Abrogation of pathogenic attributes in drug resistant Candida auris strains by farnesol

Drug Efflux ◽

Candida Auris ◽

AbstractCandida auris, a decade old Candida species, has been identified globally as a significant nosocomial multidrug resistant (MDR) pathogen responsible for causing invasive outbreaks. Biofilms and overexpression of efflux pumps such as Major Facilitator Superfamily and ATP Binding Cassette are known to cause multidrug resistance in Candida species, including C. auris. Therefore, targeting these factors may prove an effective approach to combat MDR in C. auris. In this study, 25 clinical isolates of C. auris from different hospitals of South Africa were used. All the isolates were found capable enough to form biofilms on 96-well microtiter plate that was further confirmed by MTT reduction assay. In addition, these strains have active drug efflux mechanism which was supported by rhodamine-6-G extracellular efflux and intracellular accumulation assays. Antifungal susceptibility profile of all the isolates against commonly used drugs was determined following CLSI recommended guidelines. We further studied the role of farnesol, an endogenous quorum sensing molecule, in modulating development of biofilms and drug efflux in C. auris. The MIC for planktonic cells ranged from 62.5-125 mM and for sessile cells was 125 mM (0 h and 4 h biofilm) and 500 mM (12 h and 24 h biofilm). Farnesol inhibited biofilm formation, blocked efflux pumps and downregulated biofilm- and efflux pump-associated genes. Modulation of C. auris biofilm formation and efflux pump activity by farnesol represent a promising approach for controlling life threatening infections caused by this pathogen.

Farnesol abrogates biofilm- and efflux pump- associated genes in drug resistant Candida auris strains

Access Microbiology ◽

10.1099/acmi.cc2021.po0012 ◽

2021 ◽

Vol 3 (12) ◽

Author(s):

Vartika Srivastava ◽

Aijaz Ahmad

Keyword(s):

Active Drug ◽

Efflux Pump ◽

Antifungal Susceptibility ◽

Efflux Pumps ◽

Multidrug Resistant ◽

Drug Efflux ◽

Candida Auris ◽

Efflux Mechanism ◽

Background: Candida auris, a decade old Candida species, has been identified globally as a significant nosocomial multidrug resistant (MDR) pathogen responsible for causing invasive outbreaks. Biofilms and over expression of efflux pumps such as Major Facilitator Superfamily and ATP Binding Cassette are known to cause multidrug resistance in Candida species, including C. auris. Therefore, targeting these factors may prove an effective approach to combat MDR in C. auris. Methods: In this study, 25 clinical isolates of C. auris from different hospitals of South Africa were used. Antifungal susceptibility profile of all the isolates against commonly used drugs was determined following CLSI recommended guidelines. Rhodamine-6-G extracellular efflux and intracellular accumulation assays were used to study active drug efflux mechanism. We further studied the role of farnesol in modulating development of biofilms and drug efflux in C. auris. Down-regulation of biofilm- and efflux pump- associated genes by farnesol was also investigated. CLSM analysis for examining C. auris biofilm architecture among treated and untreated isolates. Results: Most of the isolates (twenty-two) were found resistant to FLZ whereas five were resistant to AmB. All the isolates were found capable of biofilm formation and ornamented with active drug efflux mechanism. The MIC for planktonic cells ranged from 62.5-125 mM and for sessile cells was 125 mM (0 h and 4 h biofilm) and 500 mM (12 h and 24 h biofilm), CLSM studies also confirmed these findings. Farnesol also blocked efflux pumps and down-regulated biofilm- and efflux pump- associated genes. Conclusion: Modulation of biofilm- and efflux pump- associated genes by farnesol represent a promising approach in combating C. auris infection.

Berberine reverses multidrug resistance in Candida albicans by hijacking the drug efflux pump Mdr1p

10.1101/2020.06.26.173484 ◽

2020 ◽

Author(s):

Yaojun Tong ◽

Nuo Sun ◽

Xiangming Wang ◽

Qi Wei ◽

Yu Zhang ◽

...

Keyword(s):

Candida Albicans ◽

Multidrug Resistance ◽

Efflux Pump ◽

Efflux Pumps ◽

Multidrug Resistant ◽

Drug Efflux ◽

Multidrug Efflux Pump ◽

Drug Efflux Pumps ◽

AbstractClinical use of antimicrobials faces great challenges from the emergence of multidrug resistant (MDR) pathogens. The overexpression of drug efflux pumps is one of the major contributors to MDR. It is considered as a promising approach to overcome MDR by reversing the function of drug efflux pumps. In the life-threatening fungal pathogen Candida albicans, the major facilitator superfamily (MFS) transporter Mdr1p can excrete many structurally unrelated antifungals, leading to multidrug resistance. Here we report a counterintuitive case of reversing multidrug resistance in C. albicans by using a natural product berberine to hijack the overexpressed Mdr1p for its own importation. Moreover, we illustrate that the imported berberine accumulates in mitochondria, and compromises the mitochondrial function by impairing mitochondrial membrane potential and mitochondrial Complex I. It results in the selective elimination of Mdr1p overexpressed C. albicans cells. Furthermore, we show that berberine treatment can prolong the mean survival time (MST) of mice with a blood-borne dissemination of Mdr1p overexpressed multidrug resistant candidiasis. This study provided a potential direction of novel anti-MDR drug discovery by screening for multidrug efflux pump converters.

