Giardia duodenalis (syn. G. intestinalis, G. lamblia) is a widespread gastrointestinal protozoan parasite with debated taxonomic status. Currently, eight distinct genetic sub-groups, termed assemblages A-H, are defined based on a few genetic markers. Assemblages A and B may represent distinct species and are both of human public health relevance. Genomic studies are scarce and the few reference genomes available, in particular for assemblage B, are insufficient for adequate comparative genomics. Here, by combining long- and short-read sequences generated by PacBio and Illumina sequencing technologies, we provide nine annotated genome sequences for reference from new clinical isolates (four assemblage A and five assemblage B parasite isolates). Isolates chosen represent the currently accepted classification of sub-assemblages AI, AII, BIII and BIV. Synteny over the whole genome was generally high, but we report chromosome-level translocations as a feature that distinguishes assemblage A from B parasites. Orthologue gene group analysis was used to define gene content differences between assemblage A and B and to contribute a gene-set-based operational definition of respective taxonomic units. Giardia is tetraploid, and high allelic sequence heterogeneity (ASH) for assemblage B vs. assemblage A has been observed so far. Noteworthy, here we report an extremely low ASH (0.002%) for one of the assemblage B isolates (a value even lower than the reference assemblage A isolate WB-C6). This challenges the view of low ASH being a notable feature that distinguishes assemblage A from B parasites, and low ASH allowed assembly of the most contiguous assemblage B genome currently available for reference. In conclusion, the description of nine highly contiguous genome assemblies of new isolates of G. duodenalis assemblage A and B adds to our understanding of the genomics and species population structure of this widespread zoonotic parasite.

• Klíčová slova
• Giardia duodenalis, allelic sequence heterozygosity, comparative genomics, protozoa,
• MeSH
• genomika MeSH
• Giardia lamblia * genetika   MeSH
• Giardia genetika   MeSH
• giardiáza * parazitologie   MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The flagellated parasite Giardia duodenalis is a major and global cause of diarrhoeal disease. Eight genetically very distinct groups, known as assemblages A to H, have been recognized in the G. duodenalis species complex, two of which (assemblages A and B) infect humans and other mammalian hosts. Informative typing schemes are essential to understand transmission pathways, characterize outbreaks and trace zoonotic transmission. In this study, we evaluated a published multi-locus sequence typing (MLST) scheme for G. duodenalis assemblage A, which is based on six polymorphic markers. METHODS: We genotyped 60 human-derived and 11 animal-derived G. duodenalis isolates collected in Europe and on other continents based on the published protocol. After retrieving previously published genotyping data and excluding isolates whose sequences showed allelic sequence heterozygosity, we analysed a dataset comprising 146 isolates. RESULTS: We identified novel variants at five of the six markers and identified 78 distinct MLST types in the overall dataset. Phylogenetic interpretation of typing data confirmed that sub-assemblage AII only comprises human-derived isolates, whereas sub-assemblage AI comprises all animal-derived isolates and a few human-derived isolates, suggesting limited zoonotic transmission. Within sub-assemblage AII, isolates from two outbreaks, which occurred in Sweden and Italy, respectively, had unique and distinct MLST types. Population genetic analysis showed a lack of clustering by geographical origin of the isolates. CONCLUSION: The MLST scheme evaluated provides sufficient discriminatory power for epidemiological studies of G. duodenalis assemblage A.

• Klíčová slova
• MLST, Molecular epidemiology, Outbreak, Source tracing, Zoonotic transmission,
• MeSH
• feces parazitologie   MeSH
• fylogeneze MeSH
• genotyp MeSH
• Giardia lamblia * MeSH
• giardiáza * parazitologie   MeSH
• lidé MeSH
• multilokusová sekvenční typizace MeSH
• savci genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Giardia duodenalis is one of the most common intestinal parasites of humans, with a worldwide distribution. Giardia duodenalis has been reported in both wild and captive populations of non-human primates, namely chimpanzees. In this study we investigated an entire troop of clinically healthy chimpanzees (n = 21) for the presence of G. duodenalis and its association with faecal microbiota profile. Faecal samples (n = 26) were collected from the chimpanzee exhibit from a zoo in Sydney, Australia. Diagnosis of G. duodenalis was made using a Rapid Antigen Test (RAT) as a point-of-care-test and compared to a reference standard real-time PCR test. Approximately half of the chimpanzee faecal samples tested positive for G. duodenalis by both RAT (13/26, 50%) and real-time PCR (14/26, 53.85%). The RAT sensitivity was 85.7% (95% CI: 63.8%-96%) and specificity was 91.7% (95% CI: 68.3%-99%) when compared to the in-house real-time PCR. Genotyping of the samples revealed the presence of zoonotic assemblage B. Microscopic analysis revealed the presence of Troglodytella spp. (14/26), Balantioides sp. (syn. Balantidium sp.) (8/26) as well as Entamoeba spp. (3/26). Microbiota profile based on 16S rRNA gene sequencing revealed that the community was significantly different between G. duodenalis positive and negative samples if RAT results were taken into an account, but not real-time PCR diagnostics results. Proteobacteria and Chloroflexi were the significant features in the dataset that separated G. duodenalis positive and negative samples using LEfSe analysis. Being able to rapidly test for G. duodenalis in captive populations of primates assists in point-of-care diagnostics and may better identify animals with subclinical disease. Under the investigated conditions of the zoo setting, however, presence of G. duodenalis either detected by RAT or real-time PCR was not associated with clinically apparent disease in captive chimpanzees.

