1. Typification of virulent and low virulence Babesia bigemina clones by 18S rRNA and rap-1c.
- Author
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Thompson C, Baravalle ME, Valentini B, Mangold A, Torioni de Echaide S, Ruybal P, Farber M, and Echaide I
- Subjects
- Animals, Argentina epidemiology, Babesia classification, Babesia genetics, Babesiosis epidemiology, Babesiosis parasitology, Base Sequence, Cattle, Cattle Diseases epidemiology, Cloning, Molecular, DNA, Protozoan chemistry, DNA, Protozoan isolation & purification, Erythrocytes parasitology, Genotype, Genotyping Techniques, Haplotypes, Male, Molecular Sequence Data, RNA, Ribosomal, 18S chemistry, Real-Time Polymerase Chain Reaction standards, Sequence Alignment, Virulence, Babesia pathogenicity, Babesiosis veterinary, Cattle Diseases parasitology, Protozoan Proteins genetics, RNA, Ribosomal, 18S genetics
- Abstract
The population structure of original Babesia bigemina isolates and reference strains with a defined phenotypic profile was assessed using 18S rRNA and rap-1c genes. Two reference strains, BbiS2P-c (virulent) and BbiS1A-c (low virulence), were biologically cloned in vitro. The virulence profile of the strains and clones was assessed in vivo. One fully virulent and one low-virulence clone were mixed in identical proportions to evaluate their growth efficiency in vitro. Each clone was differentiated by two microsatellites and the gene gp45. The 18S rRNA and rap-1c genes sequences from B. bigemina biological clones and their parental strains, multiplied exclusively in vivo or in vitro, were compared with strain JG-29. The virulence of clones derived from the BbiS2P-c strain was variable. Virulent clone Bbi9P1 grew more efficiently in vitro than did the low-virulence clone Bbi2A1. The haplotypes generated by the nucleotide polymorphism, localized in the V4 region of the 18S rRNA, allowed the identification of three genotypes. The rap-1c haplotypes allowed defining four genotypes. Parental and original strains were defined by multiple haplotypes identified in both genes. The rap-1c gene, analyzed by high-resolution melting (HRM), allowed discrimination between two genotypes according to their phenotype, and both were different from JG-29. B. bigemina biological clones made it possible to define the population structure of isolates and strains. The polymorphic regions of the 18S rRNA and rap-1c genes allowed the identification of different subpopulations within original B. bigemina isolates by the definition of several haplotypes and the differentiation of fully virulent from low virulence clones., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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