Detection of an Undescribed Babesia sp. in Capybaras and Amblyomma Ticks in Central-Western Brazil

Abstract

Capybaras (Hydrochoerus hydrochaeris) are the largest rodents on Earth. While capybaras are hosts for various tick species, there is limited information regarding the tick-borne pathogens they can carry. We investigated the presence of piroplasmids and Ehrlichia spp. in capybaras and their associated ticks in two peri-urban areas in Goiás state, central-western Brazil. Blood samples collected from 23 capybaras were used to investigate the presence of piroplasmids and Ehrlichia spp. in stained-blood smears and by PCR. Ticks collected from the capybaras were identified morphologically and also tested using PCR for the same pathogens. A total of 955 ticks were collected, including 822 (86.1%) Amblyomma sculptum, 132 (13.8%) Amblyomma dubitatum, and one (0.1%) unidentified larva of Amblyomma sp. Neither the capybaras nor ticks were positive for Ehrlichia spp. However, a stained-blood smear examination revealed the presence of ring-stage and pyriform-shaped merozoites in the erythrocytes of one (4.4%) capybara. In the same way, 47.8% (11/23) and 19.9% (36/181) of blood samples and ticks, respectively, were positive for piroplasmids in the PCR. We successfully sequenced a partial 18S rRNA gene fragment of four samples (two capybaras, one A. sculptum, and one A. dubitatum), and the phylogenetic reconstruction disclosed that the organism reported in the present study clusters within the genus Babesia. Further research is required for a formal delineation of this species (designated as Babesia sp. strain Capybara) and to investigate the hypothesis of A. dubitatum and A. sculptum ticks being vectors.

Detection of Rickettsia spp. in Animals and Ticks in Midwestern Brazil, Where Human Cases of Rickettsiosis Were Reported

“…Once trapped and physically restrained with the net, capybaras were anesthetized with an intramuscular injection of ketamine (10 mg/kg) plus xylazine (0.5 mg/kg). Capybaras were identified with a subcutaneous microchip (Allflex), clinically monitored during the procedure until recovery from anesthesia, and released at the same capture site, as suggested by Neves et al [ 25 ].…”

Phylogenetic Inferences Based on Distinct Molecular Markers Confirm a Novel Babesia Species (Babesia goianiaensis nov. sp.) in Capybaras (Hydrochoerus hydrochaeris) and Associated Ticks

“…Although South America is not considered to be endemic for zoonotic Babesia spp., which have not been reported in wild animals so far, the circulation of competent tick vectors for other Piroplasmida species that can parasitize domestic and wild animals emphasizes the need for constant surveillance [ 1 ]. In this sense, some studies have pointed out the participation of wild animals, such as the capybara ( Hydrochoerus hydrochaeris ), the largest rodent in the world, in the life cycle of piroplasmids and/or associated ticks, such as Amblyomma sculptum and Amblyomma dubitatum [ 5 ]. Since capybaras are hosts for A. sculptum ticks and amplifying hosts for Rickettsia rickettsii , the agent of Brazilian spotted fever, understanding the role of these rodents as hosts for other microorganisms is important [ 6 , 7 ].…”

“…Twelve years later, Gonçalves et al [ 9 ] reported the presence of Piroplasmida partial 18S rRNA sequences, showing >97% identity with the previously reported capybara-associated piroplasmid [ 8 ] in a female and a nymph of A. dubitatum , collected from a capybara and a black rat ( Rattus rattus ), respectively, in the state of Mato Grosso do Sul. In the state of Goiás, central-western Brazil, Neves et al [ 5 ] reported the presence of capybara-associated Babesia sp. DNA in capybaras and two female ticks of A. sculptum and A. dubitatum .…”

“…DNA in capybaras and two female ticks of A. sculptum and A. dubitatum . Additionally, large merozoites were found parasitizing the erythrocytes of a capybara with very low parasitemia [ 5 ]. Perles et al [ 10 ] molecularly detected the capybara-associated Piroplasmida in A. sculptum and A. dubitatum collected from coatis ( Nasua nasua ) in the state of Mato Grosso do Sul.…”

“…In the same way, a putative novel Babesia sp. in capybaras and Amblyomma ticks in three Brazilian states has also been described [ 5 , 8 , 9 , 10 ]. In the present work, we used phylogenetic assessments based on distinct molecular markers to describe this novel Babesia species, recently reported from capybaras and associated ticks ( A. sculptum and A. dubitatum ) in Goiânia city, Goiás state, midwestern Brazil [ 5 ].…”