scholarly journals Staphylococcus epidermidis, Clonality and Accessory Gene Regulator Diversity in Clinical Isolates

2018 ◽  
Vol 13 (4) ◽  
Author(s):  
Shahin Najar-Peerayeh ◽  
Mehrdad Behmanesh ◽  
Ali Jazayeri Moghadas
Keyword(s):  
Staphylococcus Epidermidis ◽  
Clinical Isolates ◽  
Accessory Gene ◽  
Accessory Gene Regulator

scholarly journals Construction and Characterization of anagr Deletion Mutant of Staphylococcus epidermidis

2000 ◽  
Vol 68 (3) ◽  
pp. 1048-1053 ◽  
Author(s):  
Cuong Vuong ◽  
Friedrich Götz ◽  
Michael Otto
Keyword(s):  
Staphylococcus Epidermidis ◽  
Deletion Mutant ◽  
Protein Pattern ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Surface Proteins ◽  
Accessory Gene ◽  
Accessory Gene Regulator ◽  
Sds Page ◽  
The Difference

ABSTRACT The physiological significance of the accessory gene regulator (agr) system of Staphylococcus epidermidis was investigated by construction of an agr deletion mutant via allelic replacement with a spectinomycin resistance cassette. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the protein pattern was strongly altered in the mutant; the amounts of most surface proteins were higher, whereas the amounts of most exoproteins were lower. The agrsystem of S. epidermidis thus appears to have an important impact on growth phase-dependent protein synthesis as has been shown for Staphylococcus aureus. The activity of the exoenzymes lipase and protease, assumed to be involved in staphylococcal pathogenicity, was investigated by agar diffusion assays and SDS-PAGE activity staining. A general reduction of these enzyme activities in the agr mutant was found. The difference in overall lipase activity was small, but zymographic analysis suggested a clear defect in lipase processing in the agr mutant.

scholarly journals Staphylococcus aureusClinical Isolates: Antibiotic Susceptibility, Molecular Characteristics, and Ability to Form Biofilm

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
N. Indrawattana ◽  
O. Sungkhachat ◽  
N. Sookrung ◽  
M. Chongsa-nguan ◽  
A. Tungtrongchitr ◽  
...  
Keyword(s):  
Early Recognition ◽  
Clinical Isolates ◽  
Resistant Bacteria ◽  
Molecular Characteristics ◽  
Toxin Gene ◽  
Accessory Gene ◽  
Toxin Genes ◽  
Accessory Gene Regulator ◽  
Periodic Monitoring ◽  
Group 2

Periodic monitoring ofStaphylococcus aureuscharacteristics in a locality is imperative as their drug-resistant variants cause treatment problem. In this study, antibiograms, prevalence of toxin genes (sea-see, seg-ser, seu, tsst-1, eta, etb, andetd), PFGE types, accessory gene regulator (agr) groups, and ability to form biofilm of 92S. aureusThailand clinical isolates were investigated. They were classified into 10 drug groups: groups 1–7 (56 isolates) were methicillin resistant (MRSA) and 8–10 (36 isolates) were methicillin sensitive (MSSA). One isolate did not have any toxin gene, 4 isolates carried one toxin gene (seq), and 87 isolates had two or more toxin genes. No isolate hadsee, etb, ortsst-1; six isolates hadetaoretd. Combinedseg-sei-sem-sen-seoof the highly prevalentegclocus was 26.1%. Theseb, sec, sel, seu, andetaassociated significantly with MSSA;sekwas more in MRSA. Thesek-seqassociation was 52.17% while combinedsed-sejwas not found. Twenty-three PFGE types were revealed, no association of toxin genes with PFGE types. All fouragrgroups were present;agrgroup 1 was predominant (58.70%) butagrgroup 2 strains carried more toxin genes and were more frequent toxin producers. Biofilm formation was found in 72.83% of the isolates but there was no association with antibiograms. This study provides insight information on molecular and phenotypic markers of ThailandS. aureusclinical isolates which should be useful for future active surveillance that aimed to control a spread of existing antimicrobial resistant bacteria and early recognition of a newly emerged variant.

scholarly journals Mutation of traP in Staphylococcus aureus Has No Impact on Expression of agr or Biofilm Formation

2007 ◽  
Vol 75 (9) ◽  
pp. 4528-4533 ◽  
Author(s):  
Laura H. Tsang ◽  
Sonja T. Daily ◽  
Elizabeth C. Weiss ◽  
Mark S. Smeltzer
Keyword(s):  
Staphylococcus Aureus ◽  
Hemolytic Activity ◽  
Biofilm Formation ◽  
Laboratory Strain ◽  
Clinical Isolates ◽  
Regulatory Role ◽  
Accessory Gene ◽  
Accessory Gene Regulator ◽  
Affect Expression

