-
Nature Reviews. Microbiology Aug 2009Although nosocomial infections by Staphylococcus epidermidis have gained much attention, this skin-colonizing bacterium has apparently evolved not to cause disease, but... (Review)
Review
Although nosocomial infections by Staphylococcus epidermidis have gained much attention, this skin-colonizing bacterium has apparently evolved not to cause disease, but to maintain the commonly benign relationship with its host. Accordingly, S. epidermidis does not produce aggressive virulence determinants. Rather, factors that normally sustain the commensal lifestyle of S. epidermidis seem to give rise to additional benefits during infection. Furthermore, we are beginning to comprehend the roles of S. epidermidis in balancing the epithelial microflora and serving as a reservoir of resistance genes. In this Review, I discuss the molecular basis of the commensal and infectious lifestyles of S. epidermidis.
Topics: Animals; Anti-Bacterial Agents; Biofilms; Drug Resistance; Host-Pathogen Interactions; Humans; Skin; Staphylococcal Infections; Staphylococcus epidermidis; Virulence
PubMed: 19609257
DOI: 10.1038/nrmicro2182 -
PLoS Pathogens Nov 2020Our skin is our first line of defense against environmental and pathogenic challenges. It is densely populated by a flora of bacteria, fungi, and viruses that normally... (Review)
Review
Our skin is our first line of defense against environmental and pathogenic challenges. It is densely populated by a flora of bacteria, fungi, and viruses that normally interact with each other and with our immune system to promote skin health and homeostasis. Staphylococcus epidermidis is one of the most abundant bacterial colonizers of healthy human skin. While the field has historically assumed that all S. epidermidis isolates behave similarly, emerging evidence suggests that colonization by specific strains of S. epidermidis can either help or hurt the skin barrier depending on the context. In this short review, we discuss what is currently understood about S. epidermidis strain-level diversity and evaluate costs and benefits of S. epidermidis skin colonization. We challenge the current dogma that "all S. epidermidis strains behave equally" and posit that behavior is in fact highly context and strain dependent. Finally, in light of current proposals to use skin commensals as nonantibiotic treatments for acute or chronic skin diseases, we conclude that more work is urgently needed to fully understand the pathogenic and protective roles of commensals before we use them therapeutically.
Topics: Humans; Skin; Staphylococcus epidermidis; Symbiosis
PubMed: 33180890
DOI: 10.1371/journal.ppat.1009026 -
Microbiology Spectrum Aug 2018Staphylococci, with the leading species and , are the most frequent causes of infections on indwelling medical devices. The biofilm phenotype that those bacteria adopt... (Review)
Review
Staphylococci, with the leading species and , are the most frequent causes of infections on indwelling medical devices. The biofilm phenotype that those bacteria adopt during device-associated infection facilitates increased resistance to antibiotics and host immune defenses. This review presents and discusses the molecular mechanisms contributing to staphylococcal biofilm development and their in-vivo importance. Furthermore, it summarizes current strategies for the development of therapeutics against staphylococcal biofilm-associated infection.
Topics: Animals; Biofilms; Drug Resistance, Bacterial; Humans; Phenotype; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus; Staphylococcus epidermidis
PubMed: 30117414
DOI: 10.1128/microbiolspec.GPP3-0023-2018 -
Trends in Microbiology Sep 2011Staphylococcus aureus and Staphylococcus epidermidis are a frequent cause of biofilm-associated infections that are a tremendous burden on our healthcare system.... (Review)
Review
Staphylococcus aureus and Staphylococcus epidermidis are a frequent cause of biofilm-associated infections that are a tremendous burden on our healthcare system. Staphylococcal biofilms exhibit extraordinary resistance to antimicrobial killing, limiting the efficacy of antibiotic therapy, and surgical intervention is often required to remove infected tissues or implanted devices. Recent work has provided new insight into the molecular basis of biofilm development in these opportunistic pathogens. Extracellular bacterial products, environmental conditions, and polymicrobial interactions have all been shown to influence profoundly the ability of these bacteria to colonize and disperse from clinically relevant surfaces. We review new developments in staphylococcal biofilm disassembly and set them in the context of potential strategies to control biofilm infections.
Topics: Animals; Biofilms; Humans; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus epidermidis
PubMed: 21784640
DOI: 10.1016/j.tim.2011.06.004 -
Microbes and Infection Apr 2002The opportunistic human pathogen Staphylococcus epidermidis has become the most important cause of nosocomial infections in recent years. Its pathogenicity is mainly due... (Review)
Review
The opportunistic human pathogen Staphylococcus epidermidis has become the most important cause of nosocomial infections in recent years. Its pathogenicity is mainly due to the ability to form biofilms on indwelling medical devices. In a biofilm, S. epidermidis is protected against attacks from the immune system and against antibiotic treatment, making S. epidermidis infections difficult to eradicate.
