| 2-oxoglutarate:nadp(+) oxidoreductase in azoarcus evansii: properties and function in electron transfer reactions in aromatic ring reduction. | the conversion of [(14)c]benzoyl-coenzyme a (coa) to nonaromatic products in the denitrifying beta-proteobacterium azoarcus evansii grown anaerobically on benzoate was investigated. with cell extracts and 2-oxoglutarate as the electron donor, benzoyl-coa reduction occurred at a rate of 10 to 15 nmol min(-1) mg(-1). 2-oxoglutarate could be replaced by dithionite (200% rate) and by nadph ( approximately 10% rate); in contrast nadh did not serve as an electron donor. anaerobic growth on aromatic co ... | 2003 | 14526024 |
| identification of genotypically mixed cryptosporidium parvum populations in humans and calves. | genotypic analyses of cryptosporidium parvum oocysts have divided the species into two genotypes, referred to as type 1 and type 2. although humans are susceptible to both types, mixed type 1/type 2 infections have rarely been identified. the paucity of mixed infections could be explained by the predominance of one type over the other in mixed infections, or by the poor sensitivity of restriction fragment length polymorphism (rflp) analyses for detecting subpopulations. using a type-specific rea ... | 2003 | 14550892 |
| study of 18s rrna and rdna stability by real-time rt-pcr in heat-inactivated cryptosporidium parvum oocysts. | the public health problem posed by cryptosporidium parvum has led the water supply industry to develop analytical tools for detecting viable oocysts in water. in this study, we report on a taqman real-time reverse transcription-polymerase chain reaction (rt-pcr) method that targets and quantifies c. parvum 18s rrna. to study the suitability of 18s rrna as an indicator of cryptosporidium oocyst viability, the stability of 18s rrna and rdna was monitored by real-time rt-pcr following various crypt ... | 2003 | 14553917 |
| characterization of a low molecular weight glycolipid antigen from cryptosporidium parvum. | cryptosporidium parvum, an apicomplexan parasite of the mammalian gut epithelium, causes a diarrheal illness in a wide range of hosts and is transmitted by contamination of food or water with oocyst-laden feces from an infected animal. we have identified a glycosylinositol phospholipid from the sporozoite stage of the parasite that is frequently recognized by serum antibodies from human cryptosporidiosis patients. the humoral immune response is dominated by igg1 subclass antibodies but can also ... | 2003 | 14557271 |
| synergistic inactivation of cryptosporidium parvum using ozone followed by free chlorine in natural water. | the synergistic effect of sequential exposure to ozone followed by free chlorine on inactivation of cryptosporidium parvum oocysts suspended in natural waters was studied in bench-scale batch reactors. animal infectivity using neonatal cd-1 mice was used to measure oocyst inactivation. the synergistic effect measured in two alkaline (ph 8.1) natural waters was statistically significant but was considerably smaller than previously reported in buffered de-ionized water at ph 6.0. temperature, ozon ... | 2003 | 14568061 |
| immobilized enzyme-linked dna-hybridization assay with electrochemical detection for cryptosporidium parvum hsp70 mrna. | an electrochemical enzyme-linked immobilized dna-hybridization assay for the detection of cryptosporidium parvum in water has been developed. the target molecule was a 121-nucleotide sequence from the c. parvum heat shock protein 70 (hsp70 mrna from u71181 gene). this analyte offers the possibility of distinguishing dead from live oocysts. the assay involves covalent attachment of a primary dna probe via its 5'-amine-terminus to self-assembled monolayers of mercaptoundecanoic acid to a gold surf ... | 2003 | 14572058 |
| cryptosporidium parvum and isospora belli infections among patients with and without diarrhoea. | to assess the importance of cryptosporidium parvum and isospora belli infections as a cause of diarrhoea among patients admitted to the medical wards in queen elizabeth central hospital (qech) in blantyre, malawi. | 2003 | 14601779 |
| new method using sedimentation and immunomagnetic separation for isolation and enumeration of cryptosporidium parvum oocysts and giardia lamblia cysts. | a new method for the isolation of cryptosporidium parvum oocysts and giardia lamblia cysts from biosolid samples has been developed that utilizes sedimentation and immunomagnetic separation. the method was used to recover stained cysts and oocysts (spike organisms) from primary settled sewage sludge, anaerobically digested sewage sludge, and bovine manure. recovery efficiencies associated with this method were approximately 40 to 60% and were significantly greater than those associated with simi ... | 2003 | 14602637 |
