Faculty Opinions recommendation of Prophylaxis for Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients.

Pneumocystis jiroveci infections can cause pneumocystis pneumonia (PCP) or lead to colonization without signs of PCP. Over the years, different genotypes of P. jiroveci have been discovered. Genomic typing of P. jiroveci in different subpopulations can contribute to unravelling the pathogenesis, transmission and spread of the different genotypes. In this study, we wanted to determine the distribution of P. jiroveci genotypes in immunocompetent and immunocompromised patients in The Netherlands and determine the clinical relevance of these detected mutations. A real-time PCR targeting the major surface glycoprotein gene (MSG) was used as a screening test for the presence of P. jiroveci DNA. Samples positive for MSG were genotyped based on the internal transcribed spacer (ITS) and dihydropteroate synthase (DHPS) genes. Of the 595 included bronchoalveolar lavage fluid samples, 116 revealed the presence of P. jiroveci DNA. A total of 52 of the 116 samples were ITS genotyped and 58 DHPS genotyped. The ITS genotyping revealed 17 ITS types, including two types that have not been described previously. There was no correlation between ITS genotype and underlying disease. All ITS- and DHPS-genotyped samples were found in immunocompromised patients. Of the 58 DHPS-genotyped samples, 50 were found to be WT. The other eight samples revealed a mixed genotype consisting of WT and type 1. The majority of the latter recovered on trimethoprim–sulfamethoxazole suggesting no clinical relevance for this mutation.

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Loop-mediated isothermal amplification method for diagnosing Pneumocystis pneumonia in HIV-uninfected immunocompromised patients with pulmonary infiltrates

Journal of Infection and Chemotherapy ◽

10.1016/j.jiac.2014.08.005 ◽

2014 ◽

Vol 20 (12) ◽

pp. 757-761 ◽

Cited By ~ 7

Author(s):

Kei Nakashima ◽

Masahiro Aoshima ◽

Yoshihiro Ohkuni ◽

Eri Hoshino ◽

Kohei Hashimoto ◽

...

Keyword(s):

Pneumocystis Pneumonia ◽

Isothermal Amplification ◽

Immunocompromised Patients ◽

Loop Mediated Isothermal Amplification ◽

Pulmonary Infiltrates ◽

Amplification Method

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Development of a Droplet Digital Polymerase Chain Reaction for Sensitive Detection of Pneumocystis jirovecii in Respiratory Tract Specimens

Frontiers in Medicine ◽

10.3389/fmed.2021.761788 ◽

2021 ◽

Vol 8 ◽

Author(s):

Jie Yi ◽

Nan Wang ◽

Jie Wu ◽

Yueming Tang ◽

Jingjia Zhang ◽

...

Keyword(s):

Respiratory Tract ◽

Digital Pcr ◽

Absolute Quantification ◽

Pneumocystis Pneumonia ◽

Pneumocystis Jirovecii ◽

Immunocompromised Patients ◽

Balf Sample ◽

Bronchoalveolar Fluid ◽

Life Threatening ◽

Digital Polymerase Chain Reaction

Background:Pneumocystis jirovecii is a human-specific opportunistic fungus that causes Pneumocystis pneumonia (PCP), a life-threatening opportunistic lung infection that affects immunocompromised patients. P. jirovecii colonization may be linked to the transmission of the infection. The detection of P. jirovecii in immunocompromised patients is thus especially important. The low fungal load and the presence of PCR inhibitors limit the usefulness of quantitative PCR (qPCR) for accurate absolute quantification of P. jirovecii in specimens. Droplet digital PCR (ddPCR), however, presents a methodology that allows higher sensitivity and accuracy. Here, we developed a ddPCR method for detecting P. jirovecii DNA in respiratory specimens, and evaluated its sensitivity against qPCR.Materials and Methods: One bronchoalveolar fluid (BALF) sample each was collected from 82 patients with potential PCP to test the presence of P. jirovecii DNA using both ddPCR and qPCR, and samples with inconsistent results between the two methods were further tested by metagenomic next generation sequencing (mNGS). In addition, 37 sputum samples from 16 patients diagnosed with PCP, as well as continuous respiratory tract specimens from nine patients with PCP and treated with sulfonamides, were also collected for P. jirovecii DNA testing using both ddPCR and qPCR.Results: ddPCR and qPCR gave the same results for 95.12% (78/82) of the BALF samples. The remaining four specimens tested positive using ddPCR but negative using qPCR, and they were found to be positive by mNGS. Detection results of 78.37% (29/37) sputum samples were consistent between ddPCR and qPCR, while the other eight samples tested positive using ddPCR but negative using qPCR. The P. jirovecii load of patients with PCP decreased to undetectable levels after treatment according to qPCR, but P. jirovecii was still detectable using ddPCR.Conclusions: ddPCR was more sensitive than qPCR, especially at detecting low-pathogen-load P. jirovecii. Thus, ddPCR represents a useful, viable, and reliable alternative to qPCR in P. jirovecii testing in patients with immunodeficiency.

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