Multidrug-Resistant pESI-Harboring Salmonella enterica Serovar Muenchen Sequence Type 82 in Poultry and Humans, Israel, 2020-2023.

Abstract

Salmonella enterica serovar Muenchen emerged in Israel in 2018 and became a major public health threat. We aimed to determine the role of poultry in rising human cases, transmission routes within the broiler industry, and genetic similarity to Salmonella Muenchen found globally. We used whole-genome sequencing to compare Salmonella Muenchen isolates from poultry, food, and humans collected in Israel (2020-2023; n = 109) and globally (n = 125). Salmonella Muenchen sequence type 82 isolates from Israel harbored pESI plasmid, exhibited high genetic similarity between human and poultry sources, and closely resembled international pESI-positive strains; we found quinolone-resistance determinants in 58.6% of isolates. Salmonella Muenchen prevalence in commercial broiler flocks was 61.5% (95% CI 51.5%-71.5%); strains could not be traced to breeder flocks, but on-farm persistence existed. The clonal spread of Salmonella Muenchen in poultry contributes to increased incidence in humans. Horizontal transmission in broilers requires control measures to protect public health.