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Riebold D, Mahnkopf M, Wicht K, Zubiria-Barrera C, Heise J, Frank M, Misch D, Bauer T, Stocker H, Slevogt H. Axenic Long-Term Cultivation of Pneumocystis jirovecii. J Fungi (Basel) 2023; 9:903. [PMID: 37755011 PMCID: PMC10533121 DOI: 10.3390/jof9090903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/18/2023] [Accepted: 08/29/2023] [Indexed: 09/28/2023] Open
Abstract
Pneumocystis jirovecii, a fungus causing severe Pneumocystis pneumonia (PCP) in humans, has long been described as non-culturable. Only isolated short-term experiments with P. jirovecii and a small number of experiments involving animal-derived Pneumocystis species have been published to date. However, P. jirovecii culture conditions may differ significantly from those of animal-derived Pneumocystis, as there are major genotypic and phenotypic differences between them. Establishing a well-performing P. jirovecii cultivation is crucial to understanding PCP and its pathophysiological processes. The aim of this study, therefore, was to develop an axenic culture for Pneumocystis jirovecii. To identify promising approaches for cultivation, a literature survey encompassing animal-derived Pneumocystis cultures was carried out. The variables identified, such as incubation time, pH value, vitamins, amino acids, and other components, were trialed and adjusted to find the optimum conditions for P. jirovecii culture. This allowed us to develop a medium that produced a 42.6-fold increase in P. jirovecii qPCR copy numbers after a 48-day culture. Growth was confirmed microscopically by the increasing number and size of actively growing Pneumocystis clusters in the final medium, DMEM-O3. P. jirovecii doubling time was 8.9 days (range 6.9 to 13.6 days). In conclusion, we successfully cultivated P. jirovecii under optimized cell-free conditions in a 70-day long-term culture for the first time. However, further optimization of the culture conditions for this slow grower is indispensable.
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Affiliation(s)
- Diana Riebold
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Marie Mahnkopf
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Kristina Wicht
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, B-9000 Gent, Belgium;
| | - Cristina Zubiria-Barrera
- Respiratory Infection Dynamics Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (C.Z.-B.); (H.S.)
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, German Center for Lung Research (DZL), BREATH, 30625 Hannover, Germany
| | - Jan Heise
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Marcus Frank
- Medical Biology and Electron Microscopy Centre (EMZ), University Medicine Rostock, 18057 Rostock, Germany;
| | - Daniel Misch
- Lungenklinik Heckeshorn, Helios Klinikum Emil-von-Behring, 14165 Berlin, Germany; (D.M.); (T.B.)
| | - Torsten Bauer
- Lungenklinik Heckeshorn, Helios Klinikum Emil-von-Behring, 14165 Berlin, Germany; (D.M.); (T.B.)
| | - Hartmut Stocker
- Clinic for Infectiology, St. Joseph’s Hospital Berlin, 12101 Berlin, Germany;
| | - Hortense Slevogt
- Respiratory Infection Dynamics Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (C.Z.-B.); (H.S.)
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, German Center for Lung Research (DZL), BREATH, 30625 Hannover, Germany
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Riebold D, Mohr E, Sombetzki M, Fritzsche C, Loebermann M, Reisinger E. Pneumocystis species in Brown Leghorn laying hens—A hint for an extra-mammalian reservoir. Poult Sci 2012; 91:1813-8. [DOI: 10.3382/ps.2011-01930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
Pneumocystis organisms can cause pneumonia in mammals that lack a strong immune defense. The genus Pneumocystis contains many different organisms that can be distinguished by DNA sequence analysis. These different organisms are different species of yeast-like fungi that are most closely related to the ascomycete, Schizosaccharomyces pombe. Each species of Pneumocystis appears to be specific for the mammal in which it is found. The species that infects humans is Pneumocystis jiroveci. P. jiroveci has not been found in any other mammal and the species of Pneumocystis found in other mammals have not been seen in humans. Genetic variation among P. jiroveci samples is common, suggesting that there are many strains. Strain analysis shows that adults can be infected by more than one strain, and suggests that pneumonia can be the result of infection occurring proximal to the time of disease, rather than to reactivation of dormant organisms acquired in early childhood. Nevertheless, long-term colonisation may be occurring. A large fraction of normal children and animals show evidence of infection. A Pneumocystis species that grows in rats has been shown to possess a complex genetic system for surface antigen variation, a strategy employed by other microbes that dwell in immunocompetent hosts. These findings, together with strong host specificity, suggest that Pneumocystis species may be obligate parasites. The source of infection is not clear. Pneumocystis DNA is detectable in the air, but is scarce except in environments occupied by individuals with Pneumocystis pneumonia. In a few cases, there is direct evidence of person to person transmission. In general, however, patients and their contacts have been found to have different strains of P. jiroveci.
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Affiliation(s)
- James R Stringer
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, OH 45220-0524, USA.
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