A novel A2 allele found in Leishmania (Leishmania) infantum chagasi

Abstract

<jats:p>Visceral leishmaniasis (VL) is a widely spread zoonotic disease. In Brazil the disease is caused by Leishmania (Leishmania) infantum chagasi. Peridomestic sandflies acquire the etiological agent by feeding on blood of infected reservoir animals, such as dogs or wildlife. The disease is endemic in Brazil and epidemic foci have been reported in densely populated cities all over the country. Many clinical features of Leishmania infection are related to the host-parasite relationship, and many candidate virulence factors in parasites that cause VL have been studied such as A2 genes. The A2 gene was first isolated in 1994 and then in 2005 three new alleles were described in Leishmania (Leishmania) infantum. In the present study we amplified by polymerase chain reaction (PCR) and sequenced the A2 gene from the genome of a clonal population of L. (L.) infantum chagasi VL parasites. The L. (L.) infantum chagasi A2 gene was amplified, cloned, and sequenced in. The amplified fragment showed approximately 90% similarity with another A2 allele amplified in Leishmania (Leishmania) donovani and in L.(L.) infantum described in literature. However, nucleotide translation shows differences in protein amino acid sequence, which may be essential to determine the variability of A2 genes in the species of the L. (L.) donovani complex and represents an additional tool to help understanding the role this gene family may have in establishing virulence and immunity in visceral leishmaniasis. This knowledge is important for the development of more accurate diagnostic tests and effective tools for disease control.</jats:p>

Serodiagnosis of visceral and cutaneous leishmaniasis in human and canine populations living in Indigenous Reserves in the Brazilian Amazon Region

“…The sample of L. infantum chagasi 13 was isolated from bone marrow aspirate from a naturally infected dog in the municipality of Olympia, São Paulo, and was characterized using molecular methods 14,15 . The parasites were cultured in Roswell Park Memorial Institute (RPMI) liquid medium supplemented with 10% heat-inactivated fetal bovine serum and, after two to three passages, the promastigote forms in the stationary phase of culturing were centrifuged at 735g for 10 minutes and the supernatant was discarded.…”

Study on coinfecting vector-borne pathogens in dogs and ticks in Rio Grande do Norte, Brazil

“…(ANDRÉ et al, 2010;SOUSA et al, 2013). A positive control for Leishmania infantum DNA was obtained from parasites maintained in culturing medium (GenBank: GQ290460) (OLIVEIRA et al, 2011). Ultra-pure sterile water was used as the negative control.…”

Expression of a recombinant protein, A2 family, from Leishmania infantum (Jaboticabal strain) and its evaluation in Canine Visceral Leishmaniasis serological test

“…The A2 locus is comprised of at least seven genes, which differ in the length of the sequences encoding the repeat peptide unit (CHAREST et al, 1996). Although A2 protein length ranges from 45 to 100 kDa (ZHANG et al, 1996), the A2 gene isolated by Oliveira et al (2011) has a length of 495 base pairs. However, after clone sequence analysis, we observed that the amino acid sequence had a predicted signal peptide in the first 26 amino acids.…”

“…The A2 gene allele was isolated by Oliveira et al (2011) and cloned into a pGEM-T Easy vector system (Promega, Madison, USA). This cloned gene was used as a template in PCR to amplify the A2 gene using 0.5 µM of the specific primers designed in this study.…”