Genetic and antigenic analysis of Babesia bigemina isolates from five geographical regions of Brazil

Abstract

A molecular epidemiological study was performed with Babesia bigemina isolates from five geographical regions of Brazil. The genetic analysis was done with random amplification of polymorphic DNA (RAPD), repetitive extragenic palindromic elements-polymerase chain reaction (REP-PCR) and enterobacterial repetitive intergenic consensus sequences-polymerase chain reaction (ERIC-PCR) that showed genetic polymorphism between these isolates and generated fingerprinting. In RAPD, ILO872 and ILO876 primers were able to detect at least one fingerprinting for each B. bigemina isolate. The amplification of B. bigemina DNA fragments by REP-PCR and ERIC-PCR gave evidence for the presence in this haemoprotozoan of the sequences described previously in microorganisms of the bacterial kingdom. For the first time it was demonstrated that both techniques can be used for genetic analysis of a protozoan parasite, although the ERIC-PCR was more discriminatory than REP-PCR. The dendogram with similarity coefficient among isolates showed two clusters and one subcluster. The Northeastern and Mid-Western isolates showed the greatest genetic diversity, while the Southeastern and Southern isolates were the closest. The antigenic analysis was done through indirect fluorescent antibody technique and Western blotting using a panel of monoclonal antibodies directed against epitopes on the merozoite membrane surface, rhoptries and membrane of infected erythrocytes. As expected, the merozoite variable surface antigens, major surface antigen (MSA)-1 and MSA-2 showed antigenic diversity. However, B cell epitopes on rhoptries and infected erythrocytes were conserved among all isolates studied. In this study it was possible to identify variable and conserved antigens, which had already been described as potential immunogens. Considering that an attenuated Babesia clone used as immunogen selected populations capable of evading the immunity induced by this vaccine, it is necessary to evaluate more deeply the cross-protection conferred by genetically more distant Brazilian B. bigemina isolates and make an evaluation of the polymorphism degree of variable antigens such as MSA-1 and MSA-2.INDEX TERMS: Babesia bigemina, Brazilian isolates, genetic polymorphism, antigenic polymorphism.

Standardization of a molecular method for epidemiologic identification of Leishmania strains

“…Given the specificity of such techniques, the detection and genetic characterization of this disease can be achieved simultaneously (Hulton et al, 1991;Harris et al, 1996;da Silva et al, 2004). Madruga et al (2002) demonstrated the use of ERIC-PCR in the characterization of a protozoan parasite. The authors conducted a molecular epidemiological study to identify the genetic diversity present among Babesia bigemina protozoa isolated from five states in Brazil.…”

Estudo genotípico e fenotípico de estafilococos coagulase positiva potencialmente enterotoxigênicos isolados de linhas de produção de queijo minas frescal no estado de São Paulo

“…Pseudomonas (LOWS et al, 1994), Shigella (LIU et al, 1995), Listeria (JERSEK et al, 1996), Brucella (TCHERNEVA 1996), Babesia bigemina (MADRUGA et al, 2002), Bartonella (RODRIGUEZ-BARRADAS et al, 1995), S.aureus (MATTOS, 2005) e Leishmania (LEAL, 2010).…”