Studies on the transmission and course of infection of a Kenyan strain of <i>Theileria mutans</i>

Young, A. S.; Purnell, R.E.; Payne, Rose; Brown, C.G.D.; Kanhai, G. K.

doi:10.1017/s0031182000047430

Cited by 40 publications

(14 citation statements)

References 23 publications

(23 reference statements)

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“…Morphologically, the schizonts observed were of T.parva-type (YOUNG et al, 1978); many appeared to be in transition from macro-to microschizonts, particularly in the brain smears. Fully-developed microschizonts were observed in 10 cases, with no obvious relation to the duration of the clinical disease.…”

Section: Resultsmentioning

confidence: 94%

“…SCHEIN et al (1978) stress that schizonts of Theileria (T.pawa, T. lawrencei, T. annulata and T. mutans) can neither be differentiated on the basis of their ultrastructure nor by light microscopic observations. Alternatively, YOUNG et al (1978) distinguish schizonts of the T.parva type from those of T. mutans morphologically. Tested in this way, our material might well show only schizonts of T.pawa type.…”

Section: Discussionmentioning

confidence: 99%

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Morphological Findings in Bovine Cerebral Theileriosis (BCT)

Bader¹,

Moll²,

Lohding³

1986

Journal of Veterinary Medicine Series A

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Summary Cattle (n = 29) from Kenya with clinical signs of Turning Sickness were subjected to gross mortem findings, post mortem smears and histological examination. As Theileria schizonts were seen in smears from the brain, the disease was diagnosed as Bovine Cerebral Theileriosis (BCT). As there are other infections causing Turning Sickness and as the observed occurrence of Theileria schizonts is rare in smears and histological slides in some instances, diagnosis of BCT must be based on morphological examination of the central nervous system. Intravenous accumulations of lymphoblasts with and without schizonts, venous thrombi, effects of venous alterations, and perivascular lymphocytic infiltration were regular and characteristic findings in the central nervous system in BCT. The Theileria species which causes BCT are discussed as well as the possible pathogenesis of intravasal lymphoblastic accumulations and venous thrombi within the central nervous system. Zusammenfassung Morphologische Befunde bei der bovinen zerebralen Theileriose (BCT) Rinder (n = 29) aus Kenya mit klinischen Symptomen einer Turning Sickness wurden seziert, Organabstriche und Proben zur histologischen Untersuchung wurden entnommen. Der Nachweis von Theilerienschizonten in den Hirnausstrichen führte zur Diagnose der bovinen zerebralen Theileriose (BCT). Da auch andere Erreger Symptome der Turning Sickness hervorrufen können und der Nachweis von Theilerienschizonten manchmal sowohl am Ausstrich als auch im histologischen Präparat nur unzureichend gelingt, muß die Diagnose BCT mit morphologischen Untersuchungen des Zentralnervensystems abgesichert werden. Intravenöse Ansammlungen von Lymphoblasten mit oder ohne intrazytoplasmatische Schizonten, venöse Thromben und die Folgen der Venenalterationen sind zusammen mit perivaskulären lymphozytären Infiltraten im ZNS regelmäßige und charakteristische Befunde. Die Theilerienspezies, die BCT auslöst, wird ebenso diskutiert wie die Pathogenese der Lymphoblastenansammlungen und Thromben in den Venen des ZNS.

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Section: Resultsmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Morphological Findings in Bovine Cerebral Theileriosis (BCT)

Bader¹,

Moll²,

Lohding³

1986

Journal of Veterinary Medicine Series A

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“…Deeper sequencing and larger sampling would, however, be necessary to determine the prevalence of specific variants for either buffalo or cattle. 1974;Purnell et al 1975;Young et al 1977;Young et al 1978;Perie et al 1979;de Vos and Roos, 1981). It is therefore of interest that T. mutans and T. mutans MSD were extensively found in the Eastern Cape in buffalo and cattle, whereas buffalo specific genotypes were absent from this region.…”

