Influence of P-glycoprotein and MRP efflux pump inhibitors on the intracellular activity of azithromycin and ciprofloxacin in macrophages infected by Listeria monocytogenes or Staphylococcus aureus

Seral, Cristina; Carryn, Stéphane; Tulkens, Paul M.; Bambeke, Françoise Van

doi:10.1093/jac/dkg223

Cited by 105 publications

(92 citation statements)

References 15 publications

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“…The same reasoning can be applied to explain the effect of extracellular pH on fluoroquinolone accumulation in eukaryotic cells. It is also interesting to note that both moxifloxacin and delafloxacin are found in the soluble fraction of the cells, with only a minimal amount detected in the organelles, as already observed for other fluoroquinolones (12,41). This is in opposition to what is seen with weak bases like macrolides or the biaryloxazolidinone radezolid, which are associated in large proportion with acidic vacuoles such as lysosomes (13,25).…”

Section: Discussionmentioning

confidence: 71%

“…The resulting cytoplasmic extract was further fractionated into a "granule/membrane" fraction (containing the bulk of the cell organelles and membranes; MLP fraction) and a final supernatant fraction (S fraction) by high-speed centrifugation (145,000 ϫ g) for 30 min (Ti 50 rotor; Beckman Instruments, Inc., Fullerton, CA). Antibiotic concentrations and activities of marker enzymes of the main organelles (cytochrome c oxidase for mitochondria, N-acetyl-beta-glucosaminidase for lysosomes, and lactate dehydrogenase for cytosol) were measured in each fraction (38,41).…”

Section: Methodsmentioning

confidence: 99%

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Contrasting Effects of Acidic pH on the Extracellular and Intracellular Activities of the Anti-Gram-Positive Fluoroquinolones Moxifloxacin and Delafloxacin againstStaphylococcus aureus

Lemaire

Tulkens

Bambeke

2011

Antimicrob Agents Chemother

166

140

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In contrast to currently marketed fluoroquinolones, which are zwitterionic, delafloxacin is an investigational fluoroquinolone with an anionic character that is highly active against Gram-positive bacteria. We have examined the effect of acidic pH on its accumulation in Staphylococcus aureus and in human THP-1 cells, in parallel with its activity against extracellular and intracellular S. aureus. Moxifloxacin was used as a comparator. Delafloxacin showed MICs 3 to 5 log 2 dilutions lower than those of moxifloxacin for a collection of 35 strains with relevant resistance mechanisms and also proved to be 10-fold more potent against intracellular S. aureus ATCC 25923. In medium at pH 5.5, this difference was further enhanced, with the MIC decreasing by 5 log 2 dilutions. In infected cells incubated in acidic medium, the relative potency was 10-fold higher than that at neutral pH and the maximal relative efficacy reached a bactericidal effect at 24 h. These results can be explained by a 10-fold increase in delafloxacin accumulation in both bacteria and cells at acidic pH, making delafloxacin one of the most efficient drugs tested in this model. Opposite effects were seen for moxifloxacin with respect to both activity and accumulation. As reported for zwitterionic fluoroquinolones, delafloxacin was found associated with the soluble fraction in homogenates of eukaryotic cells. Taken together, these properties may confer to delafloxacin an advantage for the eradication of S. aureus in acidic environments, including intracellular infections.Fluoroquinolones are one of the first families of fully synthetic antibiotics with large clinical use, and they represent a wide range of molecules, which permits the establishment of in-depth structure-activity relationships (16,17). Over the last 20 years, most fluoroquinolone research efforts have been focused on new molecules with improved activity toward Grampositive cocci because of the increasing spread of multiresistant staphylococci and streptococci. The 8-methoxy fluoroquinolone moxifloxacin is the first example of this new generation to reach the commercial market. It combines many desirable microbiological and pharmacokinetic properties (rapid bactericidal activity, a spectrum covering pertinent pathogens, excellent oral bioavailability, a large tissue distribution, and a propensity to accumulate within eukaryotic cells [see reference 45 for a review]). Moxifloxacin shows extensive activity toward bacteria thriving in the cytosol (Listeria monocytogenes [14]), phagosomes (Legionella pneumophila, Mycobacterium avium, and Mycobacterium tuberculosis [5,9,46]), and phagolysosomes (Staphylococcus aureus [6]), suggesting that it easily diffuses between different subcellular compartments. Yet moxifloxacin activity is partially defeated by the acidic pH prevailing in vacuolar subcellular compartments (6).Delafloxacin [RX-3341; 1-(6-amino-3,5-difluoropyridin-2-yl)-8-chloro-6-fluoro-7-(3-hydroxyazetidin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid] is an investigational fluoro...

