scholarly journals Functional Relevance of Unstructured Regions of AcrA, the Periplasmic Adaptor of the Major Multidrug Efflux System in E. coli

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Isoiza Ojo ◽  
Yinan Wei
Keyword(s):  
Multidrug Efflux ◽  
Efflux System ◽  
E Coli ◽  
Functional Relevance ◽  
Multidrug Efflux System ◽  
Unstructured Regions

scholarly journals AcrAB Efflux System: Expression and Contribution to Fluoroquinolone Resistance in Klebsiella spp

2002 ◽  
Vol 46 (12) ◽  
pp. 3984-3986 ◽  
Author(s):  
Annarita Mazzariol ◽  
Jessica Zuliani ◽  
Giuseppe Cornaglia ◽  
Gian Maria Rossolini ◽  
Roberta Fontana
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Oxytoca ◽  
Fluoroquinolone Resistance ◽  
Multidrug Efflux ◽  
Efflux System ◽  
E Coli ◽  
Almost All ◽  
Klebsiella Spp ◽  
Different Levels ◽  
Multidrug Efflux System

ABSTRACT Seven Klebsiella pneumoniae and four Klebsiella oxytoca clinical isolates with different levels of resistance to ciprofloxacin were studied. Mutations in the topoisomerase genes were found in almost all strains, but the contribution of a multidrug efflux system homologous to AcrAB in Escherichia coli was also observed. Overexpression of this efflux system was demonstrated by immunoblotting with antibodies against E. coli AcrA.

scholarly journals Study of Multidrug Efflux System Protein Degradation in E. coli Using Transposons Library

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Prasangi Irosha Rajapaksha ◽  
Yinan Wei
Keyword(s):  
Protein Degradation ◽  
Multidrug Efflux ◽  
Efflux System ◽  
E Coli ◽  
Multidrug Efflux System

NorM, a Putative Multidrug Efflux Protein, of Vibrio parahaemolyticus and Its Homolog in Escherichia coli

1998 ◽  
Vol 42 (7) ◽  
pp. 1778-1782 ◽  
Author(s):  
Yuji Morita ◽  
Kazuyo Kodama ◽  
Sumiko Shiota ◽  
Tomoyuki Mine ◽  
Atsuko Kataoka ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vibrio Parahaemolyticus ◽  
Sequence Similarity ◽  
Multidrug Efflux ◽  
Chromosomal Dna ◽  
Efflux System ◽  
Significant Sequence Similarity ◽  
E Coli ◽  
Energy Dependent ◽  
Multidrug Efflux System

ABSTRACT We found that cells of Vibrio parahaemolyticus possess an energy-dependent efflux system for norfloxacin. We cloned a gene for a putative norfloxacin efflux protein from the chromosomal DNA ofV. parahaemolyticus by using an Escherichia coli mutant lacking the major multidrug efflux system AcrAB as the host and sequenced the gene (norM). Cells of E. coli transformed with a plasmid carrying the norMgene showed elevated energy-dependent efflux of norfloxacin. The transformants showed elevated resistance not only to norfloxacin and ciprofloxacin but also to the structurally unrelated compounds ethidium, kanamycin, and streptomycin. These results suggest that this is a multidrug efflux system. The hydropathy pattern of the deduced amino acid sequence of NorM suggested the presence of 12 transmembrane domains. The deduced primary structure of NorM showed 57% identity and 88% similarity with that of a hypothetical E. coli membrane protein, YdhE. No reported drug efflux protein in the sequence databases showed significant sequence similarity with NorM. Thus, NorM seems to be a novel type of multidrug efflux protein. We cloned the ydhE gene from E. coli. Cells ofE. coli transformed with the cloned ydhE gene showed elevated resistance to norfloxacin, ciprofloxacin, acriflavine, and tetraphenylphosphonium ion, but not to ethidium, when MICs were measured. Thus, it seems that NorM and YdhE differ somehow in substrate specificity.

BmeRABC5 Is a Multidrug Efflux System That Can Confer Metronidazole Resistance inBacteroides fragilis

2007 ◽  
Vol 13 (2) ◽  
pp. 96-101 ◽  
Author(s):  
Lilian Pumbwe ◽  
Abraham Chang ◽  
Rachel L. Smith ◽  
Hannah M. Wexler
Keyword(s):  
Multidrug Efflux ◽  
Efflux System ◽  
Metronidazole Resistance ◽  
Multidrug Efflux System

scholarly journals Meropenem potentiation of aminoglycoside activity against Pseudomonas aeruginosa: involvement of the MexXY-OprM multidrug efflux system

2018 ◽  
Vol 73 (5) ◽  
pp. 1247-1255 ◽  
Author(s):  
Keith Poole ◽  
Christie Gilmour ◽  
Maya A Farha ◽  
Michael D Parkins ◽  
Rachael Klinoski ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Efflux ◽  
Efflux System ◽  
Multidrug Efflux System

scholarly journals Multidrug efflux in intrinsic resistance to trimethoprim and sulfamethoxazole in Pseudomonas aeruginosa.

1996 ◽  
Vol 40 (10) ◽  
pp. 2288-2290 ◽  
Author(s):  
T Köhler ◽  
M Kok ◽  
M Michea-Hamzehpour ◽  
P Plesiat ◽  
N Gotoh ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane Proteins ◽  
Multiple Drug ◽  
Drug Efflux ◽  
Wild Type ◽  
Multidrug Efflux ◽  
Efflux System ◽  
Intrinsic Resistance ◽  
Wild Type Parent ◽  
Multidrug Efflux System

Pseudomonas aeruginosa possesses at least two multiple drug efflux systems which are defined by the outer membrane proteins OprM and OprJ. We have found that mutants overexpressing OprM were two- and eightfold more resistant than their wild-type parent to sulfamethoxazole (SMX) and trimethoprim (TMP), respectively. For OprJ-overproducing strains, MICs of TMP increased fourfold but those of SMX were unchanged. Strains overexpressing OprM, but not those overexpressing OprJ, became hypersusceptible to TMP and SMX when oprM was inactivated. The wild-type antibiotic profile could be restored in an oprM mutant by transcomplementation with the cloned oprM gene. These results demonstrate that the mexABoprM multidrug efflux system is mainly responsible for the intrinsic resistance of P. aeruginosa to TMP and SMX.

scholarly journals Expression of Pseudomonas aeruginosa Multidrug Efflux Pumps MexA-MexB-OprM and MexC-MexD-OprJ in a Multidrug-Sensitive Escherichia coli Strain

1998 ◽  
Vol 42 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Ramakrishnan Srikumar ◽  
Tatiana Kon ◽  
Naomasa Gotoh ◽  
Keith Poole
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Crystal Violet ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Multidrug Efflux ◽  
Efflux System ◽  
E Coli ◽  
Multidrug Efflux Pumps

ABSTRACT The mexCD-oprJ and mexAB-oprM operons encode components of two distinct multidrug efflux pumps inPseudomonas aeruginosa. To assess the contribution of individual components to antibiotic resistance and substrate specificity, these operons and their component genes were cloned and expressed in Escherichia coli. Western immunoblotting confirmed expression of the P. aeruginosa efflux pump components in E. coli strains expressing and deficient in the endogenous multidrug efflux system (AcrAB), although only the ΔacrAB strain, KZM120, demonstrated increased resistance to antibiotics in the presence of the P. aeruginosa efflux genes. E. coli KZM120 expressing MexAB-OprM showed increased resistance to quinolones, chloramphenicol, erythromycin, azithromycin, sodium dodecyl sulfate (SDS), crystal violet, novobiocin, and, significantly, several β-lactams, which is reminiscent of the operation of this pump in P. aeruginosa. This confirmed previous suggestions that MexAB-OprM provides a direct contribution to β-lactam resistance via the efflux of this group of antibiotics. An increase in antibiotic resistance, however, was not observed when MexAB or OprM alone was expressed in KZM120. Thus, despite the fact that β-lactams act within the periplasm, OprM alone is insufficient to provide resistance to these agents. E. coli KZM120 expressing MexCD-OprJ also showed increased resistance to quinolones, chloramphenicol, macrolides, SDS, and crystal violet, though not to most β-lactams or novobiocin, again somewhat reminiscent of the antibiotic resistance profile of MexCD-OprJ-expressing strains ofP. aeruginosa. Surprisingly, E. coli KZM120 expressing MexCD alone also showed an increase in resistance to these agents, while an OprJ-expressing KZM120 failed to demonstrate any increase in antibiotic resistance. MexCD-mediated resistance, however, was absent in a tolC mutant of KZM120, indicating that MexCD functions in KZM120 in conjunction with TolC, the previously identified outer membrane component of the AcrAB-TolC efflux system. These data confirm that a tripartite efflux pump is necessary for the efflux of all substrate antibiotics and that the P. aeruginosa multidrug efflux pumps are functional and retain their substrate specificity in E. coli.

scholarly journals Conformational Flexibility in the Multidrug Efflux System Protein AcrA

Structure ◽  
2006 ◽  
Vol 14 (3) ◽  
pp. 577-587 ◽  
Author(s):  
Jonathan Mikolosko ◽  
Kostyantyn Bobyk ◽  
Helen I. Zgurskaya ◽  
Partho Ghosh
Keyword(s):  
Conformational Flexibility ◽  
Multidrug Efflux ◽  
Efflux System ◽  
Multidrug Efflux System
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