Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017536 (giardiasis)
 1,714 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are evidences that Giardia trophozoites contain and/or release proteolytic enzymes that may be implicated in pathogenesis of giardiasis. This report describes a preliminary characterization of the proteolytic activity in excretory/secretory (E/S) products of Giardia duodenalis trophozoites of an axenic Brazilian strain (BTU-11) and the reference strain Portland 1 (P1). The protease activity of E/S products in conditioned medium by trophozoites of each strain was analyzed using substrate (gelatin and collagen) impregnated SDS-PAGE and hemoglobin assay. The protease characterization was based on inhibition assays including synthetic inhibitors. Proteolytic products were detected in the conditioned medium by trophozoites of both assayed strains. In the gels containing copolymerized gelatin and collagen, E/S products promoted degradation of the substrates and the most evident proteolysis zones were distributed in the migration regions of 77 to 18 kDa and 145 to 18 kDa, respectively, in the patterns of gelatinolytic and collagenolytic activities. Degradation of hemoglobin was also observed, and the pattern of hydrolysis was similar in both E/S products assayed. Inhibition assays showed that the main proteolytic activity in both E/S products is due to cysteine proteases although the presence of serine proteases was also indicated, mainly in the hydrolysis of hemoglobin.
Parasitol Res 2008 Dec
PMID:Protease activity in extracellular products secreted in vitro by trophozoites of Giardia duodenalis. 1879 27

RIDA Quick immunochromatographic lateral-flow assay was evaluated for diagnosis of giardiasis and cryptosporidiosis as compared to the "gold standard" stool examination. Of the 300 specimens were examined by microscopy of direct wet films, concentrated sediments, modified trichrome and modified Ziehl-Neelsen stained slides, 35 samples of Giardia, ten Cryptosporidium, 35 of other parasites, and 20 negative controls were selected for RIDA Quick test examination. All the samples that gave discrepancy results were retested by the centrifugation prior to preparation for the permanent stained smear. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of RIDA quick test for Giardia were 91.6%, 98.4%, 97% & 95.4% respectively, while that of the microscopic stool examination were 94.5%, 100%, 100% & 96.9%. The sensitivity, specificity, PPV and NPV of RIDA quick test for Cryptosporidium was 91.6%, 100%, 100% & 98.8% respectively, while that of the microscopic stool examination were 83.3%, 100%, 100% & 97.7%.
J Egypt Soc Parasitol 2008 Dec
PMID:A single-step immunochromatographic lateral-flow assay for detection of Giardia lamblia and Cryptosporidium parvum antigens in human fecal samples. 1920 62

Giardia is frequently detected in stools of non-human primates (NHP). However, a molecular identification has been rarely applied to Giardia isolates from NHP, and the distribution of the zoonotic assemblages A and B remains unclear. Moreover, little is known about the genetic variability among the isolates, although this may contribute to the elucidation of the different transmission pathways, including the role of NHP as a reservoir for human giardiasis. Therefore, 258 Giardia samples from 31 NHP species housed in nine zoological gardens and one sanctuary in Belgium and The Netherlands were characterised based on an assemblage-specific PCR targeting the triose phosphate isomerase (tpi) gene to identify both assemblage A and B infections. In addition, a multi-locus sequencing approach based on the glutamate dehydrogenase, the tpi and the beta-giardin genes was used to examine both the genetic variability and the ability to allocate these isolates to different NHP groups. Overall, assemblage B was the most prevalent (78.6%), but mixed assemblage A and B infections occurred in 32.7% of the samples. Sequencing of the isolates revealed the presence of new polymorphisms for both assemblages and at the three loci examined. The majority of the assemblage B isolates could not be grouped into recently described sub-assemblages, particularly at the tpi gene. Isolates could only be allocated to a specific group when polymorphisms of the three loci were combined. The results confirm that NHP are a potential reservoir for zoonotic transmission and advocate the use of assemblage-specific primers in molecular epidemiological surveys, as mixed infections are likely to be underestimated. The high level of heterogeneity within assemblages indicates that a revised nomenclature of these sub-assemblages is needed, but points out the potency of a multi-locus sequencing approach to unravel the complex epidemiology of Giardia duodenalis.
Int J Parasitol 2009 Dec
PMID:Molecular characterisation of Giardiaduodenalis in captive non-human primates reveals mixed assemblage A and B infections and novel polymorphisms. 1952 72

