Abstract

The first aim of the proposal is to clone, express, purify, and characterize the DHPS from human derived Pc, similar to what was done for DHPS from rat derived Pc in earlier studies.
The second aim will be to determine whether, and to what extent, sulfa resistance is appearing in human strains of Pc.
This aim i s based upon the fact that DHPS amino acid sequence changes have been found in several (five) isolates of human-derived Pc that are consistent with the evolution of sulfa resistance. The first component of this aim will be to sequence Pc DHPS genes from several more patients and to determine whether specific mutations are associated with poor drug responses of certain strains. Strain identification will be done by PCR of the ITS regions of mitochondrial ribosomal RNA by Dr. Lee at Indiana University School of Medicine. The second component of this aim will be to perform site-directed mutagenesis to determine whether the observed mutations in DHPS affect the enzymes sensitivity to SMX and dapsone, two of the most commonly used sulfa drugs. Finally, the third aim of this proposal is to evaluate and compare the efficacies of a series of sulfa drugs in vitro (using recombinant DHPS from human-derived Pc and possibly variants--drug resistant isolates) once the recombinant tools are in place. Sulfa drugs that are effective in vitro will then be tested in vivo in a mouse model.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI031775-04A1
Application #
2003711
Study Section
AIDS and Related Research Study Section 5 (ARRE)
Project Start
1993-01-01
Project End
1999-12-31
Budget Start
1997-01-01
Budget End
1997-12-31
Support Year
4
Fiscal Year
1997
Total Cost
Indirect Cost

  Institution

Name
University of Michigan Ann Arbor
Department
Public Health & Prev Medicine
Type
Schools of Public Health
DUNS #
791277940
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109

  Publications

Kazanjian, Powel H; Fisk, David; Armstrong, Wendy et al. (2004) Increase in prevalence of Pneumocystis carinii mutations in patients with AIDS and P. carinii pneumonia, in the United States and China. J Infect Dis 189:1684-7
Kazanjian, P; Armstrong, W; Hossler, P A et al. (2001) Pneumocystis carinii cytochrome b mutations are associated with atovaquone exposure in patients with AIDS. J Infect Dis 183:819-22
Kazanjian, P; Armstrong, W; Hossler, P A et al. (2000) Pneumocystis carinii mutations are associated with duration of sulfa or sulfone prophylaxis exposure in AIDS patients. J Infect Dis 182:551-7
Kazanjian, P; Locke, A B; Hossler, P A et al. (1998) Pneumocystis carinii mutations associated with sulfa and sulfone prophylaxis failures in AIDS patients. AIDS 12:873-8
Bartlett, M S; Shaw, M M; Smith, J W et al. (1998) Efficacy of sulfamethoxypyridazine in a murine model of Pneumocystis carinii pneumonia. Antimicrob Agents Chemother 42:934-5
Lane, B R; Ast, J C; Hossler, P A et al. (1997) Dihydropteroate synthase polymorphisms in Pneumocystis carinii. J Infect Dis 175:482-5
Hong, Y L; Hossler, P; Bartlett, M et al. (1996) Evaluation of sulfa drugs against recombinant Pneumocystis carinii dihydropteroate synthetase and in vivo. J Eukaryot Microbiol 43:40S
Lane, B; Hossler, P; Bartlett, M et al. (1996) Sulfa resistance in mouse-derived Pneumocystis carinii. J Eukaryot Microbiol 43:39S
Hong, Y L; Hossler, P A; Calhoun, D H et al. (1995) Inhibition of recombinant Pneumocystis carinii dihydropteroate synthetase by sulfa drugs. Antimicrob Agents Chemother 39:1756-63
Ittarat, I; Asawamahasakda, W; Bartlett, M S et al. (1995) Effects of atovaquone and other inhibitors on Pneumocystis carinii dihydroorotate dehydrogenase. Antimicrob Agents Chemother 39:325-8

Showing the most recent 10 out of 12 publications