scholarly journals MFS1, a Pleiotropic Transporter in Dermatophytes That Plays a Key Role in Their Intrinsic Resistance to Chloramphenicol and Fluconazole

2021 ◽  
Vol 7 (7) ◽  
pp. 542
Author(s):  
Tsuyoshi Yamada ◽  
Takashi Yaguchi ◽  
Karine Salamin ◽  
Emmanuella Guenova ◽  
Marc Feuermann ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Trichophyton Rubrum ◽  
Efflux Pump ◽  
Major Facilitator Superfamily ◽  
Intrinsic Resistance ◽  
Azole Antifungals ◽  
Trichophyton Benhamiae ◽  
High Minimum Inhibitory Concentration ◽  
Major Facilitator

A recently identified Trichophyton rubrum major facilitator superfamily (MFS)-type transporter (TruMFS1) has been shown to give resistance to azole compounds and cycloheximide (CYH) when overexpressed in Saccharomyces cerevisiae. We investigated the roles of MFS1 in the intrinsic resistance of dermatophytes to CYH and chloramphenicol (CHL), which are commonly used to isolate these fungi, and to what extent MFS1 affects the susceptibility to azole antifungals. Susceptibility to antibiotics and azoles was tested in S. cerevisiae overexpressing MFS1 and ΔMFS1 mutants of Trichophyton benhamiae, a dermatophyte that is closely related to T. rubrum. We found that TruMFS1 functions as an efflux pump for CHL in addition to CYH and azoles in S. cerevisiae. In contrast, the growth of T. benhamiae ΔMFS1 mutants was not reduced in the presence of CYH but was severely impaired in the presence of CHL and thiamphenicol, a CHL analog. The suppression of MFS1 in T. benhamiae also increased the sensitivity of the fungus to fluconazole and miconazole. Our experiments revealed a key role of MFS1 in the resistance of dermatophytes to CHL and their high minimum inhibitory concentration for fluconazole. Suppression of MFS1 did not affect the sensitivity to CYH, suggesting that another mechanism was involved in resistance to CYH in dermatophytes.

Tigecycline efflux in Acinetobacter baumannii is mediated by TetA in synergy with RND-type efflux transporters

2020 ◽  
Vol 75 (5) ◽  
pp. 1135-1139 ◽  
Author(s):  
Wuen Ee Foong ◽  
Jochen Wilhelm ◽  
Heng-Keat Tam ◽  
Klaas M Pos
Keyword(s):  
Acinetobacter Baumannii ◽  
Efflux Pump ◽  
Gene Knockout ◽  
Drug Susceptibility ◽  
Major Facilitator Superfamily ◽  
Rt Pcr ◽  
E Coli ◽  
Rnd Efflux Pump ◽  
Major Facilitator

Abstract Objectives To investigate the role of Major Facilitator Superfamily (MFS)-type transporters from Acinetobacter baumannii AYE in tigecycline efflux. Methods Two putative tetracycline transporter genes of A. baumannii AYE (tetA and tetG) were heterologously expressed in Escherichia coli and drug susceptibility assays were conducted with tigecycline and three other tetracycline derivatives. The importance of TetA in tigecycline transport in A. baumannii was determined by complementation of tetA in WT and Resistance Nodulation cell Division (RND) gene knockout strains of A. baumannii ATCC 19606. Gene expression of the MFS-type tetA gene and RND efflux pump genes adeB, adeG and adeJ in A. baumannii AYE in the presence of tigecycline was analysed by quantitative real-time RT–PCR. Results Overproduction of TetA or TetG conferred resistance to doxycycline, minocycline and tetracycline in E. coli. Cells expressing tetA, but not those expressing tetG, conferred resistance to tigecycline, implying that TetA is a determinant for tigecycline transport. A. baumannii WT and RND-knockout strains complemented with plasmid-encoded tetA are significantly less susceptible to tigecycline compared with non-complemented strains. Efflux pump genes tetA and adeG are up-regulated in A. baumannii AYE in the presence of subinhibitory tigecycline concentrations. Conclusions TetA plays an important role in tigecycline efflux of A. baumannii by removing the drug from cytoplasm to periplasm and, subsequently, the RND-type transporters AdeABC and AdeIJK extrude tigecycline across the outer membrane. When challenged with tigecycline, tetA is up-regulated in A. baumannii AYE. Synergy between TetA and the RND-type transporters AdeABC and/or AdeIJK appears necessary for A. baumannii to confer higher tigecycline resistance via drug efflux.