| molecular surveillance of cryptosporidium spp. in raw wastewater in milwaukee: implications for understanding outbreak occurrence and transmission dynamics. | six cryptosporidium spp. were found in 50 of 179 milwaukee wastewater samples collected weekly over a year. of the eight subtypes of cryptosporidium hominis and cryptosporidium parvum present, allele ib was found in 14 of 16 samples, and its sequence was identical to that of the subtype in human samples from the 1993 milwaukee outbreak of cryptosporidiosis. | 2003 | 14605176 |
| evaluation of an alternative ims dissociation procedure for use with method 1622: detection of cryptosporidium in water. | u.s. epa methods 1622 and 1623 are used to detect and quantify cryptosporidium oocysts in water. the protocol consists of filtration, immunomagnetic separation (ims), staining with a fluorescent antibody, and microscopic analysis. microscopic analysis includes detection by fluorescent antibody and confirmation by the demonstration of 1-4 sporozoites or nuclei after staining with 4',6-diamidino-2-phenyl indole dihydrochloride (dapi). the purpose of this study was to evaluate a new ims dissociatio ... | 2003 | 14607401 |
| detection of antibodies to a recombinant cryptosporidium parvum p23 in serum and feces from neonatal calves. | passive transfer of maternal antibodies via colostrum is important to protect newborn ruminants against microbial pathogens. in this study, 10 sets of calf serum, a sample of the colostrum fed to the calf, and serial fecal samples through the first 6 days after birth were collected from arbitrarily selected newborn holstein heifers. a recombinant cryptosporidium parvum p23, termed rc7, was used to determine whether anti-c. parvum antibodies can be detected in clinically normal neonates. the resu ... | 2003 | 14627138 |
| preliminary molecular characterization of cryptosporidium parvum isolates of wildlife rodents from poland. | isolates of cryptosporidium were collected from 3 species of woodland and field rodents (clethrionomys glareolus, microtus arvalis, and apodemus flavicollis) and were characterized by polymerase chain reaction amplification and sequencing of fragments of the oocyst wall protein (cowp) gene and of the 18s ribosomal rna gene. sequence analysis of these markers revealed that the animals were infected with c. parvum, and that the genotype involved was almost identical to the mouse genotype previousl ... | 2003 | 14627156 |
| [changes of cellular immunity in the patients infected by cryptosporidium parvum]. | | 2003 | 14628389 |
| comparison of selected diagnostic methods for identification of cryptosporidium parvum and cryptosporidium andersoni in routine examination of faeces. | this study involved the comparison of suitability of different methods for routine diagnostics of cryptosporidium spp. two staining methods, one concentration-sedimentation method, seven concentration-floatation methods and one combined floatation-sedimentation method were compared. the methods were tested with two concentrations (1 x 10(5) and 1 x 10(6)/g) of c. parvum and c. andersoni. the methods were evaluated using light microscope, magnification 400x for concentration methods and 1000x for ... | 2003 | 14633212 |
| epidemiologic and clinical characteristics of acute diarrhea with emphasis on entamoeba histolytica infections in preschool children in an urban slum of dhaka, bangladesh. | the epidemiology, clinical features, nutritional status, and causative agents of diarrhea were studied in 289 bangladeshi children (147 boys and 142 girls) 2-5 years old. the use of improved diagnostic tests for amebiasis enabled for the first time analysis of the contribution of entamoeba histolytica to total diarrheal illness in this community setting. the average incidence rate of diarrhea was 1.8/child-year, and the average number of diarrheal days was 3.7 days/child-year over an average obs ... | 2003 | 14640500 |
| anticryptosporidial activity of furan derivative g1 and its inclusion complex with beta-cyclodextrin. | the capacity of beta-cyclodextrin (betacd) to form a complex with a new furanic derivative, g1, was investigated. interactions of the drug and betacd in solution and in the solid state were studied using phase solubility techniques, thermal methods, x-ray, and ir spectroscopy. preparation of a kneaded mix of g1/betacd increased both the aqueous solubility and the dissolution rate of the furan derivative. the anticryptosporidial efficacies of the drug and of the inclusion complex were evaluated u ... | 2004 | 14648649 |
| identification of cryptosporidium parvum 'cattle' genotype from a severe outbreak of neonatal foal diarrhoea. | | 2003 | 14653344 |
| use of multiwavelength transmission spectroscopy for the characterization of cryptosporidium parvum oocysts: quantitative interpretation. | combined scattering and absorption properties of suspended particles can be obtained as a function of wavelength by measuring the complete ultraviolet-visible (uv-vis) spectrum. this research reports on the quantitative interpretation of measured uv-vis spectra of cryptosporidium parvum oocyst suspensions obtained from several commercial sources and evaluated using two different purification techniques. the reproducibility of the measured spectral data was assessed, and the quantitative interpre ... | 2003 | 14655715 |
