Microbial Assessment and Antibiotic Susceptibility of Isolated Pathogens in Retail Chicken

Poultry is U.S. consumers' protein of choice with an annual consumption of nearly 45 kg per person. This increasing demand has required poultry producers to minimize pathogen contamination to protect public health. This study assessed <i>Salmonella</i> and <i>Campylobacter</i> incidence and loads in retail chicken from conventional (CON) and raised without antibiotics (RWA) sources, while profiling antibiotic resistance of selected isolates. A total of 170 chicken samples from two brands (A and B), including whole carcass WOG (60), parts (80), and giblets (30) were evaluated. Both pathogens were examined by culture and BAX^® system methods and confirmed isolates were identified. Aerobic bacteria count (AC), Enterobacteriaceae (EB), and lactic acid bacteria (LAB) were also tested using Petrifilms™. Selected isolates of <i>Salmonella</i> (22) and <i>Campylobacter</i> (24) were tested for antibiotic susceptibility using the Sensititre™ system. The overall respective incidence of <i>Salmonella</i> and <i>Campylobacter</i> was 36% and 35% with no difference between CON (33% and 25%) and RWA (23% and 29%), but product types differed (<i>p</i> < 0.05). <i>Salmonella</i> incidence was not different between the brands, but <i>Campylobacter</i> differed. Giblets had a higher incidence of both pathogens at 80% and 70%, respectively. The most and least abundant <i>Salmonella</i> serotypes were Infantis (60%) and Ouakam (2%), while <i>Campylobacter jejuni</i> was the abundant species. All the indicators differed (<i>p</i> < 0.05) between CON and RWA. Many isolated pathogens possessed resistance to at least one antibiotic, <i>Salmonella</i> (91%) and <i>Campylobacter</i> (38%), with multidrug resistance in 45% of CON and 36% of RWA <i>Salmonella</i> isolates. The highest resistance was to tetracycline and nalidixic acid for both pathogens and the lowest was to antibiotics in the macrolides class. These results highlight the need for robust microbial control at all levels, as both production practices showed notable contamination and antibiotic resistance, emphasizing the need for continued surveillance at the retail level and encouraging consumers to properly cook poultry to 165 °F.