55 results on '"Pneumonia, Pneumocystis transmission"'
Search Results
2. The ecology of pneumocystis: perspectives, personal recollections, and future research opportunities.
- Author
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Walzer PD
- Subjects
- Disease Outbreaks, Humans, Inhalation Exposure, Pneumocystis pathogenicity, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis transmission, Risk Factors, Ecology, Immunocompromised Host, Pneumocystis physiology, Pneumonia, Pneumocystis parasitology
- Abstract
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., (© 2013 The Author(s) Journal of Eukaryotic Microbiology © 2013 International Society of Protistologists.)
- Published
- 2013
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3. Outbreaks of Pneumocystis pneumonia in 2 renal transplant centers linked to a single strain of Pneumocystis: implications for transmission and virulence.
- Author
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Sassi M, Ripamonti C, Mueller NJ, Yazaki H, Kutty G, Ma L, Huber C, Gogineni E, Oka S, Goto N, Fehr T, Gianella S, Konrad R, Sing A, and Kovacs JA
- Subjects
- Cluster Analysis, Disease Transmission, Infectious, Genotype, Germany epidemiology, Humans, Japan epidemiology, Molecular Typing, Mycological Typing Techniques, Pneumocystis isolation & purification, Pneumonia, Pneumocystis transmission, Polymorphism, Restriction Fragment Length, Switzerland epidemiology, Virulence, Disease Outbreaks, Kidney Transplantation adverse effects, Pneumocystis classification, Pneumocystis pathogenicity, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis microbiology
- Abstract
Background: There have been numerous reports of clustered outbreaks of Pneumocystis pneumonia (PCP) at renal transplant centers over the past 2 decades. It has been unclear whether these outbreaks were linked epidemiologically to 1 or several unique strains, which could have implications for transmission patterns or strain virulence., Methods: Restriction fragment length polymorphism (RFLP) analysis was used to compare Pneumocystis isolates from 3 outbreaks of PCP in renal transplant patients in Germany, Switzerland, and Japan, as well as nontransplant isolates from both human immunodeficiency virus (HIV)-infected and uninfected patients., Results: Based on RFLP analysis, a single Pneumocystis strain caused pneumonia in transplant patients in Switzerland (7 patients) and Germany (14 patients). This strain was different from the strain that caused an outbreak in transplant patients in Japan, as well as strains causing sporadic cases of PCP in nontransplant patients with or without HIV infection., Conclusions: Two geographically distinct clusters of PCP in Europe were due to a single strain of Pneumocystis. This suggests either enhanced virulence of this strain in transplant patients or a common, but unidentified, source of transmission. Outbreaks of PCP can be better understood by enhanced knowledge of transmission patterns and strain variation.
- Published
- 2012
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4. Pneumocystis: where does it live?
- Author
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Gigliotti F and Wright TW
- Subjects
- Animals, Humans, Pneumonia, Pneumocystis pathology, Rats, Pneumocystis immunology, Pneumocystis pathogenicity, Pneumonia, Pneumocystis immunology, Pneumonia, Pneumocystis transmission
- Published
- 2012
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5. Clinical and translational research in pneumocystis and pneumocystis pneumonia.
- Author
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Huang L
- Subjects
- AIDS-Related Opportunistic Infections epidemiology, AIDS-Related Opportunistic Infections microbiology, Drug Resistance, Fungal, Humans, Biomedical Research trends, Pneumocystis drug effects, Pneumonia, Pneumocystis diagnosis, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis therapy, Pneumonia, Pneumocystis transmission, Translational Research, Biomedical trends
- Abstract
Pneumocystis pneumonia (PcP) remains a significant cause of morbidity and mortality in immunocompromised persons, especially those with human immunodeficiency virus (HIV) infection. Pneumocystis colonization is described increasingly in a wide range of immunocompromised and immunocompetent populations and associations between Pneumocystis colonization and significant pulmonary diseases such as chronic obstructive pulmonary disease (COPD) have emerged. This mini-review summarizes recent advances in our clinical understanding of Pneumocystis and PcP, describes ongoing areas of clinical and translational research, and offers recommendations for future clinical research from researchers participating in the "First centenary of the Pneumocystis discovery".
- Published
- 2011
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6. Pneumocystis murina colonization in immunocompetent surfactant protein A deficient mice following environmental exposure.
- Author
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Linke MJ, Ashbaugh AD, Demland JA, and Walzer PD
- Subjects
- Adrenal Cortex Hormones pharmacology, Animals, Antibodies, Fungal blood, CD4-Positive T-Lymphocytes immunology, CD4-Positive T-Lymphocytes microbiology, CD8-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes microbiology, Immunosuppressive Agents pharmacology, Lung drug effects, Lung microbiology, Mice, Mice, Inbred C3H, Mice, Knockout, Mice, SCID, Pneumocystis genetics, Pneumocystis immunology, Pneumonia, Pneumocystis immunology, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission, Pulmonary Surfactant-Associated Protein A deficiency, Pulmonary Surfactant-Associated Protein A genetics, RNA, Fungal blood, RNA, Messenger blood, Time Factors, Environmental Exposure, Immunity, Innate drug effects, Immunity, Innate genetics, Immunocompetence drug effects, Immunocompetence genetics, Lung immunology, Pneumocystis pathogenicity, Pneumonia, Pneumocystis prevention & control, Pulmonary Surfactant-Associated Protein A metabolism
- Abstract
Background: Pneumocystis spp. are opportunistic pathogens that cause pneumonia in immunocompromised humans and animals. Pneumocystis colonization has also been detected in immunocompetent hosts and may exacerbate other pulmonary diseases. Surfactant protein A (SP-A) is an innate host defense molecule and plays a role in the host response to Pneumocystis., Methods: To analyze the role of SP-A in protecting the immunocompetent host from Pneumocystis colonization, the susceptibility of immunocompetent mice deficient in SP-A (KO) and wild-type (WT) mice to P. murina colonization was analyzed by reverse-transcriptase quantitative PCR (qPCR) and serum antibodies were measured by enzyme-linked immunosorbent assay (ELISA)., Results: Detection of P. murina specific serum antibodies in immunocompetent WT and KO mice indicated that the both strains of mice had been exposed to P. murina within the animal facility. However, P. murina mRNA was only detected by qPCR in the lungs of the KO mice. The incidence and level of the mRNA expression peaked at 8-10 weeks and declined to undetectable levels by 16-18 weeks. When the mice were immunosuppressed, P. murina cyst forms were also only detected in KO mice. P. murina mRNA was detected in SCID mice that had been exposed to KO mice, demonstrating that the immunocompetent KO mice are capable of transmitting the infection to immunodeficient mice. The pulmonary cellular response appeared to be responsible for the clearance of the colonization. More CD4+ and CD8+ T-cells were recovered from the lungs of immunocompetent KO mice than from WT mice, and the colonization in KO mice depleted CD4+ cells was not cleared., Conclusion: These data support an important role for SP-A in protecting the immunocompetent host from P. murina colonization, and provide a model to study Pneumocystis colonization acquired via environmental exposure in humans. The results also illustrate the difficulties in keeping mice from exposure to P. murina even when housed under barrier conditions.
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- 2009
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7. Exploring transplacental transmission of Pneumocystis oryctolagi in first-time pregnant and multiparous rabbit does.
