scholarly journals Staphylococcus aureusProtein A Mediates Interspecies Interactions at the Cell Surface ofPseudomonas aeruginosa

mBio ◽  
2016 ◽  
Vol 7 (3) ◽  
Author(s):  
Catherine R. Armbruster ◽  
Daniel J. Wolter ◽  
Meenu Mishra ◽  
Hillary S. Hayden ◽  
Matthew C. Radey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Microbial Community ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Protein A ◽  
Staphylococcal Protein A ◽  
Interspecies Interactions ◽  
Community Interactions ◽  
Staphylococcal Protein

ABSTRACTWhile considerable research has focused on the properties of individual bacteria, relatively little is known about how microbial interspecies interactions alter bacterial behaviors and pathogenesis.Staphylococcus aureusfrequently coinfects with other pathogens in a range of different infectious diseases. For example, coinfection byS. aureuswithPseudomonas aeruginosaoccurs commonly in people with cystic fibrosis and is associated with higher lung disease morbidity and mortality.S. aureussecretes numerous exoproducts that are known to interact with host tissues, influencing inflammatory responses. The abundantly secretedS. aureusstaphylococcal protein A (SpA) binds a range of human glycoproteins, immunoglobulins, and other molecules, with diverse effects on the host, including inhibition of phagocytosis ofS. aureuscells. However, the potential effects of SpA and otherS. aureusexoproducts on coinfecting bacteria have not been explored. Here, we show thatS. aureus-secreted products, including SpA, significantly alter two behaviors associated with persistent infection. We found that SpA inhibited biofilm formation by specificP. aeruginosaclinical isolates, and it also inhibited phagocytosis by neutrophils of all isolates tested. Our results indicate that these effects were mediated by binding to at least twoP. aeruginosacell surface structures—type IV pili and the exopolysaccharide Psl—that confer attachment to surfaces and to other bacterial cells. Thus, we found that the role of a well-studiedS. aureusexoproduct, SpA, extends well beyond interactions with the host immune system. Secreted SpA alters multiple persistence-associated behaviors of another common microbial community member, likely influencing cocolonization and coinfection with other microbes.IMPORTANCEBacteria rarely exist in isolation, whether on human tissues or in the environment, and they frequently coinfect with other microbes. However, relatively little is known about how microbial interspecies interactions alter bacterial behaviors and pathogenesis. We identified a novel interaction between two bacterial species that frequently infect together—Staphylococcus aureusandPseudomonas aeruginosa. We show that theS. aureus-secreted protein staphylococcal protein A (SpA), which is well-known for interacting with host targets, also binds to specificP. aeruginosacell surface molecules and alters two persistence-associatedP. aeruginosabehaviors: biofilm formation and uptake by host immune cells. BecauseS. aureusfrequently precedesP. aeruginosain chronic infections, these findings reveal how microbial community interactions can impact persistence and host interactions during coinfections.

Multilocus Sequence Typing and Staphylococcal Protein A Typing Revealed Novel and Diverse Clones of Methicillin-Resistant Staphylococcus aureus in Seafood and the Aquatic Environment

2017 ◽  
Vol 80 (3) ◽  
pp. 476-481 ◽  
Author(s):  
V. Murugadas ◽  
C. Joseph Toms ◽  
Sara A. Reethu ◽  
K. V. Lalitha
Keyword(s):  
Staphylococcus Aureus ◽  
Aquatic Environment ◽  
Multilocus Sequence Typing ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Protein A ◽  
Staphylococcal Protein A ◽  
Spa Typing ◽  
Methicillin Resistant ◽  
Staphylococcal Protein ◽  
Mrsa Strains

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) has been a global health concern since the 1960s, and isolation of this pathogen from food-producing animals has been increasing. However, little information is available on the prevalence of MRSA and its clonal characteristics in seafood and the aquatic environment. In this study, 267 seafood and aquatic environment samples were collected from three districts of Kerala, India. Staphylococcal protein A (spa) typing and multilocus sequence typing (MLST) was performed for 65 MRSA strains isolated from 20 seafood and aquatic environment samples. The MRSA clonal profiles were t657-ST772, t002-ST5, t334-ST5, t311-ST5, t121-ST8, t186-ST88, t127-ST1, and two non-spa assignable strains. Whole spa gene sequence analysis along with MLST confirmed one strain as t711-ST6 and another as a novel MRSA clone identified for the first time in seafood and the aquatic environment with a t15669 spa type and a new MLST profile of ST420-256-236-66-82-411-477. The MRSA strains were clustered into five clonal complexes based on the goeBURST algorithm, indicating high diversity among MRSA strains in seafood and the aquatic environment. The novel clone formed a separate clonal complex with matches to three loci. This study recommends large-scale spa typing and MLST of MRSA isolates from seafood and the aquatic environment to determine the prevalence of new MRSA clones. This monitoring process can be useful for tracing local spread of MRSA isolates into the seafood production chain in a defined geographical area.

scholarly journals Staphylococcus aureus Fibronectin-Binding Protein A Mediates Cell-Cell Adhesion through Low-Affinity Homophilic Bonds

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Philippe Herman-Bausier ◽  
Sofiane El-Kirat-Chatel ◽  
Timothy J. Foster ◽  
Joan A. Geoghegan ◽  
Yves F. Dufrêne
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Protein A ◽  
Intercellular Adhesion ◽  
Surface Proteins ◽  
Content Type ◽  
Fibronectin Binding ◽  
A Domains ◽  
Cell Cell

ABSTRACT Staphylococcus aureus is an important opportunistic pathogen which is a leading cause of biofilm-associated infections on indwelling medical devices. The cell surface-located fibronectin-binding protein A (FnBPA) plays an important role in the accumulation phase of biofilm formation by methicillin-resistant S. aureus (MRSA), but the underlying molecular interactions are not yet established. Here, we use single-cell and single-molecule atomic force microscopy to unravel the mechanism by which FnBPA mediates intercellular adhesion. We show that FnBPA is responsible for specific cell-cell interactions that involve the FnBPA A domain and cause microscale cell aggregation. We demonstrate that the strength of FnBPA-mediated adhesion originates from multiple low-affinity homophilic interactions between FnBPA A domains on neighboring cells. Low-affinity binding by means of FnBPA may be important for biofilm dynamics. These results provide a molecular basis for the ability of FnBPA to promote cell accumulation during S. aureus biofilm formation. We speculate that homophilic interactions may represent a generic strategy among staphylococcal cell surface proteins for guiding intercellular adhesion. As biofilm formation by MRSA strains depends on proteins rather than polysaccharides, our approach offers exciting prospects for the design of drugs or vaccines to inhibit protein-dependent intercellular interactions in MRSA biofilms. IMPORTANCE Staphylococcus aureus is a human pathogen that forms biofilms on indwelling medical devices, such as central venous catheters and prosthetic joints. This leads to biofilm infections that are difficult to treat with antibiotics because many cells within the biofilm matrix are dormant. The fibronectin-binding proteins (FnBPs) FnBPA and FnBPB promote biofilm formation by clinically relevant methicillin-resistant S. aureus (MRSA) strains, but the molecular mechanisms involved remain poorly understood. We used atomic force microscopy techniques to demonstrate that FnBPA mediates cell-cell adhesion via multiple, low-affinity homophilic bonds between FnBPA A domains on adjacent cells. Therefore, FnBP-mediated homophilic interactions represent an interesting target to prevent MRSA biofilms. We propose that such homophilic mechanisms may be widespread among staphylococcal cell surface proteins, providing a means to guide intercellular adhesion and biofilm accumulation.

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