Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky

• DOI: 10.1128/spectrum.02501-24
• Publication Date: 2025-01-23T14:00:36Z
• Authors: Ajran Kabir; William G. Kelley; Cheyenne Glover; Erdal Erol; Yosra A. Helmy
• Keywords: Salmonella enterica; Broth microdilution

ABSTRACT Salmonella is a foodborne pathogen that poses significant threat to global public health. It affects several animal species, including horses. infections in horses can be either asymptomatic or cause severe clinical illness. Infections caused by are presently controlled with antibiotics. Due the formation of biofilms and emergence antimicrobial resistance, treatment has become more complicated. Our study focused on investigating prevalence enterica necropsied horses, assessing capability for biofilm formation, motility, determining phenotypic genotypic profiles antibiotic detecting virulence genes. A total 2,182 were tested presence . Intestinal samples enriched selenite broth cultured hektoen eosin methylene blue agar plates, whereas other directly aforementioned plates. Confirmation serotypes was performed according Kauffmann–White–Le Minor Scheme followed screening using crystal violet assay. The resistance profile isolates determined microdilution assay Sensititre️ Vet (Equine EQUIN2F). (AMR) detected polymerase chain reaction (PCR). overall 1.19% (26/2182), 11 different identified. Typhimurium most prevalent serotype 19.2% prevalence. All identified as producers motile. Virulence genes related invasion ( invA, hilA, mgtC, spiA ), csgA csgB motility filA, motA, flgG, figG, flgH, fimC, fimD, fimH ) among 100% isolates. An 11.4% multidrug-resistant (MDR), gentamicin, amikacin, ampicillin, ceftazidime, ceftiofur, chloramphenicol, trimethoprim/sulfamethoxazole. We found beta-lactamase-producing bla TEM , CTXM SHV2 11.5% isolates, while only 3.8% carried OXA-9 gene. MDR pathogenic alarming human health, especially when they have high affinity forming biofilm. potential sources transmission humans. Thus, it important perform continuous monitoring surveillance studies track source infection develop preventive measures. IMPORTANCE This focuses understanding how specifically isolated from resist antibiotics disease. well-known pose risks not animals but also By studying bacteria research aims uncover certain strains which genetic factors make them dangerous. In addition explores biofilm-forming ability these strains, enhances their survival harsh environments. investigates factor contributes spread infection. findings improve strategies help prevent resistant well Ultimately, could contribute better management both veterinary health contexts, helping safeguard welfare