• Klíčová slova
• Commensal, Diagnostics, Giardiasis, Microbiome, Parasite, Zoo animals, Zoonosis,
• Publikační typ
• časopisecké články MeSH

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.

• Klíčová slova
• Cryptosporidium, Giardia, PCR, Uganda, anthropogenic disturbance, coproantigen, domestic animals, humans, microsporidia, non-human primates,
• Publikační typ
• časopisecké články MeSH

Emerging infectious diseases are frequently zoonotic, often originating in wildlife, but enteric protozoa are considered relatively minor contributors. Opinions regarding whether pathogenic enteric protozoa may be transmitted between wildlife and humans have been shaped by our investigation tools, and have led to oscillations regarding whether particular species are zoonotic or have host-adapted life cycles. When the only approach for identifying enteric protozoa was morphology, it was assumed that many enteric protozoa colonized multiple hosts and were probably zoonotic. When molecular tools revealed genetic differences in morphologically identical species colonizing humans and other animals, host specificity seemed more likely. Parasites from animals found to be genetically identical - at the few genes investigated - to morphologically indistinguishable parasites from human hosts, were described as having zoonotic potential. More discriminatory molecular tools have now sub-divided some protozoa again. Meanwhile, some infection events indicate that, circumstances permitting, some "host-specific" protozoa, can actually infect various hosts. These repeated changes in our understanding are linked intrinsically to the investigative tools available. Here we review how molecular tools have assisted, or sometimes confused, our understanding of the public health threat from nine enteric protozoa and example wildlife hosts (Balantoides coli - wild boar; Blastocystis sp. - wild rodents; Cryptosporidium spp. - wild fish; Encephalitozoon spp. - wild birds; Entamoeba spp. - non-human primates; Enterocytozoon bieneusi - wild cervids; Giardia duodenalis - red foxes; Sarcocystis nesbitti - snakes; Toxoplasma gondii - bobcats). Molecular tools have provided evidence that some enteric protozoa in wildlife may infect humans, but due to limited discriminatory power, often only the zoonotic potential of the parasite is indicated. Molecular analyses, which should be as discriminatory as possible, are one, but not the only, component of the toolbox for investigating potential public health impacts from pathogenic enteric protozoa in wildlife.

• Klíčová slova
• Emerging infection, Host specificity, Protozoa, Transmission, Wildlife, Zoonosis,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The level of genetic variability of Giardia intestinalis clinical isolates is an intensively studied and discussed issue within the scientific community. Our collection of G. intestinalis human isolates includes six in vitro-cultured isolates from assemblage B, with extensive genetic variability. Such variability prevents the precise genotype characterisation by the multi-locus genotyping (MLG) method commonly used for assemblage A. It was speculated that the intra-assemblage variations represent a reciprocal genetic exchange or true mixed infection. Thus, we analysed gene sequences of the molecular clones of the assemblage B isolates, each representing a single DNA molecule (haplotype) to determine whether the polymorphisms are present within individual haplotypes. Our results, which are based on the analysis of three standard genetic markers (bg, gdh, tpi), point to haplotype diversity and show numerous single nucleotide polymorphisms (SNPs) mostly in codon wobble positions. We do not support the recombinatory origin of the detected haplotypes. The point mutations tolerated by mismatch repair are the possible cause for the detected sequence divergence. The precise sub-genotyping of assemblage B will require finding more conservative genes, as the existing ones are hypervariable in most isolates and prevent their molecular and epidemiological characterisation.