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Section: Discussionmentioning

confidence: 71%

Section: Methodsmentioning

confidence: 99%

Contrasting Effects of Acidic pH on the Extracellular and Intracellular Activities of the Anti-Gram-Positive Fluoroquinolones Moxifloxacin and Delafloxacin againstStaphylococcus aureus

Lemaire

Tulkens

Bambeke

2011

Antimicrob Agents Chemother

166

140

View full text Add to dashboard Cite

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“…Interestingly enough, an increase in azithromycin accumulation, as obtained by inhibiting its efflux from macrophages, has been shown to decrease the extracellular concentration needed to obtain a bacteriostatic affect in the S aureus/J774 macrophage model depicted in Fig. 3 [44]. In contrast to both b-lactams and macrolides, concentration seems a critical determinant for fluoroquinolones and these antibiotics show typical concentration-dependent efficacy.…”

Section: Intracellular Activity Of Antibiotics (Cellular Pharmacodynamentioning

confidence: 94%

“…Efflux of fluoroquinolones is faster than uptake and is probably mediated by an efflux transporter, which can be inhibited by probenecid [43] and has been provisionally identified as an multiple resistance-related protein (MRP) efflux transporter. Cell-associated fluoroquinolones have been consistently recovered in the final supernate after cell fractionation studies [35,44]. This can be interpreted in two different ways: efflux from a specific subcellular compartment is fast; or fluoroquinolones are genuinely localized in the cytosol, but probably able to diffuse in the various subcellular compartments as they do through the various organs of the body.…”

Section: Fluoroquinolonesmentioning

confidence: 99%

Intracellular pharmacodynamics of antibiotics

Carryn

Chanteux

Seral

et al. 2003

Infectious Disease Clinics of North America

172

151

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“…A variety of compounds that have demonstrated activity against either resistance-nodulation-division (RND) pumps or ABC transporter-type systems were tested. Specifically, phenylalanine-arginine ␤-naphthylamide (PA␤N) (11), 1-(1-naphthylmethyl)-piperazine (NMP) (12), reserpine (13), probenecid (14), verapamil (15), and gemfibrozil (16) were all tested for their abilities to potentiate MB-1 activity in the adaptation assay. Using concentrations that were previously shown to affect the activities of various efflux pumps, improvements in MB-1 activity were not observed when it was combined with PA␤N, NMP, probenecid, verapamil, or gemfibrozil.…”

mentioning

confidence: 99%

Potentiation of Antibacterial Activity of the MB-1 Siderophore-Monobactam Conjugate Using an Efflux Pump Inhibitor

Tomaras

Crandon

McPherson

et al. 2015

Antimicrob Agents Chemother

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Preliminary enthusiasm over the encouraging spectrum and in vitro activities of siderophore conjugates, such as MB-1, was recently tempered by unexpected variability in in vivo efficacy. The need for these conjugates to compete for iron with endogenously produced siderophores has exposed a significant liability for this novel antibacterial strategy. Here, we have exploited dependence on efflux for siderophore secretion in Pseudomonas aeruginosa and provide evidence that efflux inhibition may circumvent this in vivo-relevant resistance liability.T he extent and severity of antibiotic resistance in Gram-negative pathogens require the development of innovative therapeutic interventions that not only circumvent existing clinically relevant resistance mechanisms but will also result in limited spontaneous resistance emergence. Although standard in vitro methodologies exist for predicting resistance development, translational deficiencies that can stem from their lack of in vivo physiological relevance are becoming increasingly apparent. We previously described the siderophore-monobactam conjugate MB-1 ( Fig. 1 [1]), which has broad-spectrum in vitro activities against multidrug-resistant (MDR) Gram-negative pathogens, including Pseudomonas aeruginosa, when tested using standard methods established by the Clinical and Laboratory Standards Institute (CLSI) (1). Unfortunately, we have also demonstrated that despite these encouraging in vitro activities, the efficacy of MB-1 in a neutropenic murine infection model was highly variable and not directly predictable from traditional in vitro activity assays (2). Instead, the development of a modified in vitro resistance frequency assay, which relies on the utilization of more in vivo-relevant iron conditions, has proven to be more predictive of the efficacy of MB-1 in vivo. Additionally, this assay has demonstrated a role for endogenous siderophores, such as pyoverdine, in mediating the adaptive cellular response that enables P. aeruginosa to transiently resist MB-1 activity (2). While these results suggest that the use of MB-1 as monotherapy is not a viable option, we have speculated about alternative strategies that may mitigate this adaptive response and resurrect MB-1 as a legitimate antibacterial agent. Among these potentiation-type approaches, we considered the idea that inhibiting endogenous siderophore functionality should circumvent the adaptation phenotype mediated by the competition for iron by native siderophore systems. Siderophore secretion into the extracellular milieu has been shown to be dependent on functional efflux pumps in Gram-negative bacteria (3-5). In the case of P. aeruginosa, the secretion of newly synthesized pyoverdine is accomplished by the ABC transporter-type efflux system encoded by pvdR, pvdT, and opmQ (6). Additionally, this system is responsible for pyoverdine recycling after successive rounds of iron acquisition and delivery (7).To prove that inhibiting the activity of this pump can potentiate the activity of MB-1, we generated a pvdRT-op...

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Influence of P-glycoprotein and MRP efflux pump inhibitors on the intracellular activity of azithromycin and ciprofloxacin in macrophages infected by Listeria monocytogenes or Staphylococcus aureus

Cited by 105 publications

References 15 publications

Contrasting Effects of Acidic pH on the Extracellular and Intracellular Activities of the Anti-Gram-Positive Fluoroquinolones Moxifloxacin and Delafloxacin againstStaphylococcus aureus

Contrasting Effects of Acidic pH on the Extracellular and Intracellular Activities of the Anti-Gram-Positive Fluoroquinolones Moxifloxacin and Delafloxacin againstStaphylococcus aureus

Intracellular pharmacodynamics of antibiotics

Potentiation of Antibacterial Activity of the MB-1 Siderophore-Monobactam Conjugate Using an Efflux Pump Inhibitor

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