Phylogenetic Analysis of MexicanBabesia bovisIsolates UsingmsaandssrRNAGene Sequences

Abstract

Variable merozoite surface antigens of Babesia bovis are exposed glycoproteins having a role in erythrocyte invasion. Members of this gene family include msa-1 and msa-2 (msa-2c, msa-2a(1), msa-2a(2), and msa-2b). Small subunit ribosomal (ssr)RNA gene is subject to evolutive pressure and has been used in phylogenetic studies. To determine the phylogenetic relationship among B. bovis Mexican isolates using different genetic markers, PCR amplicons, corresponding to msa-1, msa-2c, msa-2b, and ssrRNA genes, were cloned and plasmids carrying the corresponding inserts were sequenced. Comparative analysis of nucleotide and deduced amino acid sequences revealed distinct degrees of variability and identity among the coding gene sequences obtained from 12 geographically different B. bovis isolates and a reference strain. Overall sequence identities of 47.7%, 72.3%, 87.7%, and 94% were determined for msa-1, msa-2b, msa-2c, and ssrRNA, respectively. A robust phylogenetic tree was obtained with msa-2b sequences. The phylogenetic analysis suggests that Mexican B. bovis isolates group in clades not concordant with the Mexican geography. However, the Mexican isolates group together in an American clade separated from the Australian clade. Sequence heterogeneity in msa-1, msa-2b, and msa-2c coding regions of Mexican B. bovis isolates present in different geographical regions can be a result of either differential evolutive pressure or cattle movement from commercial trade.

Genotypic diversity of merozoite surface antigen 1 of Babesia bovis within an endemic population

“…Further, with the exception of the isolates designated Veracruz 2/Guerrero (EF640951/EF640947) and Tamaulipas 2 (EF640949), whose sequences are more divergent and belong to the cluster group 2, all genotypes previously identified in Mexico belong to cluster group 1 identified in this study. A recent study by Genis et al using MSA2a and 2b (other members of the VMSA family) also demonstrated that B. bovis isolates in Mexico group into “clades” with no geographical association of genotypes [9]. The high sequence identity, with only a few amino acid substitutions between members of the cluster groups in our study and those reported previously throughout Mexico could be accounted for in several ways.…”

Genetic variations in merozoite surface antigen genes of Babesia bovis detected in Vietnamese cattle and water buffaloes

“…The involvement of genetic diversity in the immune evasion of B. bovis is well documented in the literature (Berens et al, 2005;Leroith et al, 2005). Consequently, the genetic diversity among the MSA genes has been studied in several endemic countries (Altangeral et al, 2012;Berens et al, 2005;Borgonio et al, 2008;Genis et al, 2008Genis et al, , 2009Leroith et al, 2005;Molad et al, 2014;Nagano et al, 2013;Sivakumar et al, 2013b;Tattiyapong et al, 2014). Almost all these studies invariably focused on the genetic diversity of the MSA genes of B. bovis derived from cattle, whereas B. bovis in buffaloes has rarely been investigated, although this host species is considered to play a significant role in its epidemiology (da Silva et al, 2013;Elsify et al, 2015;He et al, 2012;Sivakumar et al, 2013a).…”

“…Studies conducted in Australia (Berens et al, 2005;Leroith et al, 2005), Sri Lanka (Sivakumar et al, 2013b), the Philippines (Tattiyapong et al, 2014), Thailand (Simking et al, 2013), Israel (Molad et al, 2014), Brazil (Nagano et al, 2013), and Mexico Genis et al, 2008Genis et al, , 2009) have found that B. bovis isolates in these countries are genetically diverse, according to their MSA gene sequences.…”

“…Against this background, the genetic diversities of MSAs (MSA-1, MSA-2b, and MSA-2c) have been analyzed in several B. bovis-endemic countries in the recent past (Altangeral et al, 2012;Genis et al, 2008Genis et al, , 2009Sivakumar et al, 2013b). Studies conducted in Australia (Berens et al, 2005;Leroith et al, 2005), Sri Lanka (Sivakumar et al, 2013b), the Philippines (Tattiyapong et al, 2014), Thailand (Simking et al, 2013), Israel (Molad et al, 2014), Brazil (Nagano et al, 2013), and Mexico Genis et al, 2008Genis et al, , 2009) have found that B. bovis isolates in these countries are genetically diverse, according to their MSA gene sequences.…”

Sığırlarda Babesia bovis ve Babesia bigemina'nın Real-Time PCR ile araştırılması ve izolatların moleküler karakterizasyonu

“…Her iki antijen de farklı Babesia suşları arasında yüksek immunojenik T ve B hücre epitoplarına sahip olup aşı çalışmalarında kullanıl-maktadır. B. bovis yüzey antijenlerinden msa-2c geni, diğer yüzey antijenlerine göre farklı suşlar arasında yüksek korunmuşluk özelliği ile ön plana çıkmaktadır (3,10,14,33). B. bigemina rap-1 proteinleri de benzer şekilde farklı coğrafyalardaki suşlar arasında yüksek düzeyde konservatif özellik gösteren antijenlerdir (25,32).…”