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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety and Processing Research Unit » Research » Publications at this Location » Publication #424093
Research Project: Alternatives to Antibiotics and Genomics of Antimicrobial Resistance to Control Foodborne Pathogens in Poultry

Location: Poultry Microbiological Safety and Processing Research Unit

Title: Comparative genomic profiles of Salmonella Typhimurium and Salmonella Dublin bovine isolates from the U.S. indicate possible factors associated with host adaptation of Salmonella Dublin in the region

Author
item BENTUM, KINGSLEY - Tuskegee University
item KUUFIRE, EMMANUEL - Tuskegee University
item NYARKU, REJOICE - Tuskegee University
item OSEI, VIONA - Tuskegee University
item ADU-ADDAI, BENJAMIN - Tuskegee University
item Frye, Jonathan
item Jackson, Charlene
item SAMUEL, TEMESGEN - Tuskegee University
item ABEBE, WOUBIT - Tuskegee University

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2025
Publication Date: 4/12/2025
Citation: Bentum, K., Kuufire, E., Nyarku, R., Osei, V., Adu-Addai, B., Frye, J.G., Jackson, C.R., Samuel, T., Abebe, W. 2025. Comparative genomic profiles of Salmonella Typhimurium and Salmonella Dublin bovine isolates from the U.S. indicate possible factors associated with host adaptation of Salmonella Dublin in the region. Microorganisms. 13(4):886. https://doi.org/10.3390/microorganisms13040886.
DOI: https://doi.org/10.3390/microorganisms13040886

Interpretive Summary: There are over 2000 Salmonella serovars that are variable in their ability to cause disease in specific host animals. Discovering the biology behind these differences will help us understand what makes some Salmonella host specific and will enable identification of better methods to block these host specific serovars from infecting cattle. Salmonella Dublin (S. Dublin) and Salmonella Typhimurium (S. Typhimurium) are commonly linked to causing infections in cattle. S. Dublin is however considered a bovine-adapted serovar for primarily infecting and thriving in cattle. S. Typhimurium is a generalist serovar and can infect many hosts. S. Typhimurium was used as a benchmark to compare to S. Dublin to identify unique genetic factors contributing to S. Dublin’s adaptation to cattle hosts in the U.S. A total of 1,337 S. Dublin and 787 S. Typhimurium whole-genome sequences from bovine sources were analyzed for antimicrobial resistance (AMR), stress, and virulence genes, and plasmids. Results revealed minimal genomic variation among S. Dublin isolates, each of which carried an average of four plasmids. S. Dublin isolates carried more AMR genes against key antimicrobials, including aminoglycosides, beta-lactams, tetracyclines, and sulfonamides, commonly used in U.S. cattle production. Additionally, Type VI secretion system virulence genes tssJKLM and hcp2/tssD2, used in colonization, were found exclusively in S. Dublin isolates with over 50% of these isolates also possessing genes conferring resistance to heavy metal stressers, like mercury. These findings suggest that S. Dublin’s adaptation to bovine hosts in the U.S. is supported by a conserved genetic makeup enriched with AMR genes, virulence factors, and stress-related genes, enabling it to colonize and persist in the bovine gut. With this information we can now target the Type VI secretion system with interventions to prevent colonization of cattle.

Technical Abstract: Salmonella Dublin (S. Dublin) and Salmonella Typhimurium (S. Typhimurium) are commonly linked to bovine salmonellosis. S. Dublin is however considered a bovine-adapted serovar for primarily infecting and thriving in cattle. Using S. Typhimurium (a generalist serovar) as a benchmark, this study investigates genomic factors contributing to S. Dublin’s adaptation to cattle hosts in the U.S.A total of 1,337 S. Dublin and 787 S. Typhimurium whole-genome sequences from bovine sources were analyzed for antimicrobial resistance (AMR), stress, and virulence genes, and plasmids. Results revealed minimal genomic variation among S. Dublin isolates, each carrying an average of four plasmids. S. Dublin isolates exhibited a higher prevalence of AMR genes against key antimicrobials, including aminoglycosides, beta-lactams, tetracyclines, and sulfonamides, commonly used in U.S. cattle production. Additionally, Type VI secretion system virulence genes tssJKLM and hcp2/tssD2, essential for colonization, were found exclusively in S. Dublin isolates with over 50% of these isolates also possessing genes conferring resistance to heavy metal stressors, like mercury. These findings suggest that S. Dublin’s adaptation to bovine hosts in the U.S. is supported by a conserved genetic makeup enriched with AMR genes, virulence factors, and stress-related genes, enabling it to colonize and persist in the bovine gut.