Introduction
Kala-azar is a
disease resulting from
infection by
Leishmania donovani and
Leishmania infantum. Most
patients with the
disease exhibit prolonged
fever, wasting,
anemia and hepatosplenomegaly without
complications. However, some
patients develop severe
disease with hemorrhagic manifestations,
bacterial infections,
jaundice, and
edema dyspnea, among other symptoms, followed by
death. Among the
parasite molecules that might influence the
disease severity are the
macrophage migration inhibitory factor-like
proteins (MIF1 and MIF2) and N-
acetylglucosamine-1-
phosphotransferase (NAGT), which act in the first step of
protein N-
glycosylation. This study aimed to determine whether MIF1, MIF2 and NAGT are
virulence factors for severe
kala-azar.
Methods To determine the
parasite genotype in
kala-azar patients from Northeastern
Brazil, we sequenced the NAGT
genes of L. infantum from 68
patients as well as the MIF1 and MIF2
genes from 76 different subjects with diverse clinical manifestations. After
polymerase chain reaction (
PCR), the fragments were sequenced, followed by polymorphism identification. Results The
nucleotide sequencing of the 144 amplicons revealed the absence of genetic variability of the NAGT, MIF1 and MIF2
genes between the isolates. The conservation of these
genes suggests that the clinical variability of
kala-azar does not depend upon these
genes. Additionally, this conservation suggests that these
genes may be critical for
parasite survival. Conclusions NAGT, MIF1 and MIF2 do not alter the severity of
kala-azar. NAGT, MIF1 and MIF2 are highly conserved among different isolates of identical species and exhibit potential for use in
phylogenetic inferences or molecular
diagnosis. .