Martinez J, Rodriguez-Quintanilla MA, Ruiz-Herrera J, Garcia-Alvarado JS; American Society for Microbiology. General Meeting.
Abstr Gen Meet Am Soc Microbiol. 1999 May 30-Jun 3; 99: 2 (abstract no. A-9).
Universidad A. de Nuevo Leon, San Nicolas, Mexico.
C. albicans has emerged as an important pathogen in the last decade, mostly in immunocompromised patients, particularly those suffering of AIDS, diabetes, leukemia and cancer. Germ tube formation and mycelial formation have been recognized as important steps previous to tissue invasion. These processes are concomitant with an active metabolism and high chitin production, the latter being the most important cell wall structural component. Most drugs active against C. albicans, target sterol synthesis, whereas less work has been done on disruption of chitin synthesis, and no medicinal drugs that interfere with this process are available. Several insecticides and fungicides used in agricultural practices have been reported to inhibit chitin synthesis. However, no information is available on their activity against C. albicans or other human pathogens. Thus, in this work we determined the activity of Metalaxil, Trifumuron, Bitertanol and Maneb on growth, germ tube formation and chitin synthesis of four strains of C. albicans. The MIC of these compounds was determined by the Hector method in microtitre plates. Chitin synthetase activity was determined in membrane fractions by the Ruiz- Herrera and Bartnicki-Garcia method. All four compounds inhibited yeast growth of C. albicans (Metalaxil and Triflumuron, MIC= 19 micrograms/ml, Maneb MIC=39 micrograms/ml to 1.25 micrograms/ml; and Bitertanol, MIC= 39 to 625 micrograms/ml). The same compounds also inhibited the germ tube formation (Metalaxil, MIC=38 to 312 micrograms/ml; Triflumuron, MIC= 38 micrograms/ml; Maneb, MIC=78 micrograms/ml to 1.25 mg/ml; and Bitertanol, MCI= 78 to 625 micrograms/ml. Inhibition of chitin synthetase was strain- dependent. In many cases the chitin synthesis was increased by the compounds at certain low concentrations. In all cases the MIC of the compounds were not enough to inhibit chitin synthesis. Bitertanol was the most effective compound. At 1OX MIC, it usually reduced enzyme activity by about 63%, although at lower concentrations a slight increase was observed. Although preliminary, our data suggest that chitin synthetase may be an adequate target for the control of fungal diseases.
Publication Types:
Keywords:
- Antigens, Fungal
- Candida albicans
- Cell Wall
- Chitin
- Chitin Synthase
- Humans
- Insecticides
- Microbial Sensitivity Tests
- Pesticides
- Saccharomyces cerevisiae
- Sterols
- immunology
- metabolism
Other ID:
UI: 102195550
From Meeting Abstracts