Data from the first sentinel site (Waterloo Region, Ontario) of the Canadian Integrated Enteric Disease Surveillance System (C-EnterNet) were used in a secondary-based case-control study of laboratory-confirmed Cryptosporidium infections to study the role of various exposure factors. The incidence of cryptosporidiosis in Waterloo Region was almost double both the provincial and national rates. Persons ill with one of nine other enteric infections (amoebiasis, campylobacteriosis, cyclosporiasis, giardiasis, listeriosis, salmonellosis, shigellosis, verotoxigenic E. coli infections, yersiniosis) captured by the surveillance system were used as the control group. Of 1204 cases of enteric illness in the sentinel area between April 2005 and December 2007, 36 cases and 803 controls were selected after excluding outbreak and international travel-related cases. Univariable analyses (Pearson chi2 and Fisher's exact tests) and multivariable logistic regression were performed. Results of the multivariable analysis found that cryptosporidiosis was associated with swimming in a lake or river (OR 2.9, 95% CI 1.2-7.4), drinking municipal water (a potential surrogate for urban respondents vs. rural) (OR 2.4, 95% CI 1.04-5.7), and having a family member with a diarrhoeal illness (OR 2.9, 95% CI 1.3-6.4).
Epidemiol Infect 2009 Dec
PMID:A modified case-control study of cryptosporidiosis (using non-Cryptosporidium-infected enteric cases as controls) in a community setting. 1952 50

We investigated whether risk of sporadic enteric disease differs by drinking water source and type using surveillance data and a geographic information system. We performed a cross-sectional analysis, at the individual level, that compared reported cases of enteric disease with drinking water source (surface or ground water) and type (municipal or private). We mapped 814 cases of campylobacteriosis, cryptosporidiosis, giardiasis, salmonellosis and verotoxigenic Escherichia coli infection, in a region of British Columbia, Canada, from 1996 to 2005, and determined the water source and type for each case's residence. Over the 10-year period, the risk of disease was 5.2 times higher for individuals living on land parcels serviced by private wells and 2.3 times higher for individuals living on land parcels serviced by the municipal surface/ground water mixed system, than the municipal ground water system. Rates of sporadic enteric disease potentially differ by drinking water source and type. Geographic information system technology and surveillance data are accessible to local public health authorities and used together are an efficient and affordable way to assess the role of drinking water in sporadic enteric disease.
J Water Health 2009 Dec
PMID:Where's the pump? Associating sporadic enteric disease with drinking water using a geographic information system, in British Columbia, Canada, 1996-2005. 1959 Jan 37

Secretory immunoglobulin A (S-IgA) antibodies have a central role in anti-Giardial defence. It has been demonstrated that transforming growth factor-beta1 (TGF-beta1) stimulates B lymphocytes to produce and secrete S-IgA. We sought to determine the association between TGF-beta1 polymorphism (T+869C) with susceptibility to Giardiasis. The TGF-beta1 genotypes and levels of salivary (S-IgA) were analysed in individuals with Giardiasis (97 symptomatic and 57 asymptomatic) and controls (n = 92). Individuals with symptomatic Giardiasis had the lowest levels of S-IgA compared to individuals in asymptomatic Giardiasis and control groups (97%, 73% and 43%, <1 g L(-1), respectively, P = 0.002). The frequency of allele C and CC genotypes of TGF-beta1 polymorphism was significantly higher among symptomatic patients than asymptomatic and control groups. Logistic regression analysis demonstrated that the individuals homozygous for allele C of TGF-beta1 had a significantly higher risk for symptomatic Giardiasis with odds ratio of 2.76 (95% CI: 3.88, 1.71, P = 0.007). Among the participants with TT genotype per cent of individuals with S-IgA level of more than 1 g L(-1) was almost twice the percentage in CC genotype individuals (14% versus 7% respectively P = 0.01). Our data suggest that CC genotype of TGF-beta1 polymorphism at codon 10 is associated with occurrence of Giardiasis.
Int J Immunogenet 2009 Dec
PMID:Gene polymorphism in transforming growth factor-beta codon 10 is associated with susceptibility to Giardiasis. 1970 31

