COMPARATIVE SUSCEPTIBILITIES OF VARIOUS AIDS-ASSOCIATED AND HUMAN UROGENITAL TRACT MYCOPLASMAS AND STRAINS OF MYCOPLASMA-PNEUMONIAE TO 10 CLASSES OF ANTIMICROBIAL AGENT IN-VITRO

The susceptibilities of 40 strains of various Mycoplasma species to 10 classes of antimicrobial agents were compared in vitro by a broth mic rodilution method. The strains tested comprised 20 strains of four AID S-associated species - M. penetrans (1 strain), M. fermentas (5 strain s), M. pirum (6 strains) and M. genitalium (8 strains) nine strains of the urogenital tract species M. hominis and 11 strains of M. pneumoni ae. The results demonstrated wide variation in the susceptibilities of the different Mycoplasma spp. to different classes of antimicrobial a gent. All the mycoplasmas were susceptible or highly susceptible to th e fluoroquinolones, with sparfloxacin the most active, and to the dite rpine antibiotic tiamulin. M. pneumoniae and M. genitalium strains wer e also highly susceptible to the macrolides, particularly azithromycin and had similar antibiotic susceptibility patterns to most other anti microbial agents. However, all strains of M. genitalium were resistant to streptomycin (MIC 250->500 mg/L) whereas all M. pneumoniae isolate s, except the MAC strain, were susceptible (MICs 1.25-12.5 mg/L). M. p irum isolates varied considerably in their susceptibility to macrolide s (MIC range versus azithromycin 0.0025->100 mg/L). M. fermentans stra ins were susceptible to the tetracyclines, lincosamides and mupirocin, but varied in susceptibility to aminoglycosides. Most M. hominis stra ins mere susceptible to the tetracyclines and all were susceptible to clindamycin and mupirocin. M penetrans GTU 54 was susceptible to azith romycin, the tetracyclines and lincosamides as well as to the fluoroqu inolones and tiamulin.