Topics: Bacterial Adhesion; Bacteriocins; Biofilms; Humans; Models, Molecular; Pheromones; Staphylococcal Infections; Staphylococcus epidermidis; Virulence
PubMed: 11932199
DOI: 10.1016/s1286-4579(02)01563-0 -
Journal of Bacteriology Aug 2021Antimicrobial peptides (AMPs) are one of the key immune responses that can eliminate pathogenic bacteria through membrane perturbation. As a successful skin commensal,...
Antimicrobial peptides (AMPs) are one of the key immune responses that can eliminate pathogenic bacteria through membrane perturbation. As a successful skin commensal, Staphylococcus epidermidis can sense and respond to AMPs through the GraXRS two-component system and an efflux system comprising the VraG permease and VraF ATPase. GraS is a membrane sensor known to function in AMP resistance through a negatively charged, 9-residue extracellular loop, which is predicted to be linear without any secondary structure. An important question is how GraS can impart effective sensing of AMPs through such a small unstructured sequence. In this study, we verified the role of and in AMP sensing in S. epidermidis, as demonstrated by the failure of the Δ or Δ mutants to sense. Deletion of the extracellular loop of VraG did not affect sensing but reduced survival with polymyxin B. Importantly, a specific region within the extracellular loop, termed the guard loop (GL), has inhibitory activity since sensing of polymyxin B was enhanced in the ΔGL mutant, indicating that the GL may act as a gatekeeper for sensing. Bacterial two-hybrid analysis demonstrated that the extracellular regions of GraS and VraG interact, but interaction appears dispensable to sensing activity. Mutation of the extracellular loop of VraG, the GL, and the active site of VraF suggested that an active detoxification function of VraG is necessary for AMP resistance. Altogether, we provide evidence for a unique sensory scheme that relies on the function of a permease to impart effective information processing. Staphylococcus epidermidis has become an important opportunistic pathogen that is responsible for nosocomial and device-related infections that account for considerable morbidity worldwide. A thorough understanding of the mechanisms that enable S. epidermidis to colonize human skin successfully is essential for the development of alternative treatment strategies and prophylaxis. Here, we demonstrate the importance of an AMP response system in a clinically relevant S. epidermidis strain. Furthermore, we provide evidence for a unique sensory scheme that would rely on the detoxification function of a permease to effect information processing.
Topics: Adenosine Triphosphatases; Antimicrobial Cationic Peptides; Bacterial Proteins; Humans; Membrane Transport Proteins; Protein Conformation, alpha-Helical; Staphylococcal Infections; Staphylococcus epidermidis
PubMed: 34096781
DOI: 10.1128/JB.00178-21 -
Indian Journal of Pathology &... 2022
Topics: Anti-Bacterial Agents; Color; Exudates and Transudates; Female; Humans; Middle Aged; Pacemaker, Artificial; Pleural Effusion; Staphylococcal Infections; Staphylococcus epidermidis
PubMed: 35075002
DOI: 10.4103/ijpm.ijpm_124_21 -
PLoS Pathogens Feb 2021S. epidermidis is a substantial component of the human skin microbiota, but also one of the major causes of nosocomial infection in the context of implanted medical...
S. epidermidis is a substantial component of the human skin microbiota, but also one of the major causes of nosocomial infection in the context of implanted medical devices. We here aimed to advance the understanding of S. epidermidis genotypes and phenotypes conducive to infection establishment. Furthermore, we investigate the adaptation of individual clonal lines to the infection lifestyle based on the detailed analysis of individual S. epidermidis populations of 23 patients suffering from prosthetic joint infection. Analysis of invasive and colonizing S. epidermidis provided evidence that invasive S. epidermidis are characterized by infection-supporting phenotypes (e.g. increased biofilm formation, growth in nutrient poor media and antibiotic resistance), as well as specific genetic traits. The discriminating gene loci were almost exclusively assigned to the mobilome. Here, in addition to IS256 and SCCmec, chromosomally integrated phages was identified for the first time. These phenotypic and genotypic features were more likely present in isolates belonging to sequence type (ST) 2. By comparing seven patient-matched nasal and invasive S. epidermidis isolates belonging to identical genetic lineages, infection-associated phenotypic and genotypic changes were documented. Besides increased biofilm production, the invasive isolates were characterized by better growth in nutrient-poor media and reduced hemolysis. By examining several colonies grown in parallel from each infection, evidence for genetic within-host population heterogeneity was obtained. Importantly, subpopulations carrying IS insertions in agrC, mutations in the acetate kinase (AckA) and deletions in the SCCmec element emerged in several infections. In summary, these results shed light on the multifactorial processes of infection adaptation and demonstrate how S. epidermidis is able to flexibly repurpose and edit factors important for colonization to facilitate survival in hostile infection environments.
