The rat model of Pneumocystis carinii pneumonia is frequently used to study human P. carinii infection, but there are many differences between the rat and human infections. We studied naturally acquired P. carinii in wild rats to examine the relevance of the rat model for human infection. P. carinii DNA was detected in 47 of 51 wild rats and in 10 of 12 nonimmunosuppressed laboratory rats. Evidence for three novel formae speciales of rat-derived P. carinii was found, and these were provisionally named Pneumocystis carinii f. sp. rattus-secundi, Pneumocystis carinii f. sp. rattus-tertii, and Pneumocystis carinii f. sp. rattus-quarti. Our data suggest that low-level carriage of P. carinii in wild rats and nonimmunosuppressed laboratory rats is common and that wild rats are frequently coinfected with more than one forma specialis of P. carinii. We also examined the diversity in the internally transcribed spacer (ITS) regions of the nuclear rRNA operon of Pneumocystis carinii f. sp. carinii by using samples from wild rats and laboratory rats and spore trap samples. We report a lack of variation in the ITS1 and ITS2 regions that is consistent with an evolutionary bottleneck in the P. carinii f. sp. carinii population. This study shows that human- and rat-derived P. carinii organisms are very different, not only in genetic composition but also in population structure and natural history.
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http://dx.doi.org/10.1128/AEM.66.11.4954-4961.2000 | DOI Listing |
BMC Pulm Med
January 2025
Central Laboratory, Liaocheng People's Hospital and Liaocheng School of Clinical Medicine, Shandong First Medical University, Liaocheng, Shandong, 252000, China.
Background: Polymicrobial pulmonary infections, common in immunocompromised patients, often manifest more severe symptoms than monomicrobial infections. Clinical diagnosis delays may lead to mortality, emphasizing the importance of fast and accurate diagnosis for these patients. Metagenomic next-generation sequencing (mNGS), as an unbiased method capable of detecting all microbes, is a valuable tool to identify pathogens, particularly in cases where infections are difficult to diagnosis using conventional methods.
View Article and Find Full Text PDFZhonghua Jie He He Hu Xi Za Zhi
January 2025
Department of Pulmonary and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing100730, China.
To describe the clinical characteristics and to explore the prognostic factors of concurrent pneumonia (PJP) in patients with idiopathic inflammatory myopathy (IIM). We retrospectively enrolled consecutive IIM patients diagnosed with PJP at our center between January 2014 and December 2022. Fifty-eight IIM-PJP patients were enrolled in our study, with the age of 26-79 (56.
View Article and Find Full Text PDFJ Nippon Med Sch
January 2025
Department of Breast Surgery and Oncology, Nippon Medical School Hospital.
In patients not infected by HIV, Pneumocystis jirovecii pneumonia (PCP) is characterized by rapid disease progression, difficulty in confirming the diagnosis, and poor prognosis. PCP has also been reported in immunocompromised patients receiving chemotherapy, most often for hematologic tumors, although some patients receiving treatment for breast cancer have been affected. Dose-dense chemotherapy (DDC) which is performed with shorter dosing intervals than standard chemotherapy and is now widely used in clinical practice.
View Article and Find Full Text PDFInfect Immun
December 2024
Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, the Thoracic Diseases Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
pneumonia (PJP) remains a significant cause of morbidity and mortality during AIDS. In AIDS, the absence of CD4 immunity results in exuberant and often fatal PJP. In addition, organism clearance requires a balanced macrophage response since excessive inflammation promotes lung injury and respiratory failure.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
December 2024
Department of Hematology, The First Affiliated Hospital of Soochow University, Jiangsu Institute of Hematology, National Clinical Research Center for Hematologic Diseases, Suzhou 215006, Jiangsu Province, China.
Objective: To summarize the clinical characteristics of patients with combined pneumocystis jiroveci pneumonia (PJP) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).
Methods: The clinical manifestations, laboratory tests, imaging findings, and treatment outcomes of 21 allo-HSCT patients with PJP diagnosed at the First Affiliated Hospital of Soochow University and Soochow Hopes Hematology Hospital from July 2018 to July 2023 were retrospective analyzed.
Results: Among the 21 patients, the male -to-female ratio was 2.
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