scholarly journals Author Correction: Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ichiro Imanishi ◽  
Aurélie Nicolas ◽  
Ana-Carolina Barbosa Caetano ◽  
Thiago Luiz de Paula Castro ◽  
Natayme Rocha Tartaglia ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Specific Activity ◽  
Exfoliative Toxin

scholarly journals Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ichiro Imanishi ◽  
Aurélie Nicolas ◽  
Ana-Carolina Barbosa Caetano ◽  
Thiago Luiz de Paula Castro ◽  
Natayme Rocha Tartaglia ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Serine Proteases ◽  
Specific Activity ◽  
Bacterial Colonization ◽  
Exfoliative Toxin ◽  
New Type ◽  
Genetic Level ◽  
Staphylococcal Skin Infections ◽  
Species Specific

Abstract Exfoliative toxins (ETs) are secreted virulence factors produced by staphylococci. These serine proteases specifically cleave desmoglein 1 (Dsg1) in mammals and are key elements in staphylococcal skin infections. We recently identified a new et gene in S. aureus O46, a strain isolated from ovine mastitis. In the present study, we characterized the new et gene at a genetic level and the enzymatic activity of the deduced protein. The S. aureus O46 genome was re-assembled, annotated and compared with other publicly available S. aureus genomes. The deduced amino acid sequence of the new et gene shared 40%, 53% and 59% sequence identity to those of ETA, ETB and ETD, respectively. The new et gene shared the same genetic vicinity and was similar in other S. aureus strains bearing this gene. The recombinant enzyme of the new et gene caused skin exfoliation in vivo in neonatal mice. The new et-gene was thus named ete, encoding a new type (type E) of exfoliative toxin. We showed that ETE degraded the extracellular segments of Dsg1 in murine, ovine and caprine epidermis, as well as in ovine teat canal epithelia, but not that in bovine epidermis. We further showed that it directly hydrolyzed human and swine Dsg1 as well as murine Dsg1α and Dsg1β, but not canine Dsg1 or murine Dsg1γ. Molecular modeling revealed a correlation between the preferred orientation of ETE docking on its Dsg1 cleavage site and species-specific cleavage activity, suggesting that the docking step preceding cleavage accounts for the ETE species-specificity. This new virulence factor may contribute to the bacterial colonization on the stratified epithelia in certain ruminants with mastitis.

scholarly journals Virulence factor landscape of a Staphylococcus aureus sequence type 45 strain, MCRF184

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Vijay Aswani ◽  
Fares Najar ◽  
Madhulatha Pantrangi ◽  
Bob Mau ◽  
William R. Schwan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Sequence Type

sae is essential for expression of the staphylococcal adhesins Eap and Emp

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1789-1800 ◽  
Author(s):  
Niamh Harraghy ◽  
Jan Kormanec ◽  
Christiane Wolz ◽  
Dagmar Homerova ◽  
Christiane Goerke ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Extracellular Matrix ◽  
Virulence Factor ◽  
Eukaryotic Cells ◽  
Transcription Start Point ◽  
Chronic Infections ◽  
Transcription Start ◽  
Regulatory Mutants ◽  
Global Regulators ◽  
Glucose Analysis

Eap and Emp are two Staphylococcus aureus adhesins initially described as extracellular matrix binding proteins. Eap has since emerged as being important in adherence to and invasion of eukaryotic cells, as well as being described as an immunomodulator and virulence factor in chronic infections. This paper describes the mapping of the transcription start point of the eap and emp promoters. Moreover, using reporter-gene assays and real-time PCR in defined regulatory mutants, environmental conditions and global regulators affecting expression of eap and emp were investigated. Marked differences were found in expression of eap and emp between strain Newman and the 8325 derivatives SH1000 and 8325-4. Moreover, both genes were repressed in the presence of glucose. Analysis of expression of both genes in various regulatory mutants revealed that sarA and agr were involved in their regulation, but the data suggested that there were additional regulators of both genes. In a sae mutant, expression of both genes was severely repressed. sae expression was also reduced in the presence of glucose, suggesting that repression of eap and emp in glucose-containing medium may, in part, be a consequence of a decrease in expression of sae.

scholarly journals Total Synthesis of Xanthoangelol B and Its Various Fragments: Toward Inhibition of Virulence Factor Production of Staphylococcus aureus

2018 ◽  
Vol 61 (23) ◽  
pp. 10473-10487 ◽  
Author(s):  
Pushpak Mizar ◽  
Rekha Arya ◽  
Truc Kim ◽  
Soyoung Cha ◽  
Kyoung-Seok Ryu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Total Synthesis ◽  
Virulence Factor ◽  
Factor Production ◽  
Virulence Factor Production

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 RbsR Activates Capsule but Represses therbsUDKOperon in Staphylococcus aureus

2015 ◽  
Vol 197 (23) ◽  
pp. 3666-3675 ◽  
Author(s):  
Mei G. Lei ◽  
Chia Y. Lee
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Transcriptional Activation ◽  
Promoter Region ◽  
Mobility Shift ◽  
Content Type ◽  
Virulence Regulation ◽  
Important Virulence Factor ◽  
Dna Fragment ◽  
Mobility Shift Assay

ABSTRACTStaphylococcus aureuscapsule is an important virulence factor that is regulated by a large number of regulators. Capsule genes are expressed from a major promoter upstream of thecapoperon. A 10-bp inverted repeat (IR) located 13 bp upstream of the −35 region of the promoter was previously shown to affect capsule gene transcription. However, little is known about transcriptional activation of thecappromoter. To search for potential proteins which directly interact with thecappromoter region (Pcap), we directly analyzed the proteins interacting with the PcapDNA fragment from shifted gel bands identified by electrophoretic mobility shift assay. One of these regulators, RbsR, was further characterized and found to positively regulatecapgene expression by specifically binding to thecappromoter region. Footprinting analyses showed that RbsR protected a DNA region encompassing the 10-bp IR. Our results further showed thatrbsRwas directly controlled by SigB and that RbsR was a repressor of therbsUDKoperon, involved in ribose uptake and phosphorylation. The repression ofrbsUDKby RbsR could be derepressed byd-ribose. However,d-ribose did not affect RbsR activation of capsule.IMPORTANCEStaphylococcus aureusis an important human pathogen which produces a large number of virulence factors. We have been using capsule as a model virulence factor to study virulence regulation. Although many capsule regulators have been identified, the mechanism of regulation of most of these regulators is unknown. We show here that RbsR activates capsule by direct promoter binding and that SigB is required for the expression ofrbsR. These results define a new pathway wherein SigB activates capsule through RbsR. Our results further demonstrate that RbsR inhibits therbsoperon involved in ribose utilization, thereby providing an example of coregulation of metabolism and virulence inS. aureus. Thus, this study further advances our understanding of staphylococcal virulence regulation.

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