Objective: To compare clinical characteristics and molecular genotypes of MRSA isolates from a tertiary medical center (MC) and 7 referring community hospitals (CH) to help understand if transmission of CA- and HA-MRSA is occurring between these facilities.
Methods: Molecular genotyping and medical chart reviews were conducted on 337 patients with MRSA clinical infections from January 2007 to July 2009: 152 retrospective archived MRSA isolates from MC for baseline prevalence; 116 consecutive prospective isolates from CH; and 69 randomized prospective isolates from MC. Molecular genotyping was performed by repetitive element Polymerase Chain Reaction (rep-PCR; DiversiLab,TM Biomerieux,
Results: The isolates were distributed into 41 different rep-PCR genotype patterns. 271/337 (80%) of the isolates were clustered into 6 major patterns (A to F; 14-130 isolates). Clinical and molecular characteristics along with antibiotic susceptibilities (SUSCEPT) for clinidamycin (CLIN), tetracycline (TCN), and Trimethoprim-sulfamethoxizole (TMP/SXT) of the six major patterns are listed below.
|Total number (n)||14||61||24||130||18||24|
|SCC mecA type||II||II||III||IVa||IVa||II|
|Gender % male||64||35||57||57||43||38|
|White Race (%)||64||90||87||76||86||86|
|CLIN SUSCEPT (%)||0||5||0||66||88||7|
|TCN SUSCEPT (%)||100||94||10||98||100||85|
|TMP/SXT SUSCEPT (%)||100||98||36||97||100||100|
Conclusions: Distinct molecular and epidemiological characteristics exist between MRSA isolates within this referral network of hospitals. CA- and HA-MRSA strains were commonly shared in both the MC and CH, but relative proportions were different. We predict the applications of these tools combined with continued surveillance, social network and temporospatial analysis will allow a more complete understanding of MRSA transmission between facilities.