Attachment to the intestinal epithelium is critical to the lifestyle of the ubiquitous parasite Giardia lamblia. The ventrolateral flange is a sheet-like membrane protrusion at the interface between parasites and attached surfaces. This structure has been implicated in attachment, but its role has been poorly defined. Here, we identified a novel actin associated protein with putative WH2-like actin binding domains we named Flangin. Flangin complexes with Giardia actin (GlActin) and is enriched in the ventrolateral flange making it a valuable marker for studying the flanges' role in Giardia biology. Live imaging revealed that the flange grows to around 1 μm in width after cytokinesis, then remains uniform in size during interphase, grows in mitosis, and is resorbed during cytokinesis. A flangin truncation mutant stabilizes the flange and blocks cytokinesis, indicating that flange disassembly is necessary for rapid myosin-independent cytokinesis in Giardia. Rho family GTPases are important regulators of membrane protrusions and GlRac, the sole Rho family GTPase in Giardia, was localized to the flange. Knockdown of Flangin, GlActin, and GlRac result in flange formation defects. This indicates a conserved role for GlRac and GlActin in forming membrane protrusions, despite the absence of canonical actin binding proteins that link Rho GTPase signaling to lamellipodia formation. Flangin-depleted parasites had reduced surface contact and when challenged with fluid shear force in flow chambers they had a reduced ability to remain attached, confirming a role for the flange in attachment. This secondary attachment mechanism complements the microtubule based adhesive ventral disc, a feature that may be particularly important during mitosis when the parental ventral disc disassembles in preparation for cytokinesis. This work supports the emerging view that Giardia's unconventional actin cytoskeleton has an important role in supporting parasite attachment.

• MeSH
• aktiny metabolismus   MeSH
• Giardia lamblia * genetika   metabolismus   MeSH
• Giardia metabolismus   MeSH
• giardiáza * parazitologie   MeSH
• paraziti * metabolismus   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• aktiny MeSH
• protozoální proteiny MeSH

Giardia infections were detected in 14 out of 32 weaned, 1 to 2-month-old pigs, used in experiments with coccidia. Giardia trophozoites were present in the small intestine from the duodenum to the ileum with maximum numbers in the cranial part of the upper jejunum. They were localized mainly on the surface of intestinal crypts. No histological changes accompanied the infection and the infected animals were asymptomatic. Giardia trophozoites obtained from the intestines of necropsied pigs were isolated in axenic culture in a bile-supplemented TYI-S-33 medium. Morphological features of the trophozoites revealed by both light and scanning electron microscopy proved that the organism belongs to the Giardia intestinalis group.

• MeSH
• feces parazitologie   MeSH
• Giardia klasifikace   izolace a purifikace   ultrastruktura   MeSH
• giardiáza parazitologie   veterinární   MeSH
• mikroskopie elektronová rastrovací MeSH
• nemoci prasat parazitologie   MeSH
• prasata MeSH
• tenké střevo parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Giardia intestinalis, a cosmopolitan gastrointestinal protist, is detected mainly in patients with clinical giardiasis in high-income countries. In contrast, there is very little information on the presence of Giardia in asymptomatic individuals. Therefore, the aim of this study was to determine the presence and prevalence of Giardia in gut-healthy volunteers in the Czech Republic and to perform a comparative evaluation of different diagnostic methods, since Giardia diagnostics is complicated. Our results confirmed that the qPCR method is the most sensitive method for detecting Giardia and revealed a prevalence of 7% (22/296) in asymptomatic individuals. In most cases, the colonization intensity ranged from 10-1-101. A conventional PCR protocol targeting the TPI gene was used to identify the assemblages. However, this protocol had limited sensitivity for Giardia amplification, effectively detecting colonization above an intensity of 104. In addition, Giardia was detected in 19% of the animals, which were closely associated with the study participants. However, due to methodological limitations, zoonotic transmission could not be clearly confirmed. Notably, contact with animals proved to be the only factor that had a significant impact on the incidence of Giardia in gut-healthy humans.

