Resistance of Francisella Novicida to Fosmidomycin Associated with Mutations in the Glycerol-3-Phosphate Transporte

Mackie, Ryan S.; McKenney, Elizabeth S.; Hoek, Monique L. van

doi:10.3389/fmicb.2012.00226

Cited by 23 publications

(30 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DXR is an essential enzyme, and while mutations could theoretically occur in the active site that would alter drug activity, loss of this enzyme is unlikely. However, the same cannot be said for the GlpT transporter, as demonstrated by our use of a glpT mutant [5], [32]. GlpT is an inorganic phosphate/glycerol-3-phosphate antiporter that depends on the phosphate gradient, so any environmental conditions that affect this gradient could also affect the activity of the transporter [39].…”

Section: Discussionmentioning

confidence: 94%

Lipophilic Prodrugs of FR900098 Are Antimicrobial against Francisella novicida In Vivo and In Vitro and Show GlpT Independent Efficacy

et al. 2012

Self Cite

View full text Add to dashboard Cite

Bacteria, plants, and algae produce isoprenoids through the methylerythritol phosphate (MEP) pathway, an attractive pathway for antimicrobial drug development as it is present in prokaryotes and some lower eukaryotes but absent from human cells. The first committed step of the MEP pathway is catalyzed by 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR/MEP synthase). MEP pathway genes have been identified in many biothreat agents, including Francisella, Brucella, Bacillus, Burkholderia, and Yersinia. The importance of the MEP pathway to Francisella is demonstrated by the fact that MEP pathway mutations are lethal. We have previously established that fosmidomycin inhibits purified MEP synthase (DXR) from F. tularensis LVS. FR900098, the acetyl derivative of fosmidomycin, was found to inhibit the activity of purified DXR from F. tularensis LVS (IC50 = 230 nM). Fosmidomycin and FR900098 are effective against purified DXR from Mycobacterium tuberculosis as well, but have no effect on whole cells because the compounds are too polar to penetrate the thick cell wall. Fosmidomycin requires the GlpT transporter to enter cells, and this is absent in some pathogens, including M. tuberculosis. In this study, we have identified the GlpT homologs in F. novicida and tested transposon insertion mutants of glpT. We showed that FR900098 also requires GlpT for full activity against F. novicida. Thus, we synthesized several FR900098 prodrugs that have lipophilic groups to facilitate their passage through the bacterial cell wall and bypass the requirement for the GlpT transporter. One compound, that we termed “compound 1,” was found to have GlpT-independent antimicrobial activity. We tested the ability of this best performing prodrug to inhibit F. novicida intracellular infection of eukaryotic cell lines and the caterpillar Galleria mellonella as an in vivo infection model. As a lipophilic GlpT-independent DXR inhibitor, compound 1 has the potential to be a broad-spectrum antibiotic, and should be effective against most MEP-dependent organisms.

show abstract

Section: Discussionmentioning

confidence: 94%

Lipophilic Prodrugs of FR900098 Are Antimicrobial against Francisella novicida In Vivo and In Vitro and Show GlpT Independent Efficacy

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…The membrane potential of F. novicida was measured using the fluorescence probe [3,3 0 -Dipropylthiadicarbocyanine iodide] (DiSC3 [5]), as previously described, 39 and following manufacturer's instructions (Invitrogen). An overnight culture of Francisella was inoculated 1:50 in TSBC and grown at 37 C for 5 h. The cells were then centrifuged twice at 4000 £ g for 10 min at 4 C and washed (5 mM HEPES, 5 mM glucose).…”

Section: Membrane Depolarizationmentioning

confidence: 99%

“…An overnight culture of Francisella was inoculated 1:50 in TSBC and grown at 37 C for 5 h. The cells were then centrifuged twice at 4000 £ g for 10 min at 4 C and washed (5 mM HEPES, 5 mM glucose). The cells were then resuspended (in 5 mM glucose, 0.2 mM EDTA, 20 nM DiSC3 [5]), and incubated at room temperature for 15 min. 90 mL of the cell suspensions were put into wells of a black 96-well plate and 10 mL of drug (5 mM) or carrier (5% DMSO in PBS) was added.…”

Section: Membrane Depolarizationmentioning

confidence: 99%

“…3 Current and emerging antibiotic resistance represents a crisis on a global scale. 4 The recent detection of Francisella's antibiotic resistance, 5 and reports relating to the potential emergence of fluoroquinolone resistance [6][7][8] in Francisella species, underscores the urgent need for new antibiotics, or different antimicrobial strategies. 9 There are numerous examples of successful drug repurposing.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Screen of FDA-approved drug library identifies maprotiline, an antibiofilm and antivirulence compound with QseC sensor-kinase dependent activity in Francisella novicida

