Introduction: In the past decade, multidrug-resistant Acinetobacter baumannii has become one of the most critical challenges in treating infected patients. The AdeABC efflux pump is the most important among the various resistance mechanisms. This pump can force various antibiotics and ethidium bromide out of the bacterial cell to the surrounding environment. Methods: In this study, nine A. baum...

Introduction:Acinetobacter baumannii is an opportunistic nosocomial pathogen associated with multiple infections. This pathogen usually colonizes (first stage of microbial infection) host tissues that are in contact with the external environment. As one of the sites of entry in human hosts is the gastrointestinal tract, the pathogen must be capable of tolerating bile salts. However, studies ana...

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 s...

Increased expression of chromosomal genes for resistance-nodulation-cell division-type efflux systems plays a major role in the multidrug resistance of Acinetobacter baumannii Little is known about the genetic characteristics of clinical strains of Acinetobacter baumannii lacking the AdeABC pump. In this study, we sequenced the genome of clinical strain Ab421 GEIH-2010 (belonging to clone ST79/...

The objective of this study was to explore the molecular epidemiology and the genetic support of clinical multidrug resistant (MDR) Acinetobacter baumannii (A. baumannii) isolates in an ICU ward of a comprehensive hospital. A total of 102 non-duplicate drug-resistant A. baumannii isolates were identified and 93 (91.1%) of them were MDR strains. Molecular analysis demonstrated that carbapenemase...

AdeR-AdeS is a two-component regulatory system, which controls expression of the adeABC efflux pump involved in Acinetobacter baumannii multidrug resistance. AdeR is a response regulator consisting of an N-terminal receiver domain and a C-terminal DNA-binding-domain. AdeR binds to a direct-repeat DNA in the intercistronic region between adeR and adeABC. We demonstrate a markedly high affinity b...

Carbapenem-hydrolyzing oxacillinases are reported increasingly in Acinetobacter baumannii. Since they hydrolyze carbapenems at low levels, the roles of carbapenem-hydrolyzing oxacillinases OXA-23, OXA-40, and OXA-58 in A. baumannii were determined. The bla(OXA-23), bla(OXA-40), and bla(OXA-58) genes were inserted in broad-host-range plasmid pAT801 and transformed in Escherichia coli DH10B and i...