Emergence of Community-Associated Methicillin-Resistant Staphylococcus aureus USA300 Genotype as a Major Cause of Health Care--Associated Blood Stream Infections

Abstract

MRSA USA300 genotype, the predominant cause of community-associated MRSA infections in our area (Atlanta, GA), has now emerged as a significant cause of health care-associated and nosocomial BSI. MRSA USA300 as a nosocomial pathogen presents new challenges to infection control programs.

Changing epidemiology of methicillin-resistantStaphylococcus aureuscolonization in paediatric intensive-care units

“…The increasing prevalence of MRSA spa type 1 is consistent with other reports that CA-MRSA infection, and in particular USA300, has become more common in healthcare settings [15-19, 25, 27-30]. These reports describe an increasing number of hospital-onset bloodstream infections [17], surgical site infections [16], other skin and soft tissue infections [19], and infections in NICU patients with CA-MRSA strains [25,[28][29][30]. MRSA colonization is a precursor for hospital-onset infection, especially in patients with central venous catheters and endotracheal tubes, devices that are often necessary for ICU patients [3,4].…”

“…The relationship between CA-MRSA and hospitalassociated (HA)-MRSA infections and specific strains of MRSA is complex, but CA-MRSA infections were initially associated with strains that are genetically distinct from HA-MRSA [14]. However, recent reports show that genetically typed CA-MRSA strains are increasingly responsible for hospital-onset infections [15][16][17][18][19][20].…”

Community-acquired Staphylococcus aureus, a recent problem

“…In addition, most strains contain the PantonValentine leukocidin (PVL), a toxin that causes neutrophil lysis and induces chemotactic factor release, which promote tissue inflammation and destruction, thus resulting in necrotizing pneumonia. 3,7,8 The recent emergence of vancomycinintermediate SA strains (VISA MICs of 4-8 µg/ mL and hetero-VISA) and even resistant strains (MICs > 16 µg/mL) have forced to look for alternative antibiotic approaches. There are currently multiple options, including daptomycin, linezolid, and ceftaroline.…”

Detection of Methicillin-Resistant Staphylococcus aureus by a Duplex Droplet Digital PCR Assay

“…In the United States, methicillin-resistant Staphylococcus aureus (MRSA) has increased in both community-and health care-associated infections (1,2), and the threat of community-associated MRSA entering the hospital environment has lent an urgency to efforts to limit the spread of this organism (3). MRSA has become the most frequent cause of skin and soft tissue infections in emergency rooms, and it is associated with a variety of other infections, including nosocomial pneumonia and surgical-site and bloodstream infections (1,4).…”