10272:2017 detection methods and characterization of the isolates

This study aimed to evaluate the effectiveness of direct and indirect modified ISO 10272-1:2017 methods for detecting Campylobacter spp. in 10 sites of a poultry slaughterhouse and investigate the relationship between poultry intestinal carriage and carcasses, as well as surfaces contamination during different slaughter steps (scalding, defeathering, evisceration, and rinsing). Antibiotic resistance profiles of the isolates were also determined against 12 antibiotics. A total of 165 intestinal (feces and ceca) and non-intestinal (neck skins and surfaces) samples were collected from 10 different sampling sites before, during, and after the slaughtering of six flocks of broiler chickens. After the isolation and phenotypic identification of the isolates, an antibiotic susceptibility study was performed using the agar diffusion method. Thermotolerant bacteria of the genus Campylobacter (TC) were isolated with a prevalence of 47.04% (127/270), and 39.05% (82/210) of the TC isolates were detected in non-intestinal samples. Moreover, 76.19% (80/105) of these microorganisms were detected by a direct isolation method for a sensitivity of 97.56%, while only 1.90% (2/105) of the samples contained TC by an indirect isolation method for a sensitivity of 2.44%. The samples of intestinal origin were positive for TC with a rate of 75.00% (45/60). C. jejuni (76.38%; 97/127) was the most isolated bacterial species. Furthermore, 98.43% (125/127) of the TC isolates were multidrug-resistant and 69.29% (88/127) showed simultaneous resistance to ciprofloxacin and erythromycin. Direct isolation seems to be the best method for the detection of C. spp. A serious public health problem of multidrug-resistant C. spp. isolates with critical resistance profiles can be transmitted to broiler carcasses before, during, and after the evisceration step.