Antimicrobial Management of Complicated Skin and Skin Structure Infections in the Era of Emerging Resistance

Abstract

Complicated skin and skin structure infections (cSSSIs) are among the most common infections treated in the hospital setting. The mainstays of treatment continue to be antimicrobial therapy combined with appropriate surgical intervention. Due to increasing resistance among pathogens commonly implicated in cSSSIs, the objectives of this review were to describe the potential pathogens causing skin infections, the implications of resistance to currently used drug therapy, and the role of new antibiotics with activity for pathogens causing cSSSIs. Relevant information from the primary literature and review articles were identified through a MEDLINE search of the medical literature (1980 to the present) using the terms abscess, wound infection, skin and skin structure infection, antibiotics, resistance, quinupristin- dalfopristin, linezolid, daptomycin, tigecycline, oritavancin, and dalbavancin. Meeting posters and slides were identified from the Interscience Conference of Antimicrobial Agents and Chemotherapy (1998-2004) for supplemental data. The most commonly implicated pathogens in cSSSIs include gram-positive bacteria, specifically Staphylococcus aureus. Gram-negative and mixed organisms are additionally encountered in serious cSSSI. Antimicrobial resistance among both gram-positive and gramnegative bacteria has increased significantly during the last decade, with methicillin resistance among S. aureus approaching 60% in hospitals and becoming more frequent in the community as well. As a result, resistance is the driving factor for treatment failure and rising costs for infection management. Few antimicrobial agents are available currently to treat resistant bacteria in cSSSIs; vancomycin is currently the drug of choice against resistant grampositive cocci; however, resistance to this agent has appeared in enterococci and S. aureus. Several new antibiotics such as linezolid and daptomycin are now available for the management of cSSSIs. Other agents such as tigecycline are under investigation and should be available soon to increase treatment options for cSSSIs caused by resistant bacteria. Although the resistance of cSSSI pathogens is problematic, new antibiotics with broad-spectrum activity against resistant gram-positive and gram-negative bacteria are promising for the management of severe cSSSIs.