title: Risk factors for anti-MRSA drug resistance.
abstract: Meticillin-resistant Staphylococcus aureus (MRSA)-related infections have recently been spreading and are difficult to control, partly because affected patients are frequently in a poor condition. This study retrospectively investigated recent MRSA-related infections focusing on the relationship between clinical risk factors and anti-MRSA drug resistance. The patients with MRSA-related infections in Kobe University Hospital (Kobe, Japan) in 2009 were enrolled in the study. The relationships between various clinical risk factors as well as MRSA bacterial DNA concentration with minimum inhibitory concentrations (MICs) of anti-MRSA drugs were examined. In total, 44 patients were enrolled in the study and MRSA was isolated from blood (23 patients), urine (12 patients) and nasal secretions (9 patients). There was only one resistant strain to linezolid (LZD) among the anti-MRSA drugs tested, and this strain was considered staphylococcal cassette chromosome mec (SCCmec) type IIa from phage open-reading frame typing analyses. Statistical analyses showed that MRSA bacterial DNA concentration, cancer and use of a respirator, respectively, had a significant relationship with the MICs of LZD (P=0.0058) and arbekacin (ABK) (P=0.0003), of quinupristin/dalfopristin (Q/D) (P=0.0500) and ABK (P=0.0133), and of Q/D (P=0.0198) and vancomycin (P=0.0036). In conclusion, bacterial DNA concentration, cancer and use of a respirator were found to be significant risk factors for lower susceptibilities to anti-MRSA drugs; one strain was resistant to LZD. We suggest that further investigation and surveillance for MRSA-related infection are necessary for preventing the spread of MRSA-related infections.
authors.affiliation: Infection Control Team, Kobe University Hospital, Kobe, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Abe
authors.forename: Katsumi
authors.initials: K
authors.lastname: Shigemura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Masato
authors.initials: M
authors.lastname: Fujisawa
authors.forename: Soichi
authors.initials: S
authors.lastname: Arakawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents