Analysis Of The Nagt Gene Diversity Among Leishmania Isolates From Sudan

Abstract

Sixty one Leishmania isolates representing different clinical forms of leishmaniasis (visceral leishmaniasis and HIV/Leishmania coinfection, cutanous leishmaniasis, post kalazar dermal leishmaniasis and mucosal leishmaniasis) from Sudan were analysed using the polymerase chain reaction and the analysis of the restriction fragment length polymorphism (RFLP) of intra geneic region of (NAGT gene) and sequencing technique. PCR amplification of (NAGT) gene of sixty one leishmania isolates resulted in the amplification of a DNA fragment of 1.4kb. The amplification of the (NAGT) gene coding region followed by restriction fragment length polymorphism (PCR-RFLP) differentiated between Sudanese leishmania isolates and clustered them as two groups; leishmania donovani complex and leishmania major, but did not differentiate between the members of leishmania donovani complex. The Acc1 restriction enzyme findings revealed the high conservation of this region. The dendrogram of unweighted pair group method with arithmetic average (UPGMA) and Neighbour-Joining (NJ) was constructed from the genetic distances derived from PCR-RFLP data. The topology of the NJ and UPGMA trees were very similar. DNA sequencing and sequence alignment analysis of (NAGT) gene differentiated the leishmania donovani complex from leishmania major, but did not differentiate the member's leishmania donovani complex, and agreed with the result obtained by PCR⁄RFLP analysis. The (NJ) tree developed based on sequence alignment segregate (NAGT) gene in to two groups having a one common ancestor. In conclusion the two trees (from PCR-RFLP and from sequencing analysis) indicated that there was no genetic heterogeneity among tested Sudanese isolates, and no correlation between the PCR- RFLP polymorphic pattern, NAGT gene sequence and the clinical presentation of the human leishmaniasis.