RESUMO
The results of the genotypic characterization of Pneumocystis jirovecii are described in lung tissue samples from 41 Cubans who died of AIDS with pneumocystosis between 1995 and 2008. Histological sections of the lung preserved as formalin-fixed and paraffin-embedded tissue were examined. PCR amplification and nucleotide sequencing of the two mitochondrial genes (large and small) of the pathogen allowed verification of a predominance of genotype 3 (85T/248C) of the large mitochondrial gene and genotype 3 (160A/196T) of the small mitochondrial gene over a period of 14 years (1995-2008). These results suggest that the 85T/248C//160A/196T genotype circulates with the highest frequency (81.3%) among AIDS patients in Cuba. Multilocus analysis indicates a limited circulation of pathogen genotypes on the island with the existence of a clonal genotype with an epidemic structure. Furthermore, it appears that circulating strains of P. jirovecii have not developed mutations related to sulfonamide resistance. Taken together, the data in this study revealed important elements about pneumocystosis in Cuban patients dying of AIDS and the usefulness of formalin-fixed and paraffin-embedded samples to carry out molecular epidemiology studies of P. jirovecii.
RESUMO
A high prevalence of Pneumocystis jirovecii colonization was observed in patients positive for the human immunodeficiency virus (HIV) admitted to a tertiary hospital in southern Brazil between August 2012 and December 2012. Amplification of the mitochondrial large subunit ribosomal RNA gene in oropharyngeal samples through nested polymerase chain reaction identified P. jirovecii colonization in 26 of 58 (44.8%) HIV-positive patients admitted for causes other than Pneumocystis pneumonia. Colonization was more frequent among patients with an absolute CD4 count ≤200 cells/µl. These findings suggest that the HIV-infected population is a major reservoir and source of P. jirovecii infection and that identification of such individuals may contribute to future strategies for improving management of HIV-infected patients.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Portador Sadio/epidemiologia , Pneumocystis carinii , Pneumonia por Pneumocystis/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Adulto , Brasil/epidemiologia , Portador Sadio/microbiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Orofaringe/microbiologia , Pneumocystis carinii/genética , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/microbiologia , PrevalênciaRESUMO
A high rate of Pneumocystis jirovecii colonization was observed in Brazilian cystic fibrosis (CF) patients (13 out of 34; 38.2%) who underwent bronchoscopy between March 2006 and August 2009 at the Hospital de Clinicas de Porto Alegre, Brazil. Bronchoalveolar lavage samples were collected from these patients and studied by nested PCR amplification of the mitochondrial gene coding for the large subunit ribosomal RNA (mtLSUrDNA). The observed rate of colonization was higher than that reported in European populations. Genotypic characterization of the mtLSUrDNA locus revealed a predominance of the polymorphisms 85C/248C (genotype 1) and 85T/248C (genotype 3), with all samples possessing the wild-type genotype of dihydropteroate synthase. These findings suggest that cystic fibrosis patients could be an important reservoir and source of P. jirovecii infection. Further studies are required to elucidate the role of this common fungal colonization in the evolution of CF patients.
Assuntos
Fibrose Cística/microbiologia , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Fibrose Cística/complicações , Fibrose Cística/epidemiologia , DNA Fúngico/genética , DNA Mitocondrial/genética , DNA Ribossômico/genética , Feminino , Genes de RNAr , Humanos , Lactente , Masculino , Pneumocystis carinii/genética , Pneumonia por Pneumocystis/complicações , Pneumonia por Pneumocystis/microbiologia , Reação em Cadeia da Polimerase , Prevalência , Análise de Sequência de DNA , Adulto JovemRESUMO
Genotypes of two different loci of the Pneumocystis jirovecii mitochondrial gene were studied in specimens from a total of 75 Pneumocystis pneumonia patients in Spain, France and Cuba. A new genotype of the mitochondrial small subunit rRNA gene of P. jirovecii (160A/196T) was identified, which was revealed to be the most common in these three countries, especially in Cuba where its proportion reached 93.8%. Our data imply that the new genotype might be circulating worldwide and also suggests that the distribution of P. jirovecii genotypes could be narrower in islands such as Cuba.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Técnicas de Tipagem Micológica , Pneumocystis carinii/classificação , Pneumocystis carinii/genética , Pneumonia por Pneumocystis/epidemiologia , Pneumonia por Pneumocystis/microbiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Cuba/epidemiologia , Feminino , França/epidemiologia , Genes de RNAr , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Pneumocystis carinii/isolamento & purificação , Espanha/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Infliximab, a chimeric antitumour necrosis factor (TNF) monoclonal antibody, has become an established effective therapy for inflammatory rheumatic disease. However, TNF is a critical factor in host defence, and the suppression of its biological activity may be associated with the increased risk of opportunistic infections. The frequent use of infliximab in clinical practice has identified Pneumocystis jirovecii pneumonia (PcP) as a serious complication. Individuals colonized with Pneumocystis may be at high risk of development of PcP when they have undergone immunosuppression. Hence, we addressed the question of the frequency of Pneumocystis colonization among patients treated with infliximab. DESIGN: We examined 125 oropharyngeal washes collected from 78 individuals with rheumatoid arthritis, 30 with ankylosing spondylitis and 17 with psoriatic arthritis, half of them underwent infliximab therapy, using a real-time polymerase chain reaction assay that employs specific primers from a portion of the mitochondrial large-subunit rRNA gene of P. jirovecii. RESULTS: Pneumocystis jirovecii colonization was detected in 32 (25·6%) patients. In a multivariate regression model, only duration of infliximab treatment for more than 3 years and use of corticosteroid were significantly and independently associated with risk of Pneumocystis colonization. However, the effect of corticosteroid on P. jirovecii colonization rate was not linearly dose dependent as showed other logistic regression analysis. CONCLUSIONS: There is a high rate of P. jirovecii colonization among patients with rheumatologic diseases treated with infliximab. The identification of patients colonized by P. jirovecii before starting the treatment with infliximab could be a strategy for PcP prevention.