scholarly journals Coordinate Hyperproduction of SmeZ and SmeJK Efflux Pumps Extends Drug Resistance in Stenotrophomonas maltophilia

2012 ◽  
Vol 57 (1) ◽  
pp. 655-657 ◽  
Author(s):  
Virginia C. Gould ◽  
Aki Okazaki ◽  
Matthew B. Avison
Keyword(s):  
Drug Resistance ◽  
Clinical Isolate ◽  
Clinical Relevance ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Content Type ◽  
Resistance Nodulation Division

ABSTRACTAStenotrophomonas maltophiliamutant that coordinately hyper-expresses three resistance nodulation division-type efflux pump genes,smeZ,smeJ, andsmeK, has been identified. SmeZ is responsible for elevating aminoglycoside MICs; SmeJ and SmeK are jointly responsible for elevating tetracycline, minocycline, and ciprofloxacin MICs and conferring levofloxacin resistance. One clinical isolate with this same phenotype was identified from a sample of six, and the isolate also coordinately hyper-expressessmeZandsmeJK, confirming the clinical relevance of our findings.

scholarly journals The SmeYZ Efflux Pump of Stenotrophomonas maltophilia Contributes to Drug Resistance, Virulence-Related Characteristics, and Virulence in Mice

2015 ◽  
Vol 59 (7) ◽  
pp. 4067-4073 ◽  
Author(s):  
Yi-Tsung Lin ◽  
Yi-Wei Huang ◽  
Shiang-Jiuun Chen ◽  
Chia-Wei Chang ◽  
Tsuey-Ching Yang
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Human Serum ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Gene Replacement ◽  
Content Type ◽  
Resistance Nodulation Division ◽  
Stress Susceptibility

ABSTRACTThe resistance-nodulation-division (RND)-type efflux pump is one of the causes of the multidrug resistance ofStenotrophomonas maltophilia. The roles of the RND-type efflux pump in physiological functions and virulence, in addition to antibiotic extrusion, have attracted much attention. In this study, the contributions of the constitutively expressed SmeYZ efflux pump to drug resistance, virulence-related characteristics, and virulence were evaluated.S. maltophiliaKJ is a clinical isolate of multidrug resistance. ThesmeYZisogenic deletion mutant, KJΔYZ, was constructed by a gene replacement strategy. The antimicrobial susceptibility, virulence-related physiological characteristics, susceptibility to human serum and neutrophils, andin vivovirulence between KJ and KJΔYZ were comparatively assessed. The SmeYZ efflux pump contributed resistance to aminoglycosides and trimethoprim-sulfamethoxazole. Inactivation ofsmeYZresulted in attenuation of oxidative stress susceptibility, swimming, flagella formation, biofilm formation, and secreted protease activity. Furthermore, loss of SmeYZ increased susceptibility to human serum and neutrophils and decreasedin vivovirulence in a murine model. These findings suggest the possibility of attenuation of the resistance and virulence ofS. maltophiliawith inhibitors of the SmeYZ efflux pump.

scholarly journals Contribution of Resistance-Nodulation-Division Efflux Pump OperonsmeU1-V-W-U2-Xto Multidrug Resistance of Stenotrophomonas maltophilia

2011 ◽  
Vol 55 (12) ◽  
pp. 5826-5833 ◽  
Author(s):  
Chao-Hsien Chen ◽  
Chiang-Ching Huang ◽  
Tsao-Chuen Chung ◽  
Rouh-Mei Hu ◽  
Yi-Wei Huang ◽  
...  
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Type Systems ◽  
Resistant Mutant ◽  
Multidrug Resistant ◽  
Content Type ◽  
Membrane Fusion Protein ◽  
Resistance Nodulation Division

ABSTRACTKJ09C, a multidrug-resistant mutant ofStenotrophomonas maltophiliaKJ, was generated byin vitroselection with chloramphenicol. The multidrug-resistant phenotype of KJ09C was attributed to overexpression of a resistance nodulation division (RND)-type efflux system encoded by an operon consisting of five genes:smeU1,smeV,smeW,smeU2, andsmeX. Proteins encoded bysmeV,smeW, andsmeXwere similar to the membrane fusion protein, RND transporter, and outer membrane protein, respectively, of known RND-type systems. The proteins encoded bysmeU1andsmeU2were found to belong to the family of short-chain dehydrogenases/reductases. Mutant KJ09C exhibited increased resistance to chloramphenicol, quinolones, and tetracyclines and susceptibility to aminoglycosides; susceptibility to β-lactams and erythromycin was not affected. The expression of thesmeU1-V-W-U2-Xoperon was regulated by the divergently transcribed LysR-type regulator genesmeRv. Overexpression of the SmeVWX pump contributed to the acquired resistance to chloramphenicol, quinolones, and tetracyclines. Inactivation ofsmeVandsmeWcompletely abolished the activity of the SmeVWX pump, whereas inactivation ofsmeXalone decreased the activity of the SmeVWX pump. The enhanced aminoglycoside susceptibility observed in KJ09C resulted from SmeX overexpression.