Bifunctional Enzyme SpoT Is Involved in Biofilm Formation ofHelicobacter pyloriwith Multidrug Resistance by Upregulating Efflux Pump Hp1174 (gluP)

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00957-18 ◽

2018 ◽

Vol 62 (11) ◽

Cited By ~ 9

Author(s):

Xiaoran Ge ◽

Yuying Cai ◽

Zhenghong Chen ◽

Sizhe Gao ◽

Xiwen Geng ◽

...

Keyword(s):

Multidrug Resistance ◽

Biofilm Formation ◽

Efflux Pump ◽

Efflux Pumps ◽

Multidrug Resistant ◽

Bifunctional Enzyme ◽

Content Type ◽

H Pylori ◽

ABSTRACTThe drug resistance ofHelicobacter pyloriis gradually becoming a serious problem. Biofilm formation is an important factor that leads to multidrug resistance (MDR) in bacteria. The ability ofH. pylorito form biofilms on the gastric mucosa is known. However, there are few studies on the regulatory mechanisms ofH. pyloribiofilm formation and multidrug resistance. Guanosine 3′-diphosphate 5′-triphosphate and guanosine 3′,5′-bispyrophosphate [(p)ppGpp] are global regulatory factors and are synthesized inH. pyloriby the bifunctional enzyme SpoT. It has been reported that (p)ppGpp is involved in the biofilm formation and multidrug resistance of various bacteria. In this study, we found that SpoT also plays an important role inH. pyloribiofilm formation and multidrug resistance. Therefore, it was necessary to carry out some further studies regarding its regulatory mechanism. Considering that efflux pumps are of great importance in the biofilm formation and multidrug resistance of bacteria, we tried to determine whether efflux pumps controlled by SpoT participate in these activities. We found that Hp1174 (glucose/galactose transporter [gluP]), an efflux pump of the major facilitator superfamily (MFS), is highly expressed in biofilm-forming and multidrug-resistant (MDR)H. pyloristrains and is upregulated by SpoT. Through further research, we determined thatgluPis involved inH. pyloribiofilm formation and multidrug resistance. Furthermore, the average expression level ofgluPin the clinical MDR strains (C-MDR) was considerably higher than that in the clinical drug-sensitive strains (C-DSS). Taken together, our results revealed a novel molecular mechanism ofH. pyloriresistance to multidrug exposure.

Membrane homoeostasis and multidrug resistance in yeast

Bioscience Reports ◽

10.1042/bsr20080071 ◽

2008 ◽

Vol 28 (4) ◽

pp. 217-228 ◽

Cited By ~ 17

Author(s):

Sneh Lata Panwar ◽

Ritu Pasrija ◽

Rajendra Prasad

Keyword(s):

Multidrug Resistance ◽

Efflux Pump ◽

Efflux Pumps ◽

Membrane Lipid ◽

Drug Efflux ◽

Proper Functioning ◽

Drug Efflux Pumps ◽

Drug Efflux Pump ◽

The development of MDR (multidrug resistance) in yeast is due to a number of mechanisms. The most documented mechanism is enhanced extrusion of drugs mediated by efflux pump proteins belonging to either the ABC (ATP-binding cassette) superfamily or MFS (major facilitator superfamily). These drug-efflux pump proteins are localized on the plasma membrane, and the milieu therein affects their proper functioning. Several recent studies demonstrate that fluctuations in membrane lipid composition affect the localization and proper functioning of the MDR efflux pump proteins. Interestingly, the efflux pumps of the ABC superfamily are particularly susceptible to imbalances in membrane-raft lipid constituents. This review focuses on the importance of the membrane environment in functioning of the drug-efflux pumps and explores a correlation between MDR and membrane lipid homoeostasis.

Antifungal Azoles as Tetracycline Resistance-Modifiers in Staphylococcus aureus

Applied and Environmental Microbiology ◽

10.1128/aem.00155-21 ◽

2021 ◽

Author(s):

Nisha Mahey ◽

Rushikesh Tambat ◽

Dipesh Kumar Verma ◽

Nishtha Chandal ◽

Krishan Gopal Thakur ◽

...

