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PLoS Pathogens 2012
Review
Topics: Animals; Humans; Pneumocystis; Pneumonia, Pneumocystis; Rats
PubMed: 23209406
DOI: 10.1371/journal.ppat.1003025 -
Chest Jun 1984
Review
Topics: Acquired Immunodeficiency Syndrome; Adult; Antibodies; Child; Drug Combinations; Humans; Immunologic Deficiency Syndromes; Lung; Pentamidine; Pneumocystis; Pneumonia, Pneumocystis; Pulmonary Alveoli; Radiography; Recurrence; Risk; Sulfamethoxazole; Trimethoprim; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 6373171
DOI: 10.1378/chest.85.6.810 -
Thorax Aug 1985
Review
Topics: Animals; Disease Models, Animal; Disease Susceptibility; Humans; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 3898464
DOI: 10.1136/thx.40.8.561 -
Revue de Pneumologie Clinique Dec 2010Pneumocystis was discovered nearly a century ago. It causes fatal pneumonia in immunocompromised individuals, especially in AIDS patients. Knowledge of the different... (Review)
Review
Pneumocystis was discovered nearly a century ago. It causes fatal pneumonia in immunocompromised individuals, especially in AIDS patients. Knowledge of the different species remained rudimentary until the mid-eighties when DNA analysis revealed its extensive diversity. In fact, it is no longer considered as a zoonosis. Pneumocystis organisms derived from different hosts have very different DNA sequences, indicating multiple species. Due to the genetic and functional disparities, the organism that causes human PCP is now named Pneumocystis jirovecii/Frenkel, 1999. We continue to call Pneumocystis carinii the species found in rats. This will allow for a single international language and avoid confusion. Changing the organism's name does not preclude the use of the well-known acronym PCP because it can also be read "PneumoCystis Pneumonia." The DNA sequences and genotypage have shown that variations exist among samples of P. jiroveci. Molecular biology is helpful in the study of the mechanisms of transmission, which can only occur in the same host and the different resistances as well as providing a better understanding of the relationship between host and pathogen. P. jirovecii pneumonia in immunosuppressed patients was previously thought to result from the reactivation of a latent infection acquired in early childhood. However, today, it is believed to result from a new infection from an exogenous source.
Topics: Genetic Variation; Genotype; Humans; Morocco; Opportunistic Infections; Pneumocystis carinii; Pneumonia, Pneumocystis; Sequence Analysis, DNA; Terminology as Topic
PubMed: 21167441
DOI: 10.1016/j.pneumo.2009.09.007 -
PLoS Pathogens Dec 2018
Review
Topics: Animals; Cell Proliferation; Humans; Life Cycle Stages; Pneumocystis; Pneumonia, Pneumocystis; Reproduction, Asexual
PubMed: 30521646
DOI: 10.1371/journal.ppat.1007409 -
Medical Mycology 2000Pneumocystis carinii pneumonia (PCP) is a well-recognized lung disease of immunocompromised patients, but the real impact of Pneumocystis infection in humans remains to... (Review)
Review
Pneumocystis carinii pneumonia (PCP) is a well-recognized lung disease of immunocompromised patients, but the real impact of Pneumocystis infection in humans remains to be discovered. Pneumocystis represents probably one of the more frequent infectious agents faced by humans. Seroconversion revealed P. carinii primary infection in > 90% of infants and small children, but the infection source and the clinical or pathological changes associated with this first contact with the parasite remain unknown. Pneumocystis organisms are atypical microfungi able to attach specifically to type-I alveolar epithelial cells, and to proliferate, provoking severe pneumonitis. A deep impairment of cell-mediated immunity associated with changes in pulmonary surfactant make it possible for Pneumocystis to grow within the host. Alveolar type-II cell hypertrophy, macrophagic infiltrate and intra-alveolar foamy eosinophilic material are the most typical changes. CD4+ T-lymphocytes and interferon play a major role in host defense against P. carinii. Alveolar macrophages phagocytose P. carinii via the macrophage-mannose receptor and produce reactive free-radicals and nitric oxide under Pneumocystis stimulation. Furthermore, PCP is associated with an early decrease of surfactant phospholipids, increased hydrophilic surfactant protein (SP) levels and decreased hydrophobic SPs. Normal surfactant improves PCP, and consistently, it inhibits the parasite growth. New detection tools have revealed that hospitalized patients can be latently infected with Pneumocystis and that immunocompetent hosts develop transient Pneumocystis infections. Pneumocystis organisms circulate in human populations, being able to infect hosts with diverse susceptibility levels. In fact, airborne Pneumocystis infection can display a large spectrum of clinical presentations and most likely, we recognize at present only the tip of the iceberg.
