title: Characterization and carbon metabolism in fungi pathogenic to Triatoma infestans, a chagas disease vector.
abstract: The pathogenicity of Metarhizium anisopliae (Ma) and Beauveria bassiana (Bb) isolates against Triatoma infestans, the major vector of Chagas disease in Argentina is reported. A 100% mortality was achieved with mean lethal times varying form 5.8 (Ma6) to 7.7 (Bb5) or 11.1 days (Bb10). The fatty acid, hydrocarbon, and total lipid patterns were compared for glucose-grown and alkane-grown Bb10 cultures. The alkane-grown cells showed a lipid pattern different from that of glucose-grown cells, with triacylglyercol as the major lipid fraction, whereas sterols prevailed in the glucose-grown cells. A significant reduction in the relative amounts of linoleic acid diminished the unsaturated/saturated fatty acid ratio for alkane-grown cells; in addition, large amounts of heptacosanoic and eicosanoic acids were detected in the saturated fraction. The hydrocarbon profile of Bb10 showed a saturated chain length distribution,with a marked prevalence for straight chains, ranging from n-C18 to n-C37 in the carbon skeleton, with n-C22 as the major component. Alkane-grown cells showed no qualitative changes in their hydrocarbon fraction, but a similar ratio for odd/even carbon chains. After 48-h incubation assays,[1-(14)C]acetate uptake was largely diminished following a period of alkane growth induction. Glucose-grown cells readily incorporated 19% of the labelinto phospholipids, hydrocarbons, triacylglycerols, and free fatty acids. In contrast, incorporation was reduced to 5.3% for alkane-grown cells, accounting only for phospholipid synthesis.
authors.affiliation: Facultad de Ciencias Médicas, Instituto de Investigaciones Bioquímicas de La Plata, UNLP, calles 60 y 120, La Plata, 1900, Argentina.
authors.forename: M P
authors.initials: MP
authors.lastname: Juárez
authors.forename: R
authors.initials: R
authors.lastname: Crespo
authors.forename: G C
authors.initials: GC
authors.lastname: Fernández
authors.forename: R
authors.initials: R
authors.lastname: Lecuona
authors.forename: L F
authors.initials: LF
authors.lastname: Cafferata
mesh_terms: D000818:Animals; D002244:Carbon / Q000378:metabolism*; D014355:Chagas Disease / Q000635:transmission*; D007303:Insect Vectors; D003904:Mitosporic Fungi / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D014224:Triatoma / Q000382:microbiology*
chemical_list: D002244:Carbon