scholarly journals Identification, Cloning, and Characterization ofStaphylococcus pseudintermediusCoagulase

2018 ◽  
Vol 86 (8) ◽  
Author(s):  
Alaa H. Sewid ◽  
M. Nabil Hassan ◽  
A. M. Ammar ◽  
David A. Bemis ◽  
Stephen A. Kania
Keyword(s):  
Staphylococcus Aureus ◽  
Recombinant Protein ◽  
Immune Evasion ◽  
Complement C3 ◽  
Fibrin Deposition ◽  
Staphylococcus Pseudintermedius ◽  
Content Type ◽  
Chromogenic Assay ◽  
Prothrombin Activation ◽  
Multifunctional Properties

ABSTRACTCoagulase activation of prothrombin by staphylococcus induces the formation of fibrin deposition that facilitates the establishment of infection byStaphylococcusspecies. Coagulase activity is a key characteristic ofStaphylococcus pseudintermedius; however, no coagulase gene or associated protein has been studied to characterize this activity. We report a recombinant protein sharing 40% similarity toStaphylococcus aureuscoagulase produced from a putativeS. pseudintermediuscoagulase gene. Prothrombin activation by the protein was measured with a chromogenic assay using thrombin tripeptide substrate. Stronger interaction with bovine prothrombin than with human prothrombin was observed. TheS. pseudintermediuscoagulase protein also bound complement C3 and immunoglobulin. Recombinant coagulase facilitated the escape ofS. pseudintermediusfrom phagocytosis, presumably by forming a bridge between opsonizing antibody, complement, and fibrinogen. Evidence from this work suggests thatS. pseudintermediuscoagulase has multifunctional properties that contribute to immune evasion that likely plays an important role in virulence.

scholarly journals Surface Glycopolymers Are Crucial forIn VitroAnti-Wall Teichoic Acid IgG-Mediated Complement Activation and Opsonophagocytosis of Staphylococcus aureus

2015 ◽  
Vol 83 (11) ◽  
pp. 4247-4255 ◽  
Author(s):  
Jong-Ho Lee ◽  
Na-Hyang Kim ◽  
Volker Winstel ◽  
Kenji Kurokawa ◽  
Jesper Larsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Teichoic Acid ◽  
Complement C3 ◽  
Glycerol Phosphate ◽  
Glycosylation Pattern ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Capsule Production ◽  
Cell Envelopes

ABSTRACTThe cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs).Staphylococcus aureusWTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted withd-alanine andN-acetyl-d-glucosamine (GlcNAc) orN-acetyl-d-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis ofS. aureuslaboratory strains. This prompted us to examine whether anti-WTA IgG can induce C3 deposition on a diverse set of clinicalS. aureusisolates. To this end, we compared anti-WTA IgG-mediated C3 deposition and opsonophagocytosis abilities using 13 different staphylococcal strains. Of note, the majority ofS. aureusstrains tested was recognized by anti-WTA IgG, resulting in C3 deposition and opsonophagocytosis. A minority of strains was not recognized by anti-WTA IgG, which correlated with either extensive capsule production or an alteration in the WTA glycosylation pattern. Our results demonstrate that the presence of WTAs with TarS-mediated glycosylation with β-GlcNAc in clinically isolatedS. aureusstrains is an important factor for induction of anti-WTA IgG-mediated C3 deposition and opsonophagocytosis.

scholarly journals The Sbi Protein Is a Multifunctional Immune Evasion Factor of Staphylococcus aureus

2011 ◽  
Vol 79 (9) ◽  
pp. 3801-3809 ◽  
Author(s):  
Emma Jane Smith ◽  
Livia Visai ◽  
Steven W. Kerrigan ◽  
Pietro Speziale ◽  
Timothy J. Foster
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Capsular Polysaccharide ◽  
Cell Envelope ◽  
Protein A ◽  
Biologically Active ◽  
Complement Protein ◽  
Content Type ◽  
Binding Domains ◽  
Terminal Domains

