title: Evidence of a conjugal erythromycin resistance element in the Lyme disease spirochete Borrelia burgdorferi.
abstract: We report the identification of isolates of Borrelia burgdorferi strain B31 that exhibit an unusual macrolide-lincosamide (ML) or macrolide-lincosamide-streptogramin A (MLS(A)) antibiotic resistance pattern. Low-passage isolates were resistant to high levels (>100 microg/mL) of erythromycin, spiramycin and the lincosamides but were sensitive to dalfopristin, an analogue of streptogramin B. Interestingly, the high-passage erythromycin-resistant strain B31 was resistant to quinupristin, an analogue of streptogramin A (25 microg/mL). Biochemical analysis revealed that resistance was not due to antibiotic inactivation or energy-dependent efflux but was instead due to modification of ribosomes in these isolates. Interestingly, we were able to demonstrate high-frequency transfer of the resistance phenotype via conjugation from B. burgdorferi to Bacillus subtilis (10(-2)-10(-4)) or Enterococcus faecalis (10(-5)). An intergeneric conjugal system in B. burgdorferi suggests that horizontal gene transfer may play a role in its evolution and is a potential tool for developing new genetic systems to study the pathogenesis of Lyme disease.
authors: Antimicrobial Resistance Research Unit, ARS, SAA, USDA, Russell Research Center, Athens, GA 30602, USA.
authors: Charlene R
authors: CR
authors: Jackson
authors: Julie A
authors: JA
authors: Boylan
authors: Jonathan G
authors: JG
authors: Frye
authors: Frank C
authors: FC
authors: Gherardini
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D025065:Borrelia burgdorferi / Q000187:drug effects* / Q000235:genetics; D003227:Conjugation, Genetic / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics; D004917:Erythromycin / Q000378:metabolism / Q000494:pharmacology*; D022761:Gene Transfer, Horizontal; D006801:Humans; D055231:Lincosamides; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D012270:Ribosomes / Q000378:metabolism; D025364:Streptogramin A / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D055231:Lincosamides; D018942:Macrolides; D004917:Erythromycin; D025364:Streptogramin A