Analysis of Internal Transcribed Spacer 1 Sequences of Pneumocystis jiroveci from Clinical Specimens

Abstract

Pneumocystis jiroveci (formerly Pneumocystis carinii f. sp. hominis) is one of the causative agents of the most serious fungal respiratory infections in immuno-compromised patients. Although P. jiroveci infections have been increasing, there are few data on the P. jiroveci genotypes in Korea. This study was performed to investigate the genetic diversity of P. jiroveci detected from clinical specimens. Twenty-one P. jirovecipositive respiratory samples detected by polymerase chain reaction were collected from a tertiary-care hospital in Seoul between Jan 2003 and Aug 2006. Internal Transcribed Spacer (ITS) sequence analysis was performed by direct sequencing. Only 9 specimens were appropriate for sequence analysis. Twelve specimens, however, showed mixed sequences by direct sequencing. Three ITS genotypes of P. jiroveci were found. There is limited genetic diversity of ITS genes of P. jiroveci from clinical isolates analyzed in this study. The present ITS gene analysis suggests that most of P. jiroveci isolates may have genetic similarity among patients in Korea.