- Author
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Sanchez CA, Chabé M, Aliouat el M, Durand-Joly I, Gantois N, Conseil V, López C, Duriez T, Dei-Cas E, and Vargas SL
- Subjects
- Animals, DNA, Bacterial chemistry, DNA, Bacterial genetics, Disease Models, Animal, Female, Fetus, Lung microbiology, Parity, Pneumocystis genetics, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction, Pregnancy, Infectious Disease Transmission, Vertical, Placenta microbiology, Pneumocystis physiology, Pneumonia, Pneumocystis microbiology, Pregnancy Complications, Infectious microbiology, Rabbits microbiology
- Abstract
Pneumocystis sp. is transmitted through the airborne route and presents a high host-species-specificity. Occasional reports of Pneumocystis pneumonia in still births and newborn infants suggest that other routes of transmission, e.g. transplacental might occur. The latter has been reported in rabbits but available data indicate that transplacental transmission of Pneumocystis seems not to occur in corticosteroid-treated rats and in SCID mice. The present study was undertaken to evaluate transplacental transmission of Pneumocystis oryctolagi. The spontaneously-acquired pneumocystosis rabbit model using hybrid California/New Zealand white female rabbits was selected because of similarities among rabbit and human placentas. Three different experiments were conducted in France and Chile. Pneumocystis organisms were detected by microscopy in the lungs of pregnant does and Pneumocystis DNA was found in the lungs of fetuses from the multiparous does from the second week to the end of gestation. Pneumocystis DNA was not detected in fetuses from primiparous does. Detection of Pneumocystis oryctolagi--DNA in fetuses of multiparous does and not in those of primiparous ones, suggests that transplacental transmission may be favored by multiple gestations. Whether Pneumocystis-DNA in fetal tissues from multiparous does resulted from transplacental passage of viable transmissible forms requires further investigation.
- Published
- 2007
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8. Exposure of immunocompetent adult mice to Pneumocystis carinii f. sp. muris by cohousing: growth of P. carinii f. sp. muris and host immune response.
- Author
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An CL, Gigliotti F, and Harmsen AG
- Subjects
- Animals, Disease Susceptibility, Immunocompromised Host, Lung microbiology, Mice, Mice, Inbred BALB C, Mice, SCID, Pneumocystis growth & development, Pneumonia, Pneumocystis microbiology, Housing, Animal, Immunocompetence, Pneumocystis pathogenicity, Pneumonia, Pneumocystis immunology, Pneumonia, Pneumocystis transmission
- Abstract
There has been emerging evidence that immunocompetent hosts can harbor Pneumocystis in their lungs. The purpose of this study was to determine the kinetics of Pneumocystis carinii f. sp. muris infection in adult immunocompetent mice and the host immune response to the organisms. To accomplish this, we exposed adult immunocompetent mice to SCID mice infected with P. carinii f. sp. muris by cohousing. We found that P. carinii f. sp. muris was detectable in the lungs of cohoused immunocompetent mice by PCR by 3 weeks after the beginning of cohousing. At about 4 weeks of cohousing, P. carinii f. sp. muris was readily detectable in the lungs of mice by microscopic techniques. Also at this time, P. carinii f. sp. muris-specific immunoglobulin G was found in the sera of the mice, and CD62(low) CD4- and CD8-positve T cells accumulated in the lungs. Shortly after this immune response, the P. carinii f. sp. muris organisms were cleared from the lungs. Adult mice cohoused for only 1 week also contained P. carinii f. sp. muris cysts detectable by silver staining at 5 and 6 weeks after the beginning of cohousing. We also found that the P. carinii f. sp. muris organisms grew to greater numbers in the lungs of BALB/c mice than in those of C57BL6 mice. This indicates that immunocompetent hosts develop a mild infection with P. carinii f. sp. muris which resolves in 5 to 6 weeks when there is a detectable immune response to the organism. Once an acquired immune response was initiated, the P. carinii f. sp. muris organisms were quickly eliminated without clinical signs of disease.
- Published
- 2003
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9. Risk for Pneumocystis carinii transmission among patients with pneumonia: a molecular epidemiology study.
- Author
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Manoloff ES, Francioli P, Taffé P, Van Melle G, Bille J, and Hauser PM
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Pneumonia, Pneumocystis epidemiology, Polymerase Chain Reaction, Risk Factors, Molecular Epidemiology, Pneumocystis classification, Pneumocystis genetics, Pneumonia, Pneumocystis transmission
- Abstract
We report a molecular typing and epidemiologic analysis of Pneumocystis carinii pneumonia (PCP) cases diagnosed in our geographic area from 1990 to 2000. Our analysis suggests that transmission from patients with active PCP to susceptible persons caused only a few, if any, PCP cases in our setting.
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- 2003
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10. Early acquisition of Pneumocystis carinii in neonatal rats as evidenced by PCR and oral swabs.
- Author
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Icenhour CR, Rebholz SL, Collins MS, and Cushion MT
- Subjects
- Age Factors, Animals, Animals, Newborn, DNA, Fungal genetics, DNA, Fungal isolation & purification, Female, Maternal-Fetal Exchange, Mouth microbiology, Placenta microbiology, Pneumocystis genetics, Pneumocystis isolation & purification, Pneumonia, Pneumocystis etiology, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction, Pregnancy, Rats, Rats, Inbred BN, Rats, Long-Evans, Pneumocystis pathogenicity
- Abstract
The complete life cycle of Pneumocystis carinii has not been defined, but accumulating evidence suggests that the mammalian host may acquire this organism early in life. In the present study, the initial time of P. carinii acquisition was determined in rats by amplification of P. carinii DNA in oral swabs from seven sets of pups and dams and from fetal tissue obtained by cesarean section of three gravid female rats. DNA extracted from all samples was amplified by using PCR primers directed to the P. carinii mitochondrial large subunit rRNA. Amplicons were produced from 80% (28 of 35) of pups within 2 h after birth; from 97% (34 of 35) after 24 h, and in all of the serially sampled pups by 48 h. No P. carinii amplicons were produced from 48 fetuses or their placentae taken by cesarean section. Thus, P. carinii is acquired almost immediately after birth, and placental transmission occurs rarely, if ever, in rats.
- Published
- 2002
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11. Pneumocystis carinii f. sp. hominis is not infectious for SCID mice.
- Author
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Durand-Joly I, Aliouat el M, Recourt C, Guyot K, François N, Wauquier M, Camus D, and Dei-Cas E
- Subjects
- Animals, Humans, Macaca mulatta, Mice, Mice, SCID, Pneumocystis pathogenicity, Rabbits, Rats, Species Specificity, Zoonoses transmission, Pneumocystis classification, Pneumonia, Pneumocystis transmission
- Abstract
The infectious power of Pneumocystis carinii f. sp. hominis was explored by inoculating SCID mice intranasally with either P. carinii f. sp. hominis or P. carinii f. sp. muris isolates. Only mice inoculated with mouse parasites developed Pneumocystis pneumonia, as assessed by microscopy and PCR. These results suggest that humans do not contract pneumocystosis from animals.
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- 2002
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12. Probable mother-to-infant transmission of Pneumocystis carinii f. sp. hominis infection.