| the wisconsin state laboratory of hygiene and emerging enteric pathogens. | at the turn of the 20th century, typhoid fever was common in wisconsin, and was a major impetus for the establishment of the wisconsin state laboratory of hygiene (wslh) in 1903. by the 1940s, typhoid was virtually eliminated in the united states due to public health measures such as disinfection of drinking water, sewage treatment, pasteurization, and shellfish bed sanitation. however, new food and waterborne pathogens have emerged to take the place of salmonella typhi. infections with non-typh ... | 2003 | 14658567 |
| a narf-like gene from cryptosporidium parvum resembles homologues observed in aerobic protists and higher eukaryotes. | here we report a narf-like gene from the apicomplexan cryptosporidium parvum (cpnarf). cpnarf is an intronless, single-copy gene of 1680 bp which encodes a putative protein of 560 amino acids with a calculated molecular mass of 63.1 kda. this gene contains a single highly conserved n-terminal iron-sulfur cluster ([4fe-4s]) binding site, as well as most of the h-cluster conserved residues. reverse transcription polymerase chain reaction analysis indicates that cpnarf is expressed by the intracell ... | 2003 | 14659547 |
| mitochondrial-type iron-sulfur cluster biosynthesis genes (iscs and iscu) in the apicomplexan cryptosporidium parvum. | several reports have indicated that the iron-sulfur cluster [fe-s] assembly machinery in most eukaryotes is confined to the mitochondria and chloroplasts. the best-characterized and most highly conserved [fe-s] assembly proteins are a pyridoxal-5'-phosphate-dependent cysteine desulfurase (iscs), and iscu, a protein functioning as a scaffold for the assembly of [fe-s] prior to their incorporation into apoproteins. in this work, genes encoding iscs and iscu homologues have been isolated and charac ... | 2003 | 14663084 |
| biological characterisation of cryptosporidium parvum isolates of wildlife rodents in poland. | the study was undertaken to characterise the c. parvum isolates originating from naturally infected woodland and field rodents: clethrionomys glareolus (cg), apodemus flavicollis (af) and microtus arvalis (ma). we found that the measurements of oocyst dimensions and oocyst morphology did not allow distinction between the parasite isolates from the 3 rodent species. the mean dimensions were: for cg 4.67 x 4.21, for af 4.65 x 4.14 and for ma 4.66 x 4.16. these 3 groups of isolates have produced si ... | 2003 | 14677907 |
| analysis of parasites by electrorotation. | the application of the ac electrokinetic technique of electrorotation for studying eukaryotic parasite transmission stages is reviewed. electrorotation is a noninvasive technique that utilizes electrically energized microelectrode structures within micro-fluidic chambers to probe the physiological structure of micro-organisms. application of the technique to the transmission life cycle stages of three separate genera of protozoan parasites, cryptosporidium, giardia and cyclospora, and one nemato ... | 2004 | 14678156 |
| cryptodb: the cryptosporidium genome resource. | cryptodb (http://cryptodb.org) represents a collaborative effort to locate all genome data for the apicomplexan parasite cryptosporidium parvum in a single user-friendly database. cryptodb currently houses the genomic sequence data for both the human type 1 h strain and the bovine type 2 iowa strain in addition to all other available est and gss sequences obtained from public repositories. all data are available for data mining via blast, keyword searches of pre-computed blastx results and user- ... | 2004 | 14681426 |
| evolution of cryptosporidium parvum lactate dehydrogenase from malate dehydrogenase by a very recent event of gene duplication. | we have expressed the l-lactate dehydrogenase (ldh) and l-malate dehydrogenase (maldh) genes from the apicomplexan cryptosporidium parvum (cpldh1 and cpmaldh1) as maltose-binding protein (mbp) fusion proteins in escherichia coli. the substrate specificities, enzymatic kinetics, and oligomeric states of these two parasite enzymes have been characterized. by taking advantage of recently completed and ongoing apicomplexan genome sequencing projects, we identified additional maldh genes from plasmod ... | 2004 | 14694073 |
| population genetics of cryptosporidium parvum. | | 2004 | 14700579 |
