Hidden Diversity within Common Protozoan Parasites Revealed by a Novel Genomotyping Scheme.

Hidden Diversity within Common Protozoan Parasites Revealed by a Novel Genomotyping Scheme. Appl Environ Microbiol. 2021 Jan 04;: Authors: Seabolt MH, Konstantinidis KT, Roellig DM Abstract Giardia duodenalis (syn. G. lamblia, G. intestinalis) is the causative agent of giardiasis, one of the most common diarrheal infections in humans. Evolutionary relationships among G. duodenalis genotypes (or subtypes) of assemblage B, one of two genetic assemblages causing the majority of human infections, remain unclear due to poor phylogenetic resolution of current typing methods. Here, we devised a methodology to identify new markers for a streamlined multi-locus sequence typing (MLST) scheme based on comparisons of all core genes against the phylogeny of whole-genome sequences (WGS). Our analysis identified three markers with comparable resolution to WGS data. Using newly designed PCR primers for our novel MLST loci, we typed an additional 68 strains of assemblage B. Analyses of these strains and previously determined genome sequences showed that genomes of this assemblage can be assigned to 16 clonal complexes, each with unique gene content that is apparently tuned to differential virulence and ecology. Obtaining new genomes of Giardia spp. and other eukaryotic microbial pathogens remains challenging due to difficulties in culturing the parasites in the laboratory. Hence, the methods described here are expected to be widely applicable to othe...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research