The poultry chain in Sardinia (Italy): monitoring of Salmonella contamination and antibiotic resistance profiles

This study assessed the occurrence of Salmonella along the poultry production chain in Sardinia and characterized the isolates by serotyping and antimicrobial resistance testing, providing preliminary insights into contamination routes and consumer risk. Sampling was carried out in four sessions during 2024 at one farm, one slaughterhouse, and at retail, covering different stages of the production chain: 32 farm environmental samples, 48 slaughterhouse samples, and 92 retail chicken meat samples (skin-on cuts, skinless cuts, and meat preparations) were collected overall. A total of 172 samples were tested, and Salmonella isolates were serotyped and subjected to antimicrobial susceptibility testing. Salmonella was not detected in any of the samples collected at either the farm or the slaughterhouse. The pathogen was detected in retail meat, with 21 positives out of 92 (22.8% prevalence). The highest prevalence was detected in samples of meat cuts with skin (11/40, 27.5%), followed by poultry meat preparations (3/12, 25%) and meat cuts without skin (7/40, 17.5%). Of the 21 isolates, 20 (95%) were identified as Salmonella enterica serovar Infantis, while one isolate belonged to the serovar Thompson. S. Thompson isolate was susceptible to all tested antibiotics, whereas all S. Infantis isolates (100%) showed resistance to agents from at least three classes (quinolones, sulfonamides, and tetracyclines), indicating a high level of multidrug resistance. Moreover, resistance to cefoxitin, colistin, azithromycin, and tigecycline was observed. Our findings highlight the role of the poultry production chain as an important reservoir of multidrug-resistant Salmonella Infantis and underline the need for strict control measures. Particular attention should be given to the retail stage and consumer handling, which remain critical points for the prevention of foodborne pathogen transmission.