Risk factors for isolation of low-level mupirocin-resistant versus -susceptible methicillin-resistant Staphylococcus aureus from patients in intensive care units.
OBJECTIVE
The aim of this study was to determine the risk factors for the recovery of low-level mupirocin-resistant (mup(r)) or -susceptible (mup(s)) MRSA from patients in intensive care units (ICUs).


METHODS
A case-case-control study was conducted from November 2003 to April 2004. Two case groups consisted of patients with low-level mup(r) MRSA and mup(s) MRSA. A control group was frequency matched.


RESULTS
Mup(r) MRSA and mup(s) MRSA were isolated from 20 to 51 patients, respectively, during a six-month period. Risk factors identified for mup(r) MRSA were as follows: exposure to piperacillin-tazobactam (odds ratio [OR] 13.8; 95% confidence intervals [CI], 1.8-105.0), third-generation cephalosporins (OR, 5.0; 95% CI, 1.6-15.5) and quinolones (OR, 3.4; 95% CI, 1.1-10.7). Risk factors identified for mup(s) MRSA were as follows: length of ICU stay (OR, 1.1; 95% CI, 1.0-1.1), surgery (OR, 3.7; 95% CI, 1.5-9.0), exposure to third-generation cephalosporins (OR, 8.4; 95% CI, 3.3-21.7) and quinolones (OR, 7.7; 95% CI, 2.8-21.3).


CONCLUSIONS
Our results suggest that nosocomial isolation of low-level mup(r) MRSA may be affected by piperacillin-tazobactam.
Park
Dae Won
DW
Department of Internal Medicine, The Institute of Emerging Infectious Diseases, College of Medicine, Korea University, 126-1 Anam-Dong 5th Street, Sungbuk-gu, Seoul 136-705, Republic of Korea.
Kim
Min Ja
MJ
Yang
Jin Ah
JA
Jeong
Hye Won
HW
Sohn
Jang Wook
JW
Chun
Byung Chul
BC
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016022:Case-Control Studies; D002511:Cephalosporins / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016712:Mupirocin / Q000494:pharmacology*; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D000077725:Piperacillin, Tazobactam Drug Combination; D015363:Quinolones / Q000627:therapeutic use; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D015363:Quinolones; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D016712:Mupirocin; D010878:Piperacillin