Molecular Epidemiology of Giardia Infections in the Genomic Era

Capewell, Paul; Krumrie, Sarah; Katzer, Frank; Alexander, Claire L.; Weir, William

doi:10.1016/j.pt.2020.09.013

Cited by 38 publications

(37 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In recent years, an emphasis has been placed on the use of advanced technologies including whole genome sequencing (WGS), cytometry sorting-based single cell WGS and exome capture [ 14 ] for samples with few cysts or unavailable trophozoite cultures. These approaches have been used to identify and differentiate genotypes (subtypes or assemblages) of G. duodenalis , and explore assemblage-host relationships [ 9 ], infections caused by multiple assemblages in a single host [ 8 •, 9 – 12 , 14 ], transmission dynamics between humans and companion, domestic and wildlife animal species. Comparative genomics and proteomics have been used to define markers for parasite virulence and host susceptibility for Giardia assemblages [ 8 •, 9 , 11 ].…”

Section: Giardia Assemblages and Virulencementioning

confidence: 99%

Giardia duodenalis Virulence — “To Be, or Not To Be”

Argüello-García

Ortega-Pierres

2021

Curr Trop Med Rep

View full text Add to dashboard Cite

Purpose of review Here, we review recent progress made on the genetic characterization of Giardia duodenalis assemblages and their relationship with virulence. We also discuss the implications of virulence factors in the pathogenesis of giardiasis, and advances in the development of vaccines and drugs based on knowledge of virulence markers. Recent findings The use of transcriptomic and proteomic technologies as well as whole genome sequencing (WGS) from single cysts has allowed the assembly of the draft genome sequences for assemblages C and D of G. duodenalis . These findings, along with the published genomes for assemblages A, B, and E, have allowed comparative genomic investigations. In addition, the use of these methodologies for the characterization of the secretomes of trophozoite-epithelial cell interactions for assemblages A/B has led to the identification of virulence markers including energy metabolism enzymes, proteinases, high-cysteine membrane proteins (HCMPs), and variant surface proteins (VSPs). Recently, some drugs and vaccines, targeting virulence factors have been developed, offering possible alternatives to current treatment and prevention options against giardiasis. Summary Among the nine recognized species of Giardia , G. duodenalis stands out because of its broad spectrum of hosts and its socio-economic importance. This species comprises eight genetic assemblages (A to H), of which A and B are zoonotic, and the other assemblages have narrow host specificities. Assemblages A and B may be considered as the most virulent ones, but the existence of asymptomatic carriers and considerable genetic variability within and among these assemblages hampers the definition of common virulence factors. The attachment of Giardia trophozoites to epithelial cells and structural cytoskeleton components of the adhesive disk, such as giardins or tubulins, is proposed to play key roles, but toxins have not yet been precisely defined. However, recent transcriptomic and proteomic analyses of the secretomes of trophozoites representing assemblages A and B and interacting with particular epithelial cell lines have defined a series of virulence factors, including glycolytic (e.g., enolase) and arginolytic (e.g., arginine deiminase) enzymes, cysteine proteases (e.g., giardipain-1) and VSPs (e.g., VSP9B10A). Other factors, such as HCMPs and tenascins, have been consistently found to be excreted/secreted, but their role(s) in the pathogenesis of giardiasis has not yet been elucidated. Interestingly, recent investigations of single cysts representing assemblages C and D using advanced sequencing and informatic methods have suggested that the transcription/expression profiles of virulence factors vary both within and between assemblages, thus assemblage-specific molecules might allow adaptation to the microenviron...

show abstract

Section: Giardia Assemblages and Virulencementioning

confidence: 99%

Giardia duodenalis Virulence — “To Be, or Not To Be”

Argüello-García

Ortega-Pierres

2021

Curr Trop Med Rep

View full text Add to dashboard Cite

show abstract

“…(20) However, recombination events between assemblages should also be considered, as there are a number of clues suggesting Giardia sexual reproduction. (31) The same assemblages A and B also identified in four animals (two domestic cats and two NHP of the species A. paniscus and L. cana), according TPI. Interestingly, the highest abundance was AI (one NHP, A. paniscus, and two cats), the second most abundant sub-assemblage among humans in this study.…”

