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AIDS (London, England) Oct 1993
Review
Topics: AIDS-Related Opportunistic Infections; Animals; Humans; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 8267902
DOI: No ID Found -
Emerging Infectious Diseases 1996
Review
Topics: Animals; Humans; Molecular Epidemiology; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 8903219
DOI: 10.3201/eid0202.960214 -
Seminars in Respiratory Infections Dec 1998Ultrastructural studies indicate that the attachment of Pneumocystis carinii to alveolar epithelial cells is a central feature during development of this pneumonia. P.... (Review)
Review
Ultrastructural studies indicate that the attachment of Pneumocystis carinii to alveolar epithelial cells is a central feature during development of this pneumonia. P. carinii attaches preferentially to type I alveolar epithelial cells, and rarely binds to type II cells. Extensive in vitro investigations support roles for both fibronectin and vitronectin, which bind to the organism, and mediate P. carinii attachment to respiratory epithelial cells through corresponding integrin receptors. Additional studies indicate that P. carinii cytoskeletal rearrangement occurs after initial binding of the organism to lung cells. Further, the attachment of P. carinii to host epithelial cells is believed to induce ultrastructural changes in these cells and to result in enhanced epithelial cell permeability. Further studies will be required to determine the mechanisms and consequences of P. carinii attachment to host epithelial cells in the intact host.
Topics: Animals; Cells, Cultured; Epithelial Cells; Extracellular Matrix Proteins; Humans; Lectins; Pneumocystis; Pneumonia, Pneumocystis; Respiratory System
PubMed: 9872629
DOI: No ID Found -
The New England Journal of Medicine Jan 1991
Topics: Aged; Cluster Analysis; Humans; Pneumocystis; Pneumonia, Pneumocystis; Virulence
PubMed: 1985248
DOI: 10.1056/NEJM199101243240411 -
Medical Mycology Oct 2019The genus Pneumocystis comprises potential pathogens that reside normally in the lungs of a wide range of mammals. Although they generally behave as transient or...
The genus Pneumocystis comprises potential pathogens that reside normally in the lungs of a wide range of mammals. Although they generally behave as transient or permanent commensals, they can occasionally cause life-threatening pneumonia (Pneumocystis pneumonia; PCP) in immunosuppressed individuals. Several decades ago, the presence of Pneumocystis morphotypes (trophic forms and cysts) was described in the lungs of normal cats and cats with experimentally induced symptomatic PCP (after immunosuppression by corticosteroids); yet to date spontaneous or drug-induced PCP has not been described in the clinical feline literature, despite immunosuppression of cats by long-standing retrovirus infections or after kidney transplantation. In this study, we describe the presence of Pneumocystis DNA in the lungs of normal cats (that died of various unrelated causes; n = 84) using polymerase chain reactions (PCRs) targeting the mitochondrial small and large subunit ribosomal RNA gene (mtSSU rRNA and mtLSU rRNA). The presence of Pneumocystis DNA was confirmed by sequencing in 24/84 (29%) cats, with evidence of two different sequence types (or lineages). Phylogenetically, lineage1 (L1; 19 cats) and lineage 2 (L2; 5 cats) formed separate clades, clustering with Pneumocystis from domestic pigs (L1) and carnivores (L2), respectively. Results of the present study support the notion that cats can be colonized or subclinically infected by Pneumocystis, without histological evidence of damage to the pulmonary parenchyma referable to pneumocystosis. Pneumocystis seems most likely an innocuous pathogen of cats' lungs, but its possible role in the exacerbation of chronic pulmonary disorders or viral/bacterial coinfections should be considered further in a clinical setting.
Topics: Animals; Cat Diseases; Cats; DNA, Fungal; Female; Lung; Male; Phylogeny; Pneumocystis; Pneumonia, Pneumocystis; RNA, Mitochondrial; RNA, Ribosomal
PubMed: 30566653
DOI: 10.1093/mmy/myy139 -
Current Opinion in Pulmonary Medicine May 2008Pneumocystis pneumonia remains the most prevalent opportunistic infection in patients with AIDS. It is also a common devastating infection in patients with other causes... (Review)
Review
PURPOSE OF REVIEW
Pneumocystis pneumonia remains the most prevalent opportunistic infection in patients with AIDS. It is also a common devastating infection in patients with other causes of altered immunity. Though scientific study of this fungal pathogen is challenging given the inability to propagate the organism outside of the host lung, studies utilizing advanced molecular techniques and genomic analysis have broadened our understanding of the epidemiology and pathogenesis of Pneumocystis and will be described herein.
RECENT FINDINGS
Results from advanced molecular techniques suggest that Pneumocystis organisms not only cause infection in patients with impaired immunity but also colonize mammals with normal immune systems. Advanced technology has also identified acquired Pneumocystis genetic mutations that confer resistance to currently utilized therapeutics. Though not yet widely utilized in clinical medicine, advanced polymerase chain reaction techniques improve the diagnostic yield of respiratory specimen analysis. Preliminary results from serum beta-glucan testing suggest that a noninvasive marker of Pneumocystis pneumonia infection and response to therapy may be on the horizon.