| direct evidence for cyanide-insensitive quinol oxidase (alternative oxidase) in apicomplexan parasite cryptosporidium parvum: phylogenetic and therapeutic implications. | cryptosporidium parvum is a parasitic protozoan that causes the diarrheal disease cryptosporidiosis, for which no satisfactory chemotherapy is currently available. although the presence of mitochondria in this parasite has been suggested, its respiratory system is poorly understood due to difficulties in performing biochemical analyses. in order to better understand the respiratory chain of c. parvum, we surveyed its genomic dna database in genbank and identified a partial sequence encoding cyan ... | 2004 | 14706648 |
| detection and counting of cryptosporidium parvum in hct-8 cells by flowcytometry. | the objective of the present study was to evaluate flowcytometry analysis (fca) as a tool for rapidly and objectively estimating the percentage of cells infected with cryptosporidium parvum in an in vitro model. we compared the results to those obtained with immunofluorescence assay (ifa) and evaluated the intra-assay variability of both assays and the inter-assay variability of ifa. human ileocecal adenocarcinoma cells (hct-8) were infected with different doses of excysted oocysts. after 24 hou ... | 2003 | 14710625 |
| a complete shikimate pathway in toxoplasma gondii: an ancient eukaryotic innovation. | the shikimate pathway is essential for survival of the apicomplexan parasites plasmodium falciparum, toxoplasma gondii and cryptosporidium parvum. as it is absent in mammals it is a promising therapeutic target. herein, we describe the genes encoding the shikimate pathway enzymes in t. gondii. the molecular arrangement and phylogeny of the proteins suggests homology with the eukaryotic fungal enzymes, including a pentafunctional arom. current rooting of the eukaryotic evolutionary tree infers th ... | 2004 | 14711585 |
| cryptosporidium parvum regulation of human epithelial cell gene expression. | cryptosporidium parvum is an obligate intracellular protozoan capable of causing life-threatening diarrhoeal disease in immunocompromised individuals. efforts to develop novel therapeutic strategies have been hampered by the lack of understanding of the pathogenesis of infection. to better understand the host response to c. parvum infection, gene expression profiles of infected human ileocecal adenocarcinoma cells were analysed by using affymetrix oligonucleotide microarrays containing probe set ... | 2004 | 14711592 |
| quantum dots as a novel immunofluorescent detection system for cryptosporidium parvum and giardia lamblia. | semiconductor quantum dot-conjugated antibodies were successfully developed to label cryptosporidium parvum and giardia lamblia. this novel fluorescence system exhibited superior photostability, gave 1.5- to 9-fold-higher signal-to-noise ratios than traditional organic dyes in detecting c. parvum, and allowed dual-color detection for c. parvum and g. lamblia. | 2004 | 14711692 |
| neonatal-mouse infectivity of intact cryptosporidium parvum oocysts isolated after optimized in vitro excystation. | we reexamined the finding of neumann et al. that intact cryptosporidium parvum oocysts obtained after in vitro excystation were infectious for neonatal cd-1 mice. we used both established excystation protocols and our own protocol that maximized excystation. although intact oocysts isolated after any of three protocols were infectious for neonatal cd-1 mice, the infectivity of intact oocysts isolated with our optimized excystation protocol was significantly lower than the infectivity of intact o ... | 2004 | 14711704 |
| determination of cryptosporidium parvum oocyst viability by fluorescence in situ hybridization using a ribosomal rna-directed probe. | fluorescence in situ hybridization (fish) has been proposed for species-specific detection, and viability determination of cryptosporidium parvum oocysts. fish-based viability determination depends on rrna decay after loss of viability. we examined the effects of rnase(s) and rnase inhibitors on fish of c. parvum. | 2004 | 14723702 |
| a novel cryptosporidium parvum antigen, cp2, preferentially associates with membranous structures. | the present study addresses the cloning and characterization of a cryptosporidium parvum antigen, cp2. sequencing of cdna and genomic clones revealed a novel gene capable of coding a message of 2,136 nucleotides flanked by 28 and 140 nucleotides of the 5'- and 3'-noncoding regions, respectively. the deduced amino acid sequence suggests that cp2 is a secreted and/or membrane protein. immunofluorescence microscopy detected cp2 enrichment in sporozoites that subsequently appeared to encase type i m ... | 2004 | 14727189 |
| comment on: effect of antiretroviral protease inhibitors alone, and in combination with paromomycin, on the excystation, invasion and in vitro development of cryptosporidium parvum. | | 2004 | 14729752 |
| microsatellite analysis of cryptosporidium hominis and c. parvum in portugal: a preliminary study. | | 2003 | 14736152 |
