scholarly journals Substrate Specificities and Efflux Efficiencies of RND Efflux Pumps ofAcinetobacter baumannii

2018 ◽  
Vol 200 (13) ◽  
pp. e00049-18 ◽  
Author(s):  
Inga V. Leus ◽  
Jon W. Weeks ◽  
Vincent Bonifay ◽  
Lauren Smith ◽  
Sophie Richardson ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Antibacterial Activities ◽  
Permeability Barrier ◽  
Bacterial Cells ◽  
Content Type ◽  
Active Efflux ◽  
Rnd Efflux Pumps ◽  
The Impact

ABSTRACTAntibiotic-resistantAcinetobacter baumanniicauses infections that are extremely difficult to treat. A significant role in these resistance profiles is attributed to multidrug efflux pumps, especially those belonging to the resistance-nodulation-cell division (RND) superfamily of transporters. In this study, we analyzed functions and properties of RND efflux pumps inA. baumanniiATCC 17978. This strain is susceptible to antibiotics and does not contain mutations that are commonly selected upon exposure to high concentrations of antibiotics. We constructed derivatives of ATCC 17978 lacking chromosomally encoded RND pumps and complemented these strains by the plasmid-borne genes. We analyzed the substrate selectivities and efficiencies of the individual pumps in the context of native outer membranes and their hyperporinated variants. Our results show that inactivation of AdeIJK provides the strongest potentiation of antibiotic activities, whereas inactivation of AdeFGH triggers the overexpression of AdeAB. The plasmid-borne overproduction complements the hypersusceptible phenotypes of the efflux deletion mutants to the levels of the parental ATCC 17978. Only a few antibiotics strongly benefitted from the overproduction of efflux pumps and antibacterial activities of some of those depended on the synergistic interaction with the low permeability barrier of the outer membrane. Either overproduction or inactivation of efflux pumps change dramatically the lipidome of ATCC 17978. We conclude that efflux pumps ofA. baumanniiare tightly integrated into physiology of this bacterium and that clinical levels of antibiotic resistance inA. baumanniiisolates are unlikely to be reached solely due to the overproduction of RND efflux pumps.IMPORTANCERND-type efflux pumps are important contributors in development of clinical antibiotic resistance inA. baumannii. However, their specific roles and the extent of contribution to antibiotic resistance remain unclear. We analyzed antibacterial activities of antibiotics in strains with different permeability barriers and found that the role of active efflux in antibiotic resistance ofA. baumanniiis limited to a few select antibiotics. Our results further show that the impact of efflux pump overproduction on antibiotic susceptibility is significantly lower than the previously reported for clinical isolates. Additional mechanisms of resistance, in particular those that improve the permeability barriers of bacterial cells and act synergistically with active efflux pumps are likely involved in antibiotic resistance of clinicalA. baumanniiisolates.

scholarly journals Efflux Pumps of Burkholderia thailandensis Control the Permeability Barrier of the Outer Membrane

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Ganesh Krishnamoorthy ◽  
Jon W. Weeks ◽  
Zhen Zhang ◽  
Courtney E. Chandler ◽  
Haotian Xue ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Lipid A ◽  
Efflux Pumps ◽  
Underlying Mechanism ◽  
Antibacterial Activities ◽  
Permeability Barrier ◽  
Contributing Factors ◽  
Burkholderia Thailandensis ◽  
Content Type ◽  
Active Efflux

ABSTRACT Burkholderia comprises species that are significant biothreat agents and common contaminants of pharmaceutical production facilities. Their extreme antibiotic resistance affects all classes of antibiotics, including polycationic polymyxins and aminoglycosides. The major underlying mechanism is the presence of two permeability barriers, the outer membrane with modified lipid A moieties and active drug efflux pumps. The two barriers are thought to be mechanistically independent and act synergistically to reduce the intracellular concentrations of antibiotics. In this study, we analyzed the interplay between active efflux pumps and the permeability barrier of the outer membrane in Burkholderia thailandensis. We found that three efflux pumps, AmrAB-OprA, BpeEF-OprC, and BpeAB-OprB, of B. thailandensis are expressed under standard laboratory conditions and provide protection against multiple antibiotics, including polycationic polymyxins. Our results further suggest that the inactivation of AmrAB-OprA or BpeAB-OprB potentiates the antibacterial activities of antibiotics not only by reducing their efflux, but also by increasing their uptake into cells. Mass spectrometry analyses showed that in efflux-deficient B. thailandensis cells, lipid A species modified with 4-amino-4-deoxy-l-aminoarabinose are significantly less abundant than in the parent strain. Taken together, our results suggest that changes in the outer membrane permeability due to alterations in lipid A structure could be contributing factors in antibiotic hypersusceptibilities of B. thailandensis cells lacking AmrAB-OprA and BpeAB-OprB efflux pumps.

