Staphylococcus epidermidis Esp inhibits Staphylococcus aureus biofilm formation and nasal colonization

Abstract

Commensal bacteria are known to inhibit pathogen colonization; however, complex host-microbe and microbe-microbe interactions have made it difficult to gain a detailed understanding of the mechanisms involved in the inhibition of colonization. Here we show that the serine protease Esp secreted by a subset of Staphylococcus epidermidis, a commensal bacterium, inhibits biofilm formation and nasal colonization by Staphylococcus aureus, a human pathogen. Epidemiological studies have demonstrated that the presence of Esp-secreting S. epidermidis in the nasal cavities of human volunteers correlates with the absence of S. aureus. Purified Esp inhibits biofilm formation and destroys pre-existing S. aureus biofilms. Furthermore, Esp enhances the susceptibility of S. aureus in biofilms to immune system components. In vivo studies have shown that Esp-secreting S. epidermidis eliminates S. aureus nasal colonization. These findings indicate that Esp hinders S. aureus colonization in vivo through a novel mechanism of bacterial interference, which could lead to the development of novel therapeutics to prevent S. aureus colonization and infection.

Protection from the acquisition of Staphylococcus aureus nasal carriage by cross-reactive antibody to a pneumococcal dehydrogenase

“…Therefore, our studies with this model focus on the initial establishment of S. aureus nasal colonization rather than on persistent carriage. Under these conditions, the levels of S. aureus detected in our model are comparable to those recovered from experimentally colonized humans (26).…”

New insights in the pathogenesis of atopic dermatitis

“…A mouse model showed that Staphylococcus epidermidis differentially upregulates the expression of IL-17 in the skin, rather than in the gut (64), suggesting a specific role of this bacteria in skin immunity. It has been shown that S. epidermidis may produce its own antimicrobial peptides that modulate the survival of other cutaneous microbial pathogens (65,66). More recently, Kong et al (67) showed that increased bacterial diversity on typically affected skin areas of AD children was linked to treatments, whereas decreased bacterial diversity was associated with increased AD severity and flare.…”

Clearance of Staphylococcus aureus Nasal Carriage Is T Cell Dependent and Mediated through Interleukin-17A Expression and Neutrophil Influx

“…Carriage may also be dependent upon the presence of certain commensal bacteria in the nares. A subset of Staphylococcus epidermidis organisms was demonstrated to inhibit S. aureus growth and nasal colonization through production of Esp, a serine protease (7). In addition, patients colonized with Esp-secreting S. epidermidis correlated with absence of S. aureus in the nasal cavity (7).…”

“…A subset of Staphylococcus epidermidis organisms was demonstrated to inhibit S. aureus growth and nasal colonization through production of Esp, a serine protease (7). In addition, patients colonized with Esp-secreting S. epidermidis correlated with absence of S. aureus in the nasal cavity (7). One study observed that single nucleotide polymorphisms (SNPs) in C-reactive protein and interleukin 4 (IL-4) genes correlated with S. aureus nasal colonization (8), whereas another found a correlation with SNPs in the glucocorticoid receptor gene (9).…”