Into the storm: Chasing the opportunistic pathogen Staphylococcus aureus from skin colonisation to life‐threatening infections

Abstract

Summary Colonisation of the human skin by Staphylococcus aureus is a precursor for a variety of infections ranging from boils to sepsis and pneumonia. The rapid emergence of methicillin‐resistant S. aureus following the clinical introduction of this antimicrobial drug and reports of resistance to all currently used anti‐staphylococcal drugs has added to its formidable reputation. S. aureus survival on the skin and in vivo virulence is underpinned by a remarkable environmental adaptability, made possible by highly orchestrated regulation of gene expression and a capacity to undertake genome remodelling. Depending on the ecological or infection niche, controlled expression of a variety of adhesins can be initiated to facilitate adherence to extracellular matrix proteins, survival against desiccation or biofilm accumulation on implanted medical devices and host tissue. These adherence mechanisms complement toxin and enzyme production, immune evasion strategies, and antibiotic resistance and tolerance to collectively thwart efforts to develop reliable antimicrobial drug regimens and an effective S. aureus vaccine.

Neutrophil Recruitment to Noninvasive MRSA at the Stratum Corneum of Human Skin Mediates Transient Colonization

“…The closely related S. aureus is a more controversial affiliate of the skin microbiota (Sollid et al, 2014). S. aureus has massive pathogenic potential; it is responsible for 76% of all skin and soft tissue infections and can cause fatal invasive infections (Moran et al, 2006;O'Gara, 2017). Approximately 20% of the population carries S. aureus in the nares, with a further 30% believed to be transient carriers (Otto, 2010).…”

“…Being a carrier of S. aureus is considered a significant risk factor for invasive infection, but conversely, patients colonized by S. aureus have lower mortality in the event of bacteremia (von Eiff et al, 2001;Wertheim et al, 2004). Due to the prevalence of antibodies against S. aureus in healthy individuals, almost all of us are thought to be at least transiently colonized by S. aureus at some point (O'Gara, 2017). Carriage of S. aureus, typically asymptomatic, has been differentiated into three types: non-carriers, persistent carriers, and intermittent carriers (Dulon et al, 2014).…”

New Insight into Genotypic and Phenotypic Relatedness of Staphylococcus aureus Strains from Human Infections or Animal Reservoirs

“…To rate types of hemolysis the transparent zones for β-hemolysis (including the second zone observed in double β-hemolysis) and dark-green opalization for α-hemolysis were evaluated (Puacz et al 2015). Lipase activity was measured by the size of a turbidity zone around colonies, nuclease activity -by the size of a transparent zone after HCl addition to the culture test, while urease activity -by the color change of the medium from yellow to purple (Black et al 1971;dos Santos Rodrigues et al 2014;Posteraro et al 2015 1 96 as either negative (no activity) or positive (with low, moderate, high or very high activity).…”

“…A common human and animal opportunistic pathogen Staphylococcus aureus occurs mostly in the skin and/or nose vestibule mucous membrane as consistent of natural microflora in healthy individuals. Colonization can lead to an invasive mode of infection under particular conditions of a host organism, mostly immunodeficiency, surgical interventions or longitudinal hospitalization of patients (Malachowa et al 2011;O'Gara 2017). The European Centre for Disease Prevention and Control alarms that the most antimicrobialresistant healthcare-associated infections are caused by the methicillin-resistant S. aureus (MRSA).…”

The dawn of phage therapy

“…Transdermal delivery of phages provides another stable and effective route of administration . Nosocomial infections caused by opportunistic pathogens including Staphylococcus aureus and Pseudomonas aeruginosa pose a serious concern. Such microbes are responsible for skin infections and diseases making chronic wounds and burns unable to heal .…”