Pneumocystis carinii Dihydropteroate Synthase but Not Dihydrofolate Reductase Gene Mutations Correlate with Prior Trimethoprim-Sulfamethoxazole or Dapsone Use
Recent studies of the human Pneumocystis carinii dihydropteroate synthase (DHPS) gene suggest that P. carinii is developing resistance to sulfamethoxazole (SMX) and dapsone. To explore whether P. carinii is also developing resistance to trimethoprim (TMP), the human P. carinii dihydrofolate reductas...
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Published in | The Journal of infectious diseases Vol. 180; no. 6; pp. 1969 - 1978 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Chicago, IL
The University of Chicago Press
01.12.1999
University of Chicago Press Oxford University Press |
Subjects | |
Online Access | Get full text |
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Summary: | Recent studies of the human Pneumocystis carinii dihydropteroate synthase (DHPS) gene suggest that P. carinii is developing resistance to sulfamethoxazole (SMX) and dapsone. To explore whether P. carinii is also developing resistance to trimethoprim (TMP), the human P. carinii dihydrofolate reductase (DHFR) gene was cloned, DHFR and DHPS genes in 37 P. carinii isolates from 35 patients were sequenced, and the relationship between TMP-SMX or dapsone use and gene mutations was analyzed. The DHFR gene sequences were identical in all isolates except 1 with a synonymous substitution. In contrast, the DHPS gene sequences showed mutations in 16 of the 37 isolates; prior sulfa/sulfone prophylaxis was associated with the presence of these mutations (P< .001). In addition to suggesting that there is less selective pressure on DHFR than on DHPS, this study reinforces the hypothesis that mutations in the DHPS gene are likely involved in the development of sulfa resistance in P. carinii. |
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Bibliography: | istex:7CCA76D6F183DAB9B37C1F2E529523EB9F46887C ark:/67375/HXZ-CH163WKD-V ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0022-1899 1537-6613 |
DOI: | 10.1086/315148 |