A novel high-resolution multilocus sequence typing of Giardia intestinalis Assemblage A isolates reveals zoonotic transmission, clonal outbreaks and recombination.

A novel high-resolution multilocus sequence typing of Giardia intestinalis Assemblage A isolates reveals zoonotic transmission, clonal outbreaks and recombination. Infect Genet Evol. 2018 Feb 10;: Authors: Ankarklev J, Lebbad M, Einarsson E, Franzén O, Ahola H, Troell K, Svärd SG Abstract Molecular epidemiology and genotyping studies of the parasitic protozoan Giardia intestinalis have proven difficult due to multiple factors, such as low discriminatory power in the commonly used genotyping loci, which has hampered molecular analyses of outbreak sources, zoonotic transmission and virulence types. Here we have focused on assemblage A Giardia and developed a high-resolution assemblage-specific multilocus sequence typing (MLST) method. Analyses of sequenced G. intestinalis assemblage A genomes from different sub-assemblages identified a set of six genetic loci with high genetic variability. DNA samples from both humans (n = 44) and animals (n = 18) that harbored Giardia assemblage A infections, were PCR amplified (557-700 bp products) and sequenced at the six novel genetic loci. Bioinformatic analyses showed five to ten-fold higher levels of polymorphic sites than what was previously found among assemblage A samples using the classic genotyping loci. Phylogenetically, a division of two major clusters in assemblage A became apparent, separating samples of human and animal origin. A subset of human samples (n = 9) from a d...
Source: Infection, Genetics and Evolution - Category: Genetics & Stem Cells Authors: Tags: Infect Genet Evol Source Type: research