strains have SCCmec types I, II, or III.
He theorized that other organisms may have a competitive advantage in non-health care settings, or that HAMRSA
may spread too slowly in the immunocompetent population.
HAMRSA strains included those belonging to other PFGE genotypes.
Twenty-six isolates (39%) were HAMRSA strains related to USA100 (n = 11), USA200 (n = 1), USA700 (n = 1), and 8 other strains had unique PFGE fingerprints (n = 13).
To analyze trends in frequency of CA-MRSA and HAMRSA, we studied changes in the proportion of isolates of each type that were found in inpatient and outpatient settings from a nationally representative sample of US hospitals during 1999-2006.
Despite increases in the proportion of CA-MRSA strains among inpatients, the continuing high level of HAMRSA suggests that in contrast to reports from local institutions (11), CA-MRSA strains are adding to the problem of MRSA rather than replacing HA-MRSA strains.
We did not evaluate whether an assessment of risk factors for HAMRSA
would have determined the likelihood of resistance to non-[beta]-lactam antimicrobial drugs.
In addition, unlike the PVL genes, lukE-lukD leukocidin genes were found in most HAMRSA
(95%) as well as in CA-MRSA.