Characterizing the role of the enterotoxin gene cluster in Staphylococcus aureus diseases

2015 ◽  
Author(s):  
Christopher Stach
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Enterotoxin Gene

scholarly journals Discovery of genes encoding a Streptolysin S-like toxin biosynthetic cluster in a select highly pathogenic methicillin resistant Staphylococcus aureus JKD6159 strain

2019 ◽  
Author(s):  
Trevor Kane ◽  
Katelyn E. Carothers ◽  
Yunjuan Bao ◽  
Won-Sik Yeo ◽  
Taeok Bae ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Virulence Factor ◽  
Gene Organization ◽  
Biosynthetic Gene ◽  
Bacterial Gene ◽  
Methicillin Resistant ◽  
Streptolysin S

AbstractBackgroundStaphylococcus aureus (S. aureus) is a major human pathogen owing to its arsenal of virulence factors, as well as its acquisition of multi-antibiotic resistance. Here we report the identification of a Streptolysin S (SLS) like biosynthetic gene cluster in a highly virulent community-acquired methicillin resistant S. aureus (MRSA) isolate, JKD6159. Examination of the SLS-like gene cluster in JKD6159 shows significant homology and gene organization to the SLS-associated biosynthetic gene (sag) cluster responsible for the production of the major hemolysin SLS in Group A Streptococcus.ResultsWe took a comprehensive approach to elucidating the putative role of the sag gene cluster in JKD6159 by constructing a mutant in which one of the biosynthesis genes (sagB homologue) was deleted in the parent JKD6159 strain. Assays to evaluate bacterial gene regulation, biofilm formation, antimicrobial activity, as well as complete host cell response profile and comparative in vivo infections in Balb/Cj mice were conducted.ConclusionsAlthough no significant phenotypic changes were observed in our assays, we postulate that the SLS-like toxin produced by this strain of S. aureus may be a highly specialized virulence factor utilized in specific environments for selective advantage; studies to better understand the role of this newly discovered virulence factor in S. aureus warrant further investigation.

scholarly journals Novel Tissue Level Effects of the Staphylococcus aureus Enterotoxin Gene Cluster Are Essential for Infective Endocarditis

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0154762 ◽  
Author(s):  
Christopher S. Stach ◽  
Bao G. Vu ◽  
Joseph A. Merriman ◽  
Alfa Herrera ◽  
Michael P. Cahill ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Infective Endocarditis ◽  
Gene Cluster ◽  
Tissue Level ◽  
Enterotoxin Gene

scholarly journals Associations between enterotoxin gene cluster types egc1, egc2 and egc3, agr types, enterotoxin and enterotoxin-like gene profiles, and molecular typing characteristics of human nasal carriage and animal isolates of Staphylococcus aureus

2009 ◽  
Vol 58 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Mark M. Collery ◽  
Davida S. Smyth ◽  
John J. G. Tumilty ◽  
Jane M. Twohig ◽  
Cyril J. Smyth
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Intergenic Region ◽  
Nasal Carriage ◽  
Pcr Primers ◽  
Type I ◽  
Enterotoxin Gene ◽  
Type Iii ◽  
Pcr Rflp ◽  
Animal Isolates

Twenty genes encoding enterotoxin and enterotoxin-like proteins have been described in Staphylococcus aureus strains. Five of these occur commonly in the enterotoxin gene cluster (egc: selo, selm, sei, seln and seg). In the sei–seln intergenic region, two pseudogenes, ψent1 and ψent2, can be present or an additional gene designated selu or a variant selu v. Whilst frequencies of loci bearing pseudogenes (egc1) or the selu gene (egc2) have been reported, the distinction between selu-bearing and selu v-bearing (egc3) loci has rarely been made. A PCR-RFLP procedure involving cleavage of the sei–seln intergenic region by restriction endonuclease BbvI or TseI was developed that allowed differentiation of selu + and selu v + loci. In addition, PCR primers were designed to yield a 203 bp amplimer for sequencing of a selu or selu v intragenic region, which encompassed ten signature nucleotide differences. A total of 43 egc + human nasal isolates and 53 egc + bovine, ovine, caprine, leporine and gallinaceous isolates were egc typed and agr typed. None of the animal isolates was of agr type III. A total of 12 out of 17 egc3 + human nasal isolates were of agr type III, the other 5 being agr type I. On the basis of representative multilocus sequence typing, agr type III/egc3 + strains belonged to CC30. Human nasal isolates bearing an egc1 locus were distributed evenly across agr types I, II and III. Only two nasal isolates had an egc2 locus. All 14 agr type IV isolates, only 1 of which was of human origin, possessed an egc2 locus. The agr IV nasal isolate was fusidic acid sensitive and was found to be ST123 (CC121). There were strong associations between bovine, leporine and gallinaceous S. aureus clonal types and egc locus types. The PCR-RFLP procedure was used to screen an additional 45 S. aureus isolates from dogs, cats, rats, pigs and horses for egc locus types. Of these, 33 were egc −. Six equine isolates were selu +. One canine and three porcine isolates possessed pseudogenes ψent1 and ψent2. One porcine and one canine isolate each had the selu v gene. Putative relationships between disease-causing propensity and egc type need (re-)evaluation.