scholarly journals Molecular Mechanism of MBX2319 Inhibition of Escherichia coli AcrB Multidrug Efflux Pump and Comparison with Other Inhibitors

2014 ◽  
Vol 58 (10) ◽  
pp. 6224-6234 ◽  
Author(s):  
Attilio V. Vargiu ◽  
Paolo Ruggerone ◽  
Timothy J. Opperman ◽  
Son T. Nguyen ◽  
Hiroshi Nikaido
Keyword(s):  
Efflux Pump ◽  
Efflux Pumps ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Efflux Pump Inhibitor ◽  
Content Type ◽  
X Ray Crystallography ◽  
Resistance Nodulation Division ◽  
Hydrophobic Portion ◽  
Dynamics Simulations

ABSTRACTEfflux pumps of the resistance nodulation division (RND) superfamily, such as AcrB, make a major contribution to multidrug resistance in Gram-negative bacteria. The development of inhibitors of the RND pumps would improve the efficacy of current and next-generation antibiotics. To date, however, only one inhibitor has been cocrystallized with AcrB. Thus,in silicostructure-based analysis is essential for elucidating the interaction between other inhibitors and the efflux pumps. In this work, we used computer docking and molecular dynamics simulations to study the interaction between AcrB and the compound MBX2319, a novel pyranopyridine efflux pump inhibitor with potent activity against RND efflux pumps ofEnterobacteriaceaespecies, as well as other known inhibitors (D13-9001, 1-[1-naphthylmethyl]-piperazine, and phenylalanylarginine-β-naphthylamide) and the binding of doxorubicin to the efflux-defective F610A variant of AcrB. We also analyzed the binding of a substrate, minocycline, for comparison. Our results show that MBX2319 binds very tightly to the lower part of the distal pocket in the B protomer of AcrB, strongly interacting with the phenylalanines lining the hydrophobic trap, where the hydrophobic portion of D13-9001 was found to bind by X-ray crystallography. Additionally, MBX2319 binds to AcrB in a manner that is similar to the way in which doxorubicin binds to the F610A variant of AcrB. In contrast, 1-(1-naphthylmethyl)-piperazine and phenylalanylarginine-β-naphthylamide appear to bind to somewhat different areas of the distal pocket in the B protomer of AcrB than does MBX2319. However, all inhibitors (except D13-9001) appear to distort the structure of the distal pocket, impairing the proper binding of substrates.

scholarly journals Characterization of a Novel Pyranopyridine Inhibitor of the AcrAB Efflux Pump of Escherichia coli

2013 ◽  
Vol 58 (2) ◽  
pp. 722-733 ◽  
Author(s):  
Timothy J. Opperman ◽  
Steven M. Kwasny ◽  
Hong-Suk Kim ◽  
Son T. Nguyen ◽  
Chad Houseweart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Resistance Nodulation Division ◽  
Rnd Efflux Pumps ◽  
Acrab Efflux Pump

ABSTRACTMembers of the resistance-nodulation-division (RND) family of efflux pumps, such as AcrAB-TolC ofEscherichia coli, play major roles in multidrug resistance (MDR) in Gram-negative bacteria. A strategy for combating MDR is to develop efflux pump inhibitors (EPIs) for use in combination with an antibacterial agent. Here, we describe MBX2319, a novel pyranopyridine EPI with potent activity against RND efflux pumps of theEnterobacteriaceae. MBX2319 decreased the MICs of ciprofloxacin (CIP), levofloxacin, and piperacillin versusE. coliAB1157 by 2-, 4-, and 8-fold, respectively, but did not exhibit antibacterial activity alone and was not active against AcrAB-TolC-deficient strains. MBX2319 (3.13 μM) in combination with 0.016 μg/ml CIP (minimally bactericidal) decreased the viability (CFU/ml) ofE. coliAB1157 by 10,000-fold after 4 h of exposure, in comparison with 0.016 μg/ml CIP alone. In contrast, phenyl-arginine-β-naphthylamide (PAβN), a known EPI, did not increase the bactericidal activity of 0.016 μg/ml CIP at concentrations as high as 100 μM. MBX2319 increased intracellular accumulation of the fluorescent dye Hoechst 33342 in wild-type but not AcrAB-TolC-deficient strains and did not perturb the transmembrane proton gradient. MBX2319 was broadly active againstEnterobacteriaceaespecies andPseudomonas aeruginosa. MBX2319 is a potent EPI with possible utility as an adjunctive therapeutic agent for the treatment of infections caused by Gram-negative pathogens.

