Evaluation of resistance and virulence factors in Salmonella enterica subsp. enterica serovar Thompson isolates in the poultry chain.

1.This study investigated antimicrobial resistance and virulence factors in Salmonella enterica subsp. enterica serovar Thompson (SET) isolates from broilers in the Brazilian poultry industry.2. Among 44 isolates, 18.18% showed phenotypic resistance, with tetA, sul1 and sul2 genes frequently detected, while sul3 was absent. Two isolates carried clinically relevant resistance genes: blaCTX-M-1 (ESBL) and OXA-48 (carbapenemase).3. The PFGE analysis revealed five distinct clusters with low genetic diversity, which suggested a clonal dissemination pattern. One strain from cluster E showed the highest pathogenicity in broilers, underscoring the need for continued molecular surveillance in poultry production.