- Author
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Miller RF, Ambrose HE, Novelli V, and Wakefield AE
- Subjects
- Bronchoalveolar Lavage Fluid chemistry, DNA, Fungal analysis, Female, Genotype, Humans, Infant, Newborn, Male, Pneumocystis isolation & purification, Pneumonia, Pneumocystis microbiology, Polymerase Chain Reaction, Infectious Disease Transmission, Vertical, Pneumocystis classification, Pneumocystis genetics, Pneumonia, Pneumocystis transmission
- Abstract
A mother and her 4.5-week-old infant had Pneumocystis carinii pneumonia contemporaneously. Genotyping of P. carinii f. sp. hominis DNA at three independent loci showed the same genotype in samples from mother and infant. These data suggest transmission of P. carinii organisms from the mother to her infant.
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- 2002
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13. Pneumocystis carinii.
- Author
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Wakefield AE
- Subjects
- Child, DNA, Fungal analysis, Drug Resistance, Fungal, Genome, Fungal, Humans, Pneumocystis genetics, Pneumocystis isolation & purification, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction, Immunosuppression Therapy, Pneumocystis pathogenicity, Pneumonia, Pneumocystis diagnosis
- Abstract
Pneumocystis carinii is an atypical fungus that causes pneumonia in immunocompromised individuals. P. carinii comprises a heterogeneous group of organisms that have been isolated from a wide range of mammalian host species. P. carinii infection is host species specific, the P. carinii organisms that infect humans have only been found in humans. This review discusses the application of molecular techniques to the study of the biology and epidemiology of P. carinii infection. It addresses the use of DNA amplification for the detection and diagnosis of P. carinii pneumonia. Studies investigating the reservoir of infectious P. carinii organisms, the routes of transmission of the infection, and the emergence of drug resistant strains of P. carinii are also discussed.
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- 2002
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14. New insights into transmission, diagnosis, and drug treatment of Pneumocystis carinii pneumonia.
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Kovacs JA, Gill VJ, Meshnick S, and Masur H
- Subjects
- AIDS-Related Opportunistic Infections complications, AIDS-Related Opportunistic Infections transmission, Algorithms, Anti-Infective Agents pharmacology, Atovaquone, Dihydropteroate Synthase genetics, Fungal Proteins genetics, Humans, Lymphoma, AIDS-Related complications, Lymphoma, AIDS-Related diagnosis, Male, Membrane Glycoproteins genetics, Middle Aged, Mutation, Naphthoquinones pharmacology, Naphthoquinones therapeutic use, Pentamidine therapeutic use, Pneumocystis genetics, Pneumocystis isolation & purification, Pneumonia, Pneumocystis complications, Pneumonia, Pneumocystis transmission, Sulfonamides pharmacology, Trimethoprim, Sulfamethoxazole Drug Combination pharmacology, Trimethoprim, Sulfamethoxazole Drug Combination therapeutic use, AIDS-Related Opportunistic Infections diagnosis, AIDS-Related Opportunistic Infections drug therapy, Anti-Infective Agents therapeutic use, Drug Resistance, Fungal genetics, Pneumocystis drug effects, Pneumonia, Pneumocystis diagnosis, Pneumonia, Pneumocystis drug therapy
- Abstract
Pneumocystis carinii has been recognized as a human pathogen for nearly 50 years. We present a case of P carinii infection that typifies clinical presentation in the era of the acquired immunodeficiency syndrome epidemic. The high incidence of P carinii pneumonia in persons infected with human immunodeficiency virus (HIV) has served to focus laboratory and clinical research efforts on better understanding the biology of the organism and on improving diagnosis, treatment, and prevention of this disease. Although inability to culture P carinii has hampered research efforts, molecular and immunologic approaches have led to the recognition that the organism represents a family of fungi with a very restricted host range and have allowed characterization of clinically relevant antigens and enzymes. Molecular epidemiologic studies have identified more than 50 strains of human-derived P carinii and have suggested that recently acquired infection, as opposed to reactivation of latent infection, may account for many cases of clinical disease. Diagnosis has been improved by the development of organism-specific monoclonal antibodies and, more recently, by polymerase chain reaction using multicopy gene targets, together with induced sputum or oral wash samples. Chemotherapeutic prophylaxis is very effective in preventing P carinii pneumonia; the combination of trimethoprim-sulfamethoxazole remains the first-line agent for both therapy and prophylaxis. Prophylaxis needs to be administered only during periods of high risk; in HIV-infected patients responding to effective antiretroviral therapies, prophylaxis no longer needs to be lifelong. Molecular studies have identified mutations in the target of sulfa drugs that appear to represent emerging resistance in P carinii. Resistance to atovaquone, a second-line agent, may also be developing.
- Published
- 2001
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15. Pneumocystis carinii f. sp. hominis DNA in immunocompetent health care workers in contact with patients with P. carinii pneumonia.
- Author
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Miller RF, Ambrose HE, and Wakefield AE
- Subjects
- DNA, Fungal genetics, DNA, Ribosomal Spacer genetics, Female, Genotype, Humans, Pneumocystis classification, Pneumocystis genetics, Pneumonia, Pneumocystis microbiology, Sputum microbiology, DNA, Fungal analysis, Health Personnel, Immunocompetence, Infectious Disease Transmission, Patient-to-Professional, Pneumocystis isolation & purification, Pneumonia, Pneumocystis transmission
- Abstract
The possible transmission of Pneumocystis carinii f. sp. hominis from patients with P. carinii pneumonia to asymptomatic health care workers (HCW), with or without occupational exposure to human immunodeficiency virus (HIV)-infected patients with P. carinii pneumonia, was examined. HCW in a specialist inpatient HIV-AIDS facility and a control group in the general medical-respiratory service in the same hospital provided induced sputum and/or nasal rinse samples, which were analyzed for the presence of P. carinii f. sp. hominis DNA by using DNA amplification (at the gene encoding the mitochondrial large subunit rRNA [mt LSU rRNA]). P. carinii f. sp. hominis DNA was detected in some HCW samples; those with the closest occupational contact were more likely to have detectable P. carinii DNA. P. carinii DNA was detected in one HCW who carried out bronchoscopy over a 2-year period. P. carinii-positive samples were genotyped by using DNA sequence variations at the internal transcribed spacer (ITS) regions of the nuclear rRNA operon, along with bronchoalveolar lavage samples from patients with P. carinii pneumonia hospitalized at the same time. Genotyping identified 31 different P. carinii f. sp. hominis ITS genotypes, 26 of which were found in the patient samples. Five of the eight ITS genotypes detected in HCW samples were not observed in the patient samples. The results suggested that HCW in close occupational contact with patients who had P. carinii pneumonia may have become colonized with P. carinii. Carriage was asymptomatic and did not result in the development of clinical disease.
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- 2001
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16. Development and characterization of a molecular viability assay for Pneumocystis carinii f sp hominis.
- Author
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Maher NH, Vermund SH, Welsh DA, Dillon HK, Awooda A, and Unnasch TR
- Subjects
- AIDS-Related Opportunistic Infections genetics, Adult, Bronchoalveolar Lavage Fluid microbiology, Female, Humans, Male, Middle Aged, Molecular Sequence Data, Pneumocystis isolation & purification, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis transmission, RNA, Messenger analysis, RNA, Ribosomal, 18S, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Sputum microbiology, AIDS-Related Opportunistic Infections microbiology, DNA, Bacterial analysis, Pneumocystis genetics, Pneumonia, Pneumocystis microbiology
- Abstract
Pneumocystis carinii pneumonia (PCP) remains the most common opportunistic infection among human immunodeficiency virus-infected persons. Despite this, little is known concerning the transmission dynamics of this infection. In the absence of a reliable method to isolate and culture P. carinii from environmental samples, it has not been possible to assess the importance of person-to-person transmission in the epidemiology of PCP. A molecular viability assay was developed for the human form of P. carinii (P. carinii f sp hominis) that is applicable to both clinical specimens and environmental samples. This assay will enable the evaluation of the spread and persistence of viable human P. carinii in the environment.