scholarly journals CraA, a Major Facilitator Superfamily Efflux Pump Associated with Chloramphenicol Resistance in Acinetobacter baumannii

2009 ◽  
Vol 53 (9) ◽  
pp. 4013-4014 ◽  
Author(s):  
I. Roca ◽  
S. Marti ◽  
P. Espinal ◽  
P. Martínez ◽  
I. Gibert ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Acinetobacter Baumannii ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Major Facilitator Superfamily ◽  
Intrinsic Resistance ◽  
Chloramphenicol Resistance ◽  
Hospital Acquired Infections ◽  
Major Facilitator ◽  
Hospital Acquired

ABSTRACT Acinetobacter baumannii has been increasingly associated with hospital-acquired infections, and the presence of multidrug resistance strains is of great concern to clinicians. A. baumannii is thought to possess a great deal of intrinsic resistance to several antimicrobial agents, including chloramphenicol, although the mechanisms involved in such resistance are not well understood. In this work, we have identified a major facilitator superfamily efflux pump present in most A. baumannii strains, displaying strong substrate specificity toward chloramphenicol.

scholarly journals Antibiotic Susceptibility Profiles ofEscherichia coli Strains Lacking Multidrug Efflux Pump Genes

2001 ◽  
Vol 45 (4) ◽  
pp. 1126-1136 ◽  
Author(s):  
Mark C. Sulavik ◽  
Chad Houseweart ◽  
Christina Cramer ◽  
Nilofer Jiwani ◽  
Nicholas Murgolo ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Efflux Pump ◽  
Major Facilitator Superfamily ◽  
Multidrug Efflux ◽  
Intrinsic Resistance ◽  
Multidrug Efflux Pump ◽  
Gene Deletions ◽  
Small Multidrug Resistance ◽  
Major Facilitator ◽  
Susceptibility Profiles

ABSTRACT The contribution of seven known and nine predicted genes or operons associated with multidrug resistance to the susceptibility of Escherichia coli W3110 was assessed for 20 different classes of antimicrobial compounds that include antibiotics, antiseptics, detergents, and dyes. Strains were constructed with deletions for genes in the major facilitator superfamily, the resistance nodulation-cell division family, the small multidrug resistance family, the ATP-binding cassette family, and outer membrane factors. The agar dilution MICs of 35 compounds were determined for strains with deletions for multidrug resistance (MDR) pumps. Deletions in acrAB or tolC resulted in increased susceptibilities to the majority of compounds tested. The remaining MDR pump gene deletions resulted in increased susceptibilities to far fewer compounds. The results identify which MDR pumps contribute to intrinsic resistance under the conditions tested and supply practical information useful for designing sensitive assay strains for cell-based screening of antibacterial compounds.

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

2009 ◽  
Vol 53 (11) ◽  
pp. 4673-4677 ◽  
Author(s):  
James J. Vecchione ◽  
Blair Alexander ◽  
Jason K. Sello
Keyword(s):  
Efflux Pump ◽  
Streptomyces Coelicolor ◽  
Efflux Pumps ◽  
Major Facilitator Superfamily ◽  
Close Relative ◽  
Gram Positive ◽  
Antibacterial Drugs ◽  
Chloramphenicol Resistance ◽  
Drug Activity ◽  
Major Facilitator

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.

scholarly journals Structural and Functional Study of the Phenicol-Specific Efflux Pump FloR Belonging to the Major Facilitator Superfamily

2005 ◽  
Vol 49 (7) ◽  
pp. 2965-2971 ◽  
Author(s):  
Martine Braibant ◽  
Jacqueline Chevalier ◽  
Elisabeth Chaslus-Dancla ◽  
Jean-Marie Pagès ◽  
Axel Cloeckaert
Keyword(s):  
Efflux Pump ◽  
Major Facilitator Superfamily ◽  
Site Directed Mutagenesis ◽  
Functional Study ◽  
Efflux Transporters ◽  
Chloramphenicol Resistance ◽  
Active Efflux ◽  
Transmembrane Segments ◽  
Efflux Mechanism ◽  
Major Facilitator