scholarly journals Role of smeU1VWU2X Operon in Alleviation of Oxidative Stresses and Occurrence of Sulfamethoxazole-Trimethoprim-Resistant Mutants in Stenotrophomonas maltophilia

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Chao-Jung Wu ◽  
Tsu-Ting Chiu ◽  
Yi-Tsung Lin ◽  
Yi-Wei Huang ◽  
Li-Hua Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Resistant Mutant ◽  
Efflux Pumps ◽  
Content Type ◽  
Fusion Construct ◽  
Bacterial Physiology ◽  
Stress Alleviation

ABSTRACT Overexpression of resistance-nodulation-division (RND)-type efflux pumps is an important mechanism for bacteria to combat antimicrobials. RND efflux pumps are also critical for bacterial physiology, such as oxidative stress tolerance. Stenotrophomonas maltophilia, a multidrug-resistant opportunistic pathogen, harbors eight RND-type efflux pump operons. Of these, the smeU1VWU2X operon is unique for its possession of two additional genes, smeU1 and smeU2, which encode proteins of the short-chain dehydrogenase/reductase (SDR) family. Overexpression of the SmeVWX pump is known to contribute to the acquired resistance to chloramphenicol, quinolone, and tetracycline; however, SmeU1 and SmeU2 are little involved in this phenotype. In the study described in this article, we further linked the smeU1VWU2X operon to oxidative stress alleviation and sulfamethoxazole-trimethoprim (SXT)-resistant mutant occurrence. The smeU1VWU2X operon was inducibly expressed upon challenge with menadione (MD), plumbagin (PL), and hydrogen peroxide (H2O2), as verified by the use of the chromosomal smeU1VWU2X-xylE transcriptional fusion construct and quantitative real-time PCR (qRT-PCR). The MD-mediated smeU1VWU2X upexpression was totally dependent on SoxR and partially relied on SmeRv but was less relevant to OxyR. SmeRv, but not SoxR and OxyR, played a regulatory role in the H2O2-mediated smeU1VWU2X upexpression. The significance of smeU1VWU2X upexpression was investigated with respect to oxidative stress alleviation and SXT-resistant mutant occurrence. Overexpression of the smeU1VWU2X operon contributed to the alleviation of MD-mediated oxidative stress. Of the encoded proteins, the SmeVWX pump and SmeU2, rather than SmeU1, participated in MD tolerance. Furthermore, we also demonstrated that the MD-mediated expression of the smeU1VWU2X operon decreased the SXT resistance frequency when S. maltophilia was grown in a reactive oxygen species (ROS)-rich environment.

scholarly journals Vitamin K3 Induces the Expression of the Stenotrophomonas maltophilia SmeVWX Multidrug Efflux Pump

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
P. Blanco ◽  
F. Corona ◽  
M. B. Sánchez ◽  
J. L. Martínez
Keyword(s):  
Antibiotic Resistance ◽  
Vitamin K ◽  
Stenotrophomonas Maltophilia ◽  
Fluorescent Protein ◽  
Efflux Pump ◽  
Yellow Fluorescent Protein ◽  
Efflux Pumps ◽  
Fluorescence Signal ◽  
Multidrug Efflux ◽  
Content Type

ABSTRACT Stenotrophomonas maltophilia is an opportunistic pathogen with increasing prevalence, which is able to cause infections in immunocompromised patients or in those with a previous pathology. The treatment of the infections caused by this bacterium is often complicated due to the several intrinsic antibiotic resistance mechanisms that it presents. Multidrug efflux pumps are among the best-studied mechanisms of S. maltophilia antibiotic resistance. Some of these efflux pumps have a basal expression level but, in general, their expression is often low and only reaches high levels when the local regulator is mutated or bacteria are in the presence of an effector. In the current work, we have developed a yellow fluorescent protein (YFP)-based sensor with the aim to identify effectors able to trigger the expression of SmeVWX, an efflux pump that confers resistance to quinolones, chloramphenicol, and tetracycline when it is expressed at high levels. With this purpose in mind, we tested a variety of different compounds and analyzed the fluorescence signal given by the expression of YFP under the control of the smeVWX promoter. Among the tested compounds, vitamin K3, which is a compound belonging to the 2-methyl-1,4-naphthoquinone family, is produced by plants in defense against infection, and has increasing importance in human therapy, was able to induce the expression of the SmeVWX efflux pump. In addition, a decrease in the susceptibility of S. maltophilia to ofloxacin and chloramphenicol was observed in the presence of vitamin K3, in both wild-type and smeW-deficient strains.

