Leishmania donovani is the only cause of visceral leishmaniasis in East Africa; previous descriptions of L. infantum and “L. archibaldi” from this region are a consequence of convergent evolution in the isoenzyme data
Isoenzyme-based studies have identified 3 taxa/species/‘phylogenetic complexes’ as agents of visceral leishmaniasis in Sudan: L. donovani, L. infantum and “L. archibaldi”. However, these observations remain controversial. A new chitinase gene phylogeny was constructed in which stocks of all 3 putative species isolated in Sudan formed a monophyletic clade. In order to construct a more robust classification of the L. donovani complex, a panel of 16 microsatellite markers was used to describe 39 stocks of these 3 species. All “L. donovani complex” stocks from Sudan were again found to form a single monophyletic clade. L. donovani ss stocks from India and Kenya were found to form 2 region-specific clades. The partial sequence of the glutamate oxaloacetate transaminase (GOT) gene of 17 L. donovani complex stocks was obtained. A single nucleotide polymorphism in the GOT gene appeared to underlie the isoenzyme classification. It was concluded that isoenzyme-based identification is unsafe for stocks isolated in L. donovani endemic areas and identified as L. infantum. It was also concluded that the name L. archibaldi is invalid and that only a single visceralizing species, Leishmania donovani, is found in East Africa.(Received January 29 2004)
(Revised April 7 2004)
(Accepted April 8 2004)
Key Words: aspartate aminotransferase; microsatellites; MLEE; kala azar; Ethiopia; chagasi.
c1 Animal Genomics Laboratory, Biosciences Building, School of Biological Sciences, University of Liverpool, Crown Sreet, Liverpool L69 7ZB, UK. Tel: +44 (0)151 795 4512. Fax: +44 (0)151 795 4512. E-mail: firstname.lastname@example.org
p1 Current address: King Abdulaziz University, Department of Medical Parasitology, P.O. Box 80205, Jeddah 21589, Saudi Arabia.