| characterization of a cryptosporidium parvum gene encoding a protein with homology to long chain fatty acid synthetase. | we describe here the cloning, sequencing, and characterization of a novel cryptosporidium parvum gene, encoding a protein with significant homology to the long-chain fatty acyl-coa synthetase (lcfa, ec 6.2.1.3). the gene has an open reading frame of 2,301 bp, coding for a 766 amino acid polypeptide, and with an estimated mw of 86.1 kda. by indirect immunofluorescence assay, monoclonal antibodies c3ce7 and e5d labeled the anterior pole of fixed c. parvum sporozoites and developmental stages in c. ... | 2003 | 14736154 |
| il-12 knockout c57bl/6 mice are protected from re-infection with cryptosporidium parvum after challenge. | | 2003 | 14736155 |
| efficacy of glycoconjugated dinitroanilines against cryptosporidium parvum. | | 2003 | 14736158 |
| loading of peptide on to mhc molecule is not essential for clearance of cryptosporidium parvum. | transgenic and knockout mice usefully model the mechanisms that result in the clearance of cryptosporidium parvum from the gut. cd4+ cells, cells expressing mhc class ii, and cd154/cd40 interactions are essential. unexpectedly, and rag-/- and do11.10 rag-/- mice with single specificities of t cells successfully clear cryptosporidium infection. clearance is accompanied by activation of cd4+ cells in the mln. the ability of t cells bearing receptors for apparently irrelevant and non-cross reactive ... | 2003 | 14736162 |
| lack of detectable shedding of cryptosporidium parvum oocysts by periparturient dairy cattle. | we examined whether periparturient dairy cattle shed cryptosporidium parvum oocysts within 12 hr of calving on 3 commercial dairy farms endemic for calfhood cryptosporidiosis. using a diagnostic method that can detect as few as 1 oocyst per gram of feces, we found no evidence of c. parvum oocysts in 86 fecal samples collected within 12 hr of calving from 43 dairy cows. | 2003 | 14740916 |
| the cryptosporidium oocyst wall protein is a member of a multigene family and has a homolog in toxoplasma. | coccidian parasites are transmitted via a fecal oocyst stage that is exceptionally resistant to environmental stress and harsh chemical treatments, which allows parasites to stably persist outside a host. because of its oocyst durability cryptosporidium parvum is a significant water- and food-borne pathogen of humans, as well as animals of agricultural importance. to date, only one apicomplexan oocyst membrane protein has been identified, cryptosporidium oocyst wall protein 1 (cowp1). cowp1 has ... | 2004 | 14742544 |
| expression and functional characterization of a giant type i fatty acid synthase (cpfas1) gene from cryptosporidium parvum. | a 25-kb cpfas1 gene from cryptosporidium parvum has been engineered and expressed as five individual maltose-binding protein (mbp)-fusion proteins: an n-terminal loading unit, three fatty acyl elongation modules, and a c-terminal reductase. enzymatic activities of all domains (except the reductase) were individually assayed as recombinant proteins. the preferred substrate for the fatty acyl ligase (al) domain in the loading unit was palmitic acid (c16:0). however, a competition assay suggests th ... | 2004 | 14747150 |
| a new modular protein of cryptosporidium parvum, with ricin b and lccl domains, expressed in the sporozoite invasive stage. | the recombinant sa35 peptide has been described as an antigenic portion of a larger cryptosporidium parvum protein. we identified and characterized the encoding cpa135 gene and the entire protein, cpa135. the cpa135 gene was found to consist of a single exon of 4671 bp, and the mrna transcribed in the sporozoites was identified. the predicted 1556 amino-acid protein showed the presence of domains which are widely conserved also in other unrelated phylogenetic groups (i.e. a ricin b and a lccl mo ... | 2004 | 14747151 |
| [acute diarrhea associated with cyclospora cayetanensis]. | acute diarrhea is a major problem with high morbidity and mortality rates in developing countries, especially in children. complex laboratory investigations are required to define the etiology because of the broad spectrum of etiological agents and the non-specific clinical signs. in the last decade, cyclospora cayetanensis--a new acid-fast coccidian species--was pointed to be the cause of watery self-limited or prolonged diarrhea in immunocompetent and immunocompromised patients, with very good ... | 2003 | 14756038 |
| genetic diversity of cryptosporidium spp. in captive reptiles. | the genetic diversity of cryptosporidium in reptiles was analyzed by pcr-restriction fragment length polymorphism and sequence analysis of the small subunit rrna gene. a total of 123 samples were analyzed, of which 48 snake samples, 24 lizard samples, and 3 tortoise samples were positive for cryptosporidium: nine different types of cryptosporidium were found, including cryptosporidium serpentis, cryptosporidium desert monitor genotype, cryptosporidium muris, cryptosporidium parvum bovine and mou ... | 2004 | 14766569 |