scholarly journals Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG

2012 ◽  
Vol 56 (4) ◽  
pp. 2074-2083 ◽  
Author(s):  
Santiago Ramón-García ◽  
Virginie Mick ◽  
Elisa Dainese ◽  
Carlos Martín ◽  
Charles J. Thompson ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Stationary Phase ◽  
Mycobacterium Bovis ◽  
Efflux Pump ◽  
Expression Patterns ◽  
Efflux Pumps ◽  
Gene Encoding ◽  
Content Type ◽  
Active Efflux ◽  
Bacterial Physiology

ABSTRACTEfflux pumps extrude a wide variety of chemically unrelated compounds conferring multidrug resistance and participating in numerous physiological processes.Mycobacterium tuberculosispossesses many efflux pumps, and their roles in drug resistance and physiology are actively investigated. In this work we found thattapmutant cells showed changes in morphology and a progressive loss of viability upon subcultivation in liquid medium. Transcriptome analysis inMycobacterium bovisBCG revealed that disruption of theRv1258cgene, encoding the Tap efflux pump, led to an extensive change in gene expression patterns during stationary phase, with no changes during exponential growth. In stationary phase, Tap inactivation triggered a general stress response and led to a general repression of genes involved in cell wall biosynthesis, in particular the formation of the peptidoglycan; this suggested the accumulation of an unknown Tap substrate that reaches toxic concentrations during stationary phase. We also found that both disruption and overexpression oftapaltered susceptibility to many clinically approved antibiotics inM. bovisBCG. Acriflavine and tetracycline accumulation assays and carbonyl cyanidem-chlorophenylhydrazone (CCCP) potentiation experiments demonstrated that this phenotype was due to an active efflux mechanism. These findings emphasize the important role of the Tap efflux pump in bacterial physiology and intrinsic drug resistance.

scholarly journals Overexpression of the Efflux Pumps SmeVWX and SmeDEF Is a Major Cause of Resistance to Co-trimoxazole inStenotrophomonas maltophilia

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
María Blanca Sánchez ◽  
José Luis Martínez
Keyword(s):  
Molecular Epidemiology ◽  
Drug Combination ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Efflux Pumps ◽  
Content Type ◽  
Resistant Mutants ◽  
Selection Of ◽  
Selection Of Resistance

ABSTRACTCo-trimoxazole is one of the antimicrobials of choice for treatingStenotrophomonas maltophiliainfections. Most works on the molecular epidemiology of the resistance to this drug combination are based on the analysis ofsulgenes. Nevertheless, the existence of clinical co-trimoxazole-resistantS. maltophiliaisolates that do not harborsulgenes has been reported. To investigate potential mutations that can reduce the susceptibility ofS. maltophiliato co-trimoxazole, spontaneousS. maltophiliaco-trimoxazole-resistant mutants isolated under different co-trimoxazole concentrations were studied. All mutants presented phenotypes compatible with the overexpression of either SmeVWX (94.6%) or SmeDEF (5.4%). Indeed, the analysis of a selected set of strains showed that the overexpression of either of these efflux pumps, which was due to mutations in their regulatorssmeRvandsmeT, respectively, was the cause of co-trimoxazole resistance. No other efflux pump was overexpressed in any of the studied mutants, indicating that they do not participate in the observed resistance phenotype. The analysis of mutants overexpressing or lacking SmeDEF or SmeVWX shows that SmeDEF contributes to the intrinsic and acquired resistance to co-trimoxazole inS. maltophilia, whereas SmeVWX only contributes to acquired resistance. It is important to highlight that all mutants were less susceptible to other antibiotics, including chloramphenicol and quinolones. Since both SmeVWX and SmeDEF are major determinants of quinolone resistance, the potential cross-selection of resistance to co-trimoxazole and quinolones, when either of the antimicrobials is used, is of particular concern for the treatment ofS. maltophiliainfections.

scholarly journals Roles of Efflux Pumps from Different Superfamilies in the Surface-Associated Motility and Virulence of Acinetobacter baumannii ATCC 17978

2019 ◽  
Vol 63 (3) ◽  
Author(s):  
María Pérez-Varela ◽  
Jordi Corral ◽  
Jesús Aranda ◽  
Jordi Barbé
Keyword(s):  
Acinetobacter Baumannii ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Major Facilitator Superfamily ◽  
Content Type ◽  
Small Multidrug Resistance ◽  
Genes Encoding ◽  
Resistance Nodulation Division ◽  
Major Facilitator ◽  
Reported Data

