In vitro susceptibility of methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains to N-formimidoyl thienamycin.
A total of 82 clinical isolates of methicillin-resistant Staphylococcus aureus and 21 isolates of methicillin-susceptible S. aureus were studied for in vitro susceptibility to N-forminidoyl thienamycin at incubation temperatures of 30 and 35 degrees C. The disk diffusion test results were correlated with the macrobroth dilution test by means of the error rate-bounded method of analysis. Both methicillin-susceptible and (to a lesser degree) methicillin-resistant strains were generally susceptible to the antibiotic as judged from their minimum inhibitory concentrations. The discrepancy between in vitro results obtained at 30 and at 35 degrees C was not very remarkable. However, tolerance of N-formimidoyl thienamycin was observed in 37% of methicillin-resistant strains and 24% of methicillin-susceptible strains at an incubation temperature of 30 degrees C; at 35 degrees C, the values were 54% (methicillin-resistant strains) and 14% (methicillin-susceptible strains).
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015378:Imipenem; D008712:Methicillin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D012044:Regression Analysis; D013211:Staphylococcus aureus / Q000187:drug effects*; D013845:Thienamycins / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D015378:Imipenem; D008712:Methicillin