Abstract:Três novas espécies de tripanosomatídeos foram isoladas em Alfenas, MG, Brasil: Herpetomonas anglusteri sp. n., do intestino posterior de Liopygia ruficorins (Diptera: Sarcophagidae); Crithidia roitmani sp. e.e Crithidia de souzai sp. n., do intestino médio e o posterior de Ornidia obesa (Diptera: Syrphidae). O isolamento foi feito em meio complexo de roitmanmas os três isolados cresceram bem no meio definido do mesmo Autor. Os clones foram obtidos em ágar-sangue de carneiro, desfibrinado, em placas de Petri, … Show more
“…Furthermore, it demonstrates at the ultrastructural level that such forms are capable of dividing by binary fission. (Fiorini et al 1989). A cloned strain has been axenically maintained since then in Roitman's chemically defined medium (Roitman et al 1972).…”
The flagellate Herpetomonas roitmani is a symbiont-bearing trypanosomatid that spontaneously differentiates from promastigote to para- and opisthomastigote forms when maintained in axenic culture medium. Thus, after cultivation for 72 h at 28 degrees C, 37% of the total number of cells are in the opisthomastigote form. In the present study, light microscopy observations of Giemsastained H. roitmani cells demonstrated that in early cultures (12 h at 28 degrees C) the percentage of opisthomastigotes was markedly high (about 98%). Furthermore, proliferative opisthomastigote forms (dividing cells with the kinetoplast posteriorly located relative to the nucleus) were frequently seen in these cultures. The latter observation was confirmed by analysis of routinely fixed parasites by transmission electron microscopy.
“…Furthermore, it demonstrates at the ultrastructural level that such forms are capable of dividing by binary fission. (Fiorini et al 1989). A cloned strain has been axenically maintained since then in Roitman's chemically defined medium (Roitman et al 1972).…”
The flagellate Herpetomonas roitmani is a symbiont-bearing trypanosomatid that spontaneously differentiates from promastigote to para- and opisthomastigote forms when maintained in axenic culture medium. Thus, after cultivation for 72 h at 28 degrees C, 37% of the total number of cells are in the opisthomastigote form. In the present study, light microscopy observations of Giemsastained H. roitmani cells demonstrated that in early cultures (12 h at 28 degrees C) the percentage of opisthomastigotes was markedly high (about 98%). Furthermore, proliferative opisthomastigote forms (dividing cells with the kinetoplast posteriorly located relative to the nucleus) were frequently seen in these cultures. The latter observation was confirmed by analysis of routinely fixed parasites by transmission electron microscopy.
“…Parasites H. roitmani was isolated from the¯y Ornidia obesa (Fiorini et al 1989) and has been maintained axenically in Roitman's chemically de®ned medium (Roitman et al 1972). Stock cultures were grown for 72 h at 28°C and then kept in a refrigerator (4°C) for 1±2 weeks.…”
Section: Methodsmentioning
confidence: 99%
“…Since its isolation, H. roitmani has appeared to be quite a remarkable trypanosomatid: (a) it is a member of a restricted group of symbiont-bearing trypanosomatids, which includes Crithidia deanei (Carvalho 1973), C. desouzai (Fiorini et al 1989), C. oncopelti (Newton and Horne 1957), Blastocrithidia culicis (Novy et al 1907), and T. cobitis (Lewis and Ball 1980); (b) it was ®rst described as a member of the Crithidia genus, mainly due its morphology that closely resembles choanomastigotes (Fiorini et al 1989); (c) it was reclassi®ed as Herpetomonas (Faria-e-Silva et al 1991) based on the opisthomastigote forms and on isoenzymatic analysis; (d) opisthomastigotes of H. roitmani could be obtained in a high yield (98%) and it was shown that they can proliferate in culture, unlike other Herpetomonas species (Faria-e-Silva et al 1996); (e) recent studies (Teixeira et al 1997) suggest that H. roitmani may represent a new group of¯agellates, and it was suggested to use the term opisthomorph (OPM) to designate forms in which the kinetoplast is located posteriorly to the nucleus (as in opisthomastigotes) but have a body shape somewhat resembling choanomastigote forms. In view of these characteristics, we decided to analyze further the transformation process of promastigote (PRO) into OPM forms in H. roitmani, investigating the changes that occur on the surface-exposed carbohydrate residues and also in the surface anionic sites.…”
Cell surface saccharide composition and surface charge of promastigote (PRO) and opisthomorph (OPM) forms of Herpetomonas roitmani were analyzed using labeled lectins and flow cytometry and cell electrophoresis. The FITC signals for concanavalin A, Helix pomatia agglutinin and wheat germ agglutinin were stronger in PRO forms, whereas for Limulus polyphemus agglutinin (LPA) and Wisteria floribunda agglutinin they were stronger in OPM forms. Prior treatment of the cells with neuraminidase decreased the FITC signal for LPA in OPM but not in PRO forms. Furthermore OPMs displayed a high negative charge (-15.45+/-1.10 mV) than PROs (-9.47+/-1.01 mV). Neuraminidase and phospholipase C treatment of the parasites significantly reduced the surface charge, especially in OPM forms. TLC analysis of the acidic components of H. roitmani showed the presence of N-acetyl-neuraminic acid. The results presented in this work indicate that changes in exposed cell surface components occur between PRO and OPM forms of H. roitmani obtained by growing the cells under different conditions.
“…Adoption of biochemical and molecular criteria confirmed misclassification of trypanosomatids in genera based exclusively on traditional criteria. This fact has been especially observed for species of Herpetomonas (Camargo et al 1992; Faria‐e‐Silva et al 1994; Fiorini et al 1989; Hollar, Lukes, and Maslov 1998; Jankevicius et al 1993; Nunes et al 1994; Roitman et al 1976; Teixeira et al 1996; Teixeira et al 1997).…”
We report the morphological, biochemical and molecular characteristics of a trypanosomatid isolated from the flower of Cucurbita moschata. Although the trypanosomatid was isolated from a plant, the lack of recognition of Phytomonas-specific molecular markers based on spliced-leader and ribosomal genes as well as by monoclonal antibodies specific for Phytomonas argues against assigning it to this genus. Because the isolate displayed typical opisthomastigote forms in culture, it is assigned to the genus Herpetomonas. Analysis of randomly amplified polymorphic DNA (RAPD) patterns and characterization of ribosomal SSU and ITS markers suggest that it is more closely related to H. samuelpessoai than to any other species. However, the presence of spined flagellates in culture (displaying lateral expansions of the plasma membrane originating near the flagellar pocket) and isolate-specific RAPD fingerprints argue strongly that the trypanosomatid belongs to a new subspecies, for which the name Herpetomonas samuelpessoai camargoi n. subsp. is proposed.
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