The first multilocus genotype analysis of Giardia intestinalis in humans in the Czech Republic

Abstract

To date, genotyping data on giardiasis have not been available in the Czech Republic. In this study, we characterized 47 human isolates of Giardia intestinalis from symptomatic as well as asymptomatic giardiasis cases. Genomic DNA from trophozoites was tested by PCR-sequence analysis at three loci (β-giardin, glutamate dehydrogenase and triose phosphate isomerase). Sequence analysis showed assemblages A and B in 41 (87.2%) and six (12.8%) isolates, respectively. Two of the 41 assemblage A samples were genotyped as sub-assemblage AI, and 39 were genotyped as sub-assemblage AII. Four previously identified multilocus genotypes (MLGs: AI-1, AII-1, AII-4 and AII-9) and six likely novel variations of MLGs were found. In agreement with previous studies, sequences from assemblage B isolates were characterized by a large genetic variability and by the presence of heterogeneous positions, which prevent the definition of MLGs. This study also investigated whether there was a relationship between the assemblage and clinical data (including drug resistance). However, due to the large number of genotypes and the relatively small number of samples, no significant associations with the clinical data were found.

Giardiasis in urban and rural Amazonas, Brazil is driven by zoonotic and cosmopolitan A and B assemblages

“…(25) According to the TPI genotyping, the AII sub-assemblage was the most prevalent, followed by AI. This scenario, in which AII(TPI) predominates, has also been shown in other studies in the Southeast Brazilian region, (21,29) and worldwide in Colombia, (23) Czech Republic, (24) France (25) and Malaysia. (28) Having recovered both genes (BG and TPI) from a number of samples, we were able to characterise homogeneous and heterogeneous genotypes.…”

“…(10,21,22,23) Likewise, the highest frequency of the AI (BG) sub-assemblage has also been identified in humans in Southeastern Brazil, (17,18) however, worldwide, the sub-assemblage AI(BG) is rare in humans. (24,25,26) The second sub-assemblage most frequent in this study AIII(BG) is also the most prevalent in the indigenous population of Brazilian Amazon. (9,10) In other Brazilian regions, AIII(BG) is a rare genotype, identified only in Paraná/ South Brazil (n = 1/10, BG).…”

The controversies surrounding Giardia intestinalis assemblages A and B

“…Assemblage A is predominantly detected in young cattle while assemblage E is more often found in older livestock. Interestingly, an Indian study was able to identify the zoonotic sub-assemblage AI in both calves and dairy farm workers ( Khan et al., 2011 ), despite humans being predominantly infected with sub-assemblage AII ( Faria et al., 2017 ; Lecová et al., 2018 ; Hernández et al, 2019 ). Moreover, there was a significant correlation ( P -value < 0.0001) between sub-assemblage AI and individuals who bred livestock observed in a Syrian study ( Skhal et al., 2017 ).…”

Treatment-refractory giardiasis: challenges and solutions

“…Several subgroups of assemblage AII and one assemblage BIII isolate were represented, and multidrug resistance was associated with one AII and one AI isolate. 40 Interestingly, in an outbreak setting of several assemblage B genotypes, 41 only one genotype remained and was present in all 17 refractory isolates examined in patients referred due to treatment failure. 42 This genotype likely possessed both virulence and MTZ tolerance traits that helped to establish a chronic MTZ-refractory infection that existed for several months in immunocompetent persons.…”