title: Epigallocatechin gallate as a modulator of Campylobacter resistance to macrolide antibiotics.
abstract: Comprehensive therapeutic use of macrolides in humans and animals is important in the selection of macrolide-resistant Campylobacter isolates. This study shows high co-resistance to erythromycin, azithromycin, clarithromycin, dirithromycin and tylosin, with contributions from the 23S rRNA gene and drug efflux systems. The CmeABC efflux pump plays an important role in reduced macrolide susceptibility, accompanied by contributions from the CmeDEF efflux pump and potentially a third efflux pump. To improve clinical performance of licensed antibiotics and chemotherapeutic agents, it is important to understand the factors in Campylobacter that affect susceptibility to macrolide antibiotics. Using mutants that lack the functional genes coding for the CmeB and CmeF efflux pump proteins and the CmeR transcriptional repressor, we show that these efflux pumps are potential targets for the development of therapeutic strategies that use a combination of a macrolide with an efflux pump inhibitor (EPI) to restore macrolide efficacy. The natural phenolic compound epigallocatechin gallate (EGCG) has good modulatory activity over the extrusion across the outer membrane of the macrolides tested, both in sensitive and resistant Campylobacter isolates. Comparing EGCG with known chemical EPIs, correlations in the effects on the particular macrolide antibiotics were seen. EGCG modifies Campylobacter multidrug efflux systems and thus could have an impact on restoring macrolide efficacy in resistant strains.
authors.affiliation: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia.
authors.forename: Marija
authors.initials: M
authors.lastname: Kurinčič
authors.forename: Anja
authors.initials: A
authors.lastname: Klančnik
authors.forename: Sonja
authors.initials: S
authors.lastname: Smole Možina
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000493:pharmacokinetics*; D001693:Biological Transport, Active / Q000187:drug effects; D002167:Campylobacter / Q000187:drug effects* / Q000378:metabolism*; D002169:Campylobacter Infections / Q000382:microbiology / Q000662:veterinary; D002392:Catechin / Q000031:analogs & derivatives* / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D006801:Humans; D018942:Macrolides / Q000378:metabolism / Q000494:pharmacology*; D026901:Membrane Transport Proteins / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D026901:Membrane Transport Proteins; D002392:Catechin; C045651:epigallocatechin gallate