In vitro susceptibility of Borrelia burgdorferi to 11 antimicrobial agents

Abstract

The in vitro susceptibility of Borrelia burgdorferi to 11 antimicrobial agents was investigated. The antimicrobial agents evaluated included ceftizoxime, FK037, cefotaxime, dirithromycin, clarithromycin and its metabolite 14-hydroxy-clarithromycin, erythromycin, doxycycline, amoxicillin, ciprofloxacin, and ofioxacin.Isolates of B. burgdorferi tested included two reference strains (B31 and ATCC 53899), six isolates from the midwestern United States, and three from Europe. A broth macrodilution method was used to determine MICs and MBCs. B. burgdorferi was inhibited by <0.5 ,ug of each of the agents except the quinolones per ml. The MBCs for 90%o of strains tested of ceftizoxime, FK037, clarithromycin, 14-OH clarithromycin, and dirithromycin (<1.0 jig of each per ml) were superior to those of amoxicillin (2.0 ,ug/ml) and doxycycline (4.0 ,ug/ml).

Antimicrobial susceptibility of Borrelia burgdorferi sensu lato: What we know, what we don't know, and what we need to know

“…No less than nine definitions of MIC and eight for MBC have been proposed in the scientific literature for susceptibility testing of borreliae [11]. For the most part, variations of common macro-and microdilution methods have been used [11,[17][18][19][20][21][22][23][24]. Testing of B. burgdorferi s.l.…”

parC Mutations in Fluoroquinolone-Resistant Borrelia burgdorferi

“…Their MICs for strain B31 are about twice our IC 50 values. We and others have also previously reported similar susceptibilities to ciprofloxacin, moxifloxacin, or sparfloxacin (5,12,21,30). Susceptibility of B. burgdorferi to newer fluoroquinolones (20) suggests that these antibiotics have potential as therapeutic agents for Lyme disease (16).…”

“…Although B. burgdorferi is not susceptible to many fluoroquinolones (5,12,20,21,30), recently developed fluoroquinolones demonstrate some therapeutic potential (16). This study provides the first description of fluoroquinolone resistance in the spirochete phylum and is only the second report, to our knowledge, in which genomic mutations have been associated with antibiotic resistance in B. burgdorferi (32).…”

Pharmacodynamics of doxycycline for chemoprophylaxis of Lyme disease: preliminary findings and possible implications for other antimicrobials

“…A range of MICs against B. burgdorferi was considered [9][10][11][12][13][14][15][16]. To be conservative, a relatively low-end estimate of the MIC of doxycycline of 0.25 g/mL and relatively highend estimate of the MIC of azithromycin (0.03 g/mL) were used in the final assessment.…”