title: Effect of chloramphenicol, erythromycin, moxifloxacin, penicillin and tetracycline concentration on the recovery of resistant mutants of Mycobacterium smegmatis and Staphylococcus aureus.
abstract: The effect of antimicrobial concentration on colony-forming ability of resistant mutant subpopulations of Mycobacterium smegmatis and Staphylococcus aureus was measured for chloramphenicol, erythromycin, moxifloxacin, penicillin and tetracycline. The relationship between drug concentration and the recovery of mutant colonies was distinct for each bacterium-antimicrobial combination; however, in each case application of large numbers of cells to drug-containing agar plates revealed a progressive reduction in mutant recovery as antimicrobial concentration increased. The minimal concentration that allowed no mutant recovery from more than 10(10) input cells was measured to estimate the minimum inhibitory concentration (MIC) of the least susceptible, single-step mutant subpopulation, a parameter also called the mutant prevention concentration (MPC). These data expand the number of antimicrobial-bacterial combinations for which a mutant selection window can be measured.
authors.affiliation: Public Health Research Institute, 225 Warren St., Newark, NJ 07103, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Lu
authors.forename: Xilin
authors.initials: X
authors.lastname: Zhao
authors.forename: Xinying
authors.initials: X
authors.lastname: Li
authors.forename: Glen
authors.initials: G
authors.lastname: Hansen
authors.forename: Joseph
authors.initials: J
authors.lastname: Blondeau
authors.forename: Karl
authors.initials: K
authors.lastname: Drlica
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003470:Culture Media; D024881:Drug Resistance, Bacterial; D008826:Microbial Sensitivity Tests; D009154:Mutation / Q000235:genetics*; D020102:Mycobacterium smegmatis / Q000187:drug effects* / Q000235:genetics*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media