A study of the systematics of Theileria spp. based upon small-subunit ribosomal RNA gene sequences

Abstract

The systematics of benign and moderately pathogenic Theileria isolates from cattle and deer originating from different geographic regions was undertaken by small-subunit ribosomal RNA (SSU rRNA) gene nucleotide-sequence analysis. A maximum-likelihood phylogenetic tree constructed from these sequences resulted in two major divisions, each with a common ancestor. One major division branches into four relatively divergent groups, including (1) bovine Theileria sp. Type D (USA and Korea), (2) T. mutans Intona and Theileria sp. MSD (Africa), (3) T. cervi (USA), and (4) well-characterized pathogenic Theileria spp. (Africa). The other major division branches into two groups: (1) T. buffeli Warwick and T. buffeli Marula and (2) a second branch of closely related isolates with SSU rRNA gene Types B, B1, C, E, and H. Putative geographically associated diversity was noted only in the Korean bovine Theileria spp. with SSU rRNA gene types C and H and in African T. mutans Intona and Theileria sp. MSD. The current results show that the United States bovine Theileria isolates are not T. mutans because they have T. buffeli Marula (Type A) and/or Type D (species undesignated) SSU rRNA gene sequences. The taxonomic separation of T. buffeli Warwick from African T. mutans is confirmed in this study.

Diversity in the 18S SSU rRNA V4 hyper-variable region ofTheileriaspp. in Cape buffalo (Syncerus caffer) and cattle from southern Africa

“…T. buffeli D-like were found in 3 buffalo samples and is similar to T. buffeli type D and T. sp. (Thung Song) found in cattle in Thailand, the USA and Korea (Chae et al 1999;Chansiri et al 1999) and a sequence designated as T. sp. MK from sheep and goats in Turkey (Altay et al 2007), but differed by at least 8 nucleotide substitutions.…”

“…(buffalo) was a distinct entity from T. parva (Allsopp et al 1993). Subsequently, the systematics of the Piroplasmida has been extensively studied by analysis of the 18S rRNA gene (Allsopp et al 1994;Chae et al 1999;Chansiri et al 1999;Criado-Fornelio et al 2004;Criado et al 2006;Reichard et al 2005;Altay et al 2007;Bhoora et al 2009). Based on this, the reverse line blot is currently used for simultaneous detection of Babesia and Theileria species diversity within a vertebrate host (Gubbels et al 1999).…”

Investigating the diversity of the 18S SSU rRNA hyper-variable region of Theileria in cattle and Cape buffalo (Syncerus caffer) from southern Africa using a next generation sequencing approach

“…A significant proportion of the systematic study of the Piroplasmorida comprise analysis of the 18S rRNA gene (Allsopp et al 1994;Chae et al 1999;Chansiri et al 1999;Criado-Fornelio et al 2004;Reichard et al 2005;Criado et al 2006;Altay et al 2007;Bhoora et al 2009). The reverse line blot (RLB) method (Gubbels et al 1999), based on simultaneous detection of the 18S rRNA gene for various Babesia and Theileria species, has been extensively used for surveillance purposes (Georges et al 2001;Almerìa et al 2002;Oura et al 2004;Nijhof et al 2003Nijhof et al , 2005Altay et al 2007;M'ghirbi et al 2008;Altay et al 2008;Matjila et al 2008;Oosthuizen et al 2008;Almerìa et al 2009;Salih et al 2010;Yusufmia et al 2010;Tomassone et al 2012;Ceci et al 2014;Githaka et al 2014;Eygelaar et al 2015;Njiiri et al 2015).…”

Geographic distribution of Theileria sp. (buffalo) and Theileria sp. (bougasvlei) in Cape buffalo (Syncerus caffer) in southern Africa: implications for speciation

“…In the Bovini (African buffalo, Asiatic water buffalo and cattle) four main groups include the Theileria buffeli, Theileria mutans, Theileria velifera and Theileria taurotragi clades . Genotypes within the T. buffeli, T. mutans and T. velifera clades are considered to represent populations of the same species (Chae et al 1999;Gubbels et al 2000). However, differences in host preference, clinical pathology, vector specificity and genetics are challenging this (Chae et al 1999;Gubbels et al 2000;Mans et al 2011a, b).…”

“…Genotypes within the T. buffeli, T. mutans and T. velifera clades are considered to represent populations of the same species (Chae et al 1999;Gubbels et al 2000). However, differences in host preference, clinical pathology, vector specificity and genetics are challenging this (Chae et al 1999;Gubbels et al 2000;Mans et al 2011a, b). Genotypes within these clades can have as many as 5-20 nucleotide differences in the 18S rRNA V4 hyper-variable region .…”