Section: Discussionmentioning

confidence: 72%

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

Reis

Silva

Braga

et al. 2021

Mem. Inst. Oswaldo Cruz

View full text Add to dashboard Cite

BACKGROUND Giardia duodenalis is a protozoan parasite that infects humans and other mammals and causes giardiasis worldwide. Giardia is genotyped into eight assemblages (A-H), with assemblages A and B considered zoonotic.OBJECTIVES The aim of this study was to determine the assemblages of G. duodenalis from individuals living in rural and urban areas of the Amazonas State.METHODS 103 human faecal specimens microscopically positive for the presence of Giardia obtained from four municipalities in Amazonas and four animal faecal specimens were genotyped based on the sequences of two genes, triosephosphate isomerase (TPI) and β-giardin (BG).FINDINGS In humans, assemblage A was the most represented with the identification of sub-assemblages AI, AII and AIII based on BG and sub-assemblages AI and AII based on TPI. Similarly, there is a diversity of sub-assemblage B considering BG (B and BIII) and TPI (B, BIII and BIV). In addition, we characterised homogeneous and heterogeneous genotypes comprising assemblages/sub-assemblages A and B in individuals from urban and rural areas. Here, for the first time, it was genotyped Giardia that infects animals from the Brazilian Amazon region. We identified sub-assemblage AI in one Ateles paniscus and two Felis catus and sub-assemblage BIV in one Lagothrix cana.MAIN CONCLUSIONS Therefore, humans and animals from the urban and rural Amazon share Giardia genotypes belonging to assemblages A and B, which are found in cosmopolitan regions around the world.

show abstract

“…Generally, samples with an infection intensity of less than 500 and 10 (oo)cysts of Cryptosporidium spp. mostly failed in immunochromatographic assays and PCR, respectively [ 64 , 65 , 66 ]. Therefore, concentrating (oo)cysts in the sample, which is not often used in parasitological studies of NHP due to the small amount of available fecal material, could increase the detection rate of the studied protists.…”

Section: Discussionmentioning

confidence: 99%

Sparse Evidence for Giardia intestinalis, Cryptosporidium spp. and Microsporidia Infections in Humans, Domesticated Animals and Wild Nonhuman Primates Sharing a Farm–Forest Mosaic Landscape in Western Uganda

et al. 2021

View full text Add to dashboard Cite

Zoonotic pathogen transmission is considered a leading threat to the survival of non-human primates and public health in shared landscapes. Giardia spp., Cryptosporidium spp. and Microsporidia are unicellular parasites spread by the fecal-oral route by environmentally resistant stages and can infect humans, livestock, and wildlife including non-human primates. Using immunoassay diagnostic kits and amplification/sequencing of the region of the triosephosphate isomerase, small ribosomal subunit rRNA and the internal transcribed spacer genes, we investigated Giardia, Cryptosporidium, and microsporidia infections, respectively, among humans, domesticated animals (livestock, poultry, and dogs), and wild nonhuman primates (eastern chimpanzees and black and white colobus monkeys) in Bulindi, Uganda, an area of remarkably high human–animal contact and spatial overlap. We analyzed 137 fecal samples and revealed the presence of G. intestinalis assemblage B in two human isolates, G. intestinalis assemblage E in one cow isolate, and Encephalitozoon cuniculi genotype II in two humans and one goat isolate. None of the chimpanzee and colobus monkey samples were positive for any of the screened parasites. Regular distribution of antiparasitic treatment in both humans and domestic animals in Bulindi could have reduced the occurrence of the screened parasites and decreased potential circulation of these pathogens among host species.

show abstract

Molecular Epidemiology of Giardia Infections in the Genomic Era

Cited by 38 publications

References 92 publications

Giardia duodenalis Virulence — “To Be, or Not To Be”

Giardia duodenalis Virulence — “To Be, or Not To Be”

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

Sparse Evidence for Giardia intestinalis, Cryptosporidium spp. and Microsporidia Infections in Humans, Domesticated Animals and Wild Nonhuman Primates Sharing a Farm–Forest Mosaic Landscape in Western Uganda

Contact Info

Product

Resources

About