Natural infection by trypanosomatids in different species
of animals in municipalities of the state of Rio Grande do Norte
Trypanosoma cruzi; Leishmania chagasi; kDNA, 18S,
domesticated animals
This work identified the natural infection by Trypanosoma cruzi in different species
of domesticated animals, and Leishmania chagasi in dogs from municipalities in the state of Rio
Grande do Norte (RN). Whole blood samples added guanidine HCl+EDTA pH 8.0
were collected from 210 animals in rural or urban areas of 13 municipalities belonging to
the four mesoregions of the state. In addition, bone marrow and lymph node aspirates were
collected in dogs from CCZ/Natal (RN) and cultivated in Schneider plus NNN medium (Neal,
Novy, Nicole). DNA from blood samples and parasite culture mass was
extracted with phenol-chloroform. The DNA extracted from the samples was submitted to three
PCR assays with different molecular markers: 18S (SSU) rRNA for
Trypanosoma spp., kDNA for T. cruzi and HSP70 for Leishmania spp. The amplified DNA
in 18S PCR were purified, subjected to genetic sequencing and compared
phylogenetically with sequences deposited in GenBank. The DNA of Trypanosoma spp.
observed with 18S was detected in 78.1% (164/210) of whole blood samples from
animals in which the animal species with the highest percentage of positive samples was Equus
caballus with 85.7% (12/14), followed by Bos taurus with 83.3% (5/6) and Ovis aries with
82.0% (50/61). Amplification of the T. cruzi kDNA was observed in 46.2% (97/210) of the
whole blood samples from the studied animals, in which Equus caballus and Canis familiaris
were the animal species with the highest percentage of positive samples being 57.1%
(8/14) and 52.4%(54/103) respectively. HSP70 PCR was amplified in 100% of cases.
culture samples from dogs and was not observed in whole blood samples. Results
of the 18S and kDNA PCRs were concordant in all orders of animals, being the
highest percentages of agreement observed Bos taurus (50.0%), followed by Equus
caballus (42.9%) and Canis familiaris (40.6). The 18S amplified DNAs that resulted
in excellent quality electropherograms were from four samples, all obtained from
dogs. These sequences were compared with the sequences deposited in GenBank, by
using the Blastn tool, which revealed one DNA from T. cruzi and three from L. chagasi whose
phylogenetic analysis is nearing completion. These results revealed a high number
and diversity of infected domesticated animals reinforcing the importance of knowing
better the maintenance cycles of parasites near human dwellings.