First Evidence of Entamoeba Parasites in Australian Wild Deer and Assessment of Transmission to Cattle

Abstract

Australian wild deer populations have significantly expanded in size and distribution in recent decades. Due to their role in pathogen transmission, these deer populations pose a biosecurity risk to the livestock industry. However, little is known about the infection status of wild deer in Australia. The intestinal parasite Entamoeba bovis has been previously detected in farm and wild ruminants worldwide, but its epidemiology and distribution in wild ruminants remain largely unexplored. To investigate this knowledge gap, faecal samples of wild deer and domestic cattle from south-eastern Australia were collected and analysed for the presence of Entamoeba spp. using PCR and phylogenetic analysis of the conserved 18S rRNA gene. E. bovis parasites were detected at high prevalence in cattle and wild deer hosts, and two distinct Entamoeba ribosomal lineages (RLs), RL1 and RL8, were identified in wild deer. Phylogenetic analysis further revealed the existance of a novel Entamoeba species in sambar deer and a novel Entamoeba RL in fallow deer. While we anticipated cross-species transmission of E. bovis between wild deer and cattle, the data generated in this study demonstrated transmission is yet to occur in Australia. Overall, this study has identified novel variants of Entamoeba and constitutes the first report of Entamoeba in fallow deer and sambar deer, expanding the host range of this parasite. Epidemiological investigations and continued surveillance of Entamoeba parasites in farm ruminants and wild animals will be required to evaluate pathogen emergence and transmission to livestock.

A review of viral and parasitic infections in wild deer in Australia with relevance to livestock and human health

“…bovis has also been detected in Australia, including in feral goats ( Capra hircus ) from Western Australia (Al-Habsi et al . 2017) and wild deer from eastern Australia (Huaman et al . 2022 b ).…”

“…2022 b ). The cross-species infection between deer and livestock species was evaluated by estimating the time to a most recent common ancestor (TMCRA) of E. bovis sequences of wild deer and cattle origin (Huaman et al . 2022 b ).…”

“…The intestinal parasite Entamoeba bovis has been previously detected in farm and wild ruminants worldwide, but its epidemiology and distribution in wild ruminants remain largely unexplored (Stensvold et al 2010). E. bovis has also been detected in Australia, including in feral goats (Capra hircus) from Western Australia (Al-Habsi et al 2017) and wild deer from eastern Australia (Huaman et al 2022b). The cross-species infection between deer and livestock species was evaluated by estimating the time to a most recent common ancestor (TMCRA) of E. bovis sequences of wild deer and cattle origin (Huaman et al 2022b).…”

“…However, data about the infection status of Australian wild deer populations are sparse, with only six studies reported before 2014, all of them identified in localised surveys conducted 41-56 years ago (Munday 1966;Munday 1972;Presidente and Westbury 1979;Slee and Presidente 1981;English 1982;McKenzie et al 1985). More recently, however, at least 11 further surveys have been reported, many of them our own work (Davies 2014;Koehler et al 2016;Panozzo 2018;Huaman et al 2020Huaman et al , 2021aHuaman et al , 2021bHuaman et al , 2021cHuaman et al , 2022aHuaman et al , 2022bJenkins et al 2020;Lamb et al 2021).…”

“…2016; Panozzo 2018; Huaman et al . 2020, 2021 a , 2021 b , 2021 c , 2022 a , 2022 b ; Jenkins et al . 2020; Lamb et al .…”