Résumé
Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.
Sujets)
Animaux , Chiroptera/microbiologie , Variation génétique , Géographie , Pneumocystis/génétique , Argentine , Chiroptera/classification , France , Guyane française , Mexique , Phylogenèse , Pneumocystis/classification , Pneumocystis/isolement et purification , Analyse de séquence d'ADN , Spécificité d'espèceRésumé
Induced sputum samples were collected from 32 AIDS patients with respiratory ailments. Pneumcystis carinii was demonstrated in 9 out of 32 AIDS cases by Indirect Immunofluorescence technique (HF). Four cases were positive by all the three techniques namely Giemsa staining, Toluidine blue staining and IIF, three were positive by both toluidine blue and IIF, and two were positive only by IIF. Among other microbial pathogens, acid fast bacilli was demonstrated in all the P carinii positive cases and Candida albicans in 53% AIDS cases from the induced sputum sample.