Keyword(s):

Staphylococcus Aureus ◽

In Silico ◽

Biofilm Formation ◽

Efflux Pump ◽

Efflux Pumps ◽

Efflux Pump Inhibitors ◽

Approved Drugs ◽

Staphylococcus aureus has developed resistance to antimicrobials since its first use. The S. aureus major facilitator superfamily (MFS) efflux pump Tet(K) contributes to resistance to tetracyclines. The efflux pump diminishes antibiotic accumulation, and biofilm hampers the diffusion of antibiotics. None of the currently known compounds have been approved as efflux pump inhibitors (EPIs) for clinical use. In the current study, we screened clinically approved drugs for possible Tet(K) efflux pump inhibition. In silico docking followed by in vitro checkerboard assays, we identified five azoles (the fungal ergosterol synthesis inhibitors) showing the putative EPI-like potential with a fractional inhibitory concentration index of ≤0.5, indicating synergism. The functionality of the azoles was confirmed using ethidium bromide (EtBr) accumulation and efflux inhibition assays. In time-kill kinetics, the combination treatment with butoconazole engendered a marked increase in the bactericidal capacity of tetracycline. When assessing the off-target effects of the azoles, we observed no disruption of bacterial membrane permeability and polarization. Finally, the combination of azoles with tetracycline led to a significant eradication of preformed mature biofilms. This study is the primary representation of azoles that can be repurposed as putative Tet(K) EPIs and to reduce biofilm formation at clinically relevant concentrations. IMPORTANCE Staphylococcus aureus use efflux pumps to transport antibiotics out of the cell and thus increase the dosage at which they endure antibiotics. Also, efflux pumps play a role in biofilm formation by the excretion of extracellular matrix molecules. One way to combat these pathogens may be to reduce the activity of efflux pumps and thereby increase pathogen sensitivity to existing antibiotics. We describe the in silico-based screen of clinically approved drugs that identified antifungal azoles inhibiting Tet(K); a pump belongs to the Major Facilitator Superfamily and shows that these compounds bind to and block the activity of the Tet(K) pump. Azoles enhanced the susceptibility of tetracycline against S. aureus and its methicillin-resistant strains. The combination of azoles with tetracycline led to a significant reduction in preformed biofilms. Repurposing of approved drugs may help solve the classical toxicity issues related to efflux pump inhibitors.

Two Distinct Major Facilitator Superfamily Drug Efflux Pumps Mediate Chloramphenicol Resistance in Streptomyces coelicolor

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00853-09 ◽

2009 ◽

Vol 53 (11) ◽

pp. 4673-4677 ◽

Cited By ~ 24

Author(s):

James J. Vecchione ◽

Blair Alexander ◽

Jason K. Sello

Keyword(s):

Efflux Pump ◽

Streptomyces Coelicolor ◽

Efflux Pumps ◽

Close Relative ◽

Gram Positive ◽

Antibacterial Drugs ◽

Chloramphenicol Resistance ◽

Drug Activity ◽

ABSTRACT Chloramphenicol, florfenicol, and thiamphenicol are used as antibacterial drugs in clinical and veterinary medicine. Two efflux pumps of the major facilitator superfamily encoded by the cmlR1 and cmlR2 genes mediate resistance to these antibiotics in Streptomyces coelicolor, a close relative of Mycobacterium tuberculosis. The transcription of both genes was observed by reverse transcription-PCR. Disruption of cmlR1 decreased the chloramphenicol MIC 1.6-fold, while disruption of cmlR2 lowered the MIC 16-fold. The chloramphenicol MIC of wild-type S. coelicolor decreased fourfold and eightfold in the presence of reserpine and Phe-Arg-β-naphthylamide, respectively. These compounds are known to potentiate the activity of some antibacterial drugs via efflux pump inhibition. While reserpine is known to potentiate drug activity against gram-positive bacteria, this is the first time that Phe-Arg-β-naphthylamide has been shown to potentiate drug activity against a gram-positive bacterium.

Functional and Structural Roles of the Major Facilitator Superfamily Bacterial Multidrug Efflux Pumps

Microorganisms ◽

10.3390/microorganisms8020266 ◽

2020 ◽

Vol 8 (2) ◽

pp. 266 ◽

Cited By ~ 5

Author(s):

Sanath Kumar ◽

Manjusha Lekshmi ◽

Ammini Parvathi ◽

Manisha Ojha ◽

Nicholas Wenzel ◽

...

