First molecular screening of Plasmodium species in ungulates from Southern Brazil

Abstract

Objective: Despite malaria epidemiology has been extensively studied in primates, few studies were conducted in ungulates. After half a century without descriptions of Plasmodium spp. in deer since its first identification, recent research has rediscovered Plasmodium on ungulates in Africa, Asia, North America and South America, including Central Brazil. Here, a captive herd was evaluated in southern Brazil using light microscopy and PCR. DNA samples were tested for fragment amplification of two Plasmodium spp. genes: mitochondrial cytochrome b and small subunit ribosomal RNA.

Results: All analyses were negative. However, the tests were performed on samples that were collected at a single time point, and parasitemia may fluctuate over the parasite's life cycle. Thus, the possibility of occult infection cannot be ruled out. Despite the negative results of all of the methods applied, it cannot be categorically stated that these animals are free from Plasmodium sp. infection. Further monitoring and/or multiple sequential sampling may improve the success rate of detecting parasites. Moreover, although this survey of Plasmodium represents the first molecular study on ungulate malaria parasites from Southern Brazil, further analysis of samples from different ungulate species is important for characterizing the epidemiology of Plasmodium of these mammals in this region.

Keywords: Brazil; Deer; Malaria; PCR; Zoo animals.

Fig. 1

Origin of samples used in the study. A Location of Brazil in South America. B Location of Bela Vista Biological Sanctuary, Itaipu Binational Hydroelectric Power Plant, Foz do Iguaçu, Parana State Source: Modified from Google Earth

Fig. 2

Agarose gel electrophoresis showing the size of amplified products by PCR with generic primers targeting a highly conserved region of 18S rRNA gene (a) or mitochondrial cytochrome b gene (b) of genus Plasmodium. (M) represents the molecular weight marker (100 bp DNA Ladder Invitrogen) (C−) negative controls (water) and (C+) a Plasmodium positive control (genomic DNA from Plasmodium brasilianum, Peru III strain). The numbers (1–7) show the results obtained for seven of all negative tested samples. a shows amplification product of ~ 240 bp only in the positive control as well as b shows amplification product of ~ 600 bp only in the positive control