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

ABSTRACT Salmonella is a foodborne pathogen that poses a significant threat to global public health. It affects several animal species, including horses. Salmonella infections in horses can be either asymptomatic or cause severe clinical illness. Infections caused by Salmonella are presently control...

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Asıl Yazarlar: Ajran Kabir, William G. Kelley, Cheyenne Glover, Erdal Erol, Yosra A. Helmy
Materyal Türü: Makale
Dil:English
Baskı/Yayın Bilgisi: American Society for Microbiology 2025-03-01
Seri Bilgileri:Microbiology Spectrum
Konular:
Online Erişim:https://journals.asm.org/doi/10.1128/spectrum.02501-24
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author Ajran Kabir
William G. Kelley
Cheyenne Glover
Erdal Erol
Yosra A. Helmy
author_facet Ajran Kabir
William G. Kelley
Cheyenne Glover
Erdal Erol
Yosra A. Helmy
author_sort Ajran Kabir
collection DOAJ
description ABSTRACT Salmonella is a foodborne pathogen that poses a significant threat to global public health. It affects several animal species, including horses. Salmonella infections in horses can be either asymptomatic or cause severe clinical illness. Infections caused by Salmonella are presently controlled with antibiotics. Due to the formation of biofilms and the emergence of antimicrobial resistance, the treatment has become more complicated. Our study focused on investigating the prevalence of Salmonella enterica in necropsied horses, assessing the capability for biofilm formation, and motility, determining the phenotypic and genotypic profiles of antibiotic resistance, and detecting virulence genes. A total of 2,182 necropsied horses were tested for the presence of Salmonella. Intestinal samples were enriched in selenite broth and cultured on hektoen and eosin methylene blue agar plates, whereas other samples were directly cultured on aforementioned plates. Confirmation of the serotypes was performed according to the Kauffmann–White–Le Minor Scheme followed by biofilm formation screening using crystal violet assay. The resistance profile of the isolates was determined by broth microdilution assay using the Sensititre️ Vet (Equine EQUIN2F). The genotypic antimicrobial resistance (AMR) and virulence profiles were detected using polymerase chain reaction (PCR). The overall prevalence of Salmonella was 1.19% (26/2182), with 11 different serotypes identified. Salmonella Typhimurium was the most prevalent serotype with 19.2% prevalence. All of the isolates were identified as biofilm producers and motile. Virulence genes related to invasion (invA, hilA, mgtC, and spiA), biofilm formation (csgA and csgB), and motility (filA, motA, flgG, figG, flgH, fimC, fimD, and fimH) of Salmonella were detected among 100% of the isolates. An overall 11.4% of the isolates were identified as multidrug-resistant (MDR), with resistance to gentamicin, amikacin, ampicillin, ceftazidime, ceftiofur, chloramphenicol, and trimethoprim/sulfamethoxazole. We found that beta-lactamase-producing genes blaTEM, blaCTXM, and blaSHV2 were identified in 11.5% of the isolates, while only 3.8% carried the blaOXA-9 gene. The presence of MDR pathogenic Salmonella in horses is alarming for human and animal health, especially when they have a high affinity for forming biofilm. Our study found horses as potential sources of pathogenic Salmonella transmission to humans. Thus, it is important to perform continuous monitoring and surveillance studies to track the source of infection and develop preventive measures.IMPORTANCEThis study focuses on understanding how Salmonella, specifically isolated from horses, can resist antibiotics and cause disease. Salmonella is a well-known foodborne pathogen that can pose risks not only to animals but also to humans. By studying the bacteria from necropsied horses, the research aims to uncover how certain Salmonella strains develop resistance to antibiotics and which genetic factors make them more dangerous. In addition to antibiotic resistance, the research explores the biofilm-forming ability of these strains, which enhances their survival in harsh environments. The study also investigates their motility, a factor that contributes to the spread of infection. The findings can improve treatment strategies for horses and help prevent the transmission of resistant bacteria to other animals as well as humans. Ultimately, the research could contribute to better management of antibiotic resistance in both veterinary and public health contexts, helping to safeguard animal welfare and public health.