ABSTRACTThe second immunoglobulin-binding protein (Sbi) ofStaphylococcus aureushas two N-terminal domains that bind the Fc region of IgG in a fashion similar to that of protein A and two domains that can bind to the complement protein C3 and promote its futile consumption in the fluid phase. It has been proposed that Sbi helps bacteria to avoid innate immune defenses. By comparing a mutant defective in Sbi with mutants defective in protein A, clumping factor A, iron-regulated surface determinant H, and capsular polysaccharide, it was shown that Sbi is indeed an immune evasion factor that promotes bacterial survival in whole human blood and the avoidance of neutrophil-mediated opsonophagocytosis. Sbi is present in the culture supernatant and is also associated with the cell envelope.S. aureusstrains that expressed truncates of Sbi lacking N-terminal domains D1 and D2 (D1D2) or D3 and D4 (D3D4) or a C-terminal truncate that was no longer retained in the cell envelope were analyzed. Both the secreted and envelope-associated forms of Sbi contributed to immune evasion. The IgG-binding domains contributed only when Sbi was attached to the cell, while only the secreted C3-binding domains were biologically active.

scholarly journals Staphylococcus aureus Protein A Promotes Immune Suppression

mBio ◽  
2013 ◽  
Vol 4 (5) ◽  
Author(s):  
Scott D. Kobayashi ◽  
Frank R. DeLeo
Keyword(s):  
Staphylococcus Aureus ◽  
B Cell ◽  
Immune Evasion ◽  
Bacterial Infections ◽  
Binding Capacity ◽  
Protein A ◽  
Strong Support ◽  
The United States ◽  
Content Type

ABSTRACTStaphylococcus aureusis a prominent cause of human infections worldwide and is notorious for its ability to acquire resistance to antibiotics. Methicillin-resistantS. aureus(MRSA), in particular, is endemic in hospitals and is the most frequent cause of community-associated bacterial infections in the United States. Inasmuch as treatment options for severe MRSA infections are limited, there is need for a vaccine that protects against such infections. However, recent efforts to generate a staphylococcal vaccine have met with little success in human clinical trials. These failures are somewhat puzzling, since the vaccine antigens tested promote opsonophagocytosisin vitroand confer protection in animal infection models. One possibility is that the pathogen inhibits (and/or fails to elicit) the development of protective immunity in humans. Indeed,S. aureusproduces numerous molecules that can potentially promote immune evasion, including protein A (SpA), an immunoglobulin (Ig)-binding protein present on the bacterial surface and freely secreted into the extracellular environment. SpA binds the Fc region of antibody and the Fab regions of the B-cell receptor, processes that are known to block opsonophagocytosis and cause B-cell deathin vitro. In a recent study, Falugi et al. [F. Falugi, H. K. Kim, D. M. Missiakas, and O. Schneewind, mBio 4(5):e00575-13, 2013] showed that vaccination withspamutantS. aureusstrains lacking antibody Fc- and/or Fab-binding capacity protects against subsequent challenge with the USA300 epidemic strain. The findings provide strong support for the idea that SpA promotesS. aureusimmune evasionin vivoand form the foundation for a new approach in our efforts to develop a vaccine that prevents severeS. aureusinfections.

scholarly journals Adaptive Upregulation of Clumping Factor A (ClfA) by Staphylococcus aureus in the Obese, Type 2 Diabetic Host Mediates Increased Virulence

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Christopher W. Farnsworth ◽  
Eric M. Schott ◽  
Sarah E. Jensen ◽  
Jacob Zukoski ◽  
Abigail M. Benvie ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Plasminogen Activator Inhibitor ◽  
Hypercoagulable State ◽  
Diabetic Patients ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Content Type ◽  
Host Immune Responses

