1. Characterization of cell stages and morphologies under the culture conditions used in this study.
Characterization of cell stages and morphologies under the culture conditions used in this study. (A) DAPI-stained cells were examined with confocal microscopy. The percentages of intermediate (Intermed) plus metacyclic cells during 12 days in LIT or RPMI cultures are shown. Data points represent means and standard errors of the means (SEM) of results from 3 to 5 replicate flasks collected on 2 different days. Met Tryp, metacyclic trypomastigotes. (B) Nine-day growth curve of T. cruzi in LIT and RPMI cultures. Data points represent means and SEM of results from three replicate flasks; error bars are too small to be observed with this resolution. (C) DAPI-stained cells were examined with confocal microscopy. Data represent results of a stacked-column comparison of ratios of epimastigote, metacyclic trypomastigote, intermediate, and spheromastigote development in various media on the indicated days. Day 8 (D8) RPMI cultures (total) and the top and bottom fractions of a day 8 RPMI culture (top and bottom) were examined. Data points represent means and SEM of results from 3 to 11 replicate flasks collected on 3 different days. (D) Complement-mediated lysis assay. Stacked-column comparison of sensitive (lysed) versus resistant (not lysed) cells present after treatment with active guinea pig serum relative to cells treated with heat-inactivated serum (HI). Data points represent means and SEM of results from 3 flasks collected and analyzed on a single day (LIT and TAU; n = 3) or from sets of 3 flasks collected on 2 different days (RPMI medium; n = 6). Spheromastigotes are rounded trypanosomes that appear with extended starvation but that revert to epimastigotes with the next feeding (64).
Aubie K. Shaw et al. mSphere 2016; doi: /mSphere