Functional Characterization of AbeD, an RND-Type Membrane Transporter in Antimicrobial Resistance in Acinetobacter baumannii.

Vijaya Bharathi Srinivasan,Amitabha Mondal,Govindan Rajamohan,Manjunath Venkataramaiah,Christiane Forestier

doi:10.1371/journal.pone.0141314

Vijaya Bharathi Srinivasan, Amitabha Mondal + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0141314

Copy DOI

Journal: PloS one	Publication Date: Oct 23, 2015
Citations: 47	License type: CC BY 4.0

Affiliation: Institute of Microbial Technology

Abstract

Background Acinetobacter baumannii is becoming an increasing menace in health care settings especially in the intensive care units due to its ability to withstand adverse environmental conditions and exhibit innate resistance to different classes of antibiotics. Here we describe the biological contributions of abeD, a novel membrane transporter in bacterial stress response and antimicrobial resistance in A. baumannii.ResultsThe abeD mutant displayed ~ 3.37 fold decreased survival and >5-fold reduced growth in hostile osmotic (0.25 M; NaCl) and oxidative (2.631 μM–6.574 μM; H2O2) stress conditions respectively. The abeD inactivated cells displayed increased susceptibility to ceftriaxone, gentamicin, rifampicin and tobramycin (~ 4.0 fold). The mutant displayed increased sensitivity to the hospital-based disinfectant benzalkonium chloride (~3.18-fold). In Caenorhabditis elegans model, the abeD mutant exhibited (P<0.01) lower virulence capability. Binding of SoxR on the regulatory fragments of abeD provide strong evidence for the involvement of SoxR system in regulating the expression of abeD in A. baumannii.ConclusionThis study demonstrates the contributions of membrane transporter AbeD in bacterial physiology, stress response and antimicrobial resistance in A. baumannii for the first time.

Highlights

Acinetobacter baumannii is a nosocomial pathogen that causes a wide range of clinical illnesses in immunocompromised patients including bacteremia, pneumonia, meningitis, urinary tract, wound and skin infections [1]
We describe the biological contributions of abeD, a novel membrane transporter in bacterial stress response and antimicrobial resistance in A. baumannii
This study demonstrates the contributions of membrane transporter AbeD in bacterial physiology, stress response and antimicrobial resistance in A. baumannii for the first time

Summary

Introduction

Acinetobacter baumannii is a nosocomial pathogen that causes a wide range of clinical illnesses in immunocompromised patients including bacteremia, pneumonia, meningitis, urinary tract, wound and skin infections [1]. A report from India suggests that around ~ 10% of all hospital-acquired infections were caused by A. baumannii [4, 5]. Though A. baumannii has the ability to acquire additional resistance elements, overproduction of membrane transporters having wide spectrum antibiotic preference is well correlated with the multidrug resistance (MDR) phenotype displayed by this notorious human pathogen [6, 7]. Acinetobacter baumannii is becoming an increasing menace in health care settings especially in the intensive care units due to its ability to withstand adverse environmental conditions and exhibit innate resistance to different classes of antibiotics. We describe the biological contributions of abeD, a novel membrane transporter in bacterial stress response and antimicrobial resistance in A. baumannii.

Methods

Results

Discussion

Conclusion