RESUMO
We prospectively investigated 30 healthy subjects with normal CD4+ T cell counts in blood and normal findings of spirometry and chest radiography for the presence of Pneumocystis jirovecii, by performing polymerase chain reaction on sputum specimens. Fifty patients with chronic obstructive pulmonary disease were investigated at the same time in the same manner; this group was used as controls for the diagnosis of pulmonary colonization with P. jirovecii. None of the healthy subjects had positive test results, whereas the fungus was detected in 8 patients with chronic obstructive pulmonary disease. The results suggest that in our region (Amiens, France), P. jirovecii is apparently uncommon in healthy subjects and that this population, therefore, plays a minor role in circulation of the fungus within human communities.
Assuntos
Pneumocystis carinii/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , França/epidemiologia , Humanos , Pulmão/microbiologia , Masculino , Pessoa de Meia-Idade , Pneumonia por Pneumocystis/epidemiologia , Pneumonia por Pneumocystis/microbiologia , Doença Pulmonar Obstrutiva Crônica/microbiologiaRESUMO
This study describes the genotyping of Pneumocystis jirovecii organisms isolated from three groups of patients that developed diverse forms of P. jirovecii infection; the patients were monitored in the same French hospital. Forty archival specimens from 13 adults with Pneumocystis pneumonia, eight adults colonized by P. jirovecii and 19 immunocompetent infants infected with the fungus contemporaneously with a bronchiolitis episode were analysed retrospectively. Genotyping was performed by analysis of sequences of the internal transcribed spacer (ITS)1 and ITS2 regions, and of the dihydropteroate synthase (DHPS) locus. At the ITS regions, a high diversity of genotypes, identical main genotypes (B(1)a(3) and B(2)a(1)) and the occurrence of mixed infections (more than one genotype) were observed in the three patient groups. At the DHPS locus, the results indicated the presence of mutants in the two adult groups, as well as in the infant group. Consequently, at these two independent genomic regions, P. jirovecii isolates from patients who developed different forms of infection and who lived in the same geographical region presented common characteristics. These results suggest that patients infected with P. jirovecii, whatever the form of infection they present, are part of a common human reservoir for P. jirovecii.
Assuntos
Bronquiolite/microbiologia , Líquido da Lavagem Broncoalveolar/microbiologia , Infecções por Pneumocystis/microbiologia , Pneumocystis carinii/classificação , Pneumocystis carinii/genética , Pneumonia por Pneumocystis/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA Fúngico/análise , DNA Espaçador Ribossômico/genética , Di-Hidropteroato Sintase/genética , Feminino , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Pneumocystis carinii/isolamento & purificação , Reação em Cadeia da Polimerase , Estudos RetrospectivosRESUMO
Pneumocystis jirovecii ITS and DHPS genotypes were identified in 3 patient groups developing diverse forms of P. jirovecii infections: 13 patients with Pneumocystis pneumonia, 8 patients merely colonized by the fungus, and 19 immunocompetent infants with bronchiolitis developing mild P. jirovecii infection. Common P. jirovecii genotypes were found in the 3 patient groups, suggesting that common sources of P. jirovecii were involved in the fungus acquisition, and that transmission cycles of P. jirovecii infections in these patient groups are not independent. Parasitized patients, whatever the form of parasitism they present, may be part of a common reservoir for P. jirovecii.