Scanning Electron Microscopic Studies of Blastocrithidia triatomae (Trypanosomatidae) in the Rectum of Triatoma infestans (Reduviidae)¹²

Abstract

ABSTRACT. The morphology of Blastocrithidia triatomae, when colonizing the rectum of Triatoma infestans, was studied by scanning electron microscopy. The posterior end of the epimastigote's body is tapered and often rolled up. The “straphangers” (cyst stages) are connected with the flagellum by “cytoplasmic bridges”; after “straphanger” detachment these bridges persist as remnants. A comparison of colonization densities of B. triatomae and Trypanosoma cruzi shows that both prefer to colonize the rectal gland, but minor density differences are apparent for B. triatomae in other rectal regions. The colonization density in established infections of B. triatomae is always greater than that of T. cruzi, especially near the midgut exit.

Morphological and molecular description of Blastocrithidia cyrtomeni sp. nov. (Kinetoplastea: Trypanosomatidae) associated with Cyrtomenus bergi Froeschner (Hemiptera: Cydnidae) from Colombia

“…We did not observe the "cytoplasmatic bridge" mentioned by Schaub and Böker (1986) in their microscopic studies of B. triatomae, nor were we able to find cysts connected to the posterior end of epimastigotes as reported by the authors in three cases.…”

“…In B. cyrtomeni, it was observed as needle-like in light SEM and TEM images (Figs 1B,13). In contrast, Schaub and Böker (1986) observed that the broad posterior end was rolled up in a spiral in the first SEM images of B. triatomae and B. gerridis.…”

The development of Blastocrithidia triatomae (Trypanosomatidae) in the reduviid bug Triatoma infestans (Insecta): influence of starvation

“…First instar larvae of Triatoma infestans were infected in vitro with Blastocrithidia triatomae, using a mixture of cryopreserved cysts from in vitro cultures of the original strain and mouse blood (300,000 cysts/ml blood; Schaub and Bo¨ker 1986a). Bugs were then fed on hens 5, 6, 9 and 10 weeks p.i., getting their last feed 14 weeks p.i.…”

Cannibalism and Coprophagy Are Modes of Transmission of Blastocrithidia triatomae (Trypanosomatidae) between Triatomines

“…For disinfection of the eggs deposited in each group the method of Geering-Sacher [ 131 was adapted, using Desogenm (Ciba Geigy, Basle, Switzerland) and Chloramin T (Serva, Heidelberg, FRG). We also used a similar procedure for disinfection of suspensions of B. triatomaecysts [32]. Since it killed all bacterial contaminations but only about 90% of the cysts, we discarded those eggs which were visibly contaminated with feces.…”