ABSTRACT Obesity and associated type 2 diabetes (T2D) are important risk factors for infection following orthopedic implant surgery. Staphylococcus aureus, the most common pathogen in bone infections, adapts to multiple environments to survive and evade host immune responses. Whether adaptation of S. aureus to the unique environment of the obese/T2D host accounts for its increased virulence and persistence in this population is unknown. Thus, we assessed implant-associated osteomyelitis in normal versus high-fat-diet obese/T2D mice and found that S. aureus infection was more severe, including increases in bone abscesses relative to nondiabetic controls. S. aureus isolated from bone of obese/T2D mice displayed marked upregulation of four adhesion genes (clfA, clfB, bbp, and sdrC), all with binding affinity for fibrin(ogen). Immunostaining of infected bone revealed increased fibrin deposition surrounding bacterial abscesses in obese/T2D mice. In vitro coagulation assays demonstrated a hypercoagulable state in obese/T2D mice that was comparable to that of diabetic patients. S. aureus with an inactivating mutation in clumping factor A (clfA) showed a reduction in bone infection severity that eliminated the effect of obesity/T2D, while infections in control mice were unchanged. In infected mice that overexpress plasminogen activator inhibitor-1 (PAI-1), S. aureus clfA expression and fibrin-encapsulated abscess communities in bone were also increased, further linking fibrin deposition to S. aureus expression of clfA and infection severity. Together, these results demonstrate an adaptation by S. aureus to obesity/T2D with increased expression of clfA that is associated with the hypercoagulable state of the host and increased virulence of S. aureus.

scholarly journals Staphylococcus aureus Metalloprotease Aureolysin Cleaves Complement C3 To Mediate Immune Evasion

2011 ◽  
Vol 186 (11) ◽  
pp. 6445-6453 ◽  
Author(s):  
Alexander J. Laarman ◽  
Maartje Ruyken ◽  
Cheryl L. Malone ◽  
Jos A. G. van Strijp ◽  
Alexander R. Horswill ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Complement C3

scholarly journals Characterization of Staphylococcal Cassette Chromosome mec Elements from Methicillin-Resistant Staphylococcus pseudintermedius Infections in Australian Animals

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Kate A. Worthing ◽  
Sybille Schwendener ◽  
Vincent Perreten ◽  
Sugiyono Saputra ◽  
Geoffrey W. Coombs ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genomic Structure ◽  
Cadmium Resistance ◽  
Staphylococcus Pseudintermedius ◽  
Methicillin Resistant ◽  
Content Type ◽  
Resistance Determinants ◽  
Oxacillin Resistance ◽  
Animal Pathogens ◽  
Staphylococcal Cassette Chromosome

ABSTRACT We examined the oxacillin resistance phenotype and genomic structure of staphylococcal cassette chromosome mec (SCCmec) elements from 77 veterinary methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolates. Isolates were characterized by oxacillin broth microdilution, whole-genome sequencing, and bioformatics analysis. Five previously described SCCmec elements, and a sixth novel element, were identified: SCCmec III (also known as II-III), ΨSCCmec57395, and SCCmecNA45 (a SCCmec VII variant), all previously described in MRSP, and SCCmec IVg and SCCmec VT, previously described in both methicillin-resistant Staphylococcus aureus (MRSA) and MRSP. The sixth element was novel and found among nine geographically clustered isolates. This novel pseudostaphylococcal cassette chromosome (ΨSCCmecKW21) contained a class A mec gene complex but lacked ccr genes. It also harbored heavy metal (cadmium) resistance determinants. The median oxacillin MIC values among ΨSCCmecKW21, SCCmec III, and SCCmec VT isolates were significantly higher than those determined for the SCCmecNA45 VII variant isolates and ΨSCCmec57395 and SCCmec IVg isolates. ΨSCCmecKW21 was found exclusively in sequence type 497 (ST497), an MRSP clone that is locally successful in Victoria, Australia. Future studies are necessary to determine if this clone has disseminated further afield and if ΨSCCmecKW21 has moved into other MRSP lineages or staphylococcal species. IMPORTANCE Staphylococcus pseudintermedius is a significant veterinary pathogen and occasional cause of infections in humans. β-Lactams are an important group of antimicrobials used to treat staphylococcal infections in humans and animals. However, when staphylococci become methicillin resistant via the acquisition of a mobile genetic element called staphylococcal cassette chromosome mec (SCCmec), they become resistant to all β-lactams. This study detected a novel SCCmec element among a cluster of methicillin-resistant S. pseudintermedius isolates from animals in Australia. It also detected SCCmec elements in S. pseudintermedius that had high similarity to those identified in methicillin-resistant Staphylococcus aureus, demonstrating how human and animal pathogens can share the same resistance determinants.