Keyword(s):

Amino Acid ◽

Antimicrobial Agents ◽

Efflux Pumps ◽

Multidrug Resistant ◽

Amino Acid Sequences ◽

Multidrug Efflux ◽

Ion Translocation ◽

Multidrug Efflux Pumps ◽

Pathogenic microorganisms that are multidrug-resistant can pose severe clinical and public health concerns. In particular, bacterial multidrug efflux transporters of the major facilitator superfamily constitute a notable group of drug resistance mechanisms primarily because multidrug-resistant pathogens can become refractory to antimicrobial agents, thus resulting in potentially untreatable bacterial infections. The major facilitator superfamily is composed of thousands of solute transporters that are related in terms of their phylogenetic relationships, primary amino acid sequences, two- and three-dimensional structures, modes of energization (passive and secondary active), and in their mechanisms of solute and ion translocation across the membrane. The major facilitator superfamily is also composed of numerous families and sub-families of homologous transporters that are conserved across all living taxa, from bacteria to humans. Members of this superfamily share several classes of highly conserved amino acid sequence motifs that play essential mechanistic roles during transport. The structural and functional importance of multidrug efflux pumps that belong to the major facilitator family and that are harbored by Gram-negative and -positive bacterial pathogens are considered here.

The Varied Role of Efflux Pumps of the MFS Family in the Interplay of Bacteria with Animal and Plant Cells

Microorganisms ◽

10.3390/microorganisms7090285 ◽

2019 ◽

Vol 7 (9) ◽

pp. 285 ◽

Cited By ~ 7

Author(s):

Pasqua ◽

Grossi ◽

Zennaro ◽

Fanelli ◽

Micheli ◽

...

Keyword(s):

Regulatory Networks ◽

Efflux Pump ◽

Efflux Pumps ◽

Host Cells ◽

Multidrug Efflux ◽

Animal Cells ◽

Multidrug Efflux Pumps ◽

Wide Range ◽

Efflux pumps represent an important and large group of transporter proteins found in all organisms. The importance of efflux pumps resides in their ability to extrude a wide range of antibiotics, resulting in the emergence of multidrug resistance in many bacteria. Besides antibiotics, multidrug efflux pumps can also extrude a large variety of compounds: Bacterial metabolites, plant-produced compounds, quorum-sensing molecules, and virulence factors. This versatility makes efflux pumps relevant players in interactions not only with other bacteria, but also with plant or animal cells. The multidrug efflux pumps belonging to the major facilitator superfamily (MFS) are widely distributed in microbial genomes and exhibit a large spectrum of substrate specificities. Multidrug MFS efflux pumps are present either as single-component transporters or as tripartite complexes. In this review, we will summarize how the multidrug MFS efflux pumps contribute to the interplay between bacteria and targeted host cells, with emphasis on their role in bacterial virulence, in the colonization of plant and animal host cells and in biofilm formation. We will also address the complexity of these interactions in the light of the underlying regulatory networks required for the effective activation of efflux pump genes.

Antimicrobial Activity of a Library of Thioxanthones and Their Potential as Efflux Pump Inhibitors

Pharmaceuticals ◽

10.3390/ph14060572 ◽

2021 ◽

Vol 14 (6) ◽

pp. 572

Author(s):

Fernando Durães ◽

Andreia Palmeira ◽

Bárbara Cruz ◽

Joana Freitas-Silva ◽

Nikoletta Szemerédi ◽

...

Keyword(s):

Quorum Sensing ◽

Mammalian Cells ◽

Efflux Pump ◽

Efflux Pumps ◽

Design And Synthesis ◽

Resistance Nodulation Division ◽

Efflux Pump Inhibitors ◽

The overexpression of efflux pumps is one of the causes of multidrug resistance, which leads to the inefficacy of drugs. This plays a pivotal role in antimicrobial resistance, and the most notable pumps are the AcrAB-TolC system (AcrB belongs to the resistance-nodulation-division family) and the NorA, from the major facilitator superfamily. In bacteria, these structures can also favor virulence and adaptation mechanisms, such as quorum-sensing and the formation of biofilm. In this study, the design and synthesis of a library of thioxanthones as potential efflux pump inhibitors are described. The thioxanthone derivatives were investigated for their antibacterial activity and inhibition of efflux pumps, biofilm formation, and quorum-sensing. The compounds were also studied for their potential to interact with P-glycoprotein (P-gp, ABCB1), an efflux pump present in mammalian cells, and for their cytotoxicity in both mouse fibroblasts and human Caco-2 cells. The results concerning the real-time ethidium bromide accumulation may suggest a potential bacterial efflux pump inhibition, which has not yet been reported for thioxanthones. Moreover, in vitro studies in human cells demonstrated a lack of cytotoxicity for concentrations up to 20 µM in Caco-2 cells, with some derivatives also showing potential for P-gp modulation.