Immunocompetent Infants as a Human Reservoir for <i>Pneumocystis</i> jirovecii: Rapid Screening by Non‐Invasive Sampling and Real‐Time PCR at the Mitochondria1 Large Subunit rRNA Gene

Totet, Anne; Meliani, Leila; Lacube, Philippe; Pautard, J.C.; Raccurt, C. P.; Roux, Patricia; Nevez, Gilles

doi:10.1111/j.1550-7408.2003.tb00678.x

Cited by 34 publications

(21 citation statements)

References 5 publications

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“…Despite this wealth of knowledge, the current multilocus genotyping strategies have left many questions regarding transmission of P. jirovecii unanswered. For example, while it is clear that infants and immunocompetent adults are environmental reservoirs for P. jirovecii (83)(84)(85)(86)(87), there is not yet molecular evidence that these reservoirs are an important source of disease-causing P. jirovecii transmission to immunocompromised individuals. Because there is compelling evidence that transiently colonized immunocompetent mice can transmit P. jirovecii to immunosuppressed mice and vice versa (88,89), studies of P. jirovecii transmission among immunocompetent and immunosuppressed humans may help uncover a mechanism for disease prevention.…”

Section: Discussionmentioning

confidence: 99%

Multilocus Microsatellite Genotyping Array for Investigation of Genetic Epidemiology of Pneumocystis jirovecii

et al. 2014

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Pneumocystis jirovecii is a symbiotic respiratory fungus that causes pneumonia (PcP) in immunosuppressed patients. Because P. jirovecii cannot be reliably cultured in vitro, it has proven difficult to study and gaps in our understanding of the organism persist. The release of a draft genome for the organism opens the door for the development of new genotyping approaches for studying its molecular epidemiology and global population structure. We identified and validated 8 putatively neutral microsatellite markers and 1 microsatellite marker linked to the dihydropteroate synthase gene (dhps), the enzymatic target of sulfa drugs used for PcP prevention and treatment. Using these tools, we analyzed P. jirovecii isolates from HIV-infected patients from three geographically distant populations: Uganda, the United States, and Spain. Among the 8 neutral markers, we observed high levels of allelic heterozygosity (average H e , 0.586 to 0.842). Consistent with past reports, we observed limited global population structuring, with only the Ugandan isolates showing minor differentiation from the other two populations. In Ugandan isolates that harbored mutations in dhps, the microsatellite locus linked to dhps demonstrated a depressed H e , consistent with positive directional selection for sulfa resistance mutations. Using a subset of these microsatellites, analyses of individual and paired samples from infections in San Francisco, CA, showed reliable typeability within a single infection and high discriminatory power between infections. These features suggest that this novel microsatellite typing approach will be an effective tool for molecularepidemiological investigations into P. jirovecii population structure, transmission, and drug resistance.

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Section: Discussionmentioning

confidence: 99%

Multilocus Microsatellite Genotyping Array for Investigation of Genetic Epidemiology of Pneumocystis jirovecii

et al. 2014

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“…These patients had been hospitalized in two French university hospitals (hospitals A and B) between January 2008 and January 2012 for investigation of pulmonary symptoms (abnormal chest X-ray findings or cough) or fever. P. jirovecii was detected in BAL fluid samples by microscopic examination with methanol-Giemsa staining and an immunofluorescence assay (Monofluokit Pneumocystis; Bio-Rad, Marnes-La-Coquette, France) and/or a qualitative PCR assay targeting the mitochondrial large subunit (mtLSU) rRNA gene, as described previously (27). This assay was performed on an Applied Biosystems 7300 real-time PCR system using a plus/minus assay, which determined whether or not a specific target sequence was present.…”

Section: Methodsmentioning

confidence: 99%

Combined Quantification of Pulmonary Pneumocystis jirovecii DNA and Serum (1→3)-β- d -Glucan for Differential Diagnosis of Pneumocystis Pneumonia and Pneumocystis Colonization

et al. 2013

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This study assessed a quantitative PCR (qPCR) assay for Pneumocystis jirovecii quantification in bronchoalveolar lavage (BAL) fluid samples combined with serum (1¡3)-␤-D-glucan (BG) level detection to distinguish Pneumocystis pneumonia (PCP) from pulmonary colonization with P. jirovecii. Forty-six patients for whom P. jirovecii was initially detected in BAL fluid samples were retrospectively enrolled. Based on clinical data and results of P. jirovecii detection, 17 and 29 patients were diagnosed with PCP and colonization, respectively. BAL fluid samples were reassayed using a qPCR assay targeting the mitochondrial large subunit rRNA gene. qPCR results and serum BG levels (from a Fungitell kit) were analyzed conjointly. P. jirovecii DNA copy numbers were significantly higher in the PCP group than in the colonization group (1.3 ؋ 10 7 versus 3.4 ؋ 10 3 copies/l, P < 0.05). A lower cutoff value (1.6 ؋ 10 3 copies/l) achieving 100% sensitivity for PCP diagnosis and an upper cutoff value (2 ؋ 10 4 copies/ l) achieving 100% specificity were determined. Applying these two values, 13/17 PCP patients and 19/29 colonized patients were correctly assigned to their patient groups. For the remaining 14 patients with P. jirovecii DNA copy numbers between the cutoff values, PCP and colonization could not be distinguished on the basis of qPCR results. Four of these patients who were initially assigned to the PCP group presented BG levels of >100 pg/ml. The other 10 patients, who were initially assigned to the colonization group, presented BG levels of <100 pg/ml. These results suggest that the combination of the qPCR assay, applying cutoff values of 1.6 ؋ 10 3 and 2 ؋ 10 4 copies/l, and serum BG detection, applying a 100 pg/ml threshold, can differentiate PCP and colonization diagnoses.

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“…In another study of 60 children of HIV-infected mothers, 3.5% were Pneumocystis colonized, and those with colonization had upper respiratory symptoms (275). Other investigators have documented colonization in immunocompetent pediatric populations with either acute respiratory syndromes or chronic lung diseases (142,170,290). Although one study found a high proportion of colonization in infants dying from sudden infant death syndrome, this association has not been supported by subsequent studies (14,298,300).…”

Section: Colonization In Animalsmentioning

confidence: 96%

Colonization by Pneumocystis jirovecii and Its Role in Disease

2012

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SUMMARY Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.

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Immunocompetent Infants as a Human Reservoir for Pneumocystis jirovecii: Rapid Screening by Non‐Invasive Sampling and Real‐Time PCR at the Mitochondria1 Large Subunit rRNA Gene

Cited by 34 publications

References 5 publications

Multilocus Microsatellite Genotyping Array for Investigation of Genetic Epidemiology of Pneumocystis jirovecii

Multilocus Microsatellite Genotyping Array for Investigation of Genetic Epidemiology of Pneumocystis jirovecii

Combined Quantification of Pulmonary Pneumocystis jirovecii DNA and Serum (1→3)-β- d -Glucan for Differential Diagnosis of Pneumocystis Pneumonia and Pneumocystis Colonization

Colonization by Pneumocystis jirovecii and Its Role in Disease

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