Methicillin-resistant Staphylococcus aureus in wound cultures recovered from a combat support hospital in Iraq.
BACKGROUND
Staphylococcus aureus infections complicate care of combat-related injuries and can independently result in skin and soft-tissue infections during deployments or training. Community-associated methicillin-resistant S. aureus (CA-MRSA) strains seem to produce severe disease but retain susceptibility to many oral antimicrobials. This study characterizes 84 MRSA isolates recovered from wound cultures at a combat support hospital in Iraq.


METHODS
MRSA strains recovered from December 2007 through March 2009 were analyzed. Antimicrobial resistance testing was determined by broth microdilution and the BD Phoenix Automated Microbiology System. The genotypic pattern was analyzed by pulsed-field gel electrophoresis and polymerase chain reaction identification of resistance and virulence genes.


RESULTS
No MRSA isolates from wound cultures were resistant to vancomycin. The most active oral antistaphylococcal agents were tetracycline (95% susceptibility), trimethoprim-sulfamethoxazole (94%), and clindamycin (94%). Of agents not typically recommended as monotherapy, 98% of isolates were susceptible to rifampin, 91% to moxifloxacin, and 60% to levofloxacin. The most common pulsed-field type (PFT) was USA300 (79%). The typical staphylococcal cassette chromosome mec IV elements carrying the CA-MRSA resistance genes were present in 88% of the isolates. Panton-Valentine leukocidin virulence genes were identified in 88% of isolates, including 100% of PFT USA300. The virulence gene associated with an arginine catabolic mobile element was present in 75% of isolates, including 94% of PFT USA300.


CONCLUSIONS
This study is the first genotypic and phenotypic characterization of CA-MRSA recovered from wound cultures in a deployed combat hospital. The pattern noted was similar to that seen in soldiers stationed in the United States.
Murray
Clinton K
CK
Infectious Disease Service, San Antonio Military Medical Center, Brooke Army Medical Center, Fort Sam Houston, Texas 78234, USA. Clinton.Murray@amedd.army.mil
Griffith
Matthew E
ME
Mende
Katrin
K
Guymon
Charles H
CH
Ellis
Michael W
MW
Beckius
Miriam
M
Zera
Wendy C
WC
Yu
Xin
X
Co
Edgie-Mark A
EM
Aldous
Wade
W
Hospenthal
Duane R
DR
D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006772:Hospitals, Military; D006801:Humans; D015994:Incidence; D054542:Iraq War, 2003-2011; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*; D010351:Patient Discharge; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D014481:United States / Q000453:epidemiology; D014946:Wound Infection / Q000453:epidemiology / Q000382:microbiology*
D004269:DNA, Bacterial