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- 2001
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17. Putative transmissive form of Pneumocystis carinii f. sp. carinii.
- Author
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Icenhour CR and Cushion MT
- Subjects
- Air Microbiology, Air Pollution, Indoor, Animals, DNA, Fungal analysis, Image Processing, Computer-Assisted, Immunomagnetic Separation, Microscopy methods, Mouth microbiology, Pneumonia, Pneumocystis microbiology, Polymerase Chain Reaction, Rats, Specimen Handling, Pneumocystis isolation & purification, Pneumocystis physiology, Pneumonia, Pneumocystis transmission
- Published
- 2001
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18. Summary of Pneumocystis research presented at the 7th International Workshop on Opportunistic Protists.
- Author
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Cushion MT and Beck JM
- Subjects
- Animals, Disease Models, Animal, Fungal Proteins genetics, Genome, Fungal, Humans, Phylogeny, Rats, Terminology as Topic, Pneumocystis classification, Pneumocystis genetics, Pneumocystis pathogenicity, Pneumocystis physiology, Pneumonia, Pneumocystis immunology, Pneumonia, Pneumocystis parasitology, Pneumonia, Pneumocystis physiopathology, Pneumonia, Pneumocystis transmission
- Published
- 2001
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19. Genotypes of clustered cases of Pneumocystis carinii pneumonia.
- Author
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Olsson M, Eriksson BM, Elvin K, Strandberg M, and Wahlgren M
- Subjects
- Adult, Aged, Aged, 80 and over, Bronchoalveolar Lavage Fluid microbiology, Disease Outbreaks, Disease Transmission, Infectious, Female, Genotype, Hematologic Diseases complications, Hematologic Diseases immunology, Hospitals, Humans, Immunocompromised Host, Kidney Transplantation adverse effects, Kidney Transplantation immunology, Male, Middle Aged, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis transmission, RNA, Fungal analysis, RNA, Ribosomal analysis, Sweden epidemiology, Pneumocystis genetics, Pneumonia, Pneumocystis microbiology
- Abstract
Reports of outbreaks of Pneumocystis carinii pneumonia (PCP) among human immunodeficiency virus-negative immunocompromised patients have suggested a person-to-person transmission of P. carinii. In this study, 17 bronchoalveolar lavage isolates from patients in 3 PCP outbreaks were genotyped, 2 in renal transplant recipients and 1 outbreak among patients with haematological disorders. Genotypes in the P. carinii sp. f. hominis (P. carinii f.sp. hominis) mt large subunit ribosomal RNA site 85 were detected by 2 methods: direct sequencing and 3 different allele-specific polymerase chain reaction assays. Although limited data on patient contacts were available, the detected P. c. hominis genotypes do not support person-to-person transmission as the predominant transmission route of P. carinii in humans.
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- 2001
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20. Early acquisition of Pneumocystis carinii in neonatal rats using targeted PCR and oral swabs.
- Author
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Icenhour CR, Rebholz SL, Collins MS, and Cushion MT
- Subjects
- Animals, Animals, Newborn, Cesarean Section, Disease Models, Animal, Female, Fetus microbiology, Pneumocystis genetics, Pneumonia, Pneumocystis microbiology, Pregnancy, Rats, Rats, Long-Evans, Specimen Handling, Time Factors, Infectious Disease Transmission, Vertical, Mouth microbiology, Pneumocystis isolation & purification, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction methods, Pregnancy Complications, Infectious microbiology
- Published
- 2001
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21. Pneumocystis carinii dihydropteroate synthase genotypes in HIV-infected persons residing in San Francisco: possible implications for disease transmission.
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Huang L, Friedly J, Morris AM, Carter JL, Turner JR, Merrifield C, Navin TR, and Beard CB
- Subjects
- AIDS-Related Opportunistic Infections microbiology, Female, Genotype, Housing, Humans, Male, Mutation, Pneumocystis enzymology, Pneumonia, Pneumocystis microbiology, San Francisco, AIDS-Related Opportunistic Infections transmission, Dihydropteroate Synthase genetics, Pneumocystis classification, Pneumocystis genetics, Pneumonia, Pneumocystis transmission
- Published
- 2001
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22. Transmission of Pneumocystis carinii disease from immunocompetent contacts of infected hosts to susceptible hosts.
- Author
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Dumoulin A, Mazars E, Seguy N, Gargallo-Viola D, Vargas S, Cailliez JC, Aliouat EM, Wakefield AE, and Dei-Cas E
- Subjects
- Animals, Immunocompetence, Mice, Mice, Inbred BALB C, Mice, SCID, Pneumocystis isolation & purification, Pneumonia, Pneumocystis microbiology, Carrier State microbiology, Carrier State transmission, Immunocompromised Host, Pneumocystis pathogenicity, Pneumonia, Pneumocystis transmission
- Abstract
Pneumocystis carinii organisms constitute a large group of heterogeneous atypical microscopic fungi that are able to infect immunocompromised mammals by an airborne route and to proliferate in their lungs, inducing Pneumocystis carinii pneumonia. This pneumonia remains a crucial epidemiological challenge, since neither the source of Pneumocystis carinii infection in humans nor the process by which humans become infected has been clearly established. Polymerase chain reaction (PCR) assays have shown that profoundly immunosuppressed patients without pneumocystosis can be subclinically infected with Pneumocystis. Other PCR-based studies have suggested that healthy immunocompetent hosts are not latent carriers of the parasite. However, recent reports have indicated that Pneumocystis carinii can persist for limited periods in the lungs of convalescent rats after recovery from corticosteroid-induced pneumocystosis, and also that immunocompetent mammals can be transiently parasitized by Pneumocystis carinii after close contact with hosts with Pneumocystis carinii pneumonia. Can transiently parasitized hosts be a source of infection for immunosuppressed hosts? In order to investigate this important clinical question, the ability of immunocompetent BALB/c mice, which were carrying subclinical levels of Pneumocystis carinii, to transmit the infection by the airborne route to highly susceptible, uninfected mice with severe combined immunodeficiency was studied. The results indicated that the immunocompetent mice, transiently parasitized by Pneumocystis carinii organisms after close contact with Pneumocystis carinii-infected mice, were able to transmit the infection to Pneumocystis carinii-free mice with severe combined immunodeficiency.
- Published
- 2000
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23. Development and evaluation of a molecular viability assay for Pneumocystis carinii.
