Resistance, virulence and genetic diversity of Salmonella Typhimurium in South Africa (1999–2021)

Onderstepoort Journal of Veterinary Research

 
 
Field Value
 
Title Resistance, virulence and genetic diversity of Salmonella Typhimurium in South Africa (1999–2021)
 
Creator Moatshe, Nkagiseng Seakamela, Emmanuel Mbatha, Khanyisile R. Bester, Linda A. Ntushelo, Nombasa Matle, Itumeleng
 
Subject — Salmonella/salmonellosis; animal; environment; diarrheic FBD; zoonosis; antibiotic resistance; ERIC PCR
Description Salmonella Typhimurium is a major cause of human and animal salmonellosis, impacting global socioeconomic factors. This study examined antibiotic resistance patterns, virulence genes and plasmids in S. Typhimurium isolates from nine South African provinces (1999–2021). Among 180 randomly selected isolates, 129 were confirmed as S. Typhimurium from animal (n = 94), food (n = 16), environment (n = 7) and feed (n = 12) sources using polymerase chain reaction (PCR). Phenotypic resistance was assessed against 13 antibiotics, revealing high resistance levels: 86.8% to ciprofloxacin, 69.0% to ceftriaxone and 65.1% to piperacillin. Multidrug resistance (up to 11 antibiotics) was observed. Genetic analysis identified resistance genes, including blaPSE (32.6%), blaCMY-2 (21.7%), tetA (24.0%), tetB (22.5%), qnrB (21.7%) and qnrA (20.2%). Class 1 integrons were found in 47.4% of isolates. Virulence genes were prevalent, including sopB (95.3%), sspH1 (82.9%), sifA (82.9%), pefA (79.8%), spvC (79.1%), sspH2 (77.5%), srgA (71.3%) and invA (100%). Plasmid analysis detected 2 kb, 8 kb and 90 kb plasmids, with the 90 kb plasmid being most common (71.3%). Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR identified 44 clusters (A–RR), including 6 major clusters.Contribution: These findings highlight the urgent need for enhanced surveillance and intervention strategies to curb antibiotic resistance and virulence in S. Typhimurium populations in South Africa, stressing the importance of monitoring and control measures to address this public health threat.
 
Publisher AOSIS
 
Contributor Agricultural Research Council: Onderstepoort Veterinary Research University of South Africa
Date 2025-10-06
 
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — —
Format text/html application/epub+zip text/xml application/pdf
Identifier 10.4102/ojvr.v92i1.2217
 
Source Onderstepoort Journal of Veterinary Research; Vol 92, No 1 (2025); 14 pages 2219-0635 0030-2465
 
Language eng
 
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https://ojvr.org/index.php/ojvr/article/view/2217/2742 https://ojvr.org/index.php/ojvr/article/view/2217/2743 https://ojvr.org/index.php/ojvr/article/view/2217/2744 https://ojvr.org/index.php/ojvr/article/view/2217/2745
 
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Rights Copyright (c) 2025 Nkagiseng Moatshe, Emmanuel Seakamela, Khanyisile R. Mbatha, Linda A. Bester, Nombasa Ntushelo, Itumeleng Matle https://creativecommons.org/licenses/by/4.0
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