In vivo selection of reduced susceptibility to carbapenems in Acinetobacter baumannii related to ISAba1-mediated overexpression of the natural bla(OXA-66) oxacillinase gene.
Two clonally related Acinetobacter baumannii isolates, A1 and A2, were obtained from the same patient. Isolate A2, selected after an imipenem-containing treatment, showed reduced susceptibility to carbapenems. This resistance pattern was related to insertion of the ISAba1 element upstream of the naturally occurring bla(OXA-66) carbapenemase gene as demonstrated by sequencing, reverse transcription-PCR analysis, and inactivation of the bla(OXA-66) gene.
Figueiredo
Samy
S
Service de Bactériologie-Virologie, INSERM U914 Emerging Resistance to Antibiotics, Hôpital de Bicêtre, 78 Rue du Général Leclerc, 94275 Le Kremlin-Bicêtre Cedex, France.
Poirel
Laurent
L
Croize
Jacques
J
Recule
Christine
C
Nordmann
Patrice
P
D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D015780:Carbapenems / Q000494:pharmacology*; D004251:DNA Transposable Elements; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics*
D015780:Carbapenems; D004251:DNA Transposable Elements; D001618:beta-Lactamases; C108449:oxacillinase