- Author
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Maher N, Vermund S, Lasbury M, Lee C, Bartlett M, and Unnasch TR
- Subjects
- Air Pollution, Indoor, Base Sequence, Blotting, Southern, Humans, Molecular Sequence Data, Pneumocystis physiology, Pneumonia, Pneumocystis transmission, RNA, Fungal analysis, RNA, Messenger analysis, Reverse Transcriptase Polymerase Chain Reaction methods, Sensitivity and Specificity, Pneumocystis genetics, Pneumocystis isolation & purification
- Abstract
Despite recent declines in incidence, Pneumocystis carinii pneumonia (PCP) remains the most commonly occurring opportunistic illness among persons with AIDS in the United States. While P. carinii DNA has been detected in patient respiratory specimens and in air samples collected from various indoor environments housing PCP patients, the viability of these organisms is unknown. For this reason, we have developed and evaluated a molecular viability assay for P. carinii. This method is based upon the detection of P. carinii mRNA by a reverse transcription-PCR that employs specific primers from a member of the heat shock protein 70 family. Under optimal assay conditions, these primers were capable of detecting as few as 100 viable trophozoites as determined by ethidium bromide staining, while no signal was obtained from 10(6) trophozoites killed by heat, desiccation, or UV radiation. This assay was also capable of distinguishing P. carinii from other common fungi present in the air. Therefore, this molecular viability assay may be useful in conjunction with standard bioaerosol collection devices and procedures for the detection of viable P. carinii collected from various indoor environments. It may also be useful in confirming the presence of viable trophozoites in respiratory specimens collected by noninvasive techniques from putatively infected individuals.
- Published
- 2000
- Full Text
- View/download PDF
24. Genetic variation in Pneumocystis carinii isolates from different geographic regions: implications for transmission.
- Author
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Beard CB, Carter JL, Keely SP, Huang L, Pieniazek NJ, Moura IN, Roberts JM, Hightower AW, Bens MS, Freeman AR, Lee S, Stringer JR, Duchin JS, del Rio C, Rimland D, Baughman RP, Levy DA, Dietz VJ, Simon P, and Navin TR
- Subjects
- AIDS-Related Opportunistic Infections epidemiology, DNA Primers, Dihydropteroate Synthase genetics, Gene Frequency, Genes, rRNA, Genotype, Humans, Logistic Models, Mitochondria genetics, Pneumonia, Pneumocystis epidemiology, RNA, Ribosomal genetics, Sequence Analysis, DNA, United States epidemiology, AIDS-Related Opportunistic Infections microbiology, Genetic Variation, Pneumocystis genetics, Pneumocystis isolation & purification, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission
- Abstract
To study transmission patterns of Pneumocystis carinii pneumonia (PCP) in persons with AIDS, we evaluated P. carinii isolates from patients in five U.S. cities for variation at two independent genetic loci, the mitochondrial large subunit rRNA and dihydropteroate synthase. Fourteen unique multilocus genotypes were observed in 191 isolates that were examined at both loci. Mixed infections, accounting for 17.8% of cases, were associated with primary PCP. Genotype frequency distribution patterns varied by patients' place of diagnosis but not by place of birth. Genetic variation at the two loci suggests three probable characteristics of transmission: that most cases of PCP do not result from infections acquired early in life, that infections are actively acquired from a relatively common source (humans or the environment), and that humans, while not necessarily involved in direct infection of other humans, are nevertheless important in the transmission cycle of P. carinii f. sp. hominis.
- Published
- 2000
- Full Text
- View/download PDF
25. Transmission of Pneumocystis carinii DNA from a patient with P. carinii pneumonia to immunocompetent contact health care workers.
- Author
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Vargas SL, Ponce CA, Gigliotti F, Ulloa AV, Prieto S, Muñoz MP, and Hughes WT
- Subjects
- Adult, Antibodies, Fungal blood, Female, Humans, Immunocompetence, Infant, Male, Nasopharynx microbiology, Pneumocystis genetics, Pneumocystis immunology, Pneumocystis Infections microbiology, Polymerase Chain Reaction methods, DNA, Fungal analysis, Health Personnel, Infectious Disease Transmission, Patient-to-Professional, Pneumocystis isolation & purification, Pneumocystis Infections transmission, Pneumonia, Pneumocystis transmission
- Abstract
The transmission of Pneumocystis carinii from person to person was studied by detecting P. carinii-specific DNA in prospectively obtained noninvasive deep-nasal-swab samples from a child with a documented P. carinii pneumonia (PCP), his mother, two contact health care workers, and 30 hospital staff members who did not enter the patient's room (controls). Nested-DNA amplification was done by using oligonucleotide primers designed for the gene encoding the mitochondrial large subunit rRNA of rat P. carinii (P. carinii f. sp. carinii) that amplifies all forms of P. carinii and internal primers specific for human P. carinii (f. sp. hominis). P. carinii f. sp. hominis DNA was detected in samples from the patient and all of his contacts versus none of the 30 hospital staff members. The results, as previously shown in murine models of P. carinii pneumonia, document that person-to-person transmission of P. carinii is possible. This observation suggests that immunocompromised patients not on PCP prophylaxis should not enter the room of a patient with PCP, and it also raises the question as to whether healthy contacts can transmit the disease to immunocompromised patients at risk.
- Published
- 2000
- Full Text
- View/download PDF
26. Pneumocystis infections: the iceberg?
- Author
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Dei-Cas E
- Subjects
- Animals, Carrier State, Humans, Pneumocystis pathogenicity, Pneumocystis Infections epidemiology, Pneumocystis Infections microbiology, Pneumocystis Infections physiopathology, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis physiopathology, Pneumonia, Pneumocystis transmission
- Abstract
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.
- Published
- 2000
27. Acquisition and biodiversity of Pneumocystis carinii in a colony of wild rabbits (Oryctolagus cuniculus).
- Author
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Guillot J, ChevalierV, Queney G, Berthelemy M, Polack B, Lacube P, RouxP, and Chermette R
- Subjects
- Animals, Animals, Wild microbiology, DNA, Fungal analysis, DNA, Mitochondrial genetics, Ear microbiology, Humans, Phylogeny, Pneumocystis classification, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction methods, Genes, rRNA genetics, Pneumocystis genetics, Pneumocystis isolation & purification, Pneumonia, Pneumocystis veterinary, Rabbits microbiology
- Published
- 1999
28. Animal pneumocystosis: a model for man.
- Author
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Ceré N and Polack B
- Subjects
- AIDS-Related Opportunistic Infections microbiology, Animals, Disease Models, Animal, Disease Transmission, Infectious, Humans, Infectious Disease Transmission, Vertical, Mice, Pneumocystis genetics, Pneumonia, Pneumocystis prevention & control, Pneumonia, Pneumocystis veterinary, Rabbits, Rats, Pneumocystis pathogenicity, Pneumonia, Pneumocystis physiopathology, Pneumonia, Pneumocystis transmission
- Abstract
Pneumocystis carinii is an important pulmonary pathogen responsible for morbidity and mortality in patients with AIDS. Apart from AIDS, cases of pneumocystosis have been reported in patients receiving immunosuppressive therapy associated with organ transplantation without chemoprophylaxis and in malignant blood diseases. In vitro models are only of limited interest because there is no continuous in vitro culture. The in vivo models have contributed a great deal to the understanding of human Pneumocystis carinii pneumonia. Indeed, animal models remain of prime interest for many purposes, principally comparative medicine, pathogenesis, epidemiology and immunology. Among animal models, the rabbit is a very susceptible host to P. carinii infection, and does not need glucocorticoid treatment. Moreover, antigenic and genomic data suggest that rabbit-derived Pneumocystis strains are more closely related to human Pneumocystis than those of mice or rats. We have therefore shown that the rabbit model permits the study of the pulmonary surfactant modification due to P. carinii infection. This model should be a very interesting model for pathogenesis or immune response studies in immunocompetent animals. The rabbit model could also be used for epidemiological studies. P. carinii transmission appears to be very rapid via contact of Pneumocystis-free rabbits with infected rabbits. These Pneumocystis-free animals could be helpful for characterizing the source and the reservoir and studying parasite transmission.