• Klíčová slova
• Assemblage B, Genetic variability, Giardia intestinalis, Haplotypes, Molecular cloning,
• MeSH
• feces parazitologie   MeSH
• fylogeneze MeSH
• genotyp MeSH
• Giardia lamblia klasifikace   genetika   izolace a purifikace   MeSH
• giardiáza parazitologie   MeSH
• haplotypy MeSH
• jednonukleotidový polymorfismus MeSH
• lidé MeSH
• protozoální DNA genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protozoální DNA MeSH

IntroductionThis paper reviews the current knowledge and understanding of Cryptosporidium spp. and Giardia spp. in humans, animals and the environment in 10 countries in the eastern part of Europe: Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, Hungary, Latvia, Poland, Romania, Serbia and Slovenia. Methods: Published scientific papers and conference proceedings from the international and local literature, official national health service reports, national databases and doctoral theses in local languages were reviewed to provide an extensive overview on the epidemiology, diagnostics and research on these pathogens, as well as analyse knowledge gaps and areas for further research. Results:Cryptosporidium spp. and Giardia spp. were found to be common in eastern Europe, but the results from different countries are difficult to compare because of variations in reporting practices and detection methodologies used. Conclusion: Upgrading and making the diagnosis/detection procedures more uniform is recommended throughout the region. Public health authorities should actively work towards increasing reporting and standardising reporting practices as these prerequisites for the reported data to be valid and therefore necessary for appropriate control plans.

• Klíčová slova
• One Health, cryptosporidiosis, giardiasis, zoonosis,
• MeSH
• Cryptosporidium genetika   izolace a purifikace   MeSH
• feces parazitologie   MeSH
• Giardia genetika   izolace a purifikace   MeSH
• giardiáza epidemiologie   parazitologie   MeSH
• kryptosporidióza epidemiologie   parazitologie   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• nemoci přenášené potravou epidemiologie   parazitologie   MeSH
• prevalence MeSH
• veřejné zdravotnictví * MeSH
• životní prostředí MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Geografické názvy
• východní Evropa epidemiologie   MeSH

BACKGROUND: Infectious diseases pose one of the greatest threats to endangered species, and a risk of gastrointestinal parasite transmission from humans to wildlife has always been considered as a major concern of tourism. Increased anthropogenic impact on primate populations may result in general changes in communities of their parasites, and also in a direct exchange of parasites between humans and primates. AIMS: To evaluate the impact of close contact with humans on the occurrence of potentially zoonotic protists in great apes, we conducted a long-term monitoring of microsporidia, Cryptosporidium and Giardia infections in western lowland gorillas at different stages of the habituation process, humans, and other wildlife in Dzanga-Sangha Protected Areas in the Central African Republic. RESULTS: We detected Encephalitozoon cuniculi genotypes I and II (7.5%), Enterocytozoon bieneusi genotype D and three novel genotypes (gorilla 1-3) (4.0%), Giardia intestinalis subgroup A II (2.0%) and Cryptosporidium bovis (0.5%) in gorillas, whereas in humans we found only G. intestinalis subgroup A II (2.1%). In other wild and domestic animals we recorded E. cuniculi genotypes I and II (2.1%), G. intestinalis assemblage E (0.5%) and C. muris TS03 (0.5%). CONCLUSION: Due to the non-specificity of E. cuniculi genotypes we conclude that detection of the exact source of E. cuniculi infection is problematic. As Giardia intestinalis was recorded primarily in gorilla groups with closer human contact, we suggest that human-gorilla transmission has occurred. We call attention to a potentially negative impact of habituation on selected pathogens which might occur as a result of the more frequent presence of humans in the vicinity of both gorillas under habituation and habituated gorillas, rather than as a consequence of the close contact with humans, which might be a more traditional assumption. We encourage to observe the sections concerning hygiene from the IUCN best practice guidelines for all sites where increased human-gorilla contact occurs.

• MeSH
• časové faktory MeSH
• Cryptosporidium klasifikace   genetika   izolace a purifikace   MeSH
• Encephalitozoon cuniculi genetika   izolace a purifikace   MeSH
• Enterocytozoon klasifikace   genetika   izolace a purifikace   MeSH
• feces mikrobiologie   parazitologie   MeSH
• fylogeneze MeSH
• genotyp MeSH
• Giardia klasifikace   genetika   izolace a purifikace   MeSH
• giardiáza parazitologie   veterinární   MeSH
• Gorilla gorilla MeSH
• habituace (psychofyziologie) MeSH
• kryptosporidióza parazitologie   veterinární   MeSH
• lidé MeSH
• Microsporidia klasifikace   genetika   izolace a purifikace   MeSH
• mikrosporidióza mikrobiologie   veterinární   MeSH
• molekulární sekvence - údaje MeSH
• nemoci lidoopů mikrobiologie   parazitologie   MeSH
• sekvenční analýza DNA MeSH
• sociální prostředí MeSH
• zoonózy mikrobiologie   parazitologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Středoafrická republika MeSH