First multilocus sequence typing (MLST) of Giardia duodenalis isolates from humans in Romania

Abstract

Background: Giardia duodenalis is one of the most prevalent and highly diverse human parasites, encompassing a complex of eight genetically distinct assemblages, each further divided into sub-assemblages. While in recent years, G. duodenalis genotype distribution patterns in humans have been intensely studied, there is still very little information available on the diversity of Giardia genotypes and sub-assemblages infecting people in Romania. In the present study, we investigated the genetic diversity of Giardia duodenalis in asymptomatic patients from Romania. Methods: Over an 11-month period, human feces from 7805 healthy adults were screened by microscopic analysis for G. duodenalis cysts during their obligatory periodic check-ups. DNA extraction was performed from microscopic-positive fecal samples, followed by multilocus sequence typing of four genetic loci of the ITS region, gdh, tpi and bg genes, followed by DNA sequencing and phylogenetic analysis. Statistical analysis was performed using EpiInfo 2000 software. Results: The prevalence of giardiasis in the present study was 0.42% (33/7805). Twenty-three samples (76.67%) were successfully genotyped at each locus. The bg and tpi genes had the highest typing success rate (100%). The identified assemblages were assemblage A in 27 cases (subtypes A2 and A3), and B in 3 cases. Conclusions: To our knowledge, the present study is the first report of multilocus sequence typing of G. duodenalis isolated from humans in Romania. The present results may shed light on G. duodenalis infection in humans at a regional and national level, thus increasing awareness against this parasitic infection. [Figure not available: see fulltext.]