Time between Inoculations and Karyotype Forms of Pneumocystis carinii f. sp. carinii Influence Outcome of Experimental Coinfections in Rats
| Autor: | Sally Orr, James R. Stringer, Scott P. Keely, Melanie T. Cushion |
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| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
Male
Time Factors Immunology Population Molecular Sequence Data Biology Microbiology Polymerase Chain Reaction law.invention Adenosine Triphosphate law Genotype medicine Animals Humans education Lung Polymerase chain reaction education.field_of_study Base Sequence Pneumocystis Fungi imperfecti medicine.disease biology.organism_classification Virology In vitro Rats Pneumocystis Infections Infectious Diseases Pneumocystis carinii Karyotyping Parasitology Fungal and Parasitic Infections Pneumonia (non-human) |
| Popis: | The prevalence ofPneumocystis cariniipneumonia (PCP) in humans caused by more than a single genotype has been reported to range from 10 to 67%, depending on the method used for detection (3, 19). Most coinfections were associated with primary rather than recurrent disease. To better understand the factors influencing the development of coinfections, the time periods between inoculations and the genotype of the infecting organisms were evaluated in the chronically immunosuppressed-inoculated rat model of PCP.P. cariniif. sp.cariniiinfecting rats differentiated by karyotypic profiles exhibit the same low level of genetic divergence manifested by organisms infecting humans.P. cariniif. sp.cariniikaryotype forms 1, 2, and 6 were inoculated into immunosuppressed rats, individually and in dual combinations, spaced 0, 10, and 20 days apart. Infections comprised of both organism forms resulted from admixtures inoculated at the same time. In contrast, coinfections did not develop in most rats, where a 10- or 20-day gap was inserted between inoculations; only the first organism form inoculated was detected by pulsed-field gel electrophoresis in the resultant infection. Organism burdens were reduced with combinations of forms 1 and 2 spaced 20 days apart but not in rats inoculated with forms 1 and 6. A role for the host response in the elimination of the second population and in reduction of the organism burden was suggested by the lack of direct killing of forms 1 and 2 in an in vitro ATP assay, by reduction of the burden by autoclaved organisms, and by the specific reactions of forms 1 and 2 but not forms 1 and 6. These studies showed that the time between inoculations was critical in establishing coinfections andP. cariniif. sp.cariniikaryotype profiles were associated with differences in biological responses. This model provides a useful method for the study ofP. cariniicoinfections and their transmission in humans. |
| Databáze: | OpenAIRE |
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