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 Chlorpromazine and Amitriptyline Are Substrates and Inhibitors of the AcrB Multidrug Efflux Pump

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Elizabeth M. Grimsey ◽  
Chiara Fais ◽  
Robert L. Marshall ◽  
Vito Ricci ◽  
Maria Laura Ciusa ◽  
...  
Keyword(s):  
De Novo ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Inhibition Mechanism ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Content Type ◽  
Inhibitory Compounds ◽  
Serovar Typhimurium ◽  
Rnd Efflux Pumps

Efflux pumps of the resistance nodulation-cell division (RND) superfamily are major contributors to multidrug resistance for most of the Gram-negative ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens. The development of inhibitors of these pumps would be highly desirable; however, several issues have thus far hindered all efforts at designing new efflux inhibitory compounds devoid of adverse effects. An alternative route to de novo design relies on the use of marketed drugs, for which side effects on human health have been already assessed. In this work, we provide experimental evidence that the antipsychotic drugs chlorpromazine and amitriptyline are inhibitors of the AcrB transporter, the engine of the major RND efflux pumps in Escherichia coli and Salmonella enterica serovar Typhimurium. Furthermore, in silico calculations have provided a molecular-level picture of the inhibition mechanism, allowing rationalization of experimental data and paving the way for similar studies with other classes of marketed compounds.

scholarly journals Multiple Roles for Two Efflux Pumps in the Polycyclic Aromatic Hydrocarbon-Degrading Pseudomonas putida Strain B6-2 (DSM 28064)

2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Xuemei Yao ◽  
Fei Tao ◽  
Kunzhi Zhang ◽  
Hongzhi Tang ◽  
Ping Xu
Keyword(s):  
Antibiotic Resistance ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Pseudomonas Putida ◽  
Mutant Strain ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Content Type ◽  
Pah Degradation ◽  
Polycyclic Aromatic

ABSTRACTMicrobial bioremediation is a promising approach for the removal of polycyclic aromatic hydrocarbon (PAH) contaminants. Many degraders of PAHs possess efflux pump genes in their genomes; however, their specific roles in the degradation of PAHs have not been clearly elucidated. In this study, two efflux pumps, TtgABC and SrpABC, were systematically investigated to determine their functions in a PAH-degradingPseudomonas putidastrain B6-2 (DSM 28064). The disruption of genesttgABCorsrpABCresulted in a defect in organic solvent tolerance. TtgABC was found to contribute to antibiotic resistance; SrpABC only contributed to antibiotic resistance under an artificial overproduced condition. Moreover, a mutant strain withoutsrpABCdid not maintain its activity in long-term biphenyl (BP) degradation, which correlated with the loss of cell viability. The expression of SrpABC was significantly upregulated in the course of BP degradation. BP, 2-hydroxybiphenyl, 3-hydroxybiphenyl, and 2,3-dihydroxybiphenyl (2,3-DHBP) were revealed to be the inducers ofsrpABC. 2,3-DHBP was verified to be a substrate of pump SrpABC; SrpABC can enhance the tolerance to 2,3-DHBP by pumping it out. The mutant strain B6-2ΔsrpSprolonged BP degradation with the increase ofsrpABCexpression. These results suggest that the pump SrpABC of strain B6-2 plays a positive role in BP biodegradation by pumping out metabolized toxic substances such as 2,3-DHBP. This study provides insights into the versatile physiological functions of the widely distributed efflux pumps in the biodegradation of PAHs.IMPORTANCEPolycyclic aromatic hydrocarbons (PAHs) are notorious for their recalcitrance to degradation in the environment. A high frequency of the occurrence of the efflux pump genes was observed in the genomes of effective PAH degraders; however, their specific roles in the degradation of PAHs are still obscure. The significance of our study is in the identification of the function and mechanism of the efflux pump SrpABC ofPseudomonas putidastrain B6-2 (DSM 28064) in the biphenyl degradation process. SrpABC is crucial for releasing the toxicity caused by intermediates that are unavoidably produced in PAH degradation, which enables an understanding of how cells maintain the intracellular balance of materials. The findings from this study provide a new perspective on PAH recalcitrance and shed light on enhancing PAH degradation by genetic engineering.

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 Moraxella catarrhalis AcrAB-OprM Efflux Pump Contributes to Antimicrobial Resistance and Is Enhanced during Cold Shock Response

2015 ◽  
Vol 59 (4) ◽  
pp. 1886-1894 ◽  
Author(s):  
Violeta Spaniol ◽  
Sara Bernhard ◽  
Christoph Aebi
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Moraxella Catarrhalis ◽  
Cold Shock ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Human Respiratory Tract ◽  
Content Type ◽  
Cold Shock Response ◽  
Shock Response

ABSTRACTMoraxella catarrhalisis a common pathogen of the human respiratory tract. Multidrug efflux pumps play a major role in antibiotic resistance and virulence in many Gram-negative organisms. In the present study, the role of the AcrAB-OprM efflux pump in antibiotic resistance was investigated by constructing mutants that lack theacrA,acrB, andoprMgenes inM. catarrhalisstrain O35E. We observed a moderate (1.5-fold) decrease in the MICs of amoxicillin and cefotaxime and a marked (4.7-fold) decrease in the MICs of clarithromycin foracrA,acrB, andoprMmutants in comparison with the wild-type O35E strain. Exposure of theM. catarrhalisstrains O35E and 300 to amoxicillin triggered an increased transcription of all AcrAB-OprM pump genes, and exposure of strains O35E, 300, and 415 to clarithromycin enhanced the expression ofacrAandoprMmRNA. Inactivation of the AcrAB-OprM efflux pump genes demonstrated a decreased ability to invade epithelial cells compared to the parental strain, suggesting thatacrA,acrB, andoprMare required for efficient invasion of human pharyngeal epithelial cells. Cold shock increases the expression of AcrAB-OprM efflux pump genes in all threeM. catarrhalisstrains tested. Increased expression of AcrAB-OprM pump genes after cold shock leads to a lower accumulation of Hoechst 33342 (H33342), a substrate of AcrAB-OprM efflux pumps, indicating that cold shock results in increased efflux activity. In conclusion, the AcrAB-OprM efflux pump appears to play a role in the antibiotic resistance and virulence ofM. catarrhalisand is involved in the cold shock response.

scholarly journals Expression ofPseudomonas aeruginosaAntibiotic Resistance Genes Varies Greatly during Infections in Cystic Fibrosis Patients

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Lois W. Martin ◽  
Cynthia L. Robson ◽  
Annabelle M. Watts ◽  
Andrew R. Gray ◽  
Claire E. Wainwright ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cystic Fibrosis ◽  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Antibiotic Resistance Gene ◽  
Resistance Mechanisms ◽  
Laboratory Culture ◽  
Bacterial Cells ◽  
Content Type ◽  
Key Factor

ABSTRACTThe lungs of individuals with cystic fibrosis (CF) become chronically infected withPseudomonas aeruginosathat is difficult to eradicate by antibiotic treatment. Two keyP. aeruginosaantibiotic resistance mechanisms are the AmpC β-lactamase that degrades β-lactam antibiotics and MexXYOprM, a three-protein efflux pump that expels aminoglycoside antibiotics from the bacterial cells. Levels of antibiotic resistance gene expression are likely to be a key factor in antibiotic resistance but have not been determined during infection. The aims of this research were to investigate the expression of theampCandmexXgenes during infection in patients with CF and in bacteria isolated from the same patients and grown under laboratory conditions.P. aeruginosaisolates from 36 CF patients were grown in laboratory culture and gene expression measured by reverse transcription-quantitative PCR (RT-qPCR). The expression ofampCvaried over 20,000-fold and that ofmexXover 2,000-fold between isolates. The median expression levels of both genes were increased by the presence of subinhibitory concentrations of antibiotics. To measureP. aeruginosagene expression during infection, we carried out RT-qPCR using RNA extracted from fresh sputum samples obtained from 31 patients. The expression ofampCvaried over 4,000-fold, whilemexXexpression varied over 100-fold, between patients. Despite these wide variations, median levels of expression ofampCin bacteria in sputum were similar to those in laboratory-grown bacteria. The expression ofmexXwas higher in sputum than in laboratory-grown bacteria. Overall, our data demonstrate that genes that contribute to antibiotic resistance can be highly expressed in patients, but there is extensive isolate-to-isolate and patient-to-patient variation.

scholarly journals Antistaphylococcal and Antibiotic Resistance Modulatory Activities of Thirteen Cameroonian Edible Plants against Resistant Phenotypes

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Brice E. N. Wamba ◽  
Armelle T. Mbaveng ◽  
Paul Nayim ◽  
Joachim K. Dzotam ◽  
Ornella J. T. Ngalani ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Edible Plants ◽  
Bacterial Strains ◽  
Efflux Pump Inhibitor ◽  
Dacryodes Edulis

Background. In this study, 18 methanol extracts from Cameroonian edible plants were tested for their antibacterial activities against 26 strains ofS. aureus; the role of efflux pumps in the resistance of tested bacteria and the antibiotic resistance-modulating activities against selected multidrug-resistant (MDR) phenotypes were also investigated.Methods. Broth microdilution assay was used to evaluate the antibacterial activity, the role of efflux pumps, and the antibiotic resistance-modulating effects of plant extracts.Results. Extracts fromDacryodes edulisseeds (DES) andDacryodes edulisbark (DEB) were active against all 26 tested bacterial strains, within the minimal inhibitory concentration (MIC) range of 256–1024 µg/mL. MIC values varied from 64 to 1024 µg/mL against 96.2% of the 26 tested bacteria forPhaseolus vulgarisleaves (PVL), 92.3% forAzadirachta indicabark (AIB),Dacryodes edulisleaves (DEL), andRicinodendron heudelotiileaves (RHL). The lowest MIC value of 64 µg/mL was obtained with the extract fromCucurbita maximabeans (CMB) against MRSA4 strain and fromUapaca guineensisbark (UGB) against MRSA9 strain. Bacterial efflux pump inhibitor (EPI), carbonyl cyanidem-chlorophenyl hydrazone (CCCP), improved the activity of DES and UGB as well as that of extracts fromHibiscus esculentusleaves (HEL) andUapaca guineensisleaves (UGL) against resistantS. aureusstrains. Antibiotic-modulating effects against more than 70% of theS. aureusstrains tested were obtained when RHL (at MIC/2) was combined with CIP, ERY, and KAN (88.89%), CHL (88.89%), TET (77.78%), and STR (88.89%).Conclusion. The present study demonstrated that the 13 tested plants had antistaphylococcal effects and that DES, HEL, UGL, and UGB could be used in combination with EPI to combat resistance toStaphylococcus aureus. Also, it demonstrated that some studied extracts and mostly RHL could be used as antibiotic resistance modulators to fight against resistant strains ofS. aureus.

scholarly journals Efflux Pumps of Mycobacterium tuberculosis Play a Significant Role in Antituberculosis Activity of Potential Drug Candidates

2012 ◽  
Vol 56 (5) ◽  
pp. 2643-2651 ◽  
Author(s):  
Meenakshi Balganesh ◽  
Neela Dinesh ◽  
Sreevalli Sharma ◽  
Sanjana Kuruppath ◽  
Anju V. Nair ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Vital Role ◽  
Major Facilitator Superfamily ◽  
Content Type ◽  
Active Efflux ◽  
Drug Candidates ◽  
Small Multidrug Resistance ◽  
Major Facilitator

ABSTRACTActive efflux of drugs mediated by efflux pumps that confer drug resistance is one of the mechanisms developed by bacteria to counter the adverse effects of antibiotics and chemicals. To understand these efflux mechanisms inMycobacterium tuberculosis, we generated knockout (KO) mutants of four efflux pumps of the pathogen belonging to different classes. We measured the MICs and kill values of two different compound classes on the wild type (WT) and the efflux pump (EP) KO mutants in the presence and absence of the efflux inhibitors verapamil andl-phenylalanyl-l-arginyl-β-naphthylamide (PAβN). Among the pumps studied, the efflux pumps belonging to the ABC (ATP-binding cassette) class, encoded byRv1218c, and the SMR (small multidrug resistance) class, encoded byRv3065, appear to play important roles in mediating the efflux of different chemical classes and antibiotics. Efflux pumps encoded byRv0849andRv1258calso mediate the efflux of these compounds, but to a lesser extent. Increased killing is observed in WTM. tuberculosiscells by these compounds in the presence of either verapamil or PAβN. The efflux pump KO mutants were more susceptible to these compounds in the presence of efflux inhibitors. We have shown that these four efflux pumps ofM. tuberculosisplay a vital role in mediating efflux of different chemical scaffolds. Inhibitors of one or several of these efflux pumps could have a significant impact in the treatment of tuberculosis. The identification and characterization ofRv0849, a new efflux pump belonging to the MFS (major facilitator superfamily) class, are reported.

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.

Sign in / Sign up

Export Citation Format

Share Document