Prevalence of metallo-beta-lactamase among Pseudomonas aeruginosa and Acinetobacter baumannii isolated from burn wounds and in vitro activities of antibiotic combinations against these isolates.
The prevalence of metallo-beta-lactamases (MBLs) produced by isolates of Pseudomonas aeruginosa and Acinetobacter baumannii and the activities of various antmicrobial combinations against MBL producer strains were investigated. During the period from June 2003 till July 2004, 120 P. aeruginosa and 9 A. baumannii nonduplicate isolates were obtained from burn wounds. Forty strains (37 P. aeruginosa, 3 A. baumannii) were selected because of resistance to carbapenems. Screening for MBL production was performed in the latter isolates by the combined disk method which depends on comparing the zones given by disks containing imipenem with and without ethylenediaminetetraacetic acid (EDTA). Of imipenem resistant P. aeruginosa strains, 21 and 1 of A. baumannii were found metallo-beta-lactamase producers. Disk approximation studies were then performed to test for in vitro activities of various antimicrobial combinations. For a total of 21 P. aeruginosa strains, synergy was demonstrated predominantly by ciprofloxacin in combination with ceftazidime and imipenem, by ofloxacin in combination with astreonam. Against MBL producer A. baumannii strain, synergy was detected only with imipenem-ofloxacin combination. None of the combinations were antagonistic. These results suggest that MBL producing P. aeruginosa and A. baumanni strains have been introduced into burn centers, and to prevent the further spread of MBL producers, it is essential for carbapenem resistant isolates to be screened for MBLs.
Altoparlak
Ulku
U
Department of Microbiology and Clinical Microbiology, Ataturk University, Tip Fakultesi, Aziziye Hastanesi, Mikrobiyoloji ve Klinik Mikrobiyoloji Anabilim Dali, School of Medicine, Erzurum 25100, Turkey. ulkuca@hotmail.com
Aktas
Ferda
F
Celebi
Demet
D
Ozkurt
Zulal
Z
Akcay
Mufide N
MN
D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D002053:Burn Units; D002056:Burns / Q000382:microbiology*; D015780:Carbapenems / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology; D004338:Drug Combinations; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D009894:Opportunistic Infections / Q000382:microbiology; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D001618:beta-Lactamases / Q000096:biosynthesis*
D015780:Carbapenems; D004338:Drug Combinations; D001618:beta-Lactamases