ABSTRACT To investigate the regulatory role of traP (target of RNAIII-activating peptide) in Staphylococcus aureus, we generated traP mutations in the clinical isolates UAMS-1 and USA300. In neither case did mutation of traP affect expression of the accessory gene regulator (agr) or the ability to form a biofilm. We were also unable to confirm that mutation of traP in the prototype 8325-4 laboratory strain RN6390 results in reduced expression of agr, reduced hemolytic activity, or an altered capacity to form a biofilm.

scholarly journals Strain-Dependent Differences in the Regulatory Roles of sarA and agr in Staphylococcus aureus

2002 ◽  
Vol 70 (2) ◽  
pp. 470-480 ◽  
Author(s):  
Jon S. Blevins ◽  
Karen E. Beenken ◽  
Mohamed O. Elasri ◽  
Barry K. Hurlburt ◽  
Mark S. Smeltzer
Keyword(s):  
Staphylococcus Aureus ◽  
Opposite Effect ◽  
Laboratory Strain ◽  
Regulatory Elements ◽  
Growth Conditions ◽  
Lipase Production ◽  
Clinical Isolates ◽  
Slight Reduction ◽  
Accessory Gene ◽  
Accessory Gene Regulator

ABSTRACT The accessory gene regulator (agr) and the staphylococcal accessory regulator (sar) are central regulatory elements that control the production of Staphylococcus aureus virulence factors. To date, the functions of these loci have been defined almost exclusively using RN6390, which is representative of the laboratory strain 8325-4. However, RN6390 was recently shown to have a mutation in rsbU that results in a phenotype resembling that of a sigB mutant (I. Kullik et al., J. Bacteriol. 180:4814–4820, 1998). For that reason, it remains unclear whether the regulatory events defined in RN6390 are representative of the events that take place in clinical isolates of S. aureus. To address this issue, we generated mutations in the sarA and agr loci of three laboratory strains (RN6390, Newman, and S6C) and four clinical isolates (UAMS-1, UAMS-601, DB, and SC-1). Mutation of sarA in the cna-positive strains UAMS-1 and UAMS-601 resulted in an increased capacity to bind collagen, while mutation of agr had little impact. Northern blot analysis confirmed that the increase in collagen binding was due to increased cna transcription. Without exception, mutation of sarA resulted in increased production of proteases and a decreased capacity to bind fibronectin. Mutation of agr had the opposite effect. Although mutation of sarA resulted in a slight reduction in fnbA transcription, changes in the ability to bind fibronectin appeared to be more directly correlated with changes in protease activity. Lipase production was reduced in both sarA and agr mutants. While mutation of sarA in RN6390 resulted in reduced hemolytic activity, it had the opposite effect in all other strains. There appeared to be reduced levels of the sarC transcript in RN6390, but there was no difference in the overall pattern of sar transcription or the production of SarA. Although mutation of sarA resulted in decreased RNAIII transcription, this effect was not evident under all growth conditions. Taken together, these results suggest that studies defining the regulatory roles of sarA and agr by using RN6390 are not always representative of the events that occur in clinical isolates of S. aureus.

A novel role for SarX in Staphylococcus epidermidis biofilm regulation

Microbiology ◽  
2011 ◽  
Vol 157 (4) ◽  
pp. 1042-1049 ◽  
Author(s):  
Sarah E. Rowe ◽  
Vivienne Mahon ◽  
Stephen G. Smith ◽  
James P. O'Gara
Keyword(s):  
Staphylococcus Epidermidis ◽  
Immunoblot Analysis ◽  
Extracellular Proteins ◽  
Pcr Analysis ◽  
Wild Type ◽  
Rt Pcr ◽  
Accessory Gene ◽  
Accessory Gene Regulator ◽  
Specific Effects ◽  
Biofilm Production

Biofilm production by staphylococci is an important virulence determinant mediated by the icaADBC-encoded polysaccharide intercellular adhesin (PIA) or by surface and extracellular proteins. Deletion of the Staphylococcus accessory regulator sarX significantly reduced biofilm-forming capacity in Staphylococcus epidermidis CSF41498, whereas multicopy sarX complemented the sarX mutant and increased wild-type biofilm production. In Staphylococcus aureus, SarX negatively regulates the accessory gene regulator (Agr) system, which in turn has strain-specific effects on biofilm regulation. Here we found that purified S. epidermidis SarX protein bound specifically to the agr P3 promoter. However RT-PCR analysis revealed that both mutation of sarX and multicopy sarX activated RNAIII transcription, making it difficult to correlate sarX-mediated biofilm regulation with altered agr activity. In contrast, RT-PCR and immunoblot analysis revealed that icaA transcription and PIA expression were decreased in the sarX mutant, whereas multicopy sarX increased ica and PIA expression. Furthermore, multicopy sarX did not promote biofilms in an icaC mutant. Finally, purified SarX protein bound specifically to the ica operon promoter. Taken together, these data reveal that the S. epidermidis SarX protein regulates the transcriptional activity of the agr and ica loci and controls the biofilm phenotype, primarily by regulating icaADBC transcription and PIA production.

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