• Klíčová slova
• Giardia intestinalis; human volunteers, contact with animals, conventional-PCR, qPCR, quantification,
• MeSH
• feces MeSH
• genotyp MeSH
• Giardia lamblia * genetika   MeSH
• giardiáza * epidemiologie   diagnóza   MeSH
• lidé MeSH
• polymerázová řetězová reakce MeSH
• prevalence MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Compared was the detection of Giardia intestinalis in duodenal contents and in the stool. During endoscopic examination duodenal contents were recovered by means of a tube attached to the mucosa and by aspiration from the region of pars verticalis. In 102 persons, duodenal and stool examinations revealed four and five cases of Giardia infection, respectively. The results showed that both diagnostic methods are equivalent and demonstrated that parasitologic examinations of patients suffering from dyspeptic disorders are very useful.

• MeSH
• duodenum parazitologie   MeSH
• feces parazitologie   MeSH
• Giardia izolace a purifikace   MeSH
• giardiáza diagnóza   MeSH
• lidé MeSH
• parazitární nemoci střev diagnóza   MeSH
• střevní sekrety parazitologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

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

Here, we report a case of direct zoonotic transmission of giardiasis between a pet chinchilla and a human. Microscopic and molecular examinations of stool samples from a child and samples of chinchilla droppings revealed cysts/DNA of Giardia intestinalis. The transmission from the chinchilla to the child has been confirmed as coprophagous after the 1-year-old toddler ingested pet chinchilla droppings. Molecular analysis of the gdh gene from both hosts classified the G. intestinalis cysts into the assemblage B genetic group, which has been previously shown to be characteristic of both human and chinchilla giardiasis. Both Giardia sub-assemblages BIII and BIV were present in the chinchilla droppings, whereas only the sub-assemblage BIV was isolated from the child's stool sample. To the best of our knowledge, this is the first report of a true zoonotic transmission of giardiasis, supporting the zoonotic potential of assemblage B.

• Klíčová slova
• Assemblage B, Chinchilla, Giardia intestinalis, Zoonotic giardiasis,
• MeSH
• činčila * MeSH
• domácí zvířata * MeSH
• feces parazitologie   MeSH
• Giardia lamblia izolace a purifikace   MeSH
• giardiáza parazitologie   přenos   veterinární   MeSH
• kojenec MeSH
• koprofagie etiologie   MeSH
• lidé MeSH
• nemoci hlodavců parazitologie   přenos   MeSH
• zoonózy parazitologie   přenos   MeSH
• zvířata MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

We investigated giardiosis of dogs and cats with a view to cysts in fecal samples and antibodies in the blood serum. Cysts were found in 25 fecal samples (5.5%) out of 458. Cysts were excreted frequently in puppies and adolescent dogs. In 15 cases giardiosis was diagnosed together with canine distemper or parvovirosis as an opportunic infection. Indirect immunofluorescence was used for detection of specific antibodies. We tested sera of 588 dogs and specific antibodies were detected in 156 cases (36.5%) in titres 10-160. In basic dilution 1:10 antibodies were detected in 61% positive samples. Titres 20-160 were found in 39% of the positive sera. In cats cysts were found only in 1 fecal sample out of 135 due to the difficulties in obtaining fecal samples for repeated examinations. Specific antibodies were detected in 107 cats (56.9%) out of 188 at titres 10-320. In basic dilution 1-10 antibodies were detected only in 30% of the positive sera but on the other hand in 70% we detected higher titres, i.e. 20-320. We did not consider titre 10 as significantly positive in both dogs and cats because cross-parasitic infections frequently occur. The number of serological positive dogs and cats grew with their age because they acquired giardiosis in the course of their life mostly as asymptomatic infection. The detection of specific antibodies cannot be used for the diagnosis because their level in blood serum persists for months. We must tread every dog and cat excreting cysts in fecal samples to stop transmission to other animals and humans-zoonosis.