- Published
- 1999
29. Pneumocystis carinii: the art and science of survival in the hostile environment of the alveolar spaces.
- Author
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Martin WJ 2nd
- Subjects
- Animals, Anti-Infective Agents therapeutic use, Antifungal Agents therapeutic use, Humans, Immunocompromised Host, Pneumocystis isolation & purification, Pneumonia, Pneumocystis drug therapy, Pneumonia, Pneumocystis transmission, Prognosis, Recurrence, Risk Factors, Pneumocystis pathogenicity, Pneumonia, Pneumocystis microbiology, Pulmonary Alveoli immunology, Pulmonary Alveoli microbiology
- Abstract
Pneumocystis carinii remains an important cause of pneumonia in immunocompromised patients, particularly in those who have acquired immune deficiency syndrome. Potential mechanisms by which P. carinii escapes elimination by lung defenses and proliferates are discussed. Evidence indicates that P. carinii attachment to alveolar epithelium is an important event in the establishment of infection and occurs through a variety of means. The binding of the organisms appears to be injurious to alveolar epithelial cells. Proliferation of the organism is associated with an ineffective and at times detrimental host inflammatory response. Additional studies indicate that P. carinii has the ability to invade tissues. Future investigations using new methodologies and strategies will be required to fully control this pathogen.
- Published
- 1998
30. Current issues in the epidemiology, transmission, and reactivation of Pneumocystis carinii.
- Author
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Hughes WT
- Subjects
- Disease Transmission, Infectious, Female, Humans, Male, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission, Prevalence, Prognosis, Recurrence, Risk Factors, Survival Rate, United States epidemiology, Immunocompromised Host, Pneumocystis isolation & purification, Pneumonia, Pneumocystis epidemiology
- Abstract
Issues related to the epidemiology, transmission, and reactivation of Pneumocystis carinii remain controversial. In this article, current studies related to geographic variations in the prevalence of P. carinii pneumonia are reviewed. In addition, extensive investigations show that exposure to P. carinii occurs early in life, followed by seemingly complete clearance of the organisms. Recent molecular techniques show that P. carinii pneumonia during periods of immune suppression can occur either by reactivation or by acquisition of new organisms. These studies are analyzed and a composite model of P. carinii infection is proposed.
- Published
- 1998
31. Identification of Pneumocystis carinii f. sp. hominis gene sequences in filtered air in hospital environments.
- Author
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Olsson M, Lidman C, Latouche S, Björkman A, Roux P, Linder E, and Wahlgren M
- Subjects
- Air Pollution, Indoor, Bronchoalveolar Lavage Fluid microbiology, DNA, Fungal genetics, DNA, Mitochondrial analysis, DNA, Mitochondrial genetics, Filtration, Genotype, Humans, Pneumocystis genetics, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction methods, RNA, Fungal genetics, RNA, Ribosomal genetics, Risk Factors, Sequence Analysis, DNA, Sputum microbiology, Air Microbiology, DNA, Fungal analysis, Genes, Fungal, Hospitals, Pneumocystis classification, Pneumocystis isolation & purification
- Abstract
To evaluate the risk of a nosocomial spread of Pneumocystis carinii f. sp. hominis (P. carinii hominis), air filter samples from rooms of P. carinii pneumonia (PCP) patients, adjacent corridors, and other hospital environments have been investigated for the presence of P. carinii hominis. Amplified DNA from air filters and sputum or bronchoalveolar lavage samples from the PCP patients have been genotyped with the P. carinii hominis genes of the mitochondrial large-subunit (mtLSU) rRNA and the internal transcribed spacers (ITS1 and ITS2) of the rRNA. Genotypes of the two loci were identified by direct sequencing, and for site 85 of the mtLSU locus, three allele-specific PCR assays were used. P. carinii hominis DNA was identified in the air of five of seven PCP patient rooms and in the air of two of four air filtrations from the ward corridors. The P. carinii hominis genotypes were the same in four of the five room air samples as those in the corresponding patients, suggesting a risk of person-to-person transmission of P. carinii hominis from PCP patients. Three of 16 air samples collected in infectious disease wards without the presence of PCP patients and one sample from a cardiology unit in a separate hospital building were also positive, which further strengthens the possibility of acquisition of P. carinii hominis from the environment.
- Published
- 1998
- Full Text
- View/download PDF
32. Genetics, metabolism and host specificity of Pneumocystis carinii.
- Author
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Wakefield AE, Stringer JR, Tamburrini E, and Dei-Cas E
- Subjects
- AIDS-Related Opportunistic Infections microbiology, Adult, Air Microbiology, Animals, Carrier State, Genes, Fungal, Humans, Mice, Mice, SCID, Pneumocystis classification, Pneumocystis genetics, Pneumocystis metabolism, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis transmission, Pneumocystis physiology, Pneumonia, Pneumocystis microbiology
- Abstract
Pneumocystis carinii is a major cause of severe pneumonia in immunosuppressed individuals, especially in those with human immunodeficiency virus (HIV) infection during their period of progression to acquired immunodeficiency syndrome (AIDS), and constitutes a worldwide problem to public health. Recently, significant advances in the development of experimental animal models of P. carinii infection, as well as in our knowledge of the genetic diversity and taxonomy of P. carinii, have been made. These advances may contribute to our understanding of the transmission of P. carinii pneumonia (PCP) and to the development of new prevention and control strategies. This paper addresses questions relating to the epidemiology of PCP including the detection of the parasite in the environment and in patients, the mechanism of genetic variation of the major surface glycoprotein (MSG) of P. carinii, and host-related genetic variation among isolates of this organism, emphasizing phenotypic expression and its impact on epidemiology and taxonomy.
- Published
- 1998
33. Typing of Pneumocystis carinii sp.f. hominis by PCR-SSCP of four genomic regions.
- Author
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Hauser PM, Francioli P, Bille J, Telenti A, and Blanc DS
- Subjects
- AIDS-Related Opportunistic Infections microbiology, AIDS-Related Opportunistic Infections transmission, Bronchoalveolar Lavage Fluid microbiology, DNA, Fungal analysis, DNA, Ribosomal genetics, Humans, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission, RNA, Ribosomal genetics, Tubulin genetics, Mycological Typing Techniques, Pneumocystis genetics, Polymerase Chain Reaction methods, Polymorphism, Single-Stranded Conformational
- Published
- 1997
- Full Text
- View/download PDF
34. The use of genetic markers to characterize transmission of Pneumocystis carinii.
- Author
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Baughman RP, Keely SP, Dohn MN, and Stringer JR
- Subjects
- Animals, Genes, Fungal, Genetic Variation, Genotype, Humans, Immunocompromised Host, Phenotype, Pneumocystis classification, RNA, Fungal genetics, RNA, Ribosomal, 23S genetics, AIDS-Related Opportunistic Infections genetics, AIDS-Related Opportunistic Infections transmission, Pneumocystis genetics, Pneumonia, Pneumocystis genetics, Pneumonia, Pneumocystis transmission
