Scientists map genomes of common gut parasite found across Colombia
Researchers sequenced the genetic code of six variants of Blastocystis, a parasite infecting millions worldwide, revealing surprising differences in genome size and structure. The work could help determine when this microorganism causes disease versus harmless colonization—critical for diagnostic and treatment decisions in regions where infection is widespread.
Originaltitel: Draft genomes of Blastocystis subtypes from human samples of Colombia
<p>Background Blastocystis is one of the most common eukaryotic microorganisms colonizing the intestines of both humans and animals, but the conditions under which it may be a pathogen are unclear.Methods To study the genomic characteristics of circulating subtypes (ST) in Colombia, we established nine xenic cultures from Blastocystis isolated from human fecal samples, we identified 10 different subtypes, since one sample had a mixed infection. Thus, the genomes of the subtypes ST1 (n = 3), ST2 (n = 1), ST3 (n = 2), ST6 (n = 1), ST7 (n = 1), and ST8 (n = 2) were sequenced using Illumina and Oxford Nanopore Technologies (ONT).Results Analyses of these draft nuclear genomes indicated remarkable diversity in terms of genome size and guanine-cytosine (GC) content among the compared STs. Illumina sequencing-only draft genomes contained 824 to 2077 scaffolds, with total genome size ranging from 12 to 13.2 Mb and N-50 values ranging from 10,585 to 29,404 base pairs (bp). The genome of one ST1 isolate was sequenced using ONT. This assembly was more contiguous, with a size of 20 million base pairs (Mb) spread over 116 scaffolds, and an N-50 of 248,997 bp.Conclusion This work represents one of the few large-scale comparative genomic analyses of Blastocystis isolates, providing an additional glimpse into its genomic diversity.</p>