| biology, persistence and detection of cryptosporidium parvum and cryptosporidium hominis oocyst. | cryptosporidium parvum and cryptosporidium hominis are obligate enteric protozoan parasites which infect the gastrointestinal tract of animals and humans. the mechanism(s) by which these parasites cause gastrointestinal distress in their hosts is not well understood. the risk of waterborne transmission of cryptosporidium is a serious global issue in drinking water safety. oocysts from these organisms are extremely robust, prevalent in source water supplies and capable of surviving in the environ ... | 2004 | 14769405 |
| a universal nucleic acid sequence biosensor with nanomolar detection limits. | a quantitative universal biosensor was developed on the basis of olignucleotide sandwich hybridization for the rapid (30 min total assay time) and highly sensitive (1 nm) detection of specific nucleic acid sequences. the biosensor consists of a universal membrane and a universal dye-entrapping liposomal nanovesicle. two oligonucleotides, a reporter and a capture probe that can hybridize specifically with the target nucleic acid sequence, can be coupled to the universal biosensor components withi ... | 2004 | 14961717 |
| role of wheat germ agglutinin (wga) in treatment of experimental cryptosporidiosis. | the therapeutic effect of wheat germ agglutinin (wga) as a lectin molecule either alone or with nitazoxanide (ntz) was evaluated experimentally on cryptosporidial infection using immunosuppressed mice. a total of 100 suckling albino mice were immunosuppressed and infected with 106 purified cryptosporidium oocysts. the oocyst count in stool using modified ziehl neelsen technique on the days post infection (p.i), the histopathological examination of ileum sections and the ifn-y serum level were as ... | 2003 | 14964659 |
| epidemiologic profile of symptomatic gastroenteritis in pediatric oncology patients receiving chemotherapy. | patients with cancer who receive intensive chemotherapeutic regimens are subject to profound immunosuppression and are susceptible to an extended array of pathogens. | 2004 | 14966830 |
| resolution of cryptosporidiosis with probiotic treatment. | cryptosporidium infection is usually self limited, but can be a life threatening illness in immunocompromised patients. probiotics have been used successfully in the treatment of acute diarrhoea and they have also been shown to limit cryptosporidium parvum infection in animal models. the first case of successful resolution of prolonged cryptosporidiosis with probiotic treatment is reported. | 2004 | 14970303 |
| prevalence of infection with waterborne pathogens: a seroepidemiologic study in children 6-36 months old in san juan sacatepequez, guatemala. | water and sanitation interventions in developing countries have historically been difficult to evaluate. we conducted a seroepidemiologic study with the following goals: 1) to determine the feasibility of using antibody markers as indicators of waterborne pathogen infection in the evaluation of water and sanitation intervention projects; 2) to characterize the epidemiology of waterborne diarrheal infections in rural guatemala, and 3) to measure the age-specific prevalence of antibodies to waterb ... | 2004 | 14971703 |
| gene transfer in the evolution of parasite nucleotide biosynthesis. | nucleotide metabolic pathways provide numerous successful targets for antiparasitic chemotherapy, but the human pathogen cryptosporidium parvum thus far has proved extraordinarily refractory to classical treatments. given the importance of this protist as an opportunistic pathogen afflicting immunosuppressed individuals, effective treatments are urgently needed. the genome sequence of c. parvum is approaching completion, and we have used this resource to critically assess nucleotide biosynthesis ... | 2004 | 14973196 |
| cryptosporidium parvum-specific cd4 th1 cells from sensitized donors responding to both fractionated and recombinant antigenic proteins. | t-cell-mediated immunity plays a central role in the host response to cryptosporidium parvum. human t-cell clones (tcc) were isolated from peripheral blood mononuclear cells of five healthy donors with prior cryptosporidiosis by use of a c. parvum crude extract, two antigen fractions obtained by ion-exchange chromatography (iec1 and iec2), and two recombinant peptides (sa35 and sa40) from c. parvum sporozoites. the t-cell lines derived from the one recently infected donor had a higher proportion ... | 2004 | 14977932 |
| detection of cryptosporidium and giardia in molluscan shellfish by multiplexed nested-pcr. | a multiplexed nested-pcr procedure (abc-pcr) previously developed to detect cryptosporidium spp. and giardia duodenalis assemblages a and b in whole human faeces was applied to dna extracted from filter-feeding molluscs. species of cryptosporidium and g. duodenalis were identified by restriction fragment analysis of the pcr products and by dna sequencing. the extraction and abc-pcr procedures were shown to be suitable for application to shellfish by amplification of specific target sequences usi ... | 2004 | 14984775 |