ABSTRACT The florfenicol-chloramphenicol resistance gene floR from Salmonella enterica was previously identified and postulated to belong to the major facilitator (MF) superfamily of drug exporters. Here, we confirmed a computer-predicted transmembrane topological model of FloR, using the phoA gene fusion method, and classified this protein in the DHA12 family (containing 12 transmembrane domains) of MF efflux transporters. We also showed that FloR is a transporter specific for structurally associated phenicol drugs (chloramphenicol, florfenicol, thiamphenicol) which utilizes the proton motive force to energize an active efflux mechanism. By site-directed mutagenesis of specific charged residues belonging to putative transmembrane segments (TMS), two residues essential for active efflux function, D23 in TMS1 and R109 in TMS4, were identified. Of these, the acidic residue D23 seems to participate directly in the affinity pocket involved in phenicol derivative recognition. A third residue, E283 in TMS9, seems to be necessary for correct membrane folding of the transporter.

The mycobacterial efflux pump EfpA can induce high drug tolerance to many anti-tuberculosis drugs, including moxifloxacin, in Mycobacterium smegmatis

2021 ◽  
Author(s):  
Deepika Rai ◽  
Sarika Mehra
Keyword(s):  
Mycobacterium Smegmatis ◽  
Efflux Pump ◽  
Drug Tolerance ◽  
Inducible Promoter ◽  
Major Facilitator Superfamily ◽  
Expression Level ◽  
Efflux Pump Inhibitor ◽  
Gene Encoding ◽  
Active Efflux ◽  
Major Facilitator

Active efflux of drugs across the membrane is a major survival strategy of bacteria against many drugs. In this work, we characterize an efflux pump EfpA, from the major facilitator superfamily, that is highly conserved among both slow growing and fast-growing mycobacterium species and has been found to be upregulated in many clinical isolates of Mycobacterium tuberculosis . The gene encoding EfpA from Mycobacterium smegmatis was over-expressed under both constitutive and an inducible promoter. Expression of efpA gene under both the promoters resulted in greater than 32-fold increased drug tolerance of M. smegmatis cells to many first-line (rifampicin, isoniazid and streptomycin) and second-line (amikacin) anti-tuberculosis drugs. Notably, drug tolerance of M. smegmatis cells to moxifloxacin increased by more than 180-fold when efpA was over-expressed. The increase in minimum inhibitory concentration (MIC) correlated with the decreased uptake of drugs including norfloxacin, moxifloxacin and ethidium bromide and the high MIC could be reversed in the presence of an efflux pump inhibitor. A correlation was observed between the MIC of drugs and the efflux pump expression level, suggesting that the latter could be modulated by varying the expression level of the efflux pump. The expression of high levels of efpA did not impact the fitness of the cells when supplemented with glucose.The efpA gene is conserved across both pathogenic and non-pathogenic mycobacteria. The efpA gene from the Mycobacterium bovis BCG/ M. tuberculosis , which is 80% identical to efpA from M. smegmatis , also led to decreased antimicrobial efficacy to many drugs, although the fold-change was lower. When over-expressed in M. bovis BCG, an 8-fold higher drug tolerance to moxifloxacin was observed . This is the first report of an efflux pump from mycobacterium species that leads to higher drug tolerance to moxifloxacin, a promising new drug for the treatment of tuberculosis.

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

2019 ◽  
Vol 7 (9) ◽  
pp. 285 ◽  
Author(s):  
Pasqua ◽  
Grossi ◽  
Zennaro ◽  
Fanelli ◽  
Micheli ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Major Facilitator Superfamily ◽  
Host Cells ◽  
Multidrug Efflux ◽  
Animal Cells ◽  
Multidrug Efflux Pumps ◽  
Wide Range ◽  
Major Facilitator

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.

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

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 ◽  
Major Facilitator Superfamily ◽  
Design And Synthesis ◽  
Resistance Nodulation Division ◽  
Efflux Pump Inhibitors ◽  
Major Facilitator

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.

Sign in / Sign up

Export Citation Format

Share Document