Topics: Aged; Aged, 80 and over; Bacterial Proteins; Biofilms; Cross Infection; Female; Genotype; Hemolysis; Humans; Interspersed Repetitive Sequences; Male; Middle Aged; Mutation; Nasal Mucosa; Phenotype; Staphylococcal Infections; Staphylococcus epidermidis
PubMed: 33544760
DOI: 10.1371/journal.ppat.1009304 -
BMC Genomics Feb 2016Propionibacterium acnes and Staphylococcus epidermidis live in close proximity on human skin, and both bacterial species can be isolated from normal and acne...
BACKGROUND
Propionibacterium acnes and Staphylococcus epidermidis live in close proximity on human skin, and both bacterial species can be isolated from normal and acne vulgaris-affected skin sites. The antagonistic interactions between the two species are poorly understood, as well as the potential significance of bacterial interferences for the skin microbiota. Here, we performed simultaneous antagonism assays to detect inhibitory activities between multiple isolates of the two species. Selected strains were sequenced to identify the genomic basis of their antimicrobial phenotypes.
RESULTS
First, we screened 77 P. acnes strains isolated from healthy and acne-affected skin, and representing all known phylogenetic clades (I, II, and III), for their antimicrobial activities against 12 S. epidermidis isolates. One particular phylogroup (I-2) exhibited a higher antimicrobial activity than other P. acnes phylogroups. All genomes of type I-2 strains carry an island encoding the biosynthesis of a thiopeptide with possible antimicrobial activity against S. epidermidis. Second, 20 S. epidermidis isolates were examined for inhibitory activity against 25 P. acnes strains. The majority of S. epidermidis strains were able to inhibit P. acnes. Genomes of S. epidermidis strains with strong, medium and no inhibitory activities against P. acnes were sequenced. Genome comparison underlined the diversity of S. epidermidis and detected multiple clade- or strain-specific mobile genetic elements encoding a variety of functions important in antibiotic and stress resistance, biofilm formation and interbacterial competition, including bacteriocins such as epidermin. One isolate with an extraordinary antimicrobial activity against P. acnes harbors a functional ESAT-6 secretion system that might be involved in the antimicrobial activity against P. acnes via the secretion of polymorphic toxins.
CONCLUSIONS
Taken together, our study suggests that interspecies interactions could potentially jeopardize balances in the skin microbiota. In particular, S. epidermidis strains possess an arsenal of different mechanisms to inhibit P. acnes. However, if such interactions are relevant in skin disorders such as acne vulgaris remains questionable, since no difference in the antimicrobial activity against, or the sensitivity towards S. epidermidis could be detected between health- and acne-associated strains of P. acnes.
Topics: Acne Vulgaris; Antibiosis; Comparative Genomic Hybridization; DNA, Bacterial; Genome, Bacterial; Humans; Phylogeny; Propionibacterium acnes; Sequence Analysis, DNA; Skin; Staphylococcus epidermidis
PubMed: 26924200
DOI: 10.1186/s12864-016-2489-5 -
Frontiers in Cellular and Infection... 2015Staphylococcus epidermidis is a usually harmless commensal bacterium highly abundant on the human skin. Under defined predisposing conditions, most importantly... (Review)
Review
Staphylococcus epidermidis is a usually harmless commensal bacterium highly abundant on the human skin. Under defined predisposing conditions, most importantly implantation of a medical device, S. epidermidis, however, can switch from a colonizing to an invasive life style. The emergence of S. epidermidis as an opportunistic pathogen is closely linked to the biofilm forming capability of the species. During the past decades, tremendous advance regarding our understanding of molecular mechanisms contributing to surface colonization has been made, and detailed information is available for several factors active during the primary attachment, accumulative or dispersal phase of biofilm formation. A picture evolved in which distinct factors, though appearing to be redundantly organized, take over specific and exclusive functions during biofilm development. In this review, these mechanisms are described in molecular detail, with a highlight on recent insights into multi-functional S. epidermidis cell surface proteins contributing to surface adherence and intercellular adhesion. The integration of distinct biofilm-promoting factors into regulatory networks is summarized, with an emphasis on mechanism that could allow S. epidermidis to flexibly adapt to changing environmental conditions present during colonizing or invasive life-styles.
Topics: Animals; Bacterial Proteins; Biofilms; Humans; Staphylococcal Infections; Staphylococcus epidermidis
PubMed: 25741476
DOI: 10.3389/fcimb.2015.00014