title: Genetic diversity of Pneumocystis jirovecii strains based on sequence variation of different DNA region.
abstract: Pneumocystis jirovecii is an important opportunistic pathogen that causes severe pneumonia in immunocompromised patients. The aim of the present study was to investigate the genetic diversity of P. jirovecii strains by direct sequencing and analysis of the Upstream Conserved Sequence (UCS) region, mitochondrial large-subunit (mtLSU) rRNA and dihydrofolate reductase (DHFR) genes. We identified the polymorphisms in P. jirovecii strains of 15 immunocompromised patients, as well as detecting a new tandem repeat of 5 nucleotides in UCS region. The following three different types of repeat unit were found: type a GCCCA; type b GCCCT; and type c GCCTT. In addition, we identified the repeat unit which consisted of 10 nucleotides and three different patterns of UCS repeats with 3 and 4 repeats, i.e., 1, 2, 3 (86.7%), 1, 2, 3, 3 (6.6%) and a new genotype 2, 2, 3, 3 (6.6%). The polymorphism in the mtLSUrRNA gene was seen primarily at position 85 where we detected three different genotypes. Genotype 3 and genotype 2 were the most abundant with frequencies of 53.3% and 40%, respectively. With regard to the DHFR gene, only two (20%) patients had nucleotide substitution in position 312. In conclusion, the multilocus analysis facilitated the typing of P. jirovecii strains and proved the important genetic biodiversity of this fungus.
authors.affiliation: Fungal and Parasitic Molecular Biology Laboratory, School of Medicine, University of Sfax, Sfax, Tunisia. mohamedalijarboui@gmail.com
authors.forename: Mohamed Ali
authors.initials: MA
authors.lastname: Jarboui
authors.forename: Fatma
authors.initials: F
authors.lastname: Mseddi
authors.forename: Hayet
authors.initials: H
authors.lastname: Sellami
authors.forename: Amira
authors.initials: A
authors.lastname: Sellami
authors.forename: Fatma
authors.initials: F
authors.lastname: Makni
authors.forename: Ali
authors.initials: A
authors.lastname: Ayadi
mesh_terms: D004271:DNA, Fungal / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D045363:Pneumocystis carinii / Q000145:classification* / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D013762:Tetrahydrofolate Dehydrogenase