Abstract: | Human pathogen mycoplasmas (Mycoplasma pneumoniae, Mycoplasma hominis, Ureaplasma urealyticum) are intrinsically resistant to antibiotics which inhibit the cell wall biosynthesis (beta-lactams, vancomycin, bacitracin), to polymyxins, rifamycins, sulfonamides, trimethoprim, 5-nitroimidazoles, nitrofurans and to presently available quinolones. These three species are moderately susceptible to aminoglycosides, susceptible to chloramphenicol and highly susceptible to tetracyclines. M. pneumoniae is susceptible to macrolides, lincosamins and streptogramins. M. hominis is resistant to early macrolides (erythromycin, oleandomycin, spiramycin) and susceptible to new macrolides (josamycin, midecamycin, rosaramicin), lincosamins and streptogramins. U. urealyticum is resistant to lincosamins and susceptible to macrolides and streptogramins. Discordant results from various reports can be explained by differences in methods and breakpoint concentration values. In M. pneumoniae species, two strains resistant to macrolides and lincosamins have been described. In M. hominis species, one strain resistant to tetracyclines and another one resistant to tetracyclines and chloramphenicol have been reported. Two to ten percent of U. urealyticum strains are resistant to tetracyclines. These resistances are likely to be plasmid-mediated. |