Ticks and Rickettsia on anteaters from Southeast and Central-West Brazil

Abstract

The giant anteater (Myrmecophaga tridactyla) and the collared anteater (Tamandua tetradactyla) are widespread in Brazil and found in all Brazilian biomes. These hosts frequently use domestic animal environments such as pastures, where tick and related microorganism interchange may occur between hosts. Reports of tick infestations of these animals are scattered and refer to small samples and/or are geographically restricted. We herein present data on a wide geographic distribution of ticks and their Rickettsia collected from 72 giant and 30 collared anteaters, mostly road killed, over a period of 18 years, from Southeast and Central-West Brazil encompassing four States and 46 Municipalities. Overall nine tick species (Amblyomma auricularium, A. calcaratum, A. nodosum, A. ovale, A. parvum, A. sculptum, A. triste, Rhipicephalus microplus and R. sanguineus sensu lato) were collected from anteaters. Amblyomma sculptum, A. nodosum, and A. calcaratum were the most prevalent corresponding to, respectively, 48.8%, 39.3% and 2.7% of all ticks (n = 1775). However, A. nodosum tick numbers on collared anteaters were significantly higher (P < 0.001) than those on giant anteaters. At the same time, an abundance of A. sculptum adults on giant anteaters was significantly higher (Z = 2.875; P = 0.004) than that of A. nodosum and only eight A. sculptum nymphs were found on collared anteaters. DNA samples from 20 ticks from nine different animals yielded a visible amplicon in PCR targeting gltA. The PCR products targeting spotted-fever Rickettsia gene (ompA) from five adults of A. nodosum were sequenced and were shown to be 100% identical to Rickettsia parkeri strain NOD (MF737635.1). The product of one nymph and one adult of A. sculptum yielded a sequence 99% identical to R. parkeri strain NOD. Further, Rickettsia bellii genes were found in three A. nodosum adults. Ecological, behavioral and anatomical traits of anteaters are discussed to explain reported tick infestations and Rickettsia DNA found.

Keywords: Anteater; Brazil; Rickettsia; Ticks.