Molecular Biology of Multidrug Resistance Efflux Pumps of the Major Facilitator Superfamily from Bacterial Food Pathogens

Author(s):  
K.C. Ranjana ◽  
Ugina Shrestha ◽  
Sanath Kumar ◽  
Indrika Ranaweera ◽  
Prathusha Kakarla ◽  
...  
Author(s):  
Vanessa Kornelsen ◽  
Ayush Kumar

Acinetobacter spp. have become of increased clinical importance as studies have shown the antimicrobial resistant potential of these species. Efflux pumps can lead to reduced susceptibility to a variety of antibiotics and are present in large number across Acinetobacter spp. There are six families of efflux pumps that have been shown to be of clinical relevance: the Major Facilitator Superfamily (MFS), Small Multidrug Resistance (SMR) family, ATP-binding cassette (ABC) family, Multidrug and Toxic Compound Extrusion (MATE) family, Proteobacterial Antimicrobial Compound Efflux (PACE) family and Resistance-Nodulation-Division (RND) family. A lot of work has been done on understanding and characterizing the roles that these efflux pumps play in relation to antimicrobial resistance and the physiology of these bacteria. RND efflux pumps, with their expansive substrate profiles, are a major component of Acinetobacter spp. antimicrobial resistance. New discoveries over the last decade have shed a lot of light on to the complex regulation of these efflux pumps leading to greater understanding and potential of slowing the reduced susceptibility seen by these bacterial species.


2020 ◽  
Author(s):  
Yaojun Tong ◽  
Nuo Sun ◽  
Xiangming Wang ◽  
Qi Wei ◽  
Yu Zhang ◽  
...  

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.


2008 ◽  
Vol 28 (4) ◽  
pp. 217-228 ◽  
Author(s):  
Sneh Lata Panwar ◽  
Ritu Pasrija ◽  
Rajendra Prasad

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.


2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Xiaoran Ge ◽  
Yuying Cai ◽  
Zhenghong Chen ◽  
Sizhe Gao ◽  
Xiwen Geng ◽  
...  

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.


2009 ◽  
Vol 53 (11) ◽  
pp. 4673-4677 ◽  
Author(s):  
James J. Vecchione ◽  
Blair Alexander ◽  
Jason K. Sello

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.


2020 ◽  
Vol 8 (2) ◽  
pp. 266 ◽  
Author(s):  
Sanath Kumar ◽  
Manjusha Lekshmi ◽  
Ammini Parvathi ◽  
Manisha Ojha ◽  
Nicholas Wenzel ◽  
...  

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.


2019 ◽  
Vol 7 (9) ◽  
pp. 285 ◽  
Author(s):  
Pasqua ◽  
Grossi ◽  
Zennaro ◽  
Fanelli ◽  
Micheli ◽  
...  

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.


2001 ◽  
Vol 45 (5) ◽  
pp. 1528-1534 ◽  
Author(s):  
Patrı́cia A. Nunes ◽  
Sandra Tenreiro ◽  
Isabel Sá-Correia

ABSTRACT As predicted based on structural considerations, we show results indicating that the member of the major facilitator superfamily encoded by Saccharomyces cerevisiae open reading frameYIL120w is a multidrug resistance determinant. Yil120wp was implicated in yeast resistance to ketoconazole and quinidine, but not to the stereoisomer quinine; the gene was thus named QDR1. Qdr1p was proved to alleviate the deleterious effects of quinidine, revealed by the loss of cell viability following sudden exposure of the unadapted yeast population to the drug, and to allow the earlier eventual resumption of exponential growth under quinidine stress. However, QDR1 gene expression had no detectable effect on the susceptibility of yeast cells previously adapted to quinidine. Fluorescence microscopy observation of the distribution of the Qdr1-green fluorescent protein fusion protein in living yeast cells indicated that Qdr1p is a plasma membrane protein. We also show experimental evidence indicating that yeast adaptation to growth with quinidine involves the induction of active expulsion of the drug from preloaded cells, despite the fact that this antiarrhythmic and antimalarial quinoline ring-containing drug is not present in the yeast natural environment. However, we were not able to prove that Qdr1p is directly implicated in this export. Results clearly suggest that there are other unidentified quinidine resistance mechanisms that can be used in the absence of QDR1.


2021 ◽  
Vol 14 (6) ◽  
pp. 572
Author(s):  
Fernando Durães ◽  
Andreia Palmeira ◽  
Bárbara Cruz ◽  
Joana Freitas-Silva ◽  
Nikoletta Szemerédi ◽  
...  

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.


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