Analysis of kinetoplast cytochrome b gene of 16 Leishmania isolates from different foci of China: different species of Leishmania in China and their phylogenetic inference

Abstract

BackgroundLeishmania species belong to the family Trypanosomatidae and cause leishmaniasis, a geographically widespread disease that infects humans and other vertebrates. This disease remains endemic in China. Due to the large geographic area and complex ecological environment, the taxonomic position and phylogenetic relationship of Chinese Leishmania isolates remain uncertain. A recent internal transcribed spacer 1 and cytochrome oxidase II phylogeny of Chinese Leishmania isolates has challenged some aspects of their traditional taxonomy as well as cladistics hypotheses of their phylogeny. The current study was designed to provide further disease background and sequence analysis.MethodsWe systematically analyzed 50 cytochrome b (cyt b) gene sequences of 19 isolates (16 from China, 3 from other countries) sequenced after polymerase chain reaction (PCR) using a special primer for cyt b as well as 31 sequences downloaded from GenBank. After alignment, the data were analyzed using the maximum parsimony, Bayesian and netwok methods.ResultsSequences of six haplotypes representing 10 Chinese isolates formed a monophyletic group and clustered with Leishmania tarentolae. The isolates GS1, GS7, XJ771 of this study from China clustered with other isolates of Leishmania donovani complex. The isolate JS1 was a sister to Leishmania tropica, which represented an L. tropica complex instead of clustering with L. donovani complex or with the other 10 Chinese isolates. The isolates KXG-2 and GS-GER20 formed a monophyletic group with Leishmania turanica from central Asia. In the different phylogenetic trees, all of the Chinese isolates occurred in at least four groups regardless of geographic distribution.ConclusionsThe undescribed Leishmania species of China, which are clearly causative agents of canine leishmaniasis and human visceral leishmaniasis and are related to Sauroleishmania, may have evolved from a common ancestral parasite that came from the Americas and may have split off earlier than the other old world Leishmania. Our results also suggest the following: the isolates GS7, GS1 and XJ771 occur as part of the L. donovani complex; the JS1 isolate is L. tropica; and the isolate GS-GER20 identified as Leishmania gerbilli is close to KXG-2 which is L. turanica.

A Study of Genetic Polymorphism of Crithidia in Isfahan, Iran

“…The results of the present study to some extent are in accordance with the results of the study by Yang et al [19]. According to data, which illustrates the frequency distribution of isolated trypanosomatidae family from culturing in Isfahan and surrounding areas, a large number of samples, i.e.…”

“…This group of researchers collected 17 isolated Leishmania and 2 isolated Crithidia from different areas of China and amplified the ITS1 ribosomal gene using the PCR technique. They then sequenced a number of these isolations in terms of taxonomy, and identified the phylogenetic affinities between species of Leishmania and other parasites [19]. However, it should be mentioned that no difference was observed in analyzing the band profiles using the Ddel, ScrFI and TaqI enzymes on all the isolations, compared with the standard samples.…”

“…Yang et al [19] proposed that similar to many parasites, studying the phylogenetic relationships of different species of Leishmania and Crithidia parasites is extremely complicated. This is because defining and categorizing the subspecies in order to describe them is very hard.…”

Diagnostic Efficacy of Molecular Techniques for Detection and Identification of Leishmania Species in Human Whole Blood and Skin Samples from Ecuador

“…Data were analyzed (SeqScape ® v2.5 software, Foster City, CA) and the nucleotide sequences of the cyt-b gene for the various Leishmania species, available in the GenBank, were compared through sequence alignments and phylogenetic trees. 15,16 In three different patients, we were able to identify species-specific sequences from the eight sequenced samples; L. guyanensis and Leishmania shawi were identified from two cutaneous samples, whereas L. naiffi was detected in blood.…”

“…15,16 We amplified the cyt-b gene in skin and whole blood samples that were positive for 18S rRNA Leishmania gene (N = 20) as reported previously. 15 Eight samples that were positive for 18S rRNA also amplified for the cyt-b gene; four from skin and four from blood, Figure 1B.…”