Comparative Population Genomics Analysis of the Mammalian Fungal Pathogen Pneumocystis

Bibliographic Details
Title: Comparative Population Genomics Analysis of the Mammalian Fungal Pathogen Pneumocystis
Authors: Ousmane H. Cissé, Liang Ma, Da Wei Huang, Pavel P. Khil, John P. Dekker, Geetha Kutty, Lisa Bishop, Yueqin Liu, Xilong Deng, Philippe M. Hauser, Marco Pagni, Vanessa Hirsch, Richard A. Lempicki, Jason E. Stajich, Christina A. Cuomo, Joseph A. Kovacs
Source: mBio, Vol 9, Iss 3 (2018)
Publisher Information: American Society for Microbiology, 2018.
Publication Year: 2018
Collection: LCC:Microbiology
Subject Terms: evolutionary biology, genetic diversity, genetic recombination, pneumonia, population structure, Microbiology, QR1-502
More Details: ABSTRACT Pneumocystis species are opportunistic mammalian pathogens that cause severe pneumonia in immunocompromised individuals. These fungi are highly host specific and uncultivable in vitro. Human Pneumocystis infections present major challenges because of a limited therapeutic arsenal and the rise of drug resistance. To investigate the diversity and demographic history of natural populations of Pneumocystis infecting humans, rats, and mice, we performed whole-genome and large-scale multilocus sequencing of infected tissues collected in various geographic locations. Here, we detected reduced levels of recombination and variations in historical demography, which shape the global population structures. We report estimates of evolutionary rates, levels of genetic diversity, and population sizes. Molecular clock estimates indicate that Pneumocystis species diverged before their hosts, while the asynchronous timing of population declines suggests host shifts. Our results have uncovered complex patterns of genetic variation influenced by multiple factors that shaped the adaptation of Pneumocystis populations during their spread across mammals. IMPORTANCE Understanding how natural pathogen populations evolve and identifying the determinants of genetic variation are central issues in evolutionary biology. Pneumocystis, a fungal pathogen which infects mammals exclusively, provides opportunities to explore these issues. In humans, Pneumocystis can cause a life-threatening pneumonia in immunosuppressed individuals. In analysis of different Pneumocystis species infecting humans, rats, and mice, we found that there are high infection rates and that natural populations maintain a high level of genetic variation despite low levels of recombination. We found no evidence of population structuring by geography. Our comparisons of the times of divergence of these species to their respective hosts suggest that Pneumocystis may have undergone recent host shifts. The results demonstrate that Pneumocystis strains are widely disseminated geographically and provide a new understanding of the evolution of these pathogens.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2150-7511
Relation: https://doaj.org/toc/2150-7511
DOI: 10.1128/mBio.00381-18
Access URL: https://doaj.org/article/c0995cfe69d144e9b577c9ecad070400
Accession Number: edsdoj.0995cfe69d144e9b577c9ecad070400
Database: Directory of Open Access Journals
More Details
ISSN:21507511
DOI:10.1128/mBio.00381-18
Published in:mBio
Language:English