title: Exposure to quinolones is associated with carbapenem resistance among colistin-susceptible Acinetobacter baumannii blood isolates.
abstract: In this study, we explored risk factors associated with bacteraemia caused by colistin-susceptible/carbapenem-resistant (Co(S)/Ca(R)) Acinetobacter baumannii. A retrospective cohort study of hospitalised patients with A. baumannii bacteraemia was performed at a tertiary care hospital over a 44-month period. Thirty-nine patients with bacteraemia due to A. baumannii (35 Intensive Care Unit and 4 ward patients) were included in the analysis. Twenty-five patients (64%) had bacteraemia due to Co(S)/Ca(R)A. baumannii and 14 patients (36%) had bacteraemia due to colistin-susceptible/carbapenem-susceptible A. baumannii. Mortality was 56% (14/25) and 35.7% (5/14) for patients in the two groups, respectively (P=0.22). Bivariate analysis showed that prior exposure to fluoroquinolones (P=0.01) and antipseudomonal penicillins (P=0.004) as well as a higher number of antibiotics in use on the day of bacteraemia (P=0.02) were associated with isolation of a Co(S)/Ca(R) strain among patients with A. baumannii bacteraemia. Multivariate analysis using a backward logistic regression model showed that only exposure to fluoroquinolones was associated with development of Co(S)/Ca(R)A. baumannii bacteraemia (odds ratio=11.6; 95% confidence interval 2.4-55.9; P=0.02). The appearance of Co(S)/Ca(R)A. baumannii infections represents a major threat to critically ill hospitalised patients. Exposure to fluoroquinolones is an independent risk factor for development of Co(S)/Ca(R)A. baumannii bacteraemia.
authors.affiliation: Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Str., 151 23 Marousi, Athens, Greece.
authors.forename: Petros
authors.initials: P
authors.lastname: Kopterides
authors.forename: Patra K
authors.initials: PK
authors.lastname: Koletsi
authors.forename: Argyris
authors.initials: A
authors.lastname: Michalopoulos
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Falagas
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000302:isolation & purification; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D001769:Blood / Q000382:microbiology; D015780:Carbapenems / Q000494:pharmacology*; D015331:Cohort Studies; D003091:Colistin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010406:Penicillins / Q000627:therapeutic use; D015363:Quinolones / Q000627:therapeutic use*; D012189:Retrospective Studies; D012307:Risk Factors; D018440:beta-Lactam Resistance
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D010406:Penicillins; D015363:Quinolones; D003091:Colistin