Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant

Staphylococcal food poisoning (SFP) is a common cause of foodborne illness worldwide, and enterotoxin D (SED) is one of the most frequent Staphylococcus aureus enterotoxins associated with it. It has been reported that the expression and formation of SED in S. aureus is regulated by the quorum sensi...

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Main Authors: Yusak Budi Susilo, Henna-Maria Sihto, Peter Rådström, Roger Stephan, Sophia Johler, Jenny Schelin
Format: Article
Language:English
Published: MDPI AG 2017-08-01
Series:Toxins
Subjects:
Online Access:https://www.mdpi.com/2072-6651/9/9/263
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author Yusak Budi Susilo
Henna-Maria Sihto
Peter Rådström
Roger Stephan
Sophia Johler
Jenny Schelin
author_facet Yusak Budi Susilo
Henna-Maria Sihto
Peter Rådström
Roger Stephan
Sophia Johler
Jenny Schelin
author_sort Yusak Budi Susilo
collection DOAJ
description Staphylococcal food poisoning (SFP) is a common cause of foodborne illness worldwide, and enterotoxin D (SED) is one of the most frequent Staphylococcus aureus enterotoxins associated with it. It has been reported that the expression and formation of SED in S. aureus is regulated by the quorum sensing Agr system. In this study, the effect of agr deletion on sed expression in S. aureus grown on boiled ham was investigated. Growth, sed mRNA and SED protein levels in an S. aureus wild type strain and its isogenic Δagr mutant were monitored for 14 days at 22 °C. The results showed that although deletion of the agr gene did not affect the growth rate or maximum cell density of S. aureus on boiled ham, it had a pronounced effect on SED formation during the first 5 days of incubation. The SED concentration was not reflected in the amount of preceding sed transcripts, suggesting that sed transcription levels may not always reflect SED formation. The expression of RNAIII transcript, the regulatory signal of the Agr system, was also monitored. Similar transcription patterns were observed for RNAIII and sed. Surprisingly, in the Δagr mutant, sed expression was comparable to that in the wild type strain, and was thus unaffected by deletion of the Agr system. These results demonstrate that the Agr system appears to only partially affect SED formation, even in a real food environment.
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spelling doaj.art-a328699b5cca4fc39c5e9d8658a257c42022-12-22T04:23:08ZengMDPI AGToxins2072-66512017-08-019926310.3390/toxins9090263toxins9090263Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr MutantYusak Budi Susilo0Henna-Maria Sihto1Peter Rådström2Roger Stephan3Sophia Johler4Jenny Schelin5Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, SwedenInstitute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, SwitzerlandApplied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, SwedenInstitute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, SwitzerlandInstitute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, SwitzerlandApplied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, SwedenStaphylococcal food poisoning (SFP) is a common cause of foodborne illness worldwide, and enterotoxin D (SED) is one of the most frequent Staphylococcus aureus enterotoxins associated with it. It has been reported that the expression and formation of SED in S. aureus is regulated by the quorum sensing Agr system. In this study, the effect of agr deletion on sed expression in S. aureus grown on boiled ham was investigated. Growth, sed mRNA and SED protein levels in an S. aureus wild type strain and its isogenic Δagr mutant were monitored for 14 days at 22 °C. The results showed that although deletion of the agr gene did not affect the growth rate or maximum cell density of S. aureus on boiled ham, it had a pronounced effect on SED formation during the first 5 days of incubation. The SED concentration was not reflected in the amount of preceding sed transcripts, suggesting that sed transcription levels may not always reflect SED formation. The expression of RNAIII transcript, the regulatory signal of the Agr system, was also monitored. Similar transcription patterns were observed for RNAIII and sed. Surprisingly, in the Δagr mutant, sed expression was comparable to that in the wild type strain, and was thus unaffected by deletion of the Agr system. These results demonstrate that the Agr system appears to only partially affect SED formation, even in a real food environment.https://www.mdpi.com/2072-6651/9/9/263Staphylococcus aureusstaphylococcal food poisoningSED formationAgr quorum sensing systemRNAIIIboiled ham
spellingShingle Yusak Budi Susilo
Henna-Maria Sihto
Peter Rådström
Roger Stephan
Sophia Johler
Jenny Schelin
Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant
Toxins
Staphylococcus aureus
staphylococcal food poisoning
SED formation
Agr quorum sensing system
RNAIII
boiled ham
title Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant
title_full Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant
title_fullStr Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant
title_full_unstemmed Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant
title_short Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus aureus Δagr Mutant
title_sort reduced enterotoxin d formation on boiled ham in staphylococcus aureus δagr mutant
topic Staphylococcus aureus
staphylococcal food poisoning
SED formation
Agr quorum sensing system
RNAIII
boiled ham
url https://www.mdpi.com/2072-6651/9/9/263
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AT rogerstephan reducedenterotoxindformationonboiledhaminstaphylococcusaureusdagrmutant
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