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spelling doaj.art-bacd3a68d7ef4d2d917eadc74b9c0cee2025-03-04T14:02:03ZengAmerican Society for MicrobiologyMicrobiology Spectrum2165-04972025-03-0113310.1128/spectrum.02501-24Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in KentuckyAjran Kabir0William G. Kelley1Cheyenne Glover2Erdal Erol3Yosra A. Helmy4Department of Veterinary Science, Martin-Gatton College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, USADepartment of Veterinary Science, Martin-Gatton College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, USADepartment of Veterinary Science, Martin-Gatton College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, USAVeterinary Diagnostic Laboratory, Martin-Gatton College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, USADepartment of Veterinary Science, Martin-Gatton College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, USAABSTRACT Salmonella is a foodborne pathogen that poses a significant threat to global public health. It affects several animal species, including horses. Salmonella infections in horses can be either asymptomatic or cause severe clinical illness. Infections caused by Salmonella are presently controlled with antibiotics. Due to the formation of biofilms and the emergence of antimicrobial resistance, the treatment has become more complicated. Our study focused on investigating the prevalence of Salmonella enterica in necropsied horses, assessing the capability for biofilm formation, and motility, determining the phenotypic and genotypic profiles of antibiotic resistance, and detecting virulence genes. A total of 2,182 necropsied horses were tested for the presence of Salmonella. Intestinal samples were enriched in selenite broth and cultured on hektoen and eosin methylene blue agar plates, whereas other samples were directly cultured on aforementioned plates. Confirmation of the serotypes was performed according to the Kauffmann–White–Le Minor Scheme followed by biofilm formation screening using crystal violet assay. The resistance profile of the isolates was determined by broth microdilution assay using the Sensititre️ Vet (Equine EQUIN2F). The genotypic antimicrobial resistance (AMR) and virulence profiles were detected using polymerase chain reaction (PCR). The overall prevalence of Salmonella was 1.19% (26/2182), with 11 different serotypes identified. Salmonella Typhimurium was the most prevalent serotype with 19.2% prevalence. All of the isolates were identified as biofilm producers and motile. Virulence genes related to invasion (invA, hilA, mgtC, and spiA), biofilm formation (csgA and csgB), and motility (filA, motA, flgG, figG, flgH, fimC, fimD, and fimH) of Salmonella were detected among 100% of the isolates. An overall 11.4% of the isolates were identified as multidrug-resistant (MDR), with resistance to gentamicin, amikacin, ampicillin, ceftazidime, ceftiofur, chloramphenicol, and trimethoprim/sulfamethoxazole. We found that beta-lactamase-producing genes blaTEM, blaCTXM, and blaSHV2 were identified in 11.5% of the isolates, while only 3.8% carried the blaOXA-9 gene. The presence of MDR pathogenic Salmonella in horses is alarming for human and animal health, especially when they have a high affinity for forming biofilm. Our study found horses as potential sources of pathogenic Salmonella transmission to humans. Thus, it is important to perform continuous monitoring and surveillance studies to track the source of infection and develop preventive measures.IMPORTANCEThis study focuses on understanding how Salmonella, specifically isolated from horses, can resist antibiotics and cause disease. Salmonella is a well-known foodborne pathogen that can pose risks not only to animals but also to humans. By studying the bacteria from necropsied horses, the research aims to uncover how certain Salmonella strains develop resistance to antibiotics and which genetic factors make them more dangerous. In addition to antibiotic resistance, the research explores the biofilm-forming ability of these strains, which enhances their survival in harsh environments. The study also investigates their motility, a factor that contributes to the spread of infection. The findings can improve treatment strategies for horses and help prevent the transmission of resistant bacteria to other animals as well as humans. Ultimately, the research could contribute to better management of antibiotic resistance in both veterinary and public health contexts, helping to safeguard animal welfare and public health.https://journals.asm.org/doi/10.1128/spectrum.02501-24Salmonellabiofilmantimicrobial resistanceMDRresistance geneshorses
spellingShingle Ajran Kabir
William G. Kelley
Cheyenne Glover
Erdal Erol
Yosra A. Helmy
Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky
Microbiology Spectrum
Salmonella
biofilm
antimicrobial resistance
MDR
resistance genes
horses
title Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky
title_full Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky
title_fullStr Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky
title_full_unstemmed Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky
title_short Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky
title_sort phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of salmonella enterica serotypes isolated from necropsied horses in kentucky
topic Salmonella
biofilm
antimicrobial resistance
MDR
resistance genes
horses
url https://journals.asm.org/doi/10.1128/spectrum.02501-24
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AT erdalerol phenotypicandgenotypiccharacterizationofantimicrobialresistanceandvirulenceprofilesofsalmonellaentericaserotypesisolatedfromnecropsiedhorsesinkentucky
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