Parasitology

Original Articles

Phylogenetic analysis of Trypanosoma vivax supports the separation of South American/West African from East African isolates and a new T. vivax-like genotype infecting a nyala antelope from Mozambique

A. C. RODRIGUESa1, L. NEVESa2, H. A. GARCIAa1, L. B. VIOLAa1, A. MARCILIa1, F. MAIA DA SILVAa1, I. SIGAUQUEa3, J. S. BATISTAa4, F. PAIVAa5 and M. M. G. TEIXEIRAa1 c1

a1 Departamento de Parasitologia, Universidade de São Paulo, São Paulo, SP, Brasil

a2 Faculdade de Veterinária, Universidade Eduardo Mondlane, Maputo, Mozambique

a3 Direcção Nacional de Pecuária, Maputo, Mozambique

a4 Departamento de Patologia, Universidade Federal Rural do Semi-Árido, RN, Brasil

a5 Departamento de Patologia Veterinária, Universidade Federal do Mato Grosso do Sul, MS, Brasil

SUMMARY

In this study, we addressed the phylogenetic and taxonomic relationships of Trypanosoma vivax and related trypanosomes nested in the subgenus Duttonella through combined morphological and phylogeographical analyses. We previously demonstrated that the clade T. vivax harbours a homogeneous clade comprising West African/South American isolates and the heterogeneous East African isolates. Herein we characterized a trypanosome isolated from a nyala antelope (Tragelaphus angasi) wild-caught in Mozambique (East Africa) and diagnosed as T. vivax-like based on biological, morphological and molecular data. Phylogenetic relationships, phylogeographical patterns and estimates of genetic divergence were based on SSU and ITS rDNA sequences of T. vivax from Brazil and Venezuela (South America), Nigeria (West Africa), and from T. vivax-like trypanosomes from Mozambique, Kenya and Tanzania (East Africa). Despite being well-supported within the T. vivax clade, the nyala trypanosome was highly divergent from all other T. vivax and T. vivax-like trypanosomes, even those from East Africa. Considering its host origin, morphological features, behaviour in experimentally infected goats, phylogenetic placement, and genetic divergence this isolate represents a new genotype of trypanosome closely phylogenetically related to T. vivax. This study corroborated the high complexity and the existence of distinct genotypes yet undescribed within the subgenus Duttonella.

(Received May 06 2008)

(Revised June 12 2008)

(Revised June 26 2008)

(Accepted July 01 2008)

(Online publication August 28 2008)

Correspondence:

c1 Corresponding author: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, 05508-900, Brasil. Tel: +55 11 3091 7268. Fax: +55 11 3091 7417. E-mail: mmgteix@icb.usp.br

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