PUBLICATION
Dithiazole thione derivative as competitive NorA efflux pump inhibitor to curtail multi drug resistant clinical isolate of MRSA in a zebrafish infection model
- Authors
- Lowrence, R.C., Raman, T., Makala, H.V., Ulaganathan, V., Subramaniapillai, S.G., Kuppuswamy, A.A., Mani, A., Chittoor Neelakantan, S., Nagarajan, S.
- ID
- ZDB-PUB-160818-7
- Date
- 2016
- Source
- Applied Microbiology and Biotechnology 100(21): 9265-9281 (Journal)
- Registered Authors
- Keywords
- Ciprofloxacin, Dithiazole thiones, Efflux pump inhibitor, MIC reversal, MRSA, Zebrafish infection
- MeSH Terms
-
- Animals
- Anti-Bacterial Agents/administration & dosage*
- Bacterial Load
- Bacterial Proteins/antagonists & inhibitors*
- Ciprofloxacin/administration & dosage
- Disease Models, Animal
- Drug Resistance, Multiple, Bacterial/drug effects*
- Enzyme Inhibitors/administration & dosage
- Enzyme Inhibitors/chemical synthesis
- Enzyme Inhibitors/pharmacology*
- Gene Expression Profiling
- Methicillin-Resistant Staphylococcus aureus/drug effects*
- Multidrug Resistance-Associated Proteins/antagonists & inhibitors*
- Muscles/microbiology
- Real-Time Polymerase Chain Reaction
- Skin/microbiology
- Staphylococcal Infections/drug therapy*
- Staphylococcal Infections/microbiology
- Thiazoles/administration & dosage
- Thiazoles/pharmacology*
- Thiones/administration & dosage
- Thiones/pharmacology*
- Treatment Outcome
- Zebrafish
- PubMed
- 27531512 Full text @ Appl. Microbiol. Biotechnol.
Citation
Lowrence, R.C., Raman, T., Makala, H.V., Ulaganathan, V., Subramaniapillai, S.G., Kuppuswamy, A.A., Mani, A., Chittoor Neelakantan, S., Nagarajan, S. (2016) Dithiazole thione derivative as competitive NorA efflux pump inhibitor to curtail multi drug resistant clinical isolate of MRSA in a zebrafish infection model. Applied Microbiology and Biotechnology. 100(21):9265-9281.
Abstract
Multi drug resistant (MDR) pathogens pose a serious threat to public health since they can easily render most potent drugs ineffective. Efflux pump inhibitors (EPI) can be used to counter the MDR phenotypes arising due to increased efflux. In the present study, a series of dithiazole thione derivatives were synthesized and checked for its antibacterial and efflux pump inhibitory (EPI) activity. Among 10 dithiazole thione derivatives, real-time efflux studies revealed that seven compounds were potent EPIs relative to CCCP. Zebrafish toxicity studies identified four non-toxic putative EPIs. Both DTT3 and DTT9 perturbed membrane potential and DTT6 was haemolytic. Among DTT6 and DTT10, the latter was less toxic as evidenced by histopathology studies. Since DTT10 was non-haemolytic, did not affect the membrane potential, and was least toxic, it was chosen further for in vivo study, wherein DTT10 potentiated effect of ciprofloxacin against clinical strain of MRSA and reduced bacterial burden in muscle and skin tissue of infected zebrafish by ~ 1.7 and 2.5 log fold respectively. Gene expression profiling of major efflux transport proteins by qPCR revealed that clinical isolate of MRSA, in the absence of antibiotic, upregulated NorA, NorB and MepA pump, whereas it downregulates NorC and MgrA relative to wild-type strain of Staphylococcus aureus. In vitro studies with NorA mutant strains and substrate profiling revealed that at higher concentrations DTT10 is likely to function as a competitive inhibitor of NorA efflux protein in S. aureus, whereas at lower concentrations it might inhibit ciprofloxacin efflux through NorB and MepA as implied by docking studies. A novel non-toxic, non-haemolytic dithiazole thione derivative (DTT10) was identified as a potent competitive inhibitor of NorA efflux pump in S. aureus using in silico, in vitro and in vivo studies. This study also underscores the importance of using zebrafish infection model to screen and evaluate putative EPI for mitigating MDR strains of S. aureus.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping