scholarly journals Functional Characterization of Brucella melitensis NorMI, an Efflux Pump Belonging to the Multidrug and Toxic Compound Extrusion Family

2002 ◽  
Vol 46 (9) ◽  
pp. 3050-3053 ◽  
Author(s):  
Martine Braibant ◽  
Laurence Guilloteau ◽  
Michel S. Zygmunt

ABSTRACT Two putative proteins (NorMI and NorMII) similar to the multidrug efflux protein NorM of Vibrio parahaemolyticus are encoded by the Brucella melitensis 16 M genome. We show that a drug-hypersusceptible Escherichia coli strain overexpressing NorMI displays increased resistance to norfloxacin, ciprofloxacin, gentamicin, tetraphenylphosphonium ion, acriflavine, and berberine. This elevated resistance was proven to be mediated by an energy-dependent efflux mechanism. NorMI belongs to the multidrug and toxic compound extrusion family and is the first multidrug efflux protein identified in Brucella spp.

2000 ◽  
Vol 182 (23) ◽  
pp. 6694-6697 ◽  
Author(s):  
Yuji Morita ◽  
Atsuko Kataoka ◽  
Sumiko Shiota ◽  
Tohru Mizushima ◽  
Tomofusa Tsuchiya

ABSTRACT NorM of Vibrio parahaemolyticusapparently is a new type of multidrug efflux protein, with no significant sequence similarity to any known transport proteins. Based on the following experimental results, we conclude that NorM is an Na+-driven Na+/drug antiporter. (i) Energy-dependent ethidium efflux from cells possessing NorM was observed in the presence of Na+ but not of K+. (ii) An artificially imposed, inwardly directed Na+gradient elicited ethidium efflux from cells. (iii) The addition of ethidium to cells loaded with Na+ elicited Na+efflux. Thus, NorM is an Na+/drug antiporting multidrug efflux pump, the first to be found in the biological world. Judging from the similarity of the NorM sequence to those of putative proteins in sequence databases, it seems that Na+/drug antiporters are present not only in V. parahaemolyticus but also in a wide range of other organisms.


2003 ◽  
Vol 47 (6) ◽  
pp. 419-427 ◽  
Author(s):  
Md. Nazmul Huda ◽  
Jing Chen ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  

2002 ◽  
Vol 46 (11) ◽  
pp. 3386-3393 ◽  
Author(s):  
Patricia Sánchez ◽  
Ana Alonso ◽  
Jose L. Martinez

ABSTRACT We report on the cloning of the gene smeT, which encodes the transcriptional regulator of the Stenotrophomonas maltophilia efflux pump SmeDEF. SmeT belongs to the TetR and AcrR family of transcriptional regulators. The smeT gene is located upstream from the structural operon of the pump genes smeDEF and is divergently transcribed from those genes. Experiments with S. maltophilia and the heterologous host Escherichia coli have demonstrated that SmeT is a transcriptional repressor. S1 nuclease mapping has demonstrated that expression of smeT is driven by a single promoter lying close to the 5′ end of the gene and that expression of smeDEF is driven by an unique promoter that overlaps with promoter PsmeT. The level of expression of smeT is higher in smeDEF-overproducing S. maltophilia strain D457R, which suggests that SmeT represses its own expression. Band-shifting assays have shown that wild-type strain S. maltophilia D457 contains a cellular factor(s) capable of binding to the intergenic smeT-smeD region. That cellular factor(s) was absent from smeDEF-overproducing S. maltophilia strain D457R. The sequence of smeT from D457R showed a point mutation that led to a Leu166Gln change within the SmeT protein. This change allowed overexpression of both smeDEF and smeT in D457R. It was noteworthy that expression of wild-type SmeT did not fully complement the smeT mutation in D457R. This suggests that the wild-type protein is not dominant over the mutant SmeT.


2018 ◽  
Vol 62 (9) ◽  
Author(s):  
María Pérez-Varela ◽  
Jordi Corral ◽  
Jesús Aranda ◽  
Jordi Barbé

ABSTRACTAcinetobacter baumanniihas emerged as an important multidrug-resistant nosocomial pathogen. In previous work, we identified a putative MFS transporter, AU097_RS17040, involved in the pathogenicity ofA. baumannii(M. Pérez-Varela, J. Corral, J. A. Vallejo, S. Rumbo-Feal, G. Bou, J. Aranda, and J. Barbé, Infect Immun 85:e00327-17, 2017,https://doi.org/10.1128/IAI.00327-17). In this study, we analyzed the susceptibility to diverse antimicrobial agents ofA. baumanniicells defective in this transporter, referred to as AbaQ. Our results showed that AbaQ is mainly involved in the extrusion of quinolone-type drugs inA. baumannii.


2008 ◽  
Vol 54 (5) ◽  
pp. 411-416 ◽  
Author(s):  
Sanela Begic ◽  
Elizabeth A. Worobec

Serratia marcescens is an important nosocomial agent having high antibiotic resistance. A major mechanism for S. marcescens antibiotic resistance is active efflux. To ascertain the substrate specificity of the S. marcescens SdeCDE efflux pump, we constructed pump gene deletion mutants. sdeCDE knockout strains showed no change in antibiotic susceptibility in comparison with the parental strains for any of the substrates, with the exception of novobiocin. In addition, novobiocin was the only antibiotic to be accumulated by sdeCDE-deficient strains. Based on the substrates used in our study, we conclude that SdeCDE is a Resistance–Nodulation–Cell Division family pump with limited substrate specificity.


2003 ◽  
Vol 47 (12) ◽  
pp. 937-943 ◽  
Author(s):  
Xing-Jue Xu ◽  
Xian-Zhong Su ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  

2003 ◽  
Vol 47 (9) ◽  
pp. 2990-2992 ◽  
Author(s):  
Hiroshi Sekiya ◽  
Takehiko Mima ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  

ABSTRACT We isolated mutant YM644, which showed elevated resistance to norfloxacin, ethidium bromide, acriflavine, and rhodamine 6G, from Pseudomonas aeruginosa YM64, a strain that lacks four major multidrug efflux pumps. The genes responsible for the resistance were mexHI-opmD. Elevated ethidium extrusion was observed with cells of YM644 and YM64 harboring a plasmid carrying the genes. Disruption of the genes in the chromosomal DNA of YM644 made the cells sensitive to the drugs.


Biochemistry ◽  
2007 ◽  
Vol 46 (17) ◽  
pp. 5218-5225 ◽  
Author(s):  
Zhongge Zhang ◽  
Che Ma ◽  
Owen Pornillos ◽  
Xia Xiu ◽  
Geoffrey Chang ◽  
...  

2009 ◽  
Vol 53 (5) ◽  
pp. 1921-1925 ◽  
Author(s):  
J. Blackman Northwood ◽  
M. Del Grosso ◽  
L. R. Cossins ◽  
M. D. Coley ◽  
R. Creti ◽  
...  

ABSTRACT The macrolide efflux mechanism of resistance, mef, was characterized in community-acquired respiratory tract infections with Streptococcus pyogenes. Fifty-four (4.6%) M phenotype isolates were screen tested as negative for mef(A). Of these 54 isolates, 5 (0.4%), 27 (2.3%), and 1 (0.1%) were considered to be mef(I) positive, a novel mosaic variant of mef, or a novel subclass of mef, respectively. This study shows (i) the definitive presence of mef(E) in S. pyogenes and its global distribution, (ii) the presence of a mosaic variant of mef composed of mef(A) and mef(E), (iii) the previously undescribed presence of mef(I) in S. pyogenes, and (iv) the presence of a novel subclass of mef in S. pyogenes.


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