Giardia duodenalis is a waterborne protozoan parasite that causes the diarrhoeal disease, giardiasis. Its durable and thick cell wall allows the parasite to exhibit resistance to environmental stresses. Because G. duodenalis exists in a water system at low levels, it is necessary to develop a sensitive method to detect its viability in aquatic environments. In the present study, specific primers for the heat shock protein (hsp) 70 gene were designed on the basis of G. duodenalis genome sequence and bioinformatic analysis. Viable G. duodenalis cysts were successfully distinguished by reverse transcription-PCR (RT-PCR) analysis using these primers. The amplicon of hsp70 was obtained from one cyst of G. duodenalis/100 microl, and this detection sensitivity significantly increased by 10(3)-fold when the cysts were given heat shock treatment. These findings prove that viable G. duodenalis cysts were successfully detected with a high degree of sensitivity by RT-PCR analysis targeting the hsp70 gene of G. duodenalis, thereby suggesting its practical potential for detecting viable G. duodenalis in environmental samples.
Exp Parasitol 2009 Dec
PMID:Giardia duodenalis: improved detection of viable cysts by reverse transcription-PCR of heat shock-inducible hsp70 gene. 1970 45

Giardia duodenalis, originally regarded as a commensal organism, is the etiologic agent of giardiasis, a gastrointestinal disease of humans and animals. Giardiasis causes major public and veterinary health concerns worldwide. Transmission is either direct, through the faecal-oral route, or indirect, through ingestion of contaminated water or food. Genetic characterization of G. duodenalis isolates has revealed the existence of seven groups (assemblages A to G) which differ in their host distribution. Assemblages A and B are found in humans and in many other mammals, but the role of animals in the epidemiology of human infection is still unclear, despite the fact that the zoonotic potential of Giardia was recognised by the WHO some 30 years ago. Here, we performed an extensive genetic characterization of 978 human and 1440 animal isolates, which together comprise 3886 sequences from 4 genetic loci. The data were assembled into a molecular epidemiological database developed by a European network of public and veterinary health Institutions. Genotyping was performed at different levels of resolution (single and multiple loci on the same dataset). The zoonotic potential of both assemblages A and B is evident when studied at the level of assemblages, sub-assemblages, and even at each single locus. However, when genotypes are defined using a multi-locus sequence typing scheme, only 2 multi-locus genotypes (MLG) of assemblage A and none of assemblage B appear to have a zoonotic potential. Surprisingly, mixtures of genotypes in individual isolates were repeatedly observed. Possible explanations are the uptake of genetically different Giardia cysts by a host, or subsequent infection of an already infected host, likely without overt symptoms, with a different Giardia species, which may cause disease. Other explanations for mixed genotypes, particularly for assemblage B, are substantial allelic sequence heterogeneity and/or genetic recombination. Although the zoonotic potential of G. duodenalis is evident, evidence on the contribution and frequency is (still) lacking. This newly developed molecular database has the potential to tackle intricate epidemiological questions concerning protozoan diseases.
PLoS Negl Trop Dis 2009 Dec 01
PMID:Identification of zoonotic genotypes of Giardia duodenalis. 1995 62

Molecular characterization of Giardia duodenalis cysts from humans and animals living in well-defined contexts is useful to study the circulation of isolates and represents a tool to evaluate zoonotic infection risk. The presence of giardiasis in children living in a disadvantaged and socially deprived small Rom community, as well in dogs roaming freely in the same context was carried out by microscopic analysis and beta-giardin gene amplification. Five out of 14 children were found positive at microscopic examination for G. duodenalis and six positive at PCR, while eight out of 14 dogs tested both microscopically and molecularly positive for G. duodenalis. Moreover, most of the children and dogs were symptomatic. Molecular characterization of Giardia positive samples from children and dogs showed 99.5% identity with Giardia Assemblage A1. The dog-specific genotypes C and D were not found. The findings of this survey provide the first European evidence to support the possible role of dogs in zoonotic transmission involving children and stray dogs in a closed context with very low standards of hygiene (i.e. Rom community), and these results show the need to monitor the health of marginal populations to safeguard ethnic minority groups.
Zoonoses Public Health 2010 Dec
PMID:Genotyping of Giardia duodenalis among children and dogs in a closed socially deprived community from Italy. 2004 65

Cholesterol and bile salts are relevant modulators of Giardia encystation. Although several molecules within signaling cascades have been identified, and changes in their expression observed during giardial encystation, their underlying interactions leading to expression of cyst wall markers (CWPs and precursors of the GalNAc homopolymer) are not well defined. Recent experimental data and the completion of the Giardia Genome Project Database (GiardiaDB) allow us now to consider the role of bile salts as "natural stimuli" and the potential involvement of a Raf/MEK/ERK pathway mediating cholesterol-regulated expression of cyst-specific genes. These new findings may provide promising targets for diagnostics, drug design and prophylactic intervention against giardiasis.
Parasite 2009 Dec
PMID:Encystation commitment in Giardia duodenalis: a long and winding road. 2009 56


<< Previous 1 2 3 4 5 6 7 8 9 10