Elimination of Staphylococcus aureus nasal carriage in intensive care patients lowers infection rates

This study surveys the clinical relevance of the nasalStaphylococcus aureus colonization status on intensive care unit (ICU) –acquiredS.aureus infections and compares molecular characteristics of isolates from the nose and infectious sites. The 390 patients included comprised 278 non-carriers and 112 carriers. Among the carriers, 56 were decolonized with mupirocin. Decolonization was verified through a second (negative) culture. Spa typing and virulence gene profiling were performed for all isolates. Twenty sixS.aureus infections were detected in the carriage group and 20 in the non-carriage group. Eighteen of these 26 (69.2%) infections were among carriers, and 8 of these 26 (30.8%) infections occurred among decolonized carriers (p = 0.02). Overall, 31/112 (27.7%) of the colonized patients and 25/46 (60.1%) of infection were due to methicillin-resistantS.aureus (MRSA). The highest frequency virulence genes weresea andhlg (both 100%) in nasal isolates andsea,hlg,fnb, andclf (100%) for infectious isolates. t030 was the most abundant spa type overall.S.aureus carriers were more likely to developS.aureus infection compared with decolonized and non-carrying patients. The sources of ICUS.aureus infection appear to be exogenous mostly, and a predominant clone (spa type 030) plays an important role. We confirm that nasal mupirocin treatment prevents ICU infections even when there is an increased prevalence of nosocomial MRSA.
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research