Genotyping of Pneumocystis jirovecii isolates obtained from clinical samples by multilocus sequencing: a molecular...

Pneumocystis jirovecii is an opportunistic respiratory pathogen causing Pneumocystis pneumonia (PcP) in immunocompromised patients. The aim of this study was to investigate the genetic diversity of P. jirovecii isolates (n: 84) obtained from PcP patients using multilocus sequencing method based on mt26S, SOD, and CYB loci. Among the 84 clinical samples that were positive for P. jirovecii DNA, 31 (36.90%) of them were genotyped using at least one locus. Of the 31 clinical samples, 26 of them were successfully genotyped using all loci whereas three samples were genotyped using either mt26S/CYB loci or mt26S/SOD loci. Additionally, there were two more clinical samples that were genotyped using CYB or SOD locus. Using mt26S locus, genotypes 2, 3, 7, and 8 were detected. Frequencies of genotype 7 and 8 were higher and both of them were found in 11 (n: 29; 37.93%) clinical samples. Using SOD locus, SOD 1, 2, and 4 genotypes were detected. SOD 1 was the predominant genotype (20/28; 71.42%). During the analyses of CYB locus, CYB 1, 2, 5, 6, and 7 as well as a new CYB genotype were detected. CYB 1 (16/29; 55.17%) and 2 (10/29; 34.48%) were the predominant genotypes. Overall, according to the multilocus sequencing results E, F, M, N, P, and V multilocus genotypes were detected among the PcP patients. In addition, SOD 1 was the predominant genotype and CYB had a more polymorphic locus.