| a first glimpse into the pattern and scale of gene transfer in apicomplexa. | reports of plant-like and bacterial-like genes for a number of parasitic organisms, most notably those within the apicomplexa and kinetoplastida, have appeared in the literature over the last few years. among the apicomplexan organisms, following discovery of the apicomplexan plastid (apicoplast), the discovery of plant-like genes was less surprising although the extent of transfer and the relationship of transferred genes to the apicoplast remained unclear. we used new genome sequence data to b ... | 2004 | 15003488 |
| evidence for mitochondrial-derived alternative oxidase in the apicomplexan parasite cryptosporidium parvum: a potential anti-microbial agent target. | the observation that plasmodium falciparum possesses cyanide insensitive respiration that can be inhibited by salicylhydroxamic acid (sham) and propyl gallate is consistent with the presence of an alternative oxidase (aox). however, the completion and annotation of the p. falciparum genome project did not identify any protein with convincing similarity to the previously described aoxs from plants, fungi or protozoa. we undertook a survey of the available apicomplexan genome projects in an attemp ... | 2004 | 15003491 |
| simultaneous detection of entamoeba histolytica, giardia lamblia, and cryptosporidium parvum in fecal samples by using multiplex real-time pcr. | entamoeba histolytica, giardia lamblia, and cryptosporidium are three of the most important diarrhea-causing parasitic protozoa. for many years, microscopic examination of stool samples has been considered to be the "gold standard" for diagnosis of e. histolytica, g. lamblia, and c. parvum infections. recently, more specific and sensitive alternative methods (pcr, enzyme-linked immunosorbent assay, and direct fluorescent-antibody assay) have been introduced for all three of these parasitic infec ... | 2004 | 15004079 |
| detection of cryptosporidium parvum in soil extracts. | epifluorescent microscopy and flow cytometry were used in different combinations with fluorescein isothiocyanate-labeled immunoglobulins m and g3 to estimate the numbers of cryptosporidium parvum oocysts in soil extracts containing 10 to 10,017 oocysts/ml. no combination had a systematic effect on accuracy or precision. background debris may have produced overestimates at low oocyst concentrations when flow cytometry was used. | 2004 | 15006810 |
| antibody response of healthy adults to recombinant thrombospondin-related adhesive protein of cryptosporidium 1 after experimental exposure to cryptosporidium oocysts. | thrombospondin-related adhesive protein of cryptosporidium 1 (trap-c1) belongs to a group of proteins that are also found in toxoplasma gondii, eimeria tenella, and plasmodium species. trap-related proteins are needed for gliding motility, host-cell attachment, and invasion. the objective of this study was to characterize the antibody response to recombinant trap-c1 (rtrap-c1) in healthy volunteers exposed to c. parvum and their association with clinical illness. a total of 31 healthy adult volu ... | 2004 | 15013968 |
| manufacturer's recall of rapid cartridge assay kits on the basis of false-positive cryptosporidium antigen tests--colorado, 2004. | the colorado department of public health and environment (cdphe) has determined that a fourfold increase in the number of reported cryptosporidiosis cases in colorado during january-february 2004 might be attributed primarily to false-positive test results. since january 1, 2004, a total of 13 in-state cases and one out-of-state case were reported to cdphe. during the previous 7 years, an average of three cases were reported during january-february. in eight of 14 patients, rapid testing was per ... | 2004 | 15017377 |
| efficacy of alpha-cyclodextrin against experimental cryptosporidiosis in neonatal goats. | the efficacy of orally administered tablets containing alpha-cyclodextrin, an excipient used in the pharmaceutical industry with demonstrated anticryptosporidial activity in vitro and in neonatal mice, was evaluated in neonatal goat kids. the formulation was evaluated for hardness and was subjected to in vitro drug release studies. twenty goat kids were orally inoculated with 10(6) oocysts of c. parvum within the first 6 days of age. half of the animals were treated by oral administration of fou ... | 2004 | 15019141 |
