Characteristics and diversity of mutations in regulatory genes of resistance-nodulation-cell division efflux pumps in association with drug-resistant clinical isolates of Acinetobacter baumannii
| Autor: | Zohreh Ghalavand, Abbas Yadegar, Gita Eslami, Bahare Salehi |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Acinetobacter baumannii
Male 0301 basic medicine Microbiology (medical) Imipenem 030106 microbiology Microbial Sensitivity Tests Drug resistance Tigecycline Iran lcsh:Infectious and parasitic diseases Microbiology 03 medical and health sciences Minimum inhibitory concentration Bacterial Proteins Drug Resistance Multiple Bacterial Efflux pumps inhibitor Genes Regulator medicine Humans lcsh:RC109-216 Pharmacology (medical) Aged RND-type efflux pumps biology business.industry Research Broth microdilution Public Health Environmental and Occupational Health Membrane Transport Proteins Gene Expression Regulation Bacterial Middle Aged biology.organism_classification 030104 developmental biology Infectious Diseases Two-component systems Mutation Colistin Efflux business Cell Division medicine.drug |
| Zdroj: | Antimicrobial Resistance and Infection Control Antimicrobial Resistance and Infection Control, Vol 10, Iss 1, Pp 1-12 (2021) |
| DOI: | 10.21203/rs.3.rs-46743/v1 |
| Popis: | BackgroundThis study was aimed to characterize the genetic diversity and expression of three putative resistance-nodulation-cell division (RND)-type efflux systems and their contribution to multidrug efflux in clinical isolates ofAcinetobacter baumannii.MethodsAntimicrobial susceptibility testing of 95A. baumanniiisolates was determined by Kirby-Bauer disk diffusion for 18 antibiotics and minimum inhibitory concentration (MIC) of colistin was determined by the broth microdilution method. Moreover, the MIC of five classes of antibiotics was assessed using E-test strips in the presence and absence of phenylalanine-arginine beta-naphthylamide (PAβN). Regulatory genes of the RND efflux pumps (adeRS,adeL,adeNandbaeSR) were subjected to sequencing. The relative expression ofadeB,adeGandadeJgenes was determined by quantitative real-time PCR (qRT-PCR).ResultsOverall, the majority of isolates (94%) were extensively drug-resistant (XDR). In the phenotypic assay, efflux pump activity was observed in 40% of the isolates against multiple antibiotics mainly tigecycline. However, we found no efflux activity against imipenem. Several amino acid substitutions were detected in the products of regulatory genes; except in AdeN. Of note, G186V mutation in AdeS was found to be associated with overexpression of its efflux pump. No insertion sequences were detected.ConclusionsOur findings outlined the role of RND efflux pumps in resistance ofA. baumanniito multiple antibiotics particularly tigecycline, and pointed out the importance of a variety of single mutations in the corresponding regulatory systems. Further studies are required to decipher the precise role of RND efflux pumps in multidrug-resistant clinical isolates ofA. baumannii. |
| Databáze: | OpenAIRE |
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