Mycoplasma are intrinsically resistant to:

Mycoplasma are a class of Cell-wall free bacteria. The lack of a cell wall in mycoplasmas makes them intrinsically resistant to beta-lactams and to all antimicrobials which target the cell wall. Mycoplasma are susceptible to agents that interfere with protein synthesis, such as tetracyclines, macrolides and aminoglycosides and to the fluoroquinolones that act by inhibiting topoisomerases. Tetracyclines are the drug of choice for mycoplasma infections. Antibiotic resistance of Macrolides: Innate antibiotic resistance is defined as resistance that is found in all members of a group of bacteria. For mycoplasmas, two kinds of innate or intrinsic resistance have to be considered, one related to the class Mollicutes, and one related to the different mycoplasma and ureaplasma species. These differences in innate antibiotic susceptibility have been used to isolate mycoplasmas. Resistance related to class molecules Resistance to Macrolide-Lincosamide-Streptogramin-Ketolide (MLSK) group The lack of cell wall makes all the members of the class Mollicutes intrinsically resistant to Beta-lactams and to all antimicrobials such as glycopeptides and fosfomycin, which target the cell wall. In addition, mycoplasmas are also resistant to polymyxins, sulphonamides, trimethoprim, nalidixic acid and rifampin Resistance to the macrolide-lincosamide-streptogramin-Ketolide (MLSK) group differs between species. Mycoplasma pneumonia and M.genitalium are naturally susceptible to all MLSK antibiotics, except these two species. Ureaplasma spp. are susceptible to macrolides and ketolides. Ref: Ananthanarayana and Paniker 9th edition Pgno: 387