IN-VITRO SUSCEPTIBILITY OF 30 BORRELIA STRAINS FROM VARIOUS SOURCES AGAINST 8 ANTIMICROBIAL CHEMOTHERAPEUTICS

Minimal inhibitory concentrations (MIG) and minimal bactericidal conce ntrations (MBC) were evaluated of the antimicrobial chemotherapeutics amoxicillin, azithromycin, cefotaxime, ceftriaxone, doxycycline, penic illin G sodium, roxithromycin, and trimethoprim-sulfamethoxazole for 3 0 Borrelia strains from various sources (skin, cerebrospinal fluid, ti cks). Of these strains 29 were Lyme disease agents of the species Borr elia afzelii (n=12), Borrelia burgdorferi sensu stricto (n=4), Borreli a garinii (n=13), and one was the relapsing fever strain Borrelia turi catae (n=1), Tests were performed in microtiter plates by broth diluti on, MIC was determined after 72 hours of incubation by comparing growt h control with the antibiotic dilutions by means of dark field microsc opy, Strains tested were susceptible against amoxicillin, azithromycin , cefotaxime, ceftriaxone, doxycycline, and penicillin G sodium, partl y susceptible to roxithromycin, and resistant to trimethoprim-sulfamet hoxazole, No statistically significant differences in MIC and MBC were seen among the different antibiotics with the various Borrelia specie s.