scholarly journals The MpsB protein contributes to both the toxicity and immune evasion capacity of Staphylococcus aureus

Microbiology ◽  
2021 ◽  
Vol 167 (10) ◽  
Author(s):  
Edward J. A. Douglas ◽  
Seána Duggan ◽  
Tarcisio Brignoli ◽  
Ruth C. Massey
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Type Species ◽  
Severe Disease ◽  
Toxin Production ◽  
Content Type ◽  
Small Colony Variant ◽  
Link Type ◽  
Small Colony

Understanding the role specific bacterial factors play in the development of severe disease in humans is critical if new approaches to tackle such infections are to be developed. In this study we focus on genes we have found to be associated with patient outcome following bacteraemia caused by the major human pathogen Staphylococcus aureus . By examining the contribution these genes make to the ability of the bacteria to survive exposure to the antibacterial factors found in serum, we identify three novel serum resistance-associated genes, mdeA, mpsB and yycH. Detailed analysis of an MpsB mutant supports its previous association with the slow growing small colony variant (SCV) phenotype of S. aureus , and we demonstrate that the effect this mutation has on membrane potential prevents the activation of the Agr quorum sensing system, and as a consequence the mutant bacteria do not produce cytolytic toxins. Given the importance of both toxin production and immune evasion for the ability of S. aureus to cause disease, we believe that these findings explain the role of the mpsB gene as a mortality-associated locus during human disease.

scholarly journals A functional menadione biosynthesis pathway is required for capsule production by Staphylococcus aureus

Microbiology ◽  
2021 ◽  
Vol 167 (11) ◽  
Author(s):  
Dina Altwiley ◽  
Tarcisio Brignoli ◽  
Andrew Edwards ◽  
Mario Recker ◽  
Jean C. Lee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Type Species ◽  
Genome Wide Association Study ◽  
Clinical Isolates ◽  
Growth Defect ◽  
Content Type ◽  
Link Type ◽  
Capsule Production ◽  
A Genome

Staphylococcus aureus is a major human pathogen that utilises a wide array of pathogenic and immune evasion strategies to cause disease. One immune evasion strategy, common to many bacterial pathogens, is the ability of S. aureus to produce a capsule that protects the bacteria from several aspects of the human immune system. To identify novel regulators of capsule production by S. aureus, we applied a genome wide association study (GWAS) to a collection of 300 bacteraemia isolates that represent the two major MRSA clones in UK and Irish hospitals: CC22 and CC30. One of the loci associated with capsule production, the menD gene, encodes an enzyme critical to the biosynthesis of menadione. Mutations in this gene that result in menadione auxotrophy induce the slow growing small-colony variant (SCV) form of S. aureus often associated with chronic infections due to their increased resistance to antibiotics and ability to survive inside phagocytes. Utilising such an SCV, we functionally verified this association between menD and capsule production. Although the clinical isolates with polymorphisms in the menD gene in our collections had no apparent growth defects, they were more resistant to gentamicin when compared to those with the wild-type menD gene. Our work suggests that menadione is involved in the production of the S. aureus capsule, and that amongst clinical isolates polymorphisms exist in the menD gene that confer the characteristic increased gentamicin resistance, but not the major growth defect associated with SCV phenotype.

scholarly journals Persistent Staphylococcus aureus Isolates from Two Independent Cases of Bacteremia Display Increased Bacterial Fitness and Novel Immune Evasion Phenotypes

2015 ◽  
Vol 83 (8) ◽  
pp. 3311-3324 ◽  
Author(s):  
R. L. Richards ◽  
R. D. Haigh ◽  
B. Pascoe ◽  
S. K. Sheppard ◽  
F. Price ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Stress Responses ◽  
Galleria Mellonella ◽  
Whole Genome Sequence ◽  
Infection Model ◽  
Phenotypic Traits ◽  
Host Immune System ◽  
Content Type ◽  
Bacterial Fitness

