University of Zululand
Prevalence, virulence factors and antimicrobial resistance of salmonella species from beef in retail outlets from KwaZulu-Natal province, South Africa
Abstract
dc:description.abstractNon-typhoid Salmonella enterica subsp. enterica serotypes are one of the leading causes of foodborne infections worldwide. Furthermore, the emergence and spread of antimicrobial-resistant Salmonellastrains is a potential global challenge. This study was aimed at determining the prevalence, serovars, virulence factors and antimicrobial resistance patterns of Salmonella recovered from various beef products. Four hundred beef products (n = 169 organ meats, n = 110 raw processedmeats, n = 53 raw intactmeatsand n = 68 ready-to-eat meats) were collected between October 2019 and December 2020 from 25 retail outlets in selected districts of KwaZulu-Natal(KZN)province, South Africa. The International Organization for Standardization (ISO) 6579-1:2017 method was used for microbiological analysis,and presumptive Salmonellaisolates were confirmed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF)mass spectrometry (MS) and the VITEK system. The Salmonellaisolates were serotyped according to theWhite-Kauffmann-Le Minorscheme. The KirbyBauer disk diffusion method was used to determine antimicrobial resistance profiles of the Salmonellaisolates against Cefotaxime, Kanamycin, Ampicillin, Amoxicillin, Trimethoprim-Sulfamethoxazole, Ciprofloxacin, Chloramphenicol, Gentamicin, Cefoxitinand Tetracycline. Antimicrobial resistance results were interpretedaccording to Clinical and Laboratory Standards Institute (CLSI) guidelines. Polymerase chain reaction (PCR) was performed to screen for the presence of invA, agfA, lpfA, hilA, sivH, sefA, sopE and spvC virulence genes. Salmonellacontamination was observed in 1.25% (5/400) of the beef samples. Four serovars:Enteritidis, Hadar, Heidelberg and Stanley were identified. Almost all Salmonellaisolates were susceptible to all 10 tested antimicrobials except one (S.Enteritidis)isolate that was resistant to tetracyclineandaminopenicillins. All Salmonellaisolates carried at least two virulence factors,with S. Stanley and S. Enteritid is testing positive for sixand four of the eight tested virulence genes, respectively. The findings indicate that Salmonella prevalence in all beef meat categories of selected KZN retail outlets is low, but should be routinely surveyed to manage the risk associated with virulence factors and to avoid outbreaks. Although antimicrobial resistance was low, the presence of resistant S.Enteritid is highlights the need to continually monitor antimicrobial resistance amongst zoonotic pathogens associated with beef in order to contribute to ‘One Health’.
Degree
thesis:*- Grantor dc:publisher.institution
- University of Zululand
- Year dc:date.issued
- 2021
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Naidoo, Serisha