Anaplasma marginale: analysis of variable fragment sequences in msp1 alpha and msp4 genes in four new Mexican strains.

摘要

Bovine anaplasmosis due to Anaplasma marginale is responsible for substantial economic losses in livestock production of developing countries. Vaccine development is hampered by wide genetic and antigenic diversity in strains of distant geographical areas. The objective of this study was to compare the sequences of 4 untypeable Mexican A. marginale strains with respect to the msp1 alpha and msp4 genes. Sequences of MSP-1a and MSP4 and major surface complex proteins were used already for phylogenetic studies. Through specific initiators, for variable areas of both the msp1 alpha and msp4 genes, DNAs of the Pte. de Ixtla, Aguascalientes, Pichucalco and Sta. Martha strains were amplified. Analyses of nucleotide sequences and amino acids for msp1 alpha showed a strong similarity between the Pichucalco and Sta. Martha strains, both from Chiapas, same as against the isolates Mexico, Morelos and Veracruz. Isolates Pte. de Ixtla and Aguascalientes were different from previously identified Mexican strains and those from other countries. For msp4, no variation was reported for Mexican strains previously reported, which contained 849 pb and coincided with different isolates worldwide. Studies comprising either regions or the whole country on the conservation rank of these proteins could open possibilities for vaccines based on these antigens, and its efficacy could be predicted.