Salmonella enterica serotype Kentucky (Salmonella Kentucky) is the predominant serotype found in retail chicken products (U.S. Food and Drug Administration, 2022). Despite its high likelihood to be found in chicken, Salmonella Kentucky has caused few human illnesses relative to other Salmonella serotypes. Since the 1980s, a multidrug-resistant (MDR) Salmonella Kentucky strain has been disseminating from Egypt to other countries. This MDR strain is characterized by resistance determinants including a mutation that confers resistance to fluoroquinolones like ciprofloxacin; ciprofloxacin-resistant Salmonella are classified as high priority pathogens on the World Health Organization’s (WHO) list of priority resistant bacteria. CDC monitors U.S. cases of MDR Salmonella Kentucky.

This study aims to characterize Salmonella Kentucky isolates from U.S. surveillance systems to describe antimicrobial resistance determinants found in Salmonella Kentucky between 2009–2022. We also analyze relevant epidemiological data associated with MDR Salmonella Kentucky cases. There were 7,329 isolates including of which 5,209 were chicken, 476 were other food, and 311 were human. Significant findings include that 66% of human isolates were ciprofloxacin resistant. This MDR Salmonella Kentucky strain is a growing public health concern in the United States.