Staphylococcus aureusbacteremia cases are complicated by bacterial persistence and treatment failure despite the confirmedin vitrosusceptibility of the infecting strain to administered antibiotics. A high incidence of methicillin-resistantS. aureus(MRSA) bacteremia cases are classified as persistent and are associated with poorer patient outcomes. It is still unclear howS. aureusevades the host immune system and resists antibiotic treatment for the prolonged duration of a persistent infection. In this study, the genetic changes and associated phenotypic traits specific toS. aureuspersistent bacteremia were identified by comparing temporally dispersed isolates from persistent infections (persistent isolates) originating from two independent persistentS. aureusbacteremia cases with the initial infection isolates and with three resolvedS. aureusbacteremia isolates from the same genetic background. Several novel traits were associated specifically with both independent sets of persistentS. aureusisolates compared to both the initial isolates and the isolates from resolved infections (resolved isolates). These traits included (i) increased growth under nutrient-poor conditions; (ii) increased tolerance of iron toxicity; (iii) higher expression of cell surface proteins involved in immune evasion and stress responses; and (iv) attenuated virulence in aGalleria mellonellalarva infection model that was not associated with small-colony variation or metabolic dormancy such as had been seen previously. Whole-genome sequence analysis identified different single nucleotide mutations within themprFgenes of all the isolates with the adaptive persistence traits from both independent cases. Overall, our data indicate a novel role for MprF function during development ofS. aureuspersistence by increasing bacterial fitness and immune evasion.

scholarly journals Pseudomonas aeruginosa PA14 Enhances the Efficacy of Norfloxacin against Staphylococcus aureus Newman Biofilms

2020 ◽  
Vol 202 (18) ◽  
Author(s):  
Giulia Orazi ◽  
Fabrice Jean-Pierre ◽  
George A. O’Toole
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Respiratory Infections ◽  
Multiple Infection ◽  
Bacterial Biofilms ◽  
Interspecies Interactions ◽  
Chronic Infections ◽  
Content Type

ABSTRACT The thick mucus within the airways of individuals with cystic fibrosis (CF) promotes frequent respiratory infections that are often polymicrobial. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent pathogens that cause CF pulmonary infections, and both are among the most common etiologic agents of chronic wound infections. Furthermore, the ability of P. aeruginosa and S. aureus to form biofilms promotes the establishment of chronic infections that are often difficult to eradicate using antimicrobial agents. In this study, we found that multiple LasR-regulated exoproducts of P. aeruginosa, including 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), siderophores, phenazines, and rhamnolipids, likely contribute to the ability of P. aeruginosa PA14 to shift S. aureus Newman norfloxacin susceptibility profiles. Here, we observe that exposure to P. aeruginosa exoproducts leads to an increase in intracellular norfloxacin accumulation by S. aureus. We previously showed that P. aeruginosa supernatant dissipates the S. aureus membrane potential, and furthermore, depletion of the S. aureus proton motive force recapitulates the effect of the P. aeruginosa PA14 supernatant on shifting norfloxacin sensitivity profiles of biofilm-grown S. aureus Newman. From these results, we hypothesize that exposure to P. aeruginosa PA14 exoproducts leads to increased uptake of the drug and/or an impaired ability of S. aureus Newman to efflux norfloxacin. Surprisingly, the effect observed here of P. aeruginosa PA14 exoproducts on S. aureus Newman susceptibility to norfloxacin seemed to be specific to these strains and this antibiotic. Our results illustrate that microbially derived products can alter the ability of antimicrobial agents to kill bacterial biofilms. IMPORTANCE Pseudomonas aeruginosa and Staphylococcus aureus are frequently coisolated from multiple infection sites, including the lungs of individuals with cystic fibrosis (CF) and nonhealing diabetic foot ulcers. Coinfection with P. aeruginosa and S. aureus has been shown to produce worse outcomes compared to infection with either organism alone. Furthermore, the ability of these pathogens to form biofilms enables them to cause persistent infection and withstand antimicrobial therapy. In this study, we found that P. aeruginosa-secreted products dramatically increase the ability of the antibiotic norfloxacin to kill S. aureus biofilms. Understanding how interspecies interactions alter the antibiotic susceptibility of bacterial biofilms may inform treatment decisions and inspire the development of new therapeutic strategies.

Sign in / Sign up

Export Citation Format

Share Document