RT Journal Article
T1 Contribution of efflux pumps, porins, and β-lactamases to multidrug resistance in clinical isolates of Acinetobacter baumannii.
A1 Rumbo, C.
A1 Gato, E.
A1 López, M.
A1 Ruiz de Alegría, C.
A1 Fernández-Cuenca, F.
A1 Martínez-Martínez, L.
A1 Vila, J.
A1 Pachón, J.
A1 Cisneros, J. M.
A1 Rodríguez-Baño, J.
A1 Pascual, A.
A1 Bou, G.
A1 Tomás, M.
K1 Anti-Bacterial Agents
K1 Carbapenems
K1 Porins
K1 Quinolones
K1 Tetracyclines
K1 CL 331002
K1 beta-Lactamases
K1 Aminoglycosides
K1 Carbapenémicos
K1 Porinas
K1 Quinolonas
K1 Tetraciclinas
K1 beta-Lactamasas
K1 Aminoglicósidos
AB We investigated the mechanisms of resistance to carbapenems, aminoglycosides, glycylcyclines, tetracyclines, and quinolones in 90 multiresistant clinical strains of Acinetobacter baumannii isolated from two genetically unrelated A. baumannii clones: clone PFGE-ROC-1 (53 strains producing the OXA-58 β-lactamase enzyme and 18 strains with the OXA-24 β-lactamase) and clone PFGE-HUI-1 (19 strains susceptible to carbapenems). We used real-time reverse transcriptase PCR to correlate antimicrobial resistance (MICs) with expression of genes encoding chromosomal β-lactamases (AmpC and OXA-51), porins (OmpA, CarO, Omp33, Dcap-like, OprB, Omp25, OprC, OprD, and OmpW), and proteins integral to six efflux systems (AdeABC, AdeIJK, AdeFGH, CraA, AbeM, and AmvA). Overexpression of the AdeABC system (level of expression relative to that by A. baumannii ATCC 17978, 30- to 45-fold) was significantly associated with resistance to tigecycline, minocycline, and gentamicin and other biological functions. However, hyperexpression of the AdeIJK efflux pump (level of expression relative to that by A. baumannii ATCC 17978, 8- to 10-fold) was significantly associated only with resistance to tigecycline and minocycline (to which the TetB efflux system also contributed). TetB and TetA(39) efflux pumps were detected in clinical strains and were associated with resistance to tetracyclines and doxycycline. The absence of the AdeABC system and the lack of expression of other mechanisms suggest that tigecycline-resistant strains of the PFGE-HUI-1 clone may be associated with a novel resistance-nodulation-cell efflux pump (decreased MICs in the presence of the inhibitor Phe-Arg β-naphthylamide dihydrochloride) and the TetA(39) system.
PB American Society for Microbiology
SN 0066-4804
YR 2013
FD 2013-11
LK http://hdl.handle.net/10668/2003
UL http://hdl.handle.net/10668/2003
LA en
NO Rumbo C, Gato E, López M, Ruiz de Alegría C, Fernández-Cuenca F, Martínez-Martínez L, et al. Contribution of efflux pumps, porins, and β-lactamases to multidrug resistance in clinical isolates of Acinetobacter baumannii. Antimicrob Agents Chemother. 2013; 57(11):5247-57
NO Journal Article; Research Support, Non-U.S. Gov't;
DS RISalud
RD Apr 8, 2025