Beyond Antimicrobial Resistance: Evidence for a Distinct Role of the AcrD Efflux Pump in Salmonella Biology

被引:36
作者
Buckner, Michelle M. C. [1 ]
Blair, Jessica M. A. [1 ]
La Ragione, Roberto M. [2 ]
Newcombe, Jane [3 ]
Dwyer, Daniel J. [4 ]
Ivens, Alasdair [5 ]
Piddock, Laura J. V. [1 ]
机构
[1] Univ Birmingham, Coll Med & Dent Sci, Antimicrobials Res Grp, Inst Microbiol & Infect, Birmingham, W Midlands, England
[2] Univ Surrey, Fac Hlth & Med Sci, Sch Vet Med, Guildford, Surrey, England
[3] Univ Surrey, Fac Hlth & Med Sci, Sch Biosci & Med, Guildford, Surrey, England
[4] Univ Maryland, Inst Phys Sci & Technol, Dept Cell Biol & Mol Genet, Dept Bioengn,Maryland Pathogen Res Inst, College Pk, MD 20742 USA
[5] Univ Edinburgh, Ctr Immun Infect & Evolut, Edinburgh, Midlothian, Scotland
来源
MBIO | 2016年 / 7卷 / 06期
基金
英国医学研究理事会;
关键词
ENTERICA SEROVAR TYPHIMURIUM; ESCHERICHIA-COLI; GENE-EXPRESSION; ANTIBIOTIC-RESISTANCE; OUTER-MEMBRANE; FUMARATE REDUCTASE; NITRIC-OXIDE; BILE-SALTS; IN-VITRO; TOLC;
D O I
10.1128/mBio.01916-16
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
For over 20 years, bacterial multidrug resistance (MDR) efflux pumps have been studied because of their impact on resistance to antimicrobials. However, critical questions remain, including why produce efflux pumps under non-antimicrobial treatment conditions, and why have multiple pumps if their only purpose is antimicrobial efflux? Salmonella spp. possess five efflux pump families, including the resistance-nodulation-division (RND) efflux pumps. Notably, the RND efflux pump AcrD has a unique substrate profile, distinct from other Salmonella efflux pumps. Here we show that inactivation of acrD results in a profoundly altered transcriptome and modulation of pathways integral to Salmonella biology. The most significant transcriptome changes were central metabolism related, with additional changes observed in pathogenicity, environmental sensing, and stress response pathway expression. The extent of tricarboxylic acid cycle and fumarate metabolism expression changes led us to hypothesize that acrD inactivation may result in motility defects due to perturbation of metabolite concentrations, such as fumarate, for which a role in motility has been established. Despite minimal detectable changes in flagellar gene expression, we found that an acrD mutant Salmonella enterica serovar Typhimurium isolate was significantly impaired for swarming motility, which was restored by addition of fumarate. The acrD mutant outcompeted the wild type in fitness experiments. The results of these diverse experiments provide strong evidence that the AcrD efflux pump is not simply a redundant system providing response resilience, but also has distinct physiological functions. Together, these data indicate that the AcrD efflux pump has a significant and previously underappreciated impact on bacterial biology, despite only minor perturbations of antibiotic resistance profiles. IMPORTANCE Efflux pumps in Gram-negative bacteria are studied because of their important contributions to antimicrobial resistance. However, the role of these pumps in bacterial biology has remained surprisingly elusive. Here, we provide evidence that loss of the AcrD efflux pump significantly impacts the physiology of Salmonella enterica serovar Typhimurium. Inactivation of acrD led to changes in the expression of 403 genes involved in fundamental processes, including basic metabolism, virulence, and stress responses. Pathways such as these allow Salmonella to grow, survive in the environment, and cause disease. Indeed, our data show that the acrD mutant is more fit than wild-type Salmonella under standard lab conditions. We hypothesized that inactivation of acrD would alter levels of bacterial metabolites, impacting traits such as swarming motility. We demonstrated this by exogenous addition of the metabolite fumarate, which partially restored the acrD mutant's swarming defect. This work extends our understanding of the role of bacterial efflux pumps.