• MeSH
• feces parazitologie   MeSH
• Giardia lamblia imunologie   izolace a purifikace   MeSH
• giardiáza diagnóza   imunologie   parazitologie   veterinární   MeSH
• kočky MeSH
• nemoci koček diagnóza   imunologie   parazitologie   MeSH
• nemoci psů diagnóza   imunologie   parazitologie   MeSH
• protilátky protozoální analýza   MeSH
• psi MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• protilátky protozoální 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

Until now, few cases of coincidental giardiasis and pancreatic tumors have been described. Among these cases, three described giardiasis cases coincided with confirmed pancreatic cancer. We present another case of Giardia infection coexisting with pancreatic cancer in a 67-year-old man who suffered from stenosis of the distal ductus choledochus combined with a hypoechoic mass in the head of the pancreas. The diagnostic conclusion of suspicious adenocarcinoma was based on endoscopic ultrasound fine-needle aspiration (EUS-FNA) biopsy and confirmed by a partial duodenopancreatectomy. On bloody cytology smears prepared from the EUS-FNA specimen, trophozoites of Giardia intestinalis accompanying an inflammatory background and features that fulfilled the morphological criteria of malignancy were observed. In histological sections from the duodenopancreatectomy specimens, the parasites were observed attached to the epithelium, but individual Giardia parasites were also observed beneath the epithelial lining. According to conventional genotyping, the infecting Giardia belonged to sub-assemblage AII.

• Klíčová slova
• Adenocarcinoma, Cytology, EUS-FNA, Giardia, Pancreas, Sub-assemblage AII,
• MeSH
• asymptomatické infekce * MeSH
• duodenum cytologie   parazitologie   MeSH
• epitelové buňky parazitologie   MeSH
• Giardia lamblia genetika   izolace a purifikace   MeSH
• giardiáza komplikace   diagnóza   MeSH
• lidé MeSH
• nádory slinivky břišní komplikace   parazitologie   MeSH
• náhodný nález * MeSH
• senioři MeSH
• trofozoiti izolace a purifikace   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

Piper betle has been used as a medicinal plant in traditional medical systems throughout South and South East Asia. Experimental studies have revealed its wide and diverse biological and pharmacological effects. In this study, antigiardial activity of Piper betle was tested using experimental infections of Giardia intestinalis, the most common cause of protozoal diarrhoea worldwide, in Mongolian gerbils. Plants were extracted in water, methanol and methanol:tetrahydrofuran. Gerbils were treated for ten days intragastrically twice a day, with the dose of 40 mg of the extract per 100 g of body weight. Drug metronidazole was used as a negative control. Gerbils' faeces were taken every day and examined by flotation method, the number of shed cysts were counted using a haemocytometer. After gerbils' sacrifice and dissection, their duodena were then processed for examination using histological sectioning and scanning electron microscopy. The antigiardial activity was evaluated by the course of cyst shedding throughout the entire experiment. A significant decline in cyst shedding, evaluated by linear regression was found in gerbils treated with the aqueous extract. Our results indicate that the aqueous extract of P. betle shows giardicidal effects.

• Klíčová slova
• Antigiardial activity, Drug of choice, Giardia intestinalis, Natural antiparasitics, Parasites, Piper betle,
• MeSH
• antiprotozoální látky farmakologie   terapeutické užití   MeSH
• feces parazitologie   MeSH
• Gerbillinae MeSH
• Giardia lamblia účinky léků   ultrastruktura   MeSH
• giardiáza farmakoterapie   MeSH
• lineární modely MeSH
• listy rostlin chemie   MeSH
• lyofilizace MeSH
• metronidazol farmakologie   terapeutické užití   MeSH
• mikroskopie elektronová rastrovací MeSH
• Piper betle chemie   MeSH
• průjem farmakoterapie   parazitologie   MeSH
• rostlinné extrakty farmakologie   terapeutické užití   MeSH
• tenké střevo parazitologie   ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Indonésie MeSH
• Názvy látek
• antiprotozoální látky MeSH
• metronidazol MeSH
• rostlinné extrakty MeSH