| a quantitative risk assessment of waterborne cryptosporidiosis in france using second-order monte carlo simulation. | a pragmatic quantitative risk assessment (qra) of the risks of waterborne cryptosporidium parvum infection and cryptosporidiosis in immunocompetent and immunodeficient french populations is proposed. the model takes into account french specificities such as the french technique for oocyst enumeration performance and tap water consumption. the proportion of infective oocysts is based on literature review and expert knowledge. the probability of infection for a given number of ingested viable oocy ... | 2004 | 15027996 |
| inactivation of saccharomyces cerevisiae by ultrasonic irradiation. | we have investigated the inactivation of saccharomyces cerevisiae (yeast cells) by ultrasonic irradiation. the amplitude on the vibration face contacting the sample solution was used as an indication of the ultrasonic power intensity. the effects of the amplitude on the vibration face and the initial cell numbers on the sonolytic inactivation of yeast cells have been investigated using a horn-type sonicator (27.5 khz). the inactivation of the yeast cells by ultrasonic irradiation shows pseudo fi ... | 2004 | 15030781 |
| survival of cryptosporidium parvum oocysts after prolonged exposure to still natural mineral waters. | the survival kinetics of purified cryptosporidium parvum oocysts of both human and ovine origin, immersed in four still natural mineral waters (total dissolved salts ranging from 91 mg/liter to 430 mg/liter) and reverse osmosis water was assessed by inclusion or exclusion of the fluorogenic vital dyes 4',6-diamidino-2-phenylindole and propidium iodide over a 12-week period. semipermeable chambers were used to contain the oocysts while immersed in each mineral water type, permitting both intimate ... | 2004 | 15035367 |
| optimization of dna extraction and molecular detection of cryptosporidium oocysts in natural mineral water sources. | the numerous published methods for extracting dna from cryptosporidium oocysts for pcr identify the lack of an optimized standard method for clinical, environmental, and public health investigations of cryptosporidiosis. a method that maximizes dna extraction reliably, particularly from small numbers of partially purified or purified oocysts present in mineral waters and environmental samples, is required. we describe a maximized method for liberating dna from cryptosporidium parvum oocysts by 1 ... | 2004 | 15035368 |
| first record of cryptosporidium infection in a raccoon dog (nyctereutes procyonoides viverrinus). | cryptosporidium species have been found in more than 150 species of mammals, but there has been no report in raccoon dogs. here we found the cryptosporidium organism in a raccoon dog, nyctereutes procyonoides viverrinus, and identified this isolate using pcr-based diagnostic methods. cryptosporidium diagnostic fragments of the 18s ribosomal rna, cryptosporidium oocyst wall protein and 70-kda heat shock protein genes were amplified from the isolate and sequenced to reveal the phylogenetic relatio ... | 2004 | 15041092 |
| complete genome sequence of the apicomplexan, cryptosporidium parvum. | the apicomplexan cryptosporidium parvum is an intestinal parasite that affects healthy humans and animals, and causes an unrelenting infection in immunocompromised individuals such as aids patients. we report the complete genome sequence of c. parvum, type ii isolate. genome analysis identifies extremely streamlined metabolic pathways and a reliance on the host for nutrients. in contrast to plasmodium and toxoplasma, the parasite lacks an apicoplast and its genome, and possesses a degenerate mit ... | 2004 | 15044751 |
| cryptosporidium parvum oocyst inactivation in field soil and its relation to soil characteristics: analyses using the geographic information systems. | the need exists to understand the environmental parameters that affect inactivation of cryptosporidium parvum oocysts in soil under field conditions. the inactivation of c. parvum oocysts placed in the natural environment was studied at a dairy farm in western new york state, usa. seventy sampling points were arranged in a grid with points 150 m apart using the geographic information system. the sampling points were distributed among three distinct areas: woodland, corn field and pasture. purifi ... | 2004 | 15050384 |
| brackish water benthic shellfish (corbicula japonica) as a biological indicator for cryptosporidium parvum oocysts in river water. | | 2004 | 15058651 |
| environmental contamination with protozoan parasite infective stages: biology and risk assessment. | in the present paper some aspects of the biology and various factors influencing the potential for environmental contamination with protozoan parasites infective stages implicated in water and foodborne diseases are described. the major protozoan species that affect humans are entamoeba histolytica, acanthamoeba sp., neagleria sp. giardia intestinalis, cryptosporidium parvum, cyclospora cayetanensis, toxoplasma gondii, isospora/sarcocystis sp. encephalitozoom intestinals and enterocytozoon biene ... | 2003 | 15058818 |
| prevalence of cryptosporidiosis among the villagers