Dean

Hoek

2015

Virulence

View full text Add to dashboard Cite

Development of new therapeutics against Select Agents such as Francisella is critical preparation in the event of bioterrorism. Testing FDA-approved drugs for this purpose may yield new activities unrelated to their intended purpose and may hasten the discovery of new therapeutics. A library of 420 FDA-approved drugs was screened for antibiofilm activity against a model organism for human tularemia, Francisella (F.) novicida, excluding drugs that significantly inhibited growth. The initial screen was based on the 2-component system (TCS) dependent biofilm effect, thus, the QseC dependence of maprotiline anti-biofilm action was demonstrated. By comparing their FDA-approved uses, chemical structures, and other properties of active drugs, toremifene and polycyclic antidepressants maprotiline and chlorpromazine were identified as being highly active against F. novicida biofilm formation. Further down-selection excluded toremifene for its membrane active activity and chlorpromazine for its high antimicrobial activity. The mode of action of maprotiline against F. novicida was sought. It was demonstrated that maprotiline was able to significantly down-regulate the expression of the virulence factor IglC, encoded on the Francisella Pathogenicity Island (FPI), suggesting that maprotiline is exerting an effect on bacterial virulence. Further studies showed that maprotiline significantly rescued F. novicida infected wax worm larvae. In vivo studies demonstrated that maprotiline treatment could prolong time to disease onset and survival in F. novicida infected mice. These results suggest that an FDAapproved drug such as maprotiline has the potential to combat Francisella infection as an antivirulence agent, and may have utility in combination with antibiotics.

show abstract

“…As a result, many microorganisms, such as Mycobacterium tuberculosis and Toxoplasma gondii , are inherently resistant to FSM (due to poor cellular uptake) even though FSM potently inhibits their DXR orthologs in vitro (16,18,26). In Gram-negative organisms, FSM import is dependent on a glycerol-3-phosphate/Pi antiporter (GlpT), and FSM resistance can be achieved by reduced expression or activity of GlpT(27,28).…”

Section: Introductionmentioning

confidence: 99%

Potent, specific MEPicides for treatment of zoonotic staphylococci

Edwards¹,

Heueck²,

Lee

et al. 2019

Preprint

View full text Add to dashboard Cite

24Coagulase-positive staphylococci, which frequently colonize the mucosal surfaces of 25 animals, also cause a spectrum of opportunistic infections including skin and soft tissue 26 infections, urinary tract infections, pneumonia, and bacteremia. However, recent 27 45 robustly inhibit DXR in zoonotic staphylococci, and further, DXR represents a 46 promising, druggable target for future development. 3 47 48 Author Summary 49 The proliferation of microbial pathogens resistant to the current pool of antibiotics is a 50 major threat to public health. Drug resistance is pervasive in staphylococci, including 51 several species that can cause serious zoonotic infections in humans. Thus, new 52 antimicrobial agents are urgently need to combat these life-threatening, resistant 53 infections. Here we establish the MEP pathway as a promising new target against 54 zoonotic staphylococci. We determine that fosmidomycin (FSM) selectively targets the 55 isoprenoid biosynthesis pathway in zoonotic staphylococci, and use forward genetics to 56 identify the transporter that facilitates phosphonate antibiotic uptake. Employing this 57 knowledge, we synthesized a series of potent antibacterial prodrugs that circumvent 58 the transporter. Together, these novel prodrug inhibitors represent promising leads for 59 further drug development against zoonotic staphylococci. 60 61 65 zoonotic infections in humans that are clinically indistinguishable from infections with S. 66 aureus including pneumonia, skin and soft tissue infections, hardware infections, and 67 bacteremia(1-5). Newer clinical microbiological techniques, such as mass 68 spectrometry, now readily distinguish S. aureus from zoonotic coagulase-positive

show abstract

Resistance of Francisella Novicida to Fosmidomycin Associated with Mutations in the Glycerol-3-Phosphate Transporte

Cited by 23 publications

References 52 publications

Lipophilic Prodrugs of FR900098 Are Antimicrobial against Francisella novicida In Vivo and In Vitro and Show GlpT Independent Efficacy

Lipophilic Prodrugs of FR900098 Are Antimicrobial against Francisella novicida In Vivo and In Vitro and Show GlpT Independent Efficacy

Screen of FDA-approved drug library identifies maprotiline, an antibiofilm and antivirulence compound with QseC sensor-kinase dependent activity in Francisella novicida

Potent, specific MEPicides for treatment of zoonotic staphylococci

Contact Info

Product

Resources

About