Morphobiological characterization of Trypanosoma cruzi Chagas, 1909 and its distinction from other Trypanosomes

Trypanosoma cruzi I genotype among isolates from patients with chronic Chagas disease followed at the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, Brazil)

“…In the present paper, nine trypanosome isolates from patients with Chagas disease who were also followed at INI were characterized by different techniques for identifying the trypanosome species and its genetic type. Using classical parasitological approaches, such as the parasite morphological features (Figure 1), biometrical data, growth, and differentiation in routine culture media, all isolates under study were T. cruzi 25,26,34 . The confirmation that they were pure cultures was evidenced by their single 330-bp amplicon derived from the kDNA minicircles 25,27 , and their products from the mini-exon gene non-transcribed spacer 28,29 ( Figure 2), which had 250bp in most isolates and 200bp only in one stock (CT-IOC 541) identified as TcI.…”

“…For trypanosome species identification, each isolate was first analyzed with regard to its morphological peculiarities in Giemsa-stained smears, as seen under optical microscopy (×1,000), by comparing them with typical T. cruzi and T. rangeli forms 25,26 . Two biometrical parameters for distinguishing these species were also examined: the total length (TL, flagellum included) of the trypomastigotes and the length of rod-like kinetoplasts at their major axis (KL) of the epimastigotes 25 .…”

Epidemiological factors related to the transmission risk of Trypanosoma cruzi in a Quilombola community, State of Mato Grosso do Sul, Brazil

“…After thin blood smear slides were prepared, fixed and stained with Giemsa, they were examined under a light microscope at 100× magnification to detect parasites and characterize their morphology 12 . Molecular analysis included DNA extraction from whole animal blood and from a pool obtained from 46 cultures of the intestinal contents of triatomines that tested positive for flagellates.…”

Trypanosoma rangeli Tejera, 1920, in chronic Chagas’ disease patients under ambulatory care at the Evandro Chagas Clinical Research Institute (IPEC—Fiocruz, Brazil)

“…Subsequently, several authors reported the morphological peculiarities of T. rangeli (or T. rangeli-like parasites), either in triatomine bugs or in axenic cultures, and ascertained their usefulness for distinction of this species from T. cruzi (Pifano 1949;Groot et al 1951;Deane 1958;Tobie 1970;Hoare 1972;Lucena and Vergetti 1973;Cuba-Cuba 1974;D'Alessandro 1976;D'Alessandro and Saravia 1992;Ziccardi and Lourenço-de-Oliveira 1997;Sousa 1999;Santos-Pereira et al 2002;Sousa et al 2005). Then, considering these descriptions, besides our studies on reference strains, two isolates from chagasic patients were easily identified as T. rangeli (CT-IOC 535, 536/546), and the others as T. cruzi (CT-IOC 545 and 553).…”