Get access

Molecular Demonstration of Trypanosoma evansi and Trypanosoma lewisi DNA in Wild Rodents from Cambodia, Lao PDR and Thailand

Authors

  • C. Milocco,

    1.  Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Montpellier, France
    2.  Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, Thailand
    3.  Institut des Sciences de l’Evolution, UMR 5554 CNRS-IRD-UM2, CC65, Université de Montpellier, Montpellier, France
    Search for more papers by this author
  • K. Kamyingkird,

    1.  Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, Thailand
    Search for more papers by this author
  • M. Desquesnes,

    1.  Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Montpellier, France
    2.  Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, Thailand
    Search for more papers by this author
  • S. Jittapalapong,

    1.  Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, Thailand
    Search for more papers by this author
  • V. Herbreteau,

    1.  UR22 AGIRs CIRAD, Campus International de Baillarguet, Montpellier, France
    Search for more papers by this author
  • Y. Chaval,

    1.  UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro), Campus International de Baillarguet, Montferrier-sur-Lez Cedex, France
    Search for more papers by this author
  • B. Douangboupha,

    1.  National Agricultural and Forestry Research Institute, Vientiane, Laos
    Search for more papers by this author
  • S. Morand

    1.  Institut des Sciences de l’Evolution, UMR 5554 CNRS-IRD-UM2, CC65, Université de Montpellier, Montpellier, France
    2.  UR22 AGIRs CIRAD, Campus International de Baillarguet, Montpellier, France
    Search for more papers by this author

S. Jittapalapong. Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand. Tel.: +66(0)29 42 84 38; Fax: +66(0)29 42 86 44; E-mail: fvetspj@yahoo.com

Summary

In this study, we investigated the molecular evidence of Trypanosoma evansi in wild rodents from Cambodia, Lao PDR and Thailand. Between November 2007 and June 2009, 1664 rodents were trapped at eight sites representative of various ecological habitats. Of those animals, 94 were tested by direct microscopic blood examination, 633 using the Card Agglutination Test for Trypanosomes (CATT/T. evansi) and 145 by Polymerase Chain Reaction (PCR) with two sets of primers: TRYP1 (amplifying ITS1 of ribosomal DNA of all trypanosomes) and TBR (amplifying satellite genomic DNA of Trypanozoon parasites). Using TRYP1, based on the size of the PCR products, 15 samples from the three countries were positive for Trypanosoma lewisi (two were confirmed by sequencing), and three were positive for Trypanozoon (one was confirmed by sequencing and three by TBR primers); the specificity of the primers failed as rodent DNA was amplified in some cases. Using TBR, six samples were positive for Trypanozoon (one was confirmed by sequencing); as T. evansi is the only species of the Trypanozoon sub-genus possibly present in Asian rodents, these results confirmed its presence in rodents from Thailand (Rattus tanezumi) and Cambodia (R. tanezumi, Niviventer fulvescens & Maxomys surifer). Further investigations are necessary to establish the situation in Lao PDR. None of the 16 samples most strongly positive to the CATT proved to be positive for Trypanozoon by PCR. The merits of the CATT for such studies were not confirmed. Studying the urban and rural circulation of these parasites in rodents will enable an evaluation of human exposure and infection risk, as human infections by T. evansi were recently described in India and by T. lewisi in India and Thailand. As sequencing PCR products is expensive, the development of new molecular and serological tools for rodents would be very useful.

Ancillary