Topics: Animals; Carrier State; Humans; Pneumocystis; Pneumocystis Infections; Pneumonia, Pneumocystis
PubMed: 11204150
DOI: No ID Found -
FEMS Yeast Research Sep 2015Pneumocystis is a genus of ascomycetous fungi that are highly morbid pathogens in immunosuppressed humans and other mammals. Pneumocystis cannot easily be propagated in... (Review)
Review
Pneumocystis is a genus of ascomycetous fungi that are highly morbid pathogens in immunosuppressed humans and other mammals. Pneumocystis cannot easily be propagated in culture, which has greatly hindered understanding of its pathobiology. The Pneumocystis life cycle is intimately associated with its mammalian host lung environment, and life cycle progression is dependent on complex interactions with host alveolar epithelial cells and the extracellular matrix. The Pneumocystis cell wall is a varied and dynamic structure containing a dominant major surface glycoprotein, β-glucans and chitins that are important for evasion of host defenses and stimulation of the host immune system. Understanding of Pneumocystis cell signaling pathways is incomplete, but much has been deduced by comparison of the Pneumocystis genome with homologous genes and proteins in related fungi. In this mini-review, the pathobiology of Pneumocystis is reviewed, with particular focus on the life cycle, cell wall components and cell signal transduction.
Topics: Animals; Cell Wall; Disease Models, Animal; Host-Pathogen Interactions; Humans; Immune Evasion; Pneumocystis; Pneumonia, Pneumocystis; Signal Transduction
PubMed: 26071598
DOI: 10.1093/femsyr/fov046 -
Thorax Jul 1982
Review
Topics: Homosexuality; Humans; Immune Tolerance; Male; Pneumocystis; Pneumonia, Pneumocystis; Sarcoma, Kaposi; Skin Neoplasms; Syndrome
PubMed: 6753225
DOI: 10.1136/thx.37.7.481 -
FEMS Microbiology Reviews Nov 2006The genus Pneumocystis comprises noncultivable, highly diversified fungal pathogens dwelling in the lungs of mammals. The genus includes numerous host-species-specific... (Review)
Review
Pneumocystis oryctolagi sp. nov., an uncultured fungus causing pneumonia in rabbits at weaning: review of current knowledge, and description of a new taxon on genotypic, phylogenetic and phenotypic bases.
The genus Pneumocystis comprises noncultivable, highly diversified fungal pathogens dwelling in the lungs of mammals. The genus includes numerous host-species-specific species that are able to induce severe pneumonitis, especially in severely immunocompromised hosts. Pneumocystis organisms attach specifically to type-1 epithelial alveolar cells, showing a high level of subtle and efficient adaptation to the alveolar microenvironment. Pneumocystis species show little difference at the light microscopy level but DNA sequences of Pneumocystis from humans, other primates, rodents, rabbits, insectivores and other mammals present a host-species-related marked divergence. Consistently, selective infectivity could be proven by cross-infection experiments. Furthermore, phylogeny among primate Pneumocystis species was correlated with the phylogeny of their hosts. This observation suggested that cophylogeny could explain both the current distribution of pathogens in their hosts and the speciation. Thus, molecular, ultrastructural and biological differences among organisms from different mammals strengthen the view of multiple species existing within the genus Pneumocystis. The following species were subsequently described: Pneumocystis jirovecii in humans, Pneumocystis carinii and Pneumocystis wakefieldiae in rats, and Pneumocystis murina in mice. The present work focuses on Pneumocystis oryctolagi sp. nov. from Old-World rabbits. This new species has been described on the basis of both biological and phylogenetic species concepts.
Topics: Animals; Animals, Wild; France; Fungal Proteins; Genes, Fungal; Lung; Microscopy, Electron; Molecular Sequence Data; Phylogeny; Pneumocystis; Pneumonia, Pneumocystis; Rabbits; Species Specificity
PubMed: 17064284
DOI: 10.1111/j.1574-6976.2006.00037.x -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Oct 2023, an important opportunistic fungal pathogen that parasitizes in multiple mammalian lungs, may cause life-threatening pneumonia (PCP) and even death among... (Review)
Review
, an important opportunistic fungal pathogen that parasitizes in multiple mammalian lungs, may cause life-threatening pneumonia (PCP) and even death among immunocompromised individuals. With the rapid development of high-throughput sequencing and multi-omics technologies, systematic comparative analyses of genome, transcriptome, and whole-genome sequencing results demonstrate that is a type of obligate biotrophic fungi, and requires obtaining nutrition from hosts. In addition, sexual reproduction is an essential process for survival, production and transmission, and asexual reproduction facilitates survival, which provides new insights into understanding of the whole developmental process of in the host lung and inter-host transmission of . This review summarizes the advances in the reproduction mode of and underlying mechanisms, which provides insights into prevention and treatment of PCP, notably for the prophylaxis against nosocomial transmission of PCP.
Topics: Humans; Lung; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 38148544
DOI: 10.16250/j.32.1374.2022289