- Published
- 1997
- Full Text
- View/download PDF
35. Pneumocystis carinii hominis sequencing to study hypothetical person-to-person transmission.
- Author
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Latouche S, Poirot JL, Maury E, Bertrand V, and Roux P
- Subjects
- AIDS-Related Opportunistic Infections transmission, Adult, Bronchoalveolar Lavage Fluid microbiology, DNA, Fungal analysis, Female, Humans, Male, Middle Aged, Pneumocystis genetics, Pneumonia, Pneumocystis transmission, RNA, Fungal analysis, RNA, Ribosomal analysis, AIDS-Related Opportunistic Infections microbiology, Pneumocystis isolation & purification, Pneumonia, Pneumocystis microbiology
- Published
- 1997
36. Investigations of pneumocystosis among humans and rodents in Lithuania.
- Author
-
Bajoriniené DJ and Jucaite A
- Subjects
- Animals, Arvicolinae, Birds, Child, Disease Reservoirs, Enzyme-Linked Immunosorbent Assay, Female, Humans, Infant, Newborn, Lithuania epidemiology, Lung microbiology, Male, Pneumonia, Pneumocystis diagnosis, Pneumonia, Pneumocystis immunology, Pneumonia, Pneumocystis transmission, Pregnancy, Pregnancy Complications, Infectious diagnosis, Pregnancy Complications, Infectious immunology, Rabbits, Rats, Seroepidemiologic Studies, Serologic Tests, Species Specificity, Antibodies, Fungal analysis, Pneumocystis immunology, Pneumonia, Pneumocystis epidemiology, Pregnancy Complications, Infectious epidemiology
- Abstract
Pneumocystosis (Pneumocystis carinii pneumonia) is a parasitic disease which in Lithuania used to be diagnosed only with the use of pathohistological methods. The aim of our study was to determine prevalence of P. carinii antibodies among children and women, using immunochemical method (ELISA) and to find out which groups of patients have higher antibody titres. We also addressed the question of infection with P. carinii among rodents. After investigating 9 species of rodents it was found that mostly infected is brown rat (Rattus norvegicus)--42.9% of them were found infected. The least infected was bank vole (Clethrionomys glareolus)--5.9%. The brown rat lives on hatch of domestic birds, rabbits or drinks eggs, while rodents in nature live on insects, molluscs, amphibians etc. European water voles (Arvicola terrestris) and field voles (Microtus arvalis) are vegetable feeders. Our data shows that those species of rodents were not infected with pneumocysts.
- Published
- 1997
37. Pneumocystis carinii hominis sequencing for reactivation or de novo contamination and for hypothetic transmission from person to person.
- Author
-
Latouche S, Poirot JL, Bertrand V, and Roux P
- Subjects
- Humans, Mycological Typing Techniques, Pneumonia, Pneumocystis transmission, Recurrence, Pneumocystis classification, Pneumonia, Pneumocystis etiology
- Published
- 1997
- Full Text
- View/download PDF
38. Pneumocystis carinii: molecular taxonomy and epidemiology.
- Author
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Miller RF and Wakefield AE
- Subjects
- Animals, Genetic Variation, Humans, Pneumocystis genetics, Pneumonia, Pneumocystis epidemiology, Pneumonia, Pneumocystis transmission, Recurrence, Species Specificity, Immunocompromised Host, Pneumocystis classification, Pneumonia, Pneumocystis parasitology
- Published
- 1996
- Full Text
- View/download PDF
39. Pneumocystis carinii: an atypical fungal micro-organism.
- Author
-
Cailliez JC, Séguy N, Denis CM, Aliouat EM, Mazars E, Polonelli L, Camus D, and Dei-Cas E
- Subjects
- Animals, Antifungal Agents therapeutic use, CD4-Positive T-Lymphocytes immunology, Disease Reservoirs, Female, Genes, Fungal, Genetic Variation, Humans, Infant, Newborn, Infectious Disease Transmission, Vertical, Macrophages, Alveolar immunology, Pneumocystis pathogenicity, Pneumocystis ultrastructure, Pneumonia, Pneumocystis immunology, Pneumonia, Pneumocystis transmission, Pregnancy, Pregnancy Complications, Infectious, Terminology as Topic, Pneumocystis physiology, Pneumonia, Pneumocystis physiopathology
- Abstract
The purpose of this review is to assist mycologists in having a better understanding of Pneumocystis carinii and the disease that it causes. Now considered to be a fungus, P. carinii is unusual in its life cycle and relationship with the host. P. carinii pneumonia (PCP) pathogenesis, immunology and host defence mechanisms are examined, as well as epidemiological and control strategies. Most pneumocystosis pathophysiological changes result from the parasite's attachment and proliferation in the lungs, resulting in a filling of the alveoli with masses of the micro-organism. Pathological changes include an increase in alveolar capillary membrane permeability and injury to the alveolar epithelium, which may be mediated by the release of degradative enzymes from the pathogen. A host response takes place by hypertrophy, and hyperplasia involving type II epithelial alveolar cells. P carinii interacts with pulmonary surfactants by binding to the hydrophilic proteins A and D, and by modifying their phospholipid composition. Alveolar macrophages and CD4+ T cells play a key role in the host's defence against Pneumocystis. The epidemiology of PCP remains poorly understood. Airborne transmission has been established, but the actual infective form and its source remains unknown. Studies concerning P. carinii genetic diversity have shown that the parasite polymorphism is related, at least partially, to the host species. A strong host-species specificity in P. carinii has been found. From an epidemiological perspective, there appears to be no animal reservoir for the agent of human PCP. Thus, this disease should not be considered to be zoonotic. Although a significant decrease in the incidence of pneumocystosis has been obtained when employing chemoprophylaxis, anti-P. carinii drugs are not completely successful, often inducing deleterious side-effects. For these reasons, new prophylactic and therapeutic strategies need to be developed. One approach could be based on the anti-P. carinii effect of yeast killer toxins and antibiotic anti-idiotypic antibodies.
- Published
- 1996
- Full Text
- View/download PDF
40. Molecular epidemiology of Pneumocystis carinii pneumonia.
- Author
-
Beard CB and Navin TR
- Subjects
- Animals, Humans, Molecular Epidemiology, Pneumonia, Pneumocystis diagnosis, Pneumonia, Pneumocystis prevention & control, Pneumonia, Pneumocystis transmission, Pneumocystis classification, Pneumocystis genetics, Pneumonia, Pneumocystis epidemiology
- Published
- 1996
- Full Text
- View/download PDF
41. Detection of Pneumocystis carinii DNA by filtration of air.
- Author
-
Olsson M, Sukura A, Lindberg LA, and Linder E
- Subjects
- Animals, Electrophoresis, Agar Gel, Filtration methods, Pneumocystis genetics, Polymerase Chain Reaction, Rats, Rats, Wistar, Spores, Thymidylate Synthase genetics, Air Microbiology, DNA, Fungal isolation & purification, Pneumocystis isolation & purification, Pneumonia, Pneumocystis transmission
- Abstract
The high incidence of pneumonia caused by Pneumocystis carinii in immunosuppressed patients makes it the most important parasite in non-tropical geographical regions. It has recently been shown to be a fungus, but several aspects of this organism are still poorly understood. A major question of clinical relevance is the nature of transmission and, thereby, the related problem of prevention. The mode of P. carinii transmission is thought to be air, but this is based on circumstantial evidence, the transmissive stage has not been identified. We attempted to capture P. carinii by filtration of air in the vicinity of cages containing P. carinii infected Wistar rats. Using nested polymerase chain reaction amplification of the thymidylate synthase gene to demonstrate P. carinii we were able to demonstrate P. carinii DNA on such filters. This strongly supports the suggested mechanism of transmission of Pneumocystis by means of airborne spores and suggests an approach to their isolation and characterization.
