Difference in DNA sequences in SSU rDNA variable regions among pathogens isolated from different epidemic foci of visceral leishmaniasis in China / 中华医学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To confirm the existence of point mutations in the SSU rDNA variable regions of 5 Leishmania donovani (L.d.) isolates from different epidemic foci in China.</p><p><b>METHODS</b>Specific SSU rDNA fragments from nuclear DNA of 7 Leishmania species/isolates were amplified by PCR and then cloned into pGEM(R)-T Easy Vectors. After that, the specific fragments were sequenced by an automated DNA sequencer.</p><p><b>RESULTS</b>Sequence analysis showed that the amplified DNA fragments of 7 Leishmania species/isolates were all 392 bp in length. All 5 point mutations were located in two unique sequence blocks (UQ-I and UQ-II), and no insertions or deletions were found. The identities of comparison of Leishmania in GeneBank were more than 98%.</p><p><b>CONCLUSION</b>Five point mutations exist in the SSU rDNA variable region of 5 L.d. isolates from different epidemic foci of visceral leishmaniasis (VL) in China. Sequence differences of the SSU rDNA variable region exist among L.d. isolates from different foci.</p>