Enhanced in vitro activity of WR99210 in combination with dapsone against Mycobacterium avium complex.
WR99210, a dihydrofolate reductase inhibitor, has promising in vitro activity against Mycobacterium avium complex (MAC). The in vitro activities of WR99210 alone and in combination with a fixed concentration of dapsone (0.5 microgram/ml) were evaluated against 35 clinical MAC isolates by a broth dilution method. The MIC at which 50% of isolates were inhibited (MIC50) and MIC90 of WR99210 alone were 2 and 8 micrograms/ml, respectively. The MIC50 and MIC90 of WR99210 in combination with dapsone were 0.25 and 4 micrograms/ml, respectively. Overall, 75% of the MAC isolates displayed enhanced susceptibility to the combination.
Veterans Affairs Medical Center, Syracuse, New York 13210, USA.
L M
LM
Shah
M S
MS
DeStefano
M H
MH
Cynamon
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003622:Dapsone / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D008826:Microbial Sensitivity Tests; D015269:Mycobacterium avium Complex / Q000187:drug effects* / Q000201:enzymology; D014227:Triazines / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D014227:Triazines; C006201:BRL 6231; D003622:Dapsone