Distribution of Pneumocystis carinii f. sp. hominis types in the lung of a child dying of Pneumocystis pneumonia

Pneumocystis fi sp. hominis causes pneumonia in immunocompromised persons. In order to determine the types and distribution of P carinii organisms within a single human lung, multiple samples were obtained from the lung of a child who died of P. carinii pneumonia. P carinii DNA was detected in all of the samples and 2 different genotypes of P carinii were identified, with uneven distribution in the lung, demonstrating that infection of the human lung is not necessarily clonal, and that different P carinii genotypes may predominate in different areas of the lung.