SUMMARY
Recent scientific advances suggest opportunities for improving the diagnosis and treatment surveillance of Pneumocystis pneumonia. Further investigations are necessary to define the optimal characteristics of these laboratory tests and to develop therapeutics directed at novel Pneumocystis genomic targets.
Topics: Humans; Pneumocystis carinii; Pneumonia, Pneumocystis
PubMed: 18427246
DOI: 10.1097/MCP.0b013e3282f94abc -
BMJ Case Reports Apr 2021Pneumocystis jirovecii pneumonia (PCP) is a potential life-threatening pulmonary infection which commonly manifests in immunosuppressed patients especially with HIV,...
Pneumocystis jirovecii pneumonia (PCP) is a potential life-threatening pulmonary infection which commonly manifests in immunosuppressed patients especially with HIV, with underlying malignancies, severe malnutrition as well as those on immunosuppressive treatments. There have been case reports of symptomatic PCP in individuals with a normally functioning immune system with typical clinical features and radiologic findings of bilateral and diffuse interstitial opacities. However, PCP in immunocompetent individuals presenting with lung nodules had been rarely reported. We report a 53-year-old immunocompetent gentleman who presented with subacute cough, progressive shortness of breath and radiographic findings of multiple lung nodules with central cavitation. The diagnosis of PCP was made by detection of PCP DNA PCR in bronchoalveolar lavage sample following fibreoptic bronchoscopy. This case also highlights the atypical radiographic findings of multiple cavitating lung nodules as a presentation of PCP in an immunocompetent patient.
Topics: Bronchoalveolar Lavage; Humans; Immunocompromised Host; Lung; Middle Aged; Pneumocystis carinii; Pneumonia, Pneumocystis
PubMed: 33906876
DOI: 10.1136/bcr-2020-241061 -
Der Internist Jun 1985
Review
Topics: Adult; Animals; Antibodies; Antimalarials; Child; Drug Combinations; Drug Therapy, Combination; Humans; Lung; Pentamidine; Pneumocystis; Pneumonia, Pneumocystis; Pyrimethamine; Radiography; Rats; Sulfadiazine; Sulfamethoxazole; Trimethoprim; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 3897099
DOI: No ID Found -
Nature Reviews. Microbiology Apr 2007The fungal infection Pneumocystis pneumonia is the most prevalent opportunistic infection in patients with AIDS. Although the analysis of this opportunistic fungal... (Review)
Review
The fungal infection Pneumocystis pneumonia is the most prevalent opportunistic infection in patients with AIDS. Although the analysis of this opportunistic fungal pathogen has been hindered by the inability to isolate it in pure culture, the use of molecular techniques and genomic analysis have brought insights into its complex cell biology. Analysis of the intricate relationship between Pneumocystis and the host lung during infection has revealed that the attachment of Pneumocystis to the alveolar epithelium promotes the transition of the organism from the trophic to the cyst form. It also revealed that Pneumocystis infection elicits the production of inflammatory mediators, culminating in lung injury and impaired gas exchange. Here we discuss these and other recent findings relating to the biology and pathogenesis of this intractable fungus.
Topics: Animals; Antifungal Agents; Antigens, Fungal; Antigens, Surface; Cell Cycle; Cytokines; Drug Resistance, Fungal; Genome, Fungal; Humans; Lung; Pneumocystis; Pneumonia, Pneumocystis; Pulmonary Alveoli; Signal Transduction
PubMed: 17363968
DOI: 10.1038/nrmicro1621 -
The Journal of Eukaryotic Microbiology 2013I am honored to receive the second Lifetime Achievement Award by International Workshops on Opportunistic Protists and to give this lecture. My research involves... (Review)
Review
I am honored to receive the second Lifetime Achievement Award by International Workshops on Opportunistic Protists and to give this lecture. My research involves Pneumocystis, an opportunistic pulmonary fungus that is a major cause of pneumonia ("PcP") in the immunocompromised host. I decided to focus on Pneumocystis ecology here because it has not attracted much interest. Pneumocystis infection is acquired by inhalation, and the cyst stage appears to be the infective form. Several fungal lung infections, such as coccidiomycosis, are not communicable, but occur by inhaling < 5 μm spores from environmental sources (buildings, parks), and can be affected by environmental factors. PcP risk factors include environmental constituents (temperature, humidity, SO2 , CO) and outdoor activities (camping). Clusters of PcP have occurred, but no environmental source has been found. Pneumocystis is communicable and outbreaks of PcP, especially in renal transplant patients, are an ongoing problem. Recent evidence suggests that most viable Pneumocystis organisms detected in the air are confined to a patient's room. Further efforts are needed to define the risk of Pneumocystis transmission in health care facilities; to develop more robust preventive measures; and to characterize the effects of climatological and air pollutant factors on Pneumocystis transmission in animal models similar to those used for respiratory viruses.
Topics: Disease Outbreaks; Ecology; Humans; Immunocompromised Host; Inhalation Exposure; Pneumocystis; Pneumonia, Pneumocystis; Risk Factors
PubMed: 24001365
DOI: 10.1111/jeu.12072