ABSTRACT Although the relationship between Acinetobacter baumannii efflux pumps and antimicrobial resistance is well documented, less is known about the involvement of these proteins in the pathogenicity of this nosocomial pathogen. In previous work, we identified the AbaQ major facilitator superfamily (MFS) efflux pump and demonstrated its participation in the motility and virulence of A. baumannii. In the present study, we examined the role in these processes of A. baumannii transporters belonging to different superfamilies of efflux pumps. Genes encoding known or putative permeases belonging to efflux pump superfamilies other than the MFS were selected, and the corresponding knockouts were constructed. The antimicrobial susceptibilities of these mutants were consistent with previously reported data. In mutants of A. baumannii strain ATCC 17978 carrying inactivated genes encoding the efflux pumps A1S_2736 (resistance nodulation division [RND]), A1S_3371 (multidrug and toxic compound extrusion [MATE]), and A1S_0710 (small multidrug resistance [SMR]), as well as the newly described ATP-binding cassette (ABC) permeases A1S_1242 and A1S_2622, both surface-associated motility and virulence were reduced compared to the parental strain. However, inactivation of the genes encoding the known ABC permeases A1S_0536 and A1S_1535, the newly identified putative ABC permeases A1S_0027 and A1S_1057, or the proteobacterial antimicrobial compound efflux (PACE) transporters A1S_1503 and A1S_2063 had no effects on bacterial motility or virulence. Our results demonstrate the involvement of antimicrobial transporters belonging at least to five of the six known efflux pump superfamilies in both surface-associated motility and virulence in A. baumannii ATCC 17978.

scholarly journals Efflux Pumps in Chromobacterium Species Increase Antibiotic Resistance and Promote Survival in a Coculture Competition Model

2019 ◽  
Vol 85 (19) ◽  
Author(s):  
Saida Benomar ◽  
Kara C. Evans ◽  
Robert L. Unckless ◽  
Josephine R. Chandler
Keyword(s):  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Gene Clusters ◽  
Efflux Pumps ◽  
Resistance Mechanisms ◽  
Competition Model ◽  
Content Type ◽  
Resistance Induction ◽  
Resistance Nodulation Division

ABSTRACT Members of the Chromobacterium genus include opportunistic but often-fatal pathogens and soil saprophytes with highly versatile metabolic capabilities. In previous studies of Chromobacterium subtsugae (formerly C. violaceum) strain CV017, we identified a resistance nodulation division (RND)-family efflux pump (CdeAB-OprM) that confers resistance to several antibiotics, including the bactobolin antibiotic produced by the soil saprophyte Burkholderia thailandensis. Here, we show the cdeAB-oprM genes increase C. subtsugae survival in a laboratory competition model with B. thailandensis. We also demonstrate that adding sublethal bactobolin concentrations to the coculture increases C. subtsugae survival, but this effect is not through CdeAB-OprM. Instead, the increased survival requires a second, previously unreported pump we call CseAB-OprN. We show that in cells exposed to sublethal bactobolin concentrations, the cseAB-oprN genes are transcriptionally induced, and this corresponds to an increase in bactobolin resistance. Induction of this pump is highly specific and sensitive to bactobolin, while CdeAB-OprM appears to have a broader range of antibiotic recognition. We examine the distribution of cseAB-oprN and cdeAB-oprM gene clusters in members of the Chromobacterium genus and find the cseAB-oprN genes are limited to the nonpathogenic C. subtsugae strains, whereas the cdeAB-oprM genes are more widely distributed among members of the Chromobacterium genus. Our results provide new information on the antibiotic resistance mechanisms of Chromobacterium species and highlight the importance of efflux pumps for saprophytic bacteria existing in multispecies communities. IMPORTANCE Antibiotic efflux pumps are best known for increasing antibiotic resistance of pathogens; however, the role of these pumps in saprophytes is much less well defined. This study describes two predicted efflux pump gene clusters in the Chromobacterium genus, which is comprised of both nonpathogenic saprophytes and species that cause highly fatal human infections. One of the predicted efflux pump clusters is present in every member of the Chromobacterium genus and increases resistance to a broad range of antibiotics. The other gene cluster has more narrow antibiotic specificity and is found only in Chromobacterium subtsugae, a subset of entirely nonpathogenic species. We demonstrate the role of both pumps in increasing antibiotic resistance and demonstrate the importance of efflux-dependent resistance induction for C. subtsugae survival in a dual-species competition model. These results have implications for managing antibiotic-resistant Chromobacterium infections and for understanding the evolution of efflux pumps outside the host.

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