title: Determination of the Mutant Prevention Concentration and the Mutant Selection Window of Topical Antimicrobial Agents against Propionibacterium acnes.
abstract: Determination of the mutant prevention concentration (MPC) and the mutant selection window (MSW) of antimicrobial agents used to treat pathogenic bacteria is important in order to apply effective antimicrobial therapies. Here, we determined the MPCs of the major topical antimicrobial agents against Propionibacterium acnes and Staphylococcus aureus which cause skin infections and compared their MSWs. Among the MPCs of nadifloxacin and clindamycin, the clindamycin MPC was determined to be the lowest against P. acnes. In contrast, the nadifloxacin MPC was the lowest against S. aureus. Calculations based on the minimum inhibitory concentrations and MPCs showed that clindamycin has the lowest MSW against both P. acnes and S. aureus. Nadifloxacin MSWs were 4-fold higher against P. acnes than against S. aureus. It is more likely for P. acnes to acquire resistance to fluoroquinolones than S. aureus. Therefore, topical application of clindamycin contributes very little to the emergence of resistant P. acnes and S. aureus strains.
authors.affiliation: Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nakase
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Nakaminami
authors.forename: Yuta
authors.initials: Y
authors.lastname: Toda
authors.forename: Norihisa
authors.initials: N
authors.lastname: Noguchi
mesh_terms: D000287:Administration, Topical; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009154:Mutation / Q000187:drug effects* / Q000235:genetics*; D011425:Propionibacterium acnes / Q000187:drug effects* / Q000235:genetics*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000235:genetics; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics
chemical_list: D000890:Anti-Infective Agents