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Holarrhena antidysenterica Extract and Its Steroidal Alkaloid, Conessine, as Resistance-Modifying Agents Against Extensively Drug-Resistant Acinetobacter baumannii
- Source :
- Microbial Drug Resistance. 22:273-282
- Publication Year :
- 2016
- Publisher :
- Mary Ann Liebert Inc, 2016.
-
Abstract
- Emergence and spread of antibiotic-resistant Acinetobacter baumannii have become a major public health concern. This study was designed to investigate the efficacy of Holarrhena antidysenterica extract and its major steroidal alkaloid conessine as resistance-modifying agents (RMAs) on the susceptibility of A. baumannii to novobiocin and rifampicin. A significant synergistic activity of both the extract and conessine in combination with either novobiocin or rifampicin with fractional inhibitory concentration index ≤0.5 was demonstrated. Fluorescent dyes and different efflux pump inhibitors were used to further investigate the synergism. Increase in the uptake of 1-N-phenylnaphthylamine in the bacterial cells treated with the extract and conessine was not observed indicating that both substances did not act as permeabilizers. With regard to efflux pump inhibition, no accumulation in ethidium bromide (EtBr) was noticed suggesting that the AdeABC pump was not involved. In contrast, accumulation in Pyronin Y was significantly increased (p 0.05) demonstrating that the synergism was due to interference with the AdeIJK pump. Study on frequencies of the spontaneous mutational resistance to the extract in combination with antibiotics demonstrated attenuation in drug-resistant organisms. Thus, H. antidysenterica extract and conessine as RMAs may offer a combinatory therapy to restore antibiotic susceptibility in the extensively drug-resistant A. baumannii.
- Subjects :
- Acinetobacter baumannii
0301 basic medicine
Microbiology (medical)
030106 microbiology
Immunology
Microbial Sensitivity Tests
Drug resistance
Pharmacology
Microbiology
03 medical and health sciences
chemistry.chemical_compound
Alkaloids
Drug Resistance, Multiple, Bacterial
Ethidium
medicine
Humans
Pyronine
Novobiocin
Holarrhena
biology
Plant Extracts
Biological Transport
Drug Synergism
biology.organism_classification
Anti-Bacterial Agents
Conessine
1-Naphthylamine
030104 developmental biology
chemistry
Drug Therapy, Combination
Efflux
Rifampin
Ethidium bromide
Rifampicin
medicine.drug
Subjects
Details
- ISSN :
- 19318448 and 10766294
- Volume :
- 22
- Database :
- OpenAIRE
- Journal :
- Microbial Drug Resistance
- Accession number :
- edsair.doi.dedup.....d93bbe1200080e2a818b57ebc25ce889