- Published
- 1996
- Full Text
- View/download PDF
42. Pneumocystis carinii detected in air.
- Author
-
Bartlett MS, Lee CH, Lu JJ, Bauer NL, Bettz JF, McLaughlin GL, and Smith JW
- Subjects
- Animals, Bronchoalveolar Lavage Fluid microbiology, DNA, Fungal genetics, DNA, Fungal isolation & purification, Humans, Opportunistic Infections microbiology, Opportunistic Infections transmission, Pneumocystis genetics, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction, Rats, Air Microbiology, Pneumocystis isolation & purification
- Published
- 1994
43. Recent advances in the biology of Pneumocystis carinii.
- Author
-
Cushion MT, Harmsen A, Matsumoto Y, Stringer JR, Wakefield AE, and Yamada M
- Subjects
- Animals, Antibodies, Fungal metabolism, Humans, Lymphocyte Depletion, Mice, Pneumocystis cytology, Pneumocystis physiology, Pneumonia, Pneumocystis transmission, Rats, Genetic Variation, Pneumocystis genetics, Pneumonia, Pneumocystis immunology
- Published
- 1994
44. Alveolar macrophage interaction with Pneumocystis carinii.
- Author
-
Koziel H, O'Riordan D, Warner A, and Rose RM
- Subjects
- AIDS-Related Opportunistic Infections etiology, Animals, Cell Adhesion Molecules immunology, Cytokines immunology, Humans, Macrophages, Alveolar microbiology, Opsonin Proteins immunology, Pneumocystis growth & development, Pneumocystis pathogenicity, Pneumonia, Pneumocystis etiology, Pneumonia, Pneumocystis transmission, Macrophages, Alveolar immunology, Pneumocystis immunology
- Published
- 1994
45. Evidence of horizontal transmission of Pneumocystis carinii pneumonia in simian immunodeficiency virus-infected rhesus macaques.
- Author
-
Vogel P, Miller CJ, Lowenstine LL, and Lackner AA
- Subjects
- Animals, Antibodies, Fungal analysis, Housing, Animal, Immunohistochemistry, Lung microbiology, Lung pathology, Macaca mulatta, Pneumonia, Pneumocystis complications, Pneumonia, Pneumocystis pathology, Simian Acquired Immunodeficiency Syndrome pathology, Pneumocystis isolation & purification, Pneumonia, Pneumocystis transmission, Simian Acquired Immunodeficiency Syndrome complications, Simian Immunodeficiency Virus
- Abstract
This retrospective study used sensitive immunohistochemical methods to detect Pneumocystis carinii infections in fixed lung tissues collected from 107 simian immunodeficiency virus (SIV)-infected and 10 noninfected rhesus macaques during a 4-year period. P. carinii were detected in 51% of 85 terminally ill SIV-infected macaques but in only 2 of 22 macaques killed at earlier stages of SIV infection. P. carinii were not detected in any SIV-infected macaques held in isolators or in uninfected controls. Infection rates varied significantly between rooms, and the percentage of clinically important P. carinii infections increased from 0 in the first 2 years to > 50% during the final year. Infections were centered on terminal airways in 59% of infected animals. These results challenge the assumption that P. carinii pneumonia (PCP) results primarily from reactivated latent infections and suggest instead that horizontal spread of infection is important in the epidemiology of PCP in immunosuppressed macaques.
- Published
- 1993
- Full Text
- View/download PDF
46. DNA amplification in experimental pneumocystosis: characterization of serum Pneumocystis carinii DNA and potential P. carinii carrier states.
- Author
-
Sepkowitz K, Schluger N, Godwin T, Armstrong D, Cerami A, and Bucala R
- Subjects
- Animals, Base Sequence, DNA, Fungal analysis, Female, Lung microbiology, Molecular Sequence Data, Pneumocystis genetics, Pneumonia, Pneumocystis transmission, Polymerase Chain Reaction, Rats, Rats, Sprague-Dawley, Pneumocystis isolation & purification, Pneumonia, Pneumocystis microbiology
- Abstract
DNA amplification has identified P. carinii DNA in diverse biologic specimens, including the serum of patients with P. carinii pneumonia. To further examine the relationship between P. carinii DNA in serum and P. carinii infection, the corticosteroid-treated rat model of pneumocystosis was studied. By 4 weeks of immunosuppression, P. carinii DNA was detected in rat lungs and by 6 weeks, in their serum. P. carinii DNA persisted in lung tissue as long as 5 months after the withdrawal of steroids. Serum DNA disappeared 2 weeks after steroids were withdrawn. Nonimmunocompromised, sentinel rats housed near immunocompromised, P. carinii-infected rats also were studied. Within 6 weeks, P. carinii DNA became detectable in lung and by 8 weeks, in serum. P. carinii DNA disappeared rapidly from lungs and sera after sentinel rats were isolated away from corticosteroid-treated rats. These findings support the contagious transmission of P. carinii and suggest facile development of P. carinii carrier states.
- Published
- 1993
- Full Text
- View/download PDF
47. [Microbiology of Pneumocystis carinii].
- Author
-
Seitz HM and Sahm M
- Subjects
- AIDS-Related Opportunistic Infections diagnosis, AIDS-Related Opportunistic Infections transmission, Animals, Diagnosis, Differential, Humans, Pneumocystis ultrastructure, Pneumonia, Pneumocystis diagnosis, Pneumonia, Pneumocystis transmission, Pulmonary Alveoli microbiology, AIDS-Related Opportunistic Infections microbiology, Pneumocystis pathogenicity, Pneumonia, Pneumocystis microbiology
- Published
- 1992
48. Dissemination of Pneumocystis.
- Author
-
Pilon VA
- Subjects
- Humans, Immunity, Middle Aged, Pneumocystis immunology, Pneumocystis pathogenicity, Pneumonia, Pneumocystis microbiology, Acquired Immunodeficiency Syndrome complications, Pneumocystis physiology, Pneumonia, Pneumocystis transmission
- Published
- 1990
49. The origin of Pneumocystis carinii.
- Author
-
Beautyman W
- Subjects
- Animals, Humans, Liposomes, Mitochondria, Pneumocystis growth & development, Pneumonia, Pneumocystis transmission
- Published
- 1984
- Full Text
- View/download PDF
50. Does Pneumocystis carinii occur in Kenya?
- Author
-
Griffin L and Lucas SB
- Subjects
- Animals, Female, Hydrocortisone analogs & derivatives, Hydrocortisone pharmacology, Kenya, Mice, Pneumocystis physiology, Pneumonia, Pneumocystis transmission
- Abstract
An experiment was carried out exposing immunosuppressed mice to the atmosphere to determine if transmission of Pneumocystis carinii occurred in Kenya. Mice were killed at weekly intervals for four months and the lungs examined histologically for the presence of these parasites. None of the mice contracted even light infections and this, together with the lack of clinical evidence of this disease in immunosuppressed or neonatal cases, suggests that this parasite does not occur in Kenya. Possible reasons for this are discussed.
- Published
- 1982
- Full Text
- View/download PDF
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