Heterogeneity of Pneumocystis sterol profiles of samples from different sites in the same pair of lungs suggests coinfection by distinct organism populations.

Sterol profiles of samples taken from different sites of a Pneumocystis-infected human lung showed large variations in pneumocysterol similar to those that occur among samples from different patients. Thus, the influence of diet or drugs on pneumocysterol accumulation was ruled out, suggesting distinct phenotypic populations as the basis for the heterogeneity.