Staphylococcus Aureus Evasion of Innate Antimicrobial Defense

Abstract

Bacterial pathogens colonize human body surfaces soon after birth. In order to survive the constant threat of invasion and infection, the human innate immune system has evolved several efficient mechanisms to prevent harmful microorganisms from traversing epithelial barriers. These include cationic antimicrobial peptides (CAMPs) such as defensins and the cathelicidin LL-37, bacteriolytic enzymes such as lysozyme, antimicrobial fatty acids, toxic oxygen- or nitrogen-containing molecules, the bacteriolytic complement components and further mechanisms with indirect impacts on bacterial multiplication. Staphylococcus aureus is an important human commensal and pathogen. In order to successfully establish an infection, S. aureus has evolved several mechanisms to resist the innate immune system. In this review, we focus on the mechanisms employed by S. aureus to achieve protection against antimicrobial host defense molecules with special emphasis on CAMPs. Lessons from recent studies on antimicrobial host defense molecules and cognate bacterial resistance adaptation should help in the development of more sustainable anti-infective compounds.

Clinical Implications of Oral Candidiasis: Host Tissue Damage and Disseminated Bacterial Disease

“…Although colonization itself is a harmless state, colonized individuals are at risk of endogenous infection when S. aureus enters otherwise sterile sites via wounds or indwelling medical devices. With the emergence of methicillin-resistant S. aureus (MRSA), this ubiquitous pathogen is becoming an even greater therapeutic challenge (31)(32)(33).…”

Wall Teichoic Acid Protects Staphylococcus aureus against Antimicrobial Fatty Acids from Human Skin

“…S. aureus has developed efficient strategies to survive in its natural niches, the human anterior nares and skin, and to evade the immune system (4,8). However, only a few studies have previously addressed the molecular basis of staphylococcal resistance to AFA.…”

Chitinases as Antibacterial Proteins: A Systematic Review

“…Wang et al used M. lysodeikticus to determine if the M. purpureus chitinase had lysozyme activity, but the antibacterial tests were performed using different Gram-positive and Gram-negative bacteria. Bacteria can evolve efficient mechanisms which protect them from the lytic activity of lysozyme, 43 including M. lysodeikticus. 44,45 Therefore, the absence of lysozyme activity of M. purpureus chitinase should be carefully interpreted and re-examined, using the same species to which the protein exhibited antibacterial effects.…”