scholarly journals High Prevalence of Staphylococcus aureus Enterotoxin Gene Cluster Superantigens in Cystic Fibrosis Clinical Isolates

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1036 ◽  
Author(s):  
Anthony J. Fischer ◽  
Samuel H. Kilgore ◽  
Sachinkumar B. Singh ◽  
Patrick D. Allen ◽  
Alexis R. Hansen ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Phenotypic Diversity ◽  
Selective Advantage ◽  
Clinical Isolates ◽  
Respiratory Pathogen ◽  
Enterotoxin Gene ◽  
Chronic Infections ◽  
Genotypic Analysis

Background: Staphylococcus aureus is a highly prevalent respiratory pathogen in cystic fibrosis (CF). It is unclear how this organism establishes chronic infections in CF airways. We hypothesized that S. aureus isolates from patients with CF would share common virulence properties that enable chronic infection. Methods: 77 S. aureus isolates were obtained from 45 de-identified patients with CF at the University of Iowa. We assessed isolates phenotypically and used genotyping assays to determine the presence or absence of 18 superantigens (SAgs). Results: We observed phenotypic diversity among S. aureus isolates from patients with CF. Genotypic analysis for SAgs revealed 79.8% of CF clinical isolates carried all six members of the enterotoxin gene cluster (EGC). MRSA and MSSA isolates had similar prevalence of SAgs. We additionally observed that EGC SAgs were prevalent in S. aureus isolated from two geographically distinct CF centers. Conclusions: S. aureus SAgs belonging to the EGC are highly prevalent in CF clinical isolates. The greater prevalence in these SAgs in CF airway specimens compared to skin isolates suggests that these toxins confer selective advantage in the CF airway.

scholarly journals Necrotizing Fasciitis Due to a Methicillin-Sensitive Staphylococcus aureus Isolate Harboring an Enterotoxin Gene Cluster

2006 ◽  
Vol 45 (2) ◽  
pp. 668-671 ◽  
Author(s):  
W. R. Morgan ◽  
M. D. Caldwell ◽  
J. M. Brady ◽  
M. E. Stemper ◽  
K. D. Reed ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Necrotizing Fasciitis ◽  
Gene Cluster ◽  
Enterotoxin Gene ◽  
Aureus Isolate

scholarly journals Staphylococcal enterotoxin gene cluster: prediction of enterotoxin (SEG and SEI) production and of the source of food poisoning based on vSaβ typing

2020 ◽  
pp. AEM.02662-20
Author(s):  
L. Schwendimann ◽  
D. Merda ◽  
T. Berger ◽  
S. Denayer ◽  
C. Feraudet Tarisse ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Sandwich Elisa ◽  
Food Poisoning ◽  
Detection Methods ◽  
Whole Genome Sequencing Data ◽  
Whole Genome ◽  
Enterotoxin Gene ◽  
Sequencing Data

Currently only five (SEA-SEE) out of 27 known staphylococcal enterotoxins can be analyzed using commercially available kits.Six genes (seg, sei, sem, sen, seo, and seu), encoding putative and undetectable enterotoxins, are located on the enterotoxin gene cluster (egc) which is part of the Staphylococcus aureus genomic island vSaβ. These enterotoxins have been described as likely being involved in staphylococcal food poisoning outbreaks.The aim of the present study was to determine if whole genome data can be used for the prediction of staphylococcal egc enterotoxin production, particularly enterotoxin G (SEG) and enterotoxin I (SEI). For this purpose whole genome sequences of 75 Staphylococcus aureus (S. aureus) strains from different origins (food poisoning outbreaks, human, and animal) were investigated applying bioinformatics methods (phylogenetic analysis using the core genome and different alignments). SEG and SEI expression was tested in vitro using a sandwich ELISA method.Strains could be allocated to 14 different vSaβ types, each type being associated with a single clonal complex (CC). In addition the vSaβ type and CC were associated with the origin of the strain (human or cattle derived). The amount of SEG and SEI produced also correlated with the vSaβ type and the CC of a strain. The present results show promising indications that the in vitro production of SEG and SEI can be predicted based on the vSaβ type or CC of a strain.IMPORTANCE Beside the infection properties in human and animals, S. aureus can produce different enterotoxins in food. The enterotoxins can cause vomiting and diarrhea, often involving many people. Most of these outbreaks remain undiscovered as detection methods for enterotoxins are only available for a few enterotoxins, but not for the more recently discovered enterotoxin G (SEG) and I (SEI).In this study we show promising results that in vitro production of SEG and SEI can be predicted based on the whole genome sequencing data of a strain. In addition, this data could be used to find the source (human- or cattle-derived) of an outbreak strain, which is the key for a better understanding of the role SEG and SEI play in foodborne outbreaks caused by S. aureus.

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