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页数:10
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共 73 条
  • [1] Deletions in the pyruvate pathway of Salmonella Typhimurium alter SPI1-mediated gene expression and infectivity
    Abernathy, Jason
    Corkill, Carolina
    Hinojosa, Carolee
    Li, Xianyao
    Zhou, Huaijun
    [J]. JOURNAL OF ANIMAL SCIENCE AND BIOTECHNOLOGY, 2013, 4
  • [2] Role of Glyoxylate Shunt in Oxidative Stress Response
    Ahn, Sungeun
    Jung, Jaejoon
    Jang, In-Ae
    Madsen, Eugene L.
    Park, Woojun
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 2016, 291 (22) : 11928 - 11938
  • [3] Aminoglycosides are captured from both periplasm and cytoplasm by the AcrD multidrug efflux transporter of Escherichia coli
    Aires, JR
    Nikaido, H
    [J]. JOURNAL OF BACTERIOLOGY, 2005, 187 (06) : 1923 - 1929
  • [4] The ins and outs of RND efflux pumps in Escherichia coli
    Anes, Joao
    McCusker, Matthew P.
    Fanning, Seamus
    Martins, Marta
    [J]. FRONTIERS IN MICROBIOLOGY, 2015, 6
  • [5] Repression of Salmonella enterica phoP Expression by Small Molecules from Physiological Bile
    Antunes, L. Caetano M.
    Wang, Melody
    Andersen, Sarah K.
    Ferreira, Rosana B. R.
    Kappelhoff, Reinhild
    Han, Jun
    Borchers, Christoph H.
    Finlay, B. Brett
    [J]. JOURNAL OF BACTERIOLOGY, 2012, 194 (09) : 2286 - 2296
  • [6] Metabolomics Reveals Phospholipids as Important Nutrient Sources during Salmonella Growth in Bile In Vitro and In Vivo
    Antunes, L. Caetano M.
    Andersen, Sarah K.
    Menendez, Alfredo
    Arena, Ellen T.
    Han, Jun
    Ferreira, Rosana B. R.
    Borchers, Christoph H.
    Finlay, B. Brett
    [J]. JOURNAL OF BACTERIOLOGY, 2011, 193 (18) : 4719 - 4725
  • [7] Novel Inducers of the Envelope Stress Response BaeSR in Salmonella Typhimurium: BaeR Is Critically Required for Tungstate Waste Disposal
    Appia-Ayme, Corinne
    Patrick, Elaine
    Sullivan, Matthew J.
    Alston, Mark J.
    Field, Sarah J.
    AbuOun, Manal
    Anjum, Muna F.
    Rowley, Gary
    [J]. PLOS ONE, 2011, 6 (08):
  • [8] RamA, a Member of the AraC/XylS Family, Influences Both Virulence and Efflux in Salmonella enterica Serovar Typhimurium
    Bailey, Andrew M.
    Ivens, Al
    Kingsley, Rob
    Cottell, Jennifer L.
    Wain, John
    Piddock, Laura J. V.
    [J]. JOURNAL OF BACTERIOLOGY, 2010, 192 (06) : 1607 - 1616
  • [9] FUMARATE OR A FUMARATE METABOLITE RESTORES SWITCHING ABILITY TO ROTATING FLAGELLA OF BACTERIAL ENVELOPES
    BARAK, R
    EISENBACH, M
    [J]. JOURNAL OF BACTERIOLOGY, 1992, 174 (02) : 643 - 645
  • [10] The specificity of fumarate as a switching factor of the bacterial flagellar motor
    Barak, R
    Giebel, I
    Eisenbach, M
    [J]. MOLECULAR MICROBIOLOGY, 1996, 19 (01) : 139 - 144