Section: Geographic Distribution Of Genotypes Babesia Speciesmentioning

confidence: 99%

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

Mans

Pienaar

Ratabane

et al. 2016

Ticks and Tick-borne Diseases

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Molecular classification and systematics of the Theileria is based on the analysis of the 18S rRNA gene. Reverse line blot or conventional sequencing approaches have disadvantages in the study of 18S rRNA diversity and a next-generation 454 sequencing approach was investigated. The 18S rRNA gene was amplified using RLB primers coupled to 96 unique sequence identifiers (MIDs). Theileria positive samples from African buffalo (672) and cattle (480) from southern Africa were combined in batches of 96 and sequenced using the GS Junior 454 sequencer to produce 825711 informative sequences. Sequences were extracted based on MIDs and analysed to identify Theileria genotypes. Genotypes observed in buffalo and cattle were confirmed in the current study, while no new genotypes were discovered.Genotypes showed specific geographic distributions, most probably linked with vector distributions. Host specificity of buffalo and cattle specific genotypes were confirmed and prevalence data as well as relative parasitemia trends indicate preference for different hosts.Mixed infections are common with African buffalo carrying more genotypes compared to cattle. Associative or incongruent co-infection profiles were observed between genotypes that may have implications for speciation and systematics: specifically that more Theileria species may exist in cattle and buffalo than currently recognized. Analysis of primers used for Theileria parva diagnostics indicate that no new genotypes will be amplified by the current primer sets confirming their specificity. Theileria parva SNP variants that occur in the 18S rRNA hypervariable region were confirmed. A next generation sequencing approach is useful in obtaining comprehensive knowledge regarding 18S rRNA diversity and prevalence for the Theileria, allowing for the assessment of systematics and diagnostic assays based on the 18S gene.Keywords: 18S SSU, Diversity, Next-generation sequencing, species, Theileria, Theileria parva 3 IntroductionThe Babesia and Theileria are part of the phylum Apicomplexa (Order Piroplasmorida) (Mans et al. 2015 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). The method relies on the amplification of the V4 hypervariable region of the 18S rRNA gene, followed by hybridization t...

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“…(buffalo) (Norval et al, 1992). T. mutans (Theiler, 1906) is a parasite of buffalo, it is infective to cattle and has been shown to cause latent infections in sheep (Young et al, 1978). It occurs in parts of sub-Saharan Africa and is transmitted by different species of Amblyomma ticks (Uilenberg et al, 1982).…”

Section: Introductionmentioning

confidence: 99%

Sequence variation identified in the 18S rRNA gene of Theileria mutans and Theileria velifera from the African buffalo (Syncerus caffer)

Chaisi

Collins

Potgieter

et al. 2013

Veterinary Parasitology

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The African buffalo (Syncerus caffer) is a natural reservoir host for both pathogenic and nonpathogenic Theileria species. These often occur naturally as mixed infections in buffalo.Although the benign and mildly pathogenic forms do not have any significant economic importance, their presence could complicate the interpretation of diagnostic test results aimed at the specific diagnosis of the pathogenic T. parva in cattle and buffalo in South Africa. The 18S rRNA gene has been used as the target in a quantitative real-time PCR (qPCR) assay for the detection of T. parva infections. However, the extent of sequence variation within this gene in the non-pathogenic Theileria spp. of the Africa buffalo is not well known. The aim of this study was, therefore, to characterize the full-length 18S rRNA genes of T. mutans, Theileria sp. (strain MSD) and T. velifera and to determine the possible influence of any 2 sequence variation on the specific detection of T. parva using the 18S rRNA qPCR. The reverse line blot (RLB) hybridization assay was used to select samples which either tested positive for several different Theileria spp., or which hybridized only with the Babesia/Theileria genus-specific probe and not with any of the Babesia or Theileria speciesspecific probes. The full-length 18S rRNA genes from 14 samples, originating from 13 buffalo and one bovine from different localities in South Africa, were amplified, cloned and the resulting recombinants sequenced. Variations in the 18S rRNA gene sequences were identified in T. mutans, Theileria sp. (strain MSD) and T. velifera, with the greatest diversity observed amongst the T. mutans variants. This variation possibly explained why the RLB hybridization assay failed to detect T. mutans and T. velifera in some of the analysed samples.

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Studies on the transmission and course of infection of a Kenyan strain of Theileria mutans

Cited by 40 publications

References 23 publications

Morphological Findings in Bovine Cerebral Theileriosis (BCT)

Morphological Findings in Bovine Cerebral Theileriosis (BCT)

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

Sequence variation identified in the 18S rRNA gene of Theileria mutans and Theileria velifera from the African buffalo (Syncerus caffer)

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