Partial sequence of the rRNA operon of Pneumocystis carinii isolates from Puerto Rico.

Several reports indicate geographic variation of isolates of Pneumocystis carinii hominis. We have sequenced the internal transcribed spacer (ITS) region and large subunit Group I intron of rRNA genes from P. carinii DNA obtained from two patients from Puerto Rico. Both can be subclassified as Type II, according to the sequence of the ITS region. A system capable of identifying individual isolates will be an essential tool for epidemiological studies of the organism. The amplification of DNA from fixed tissues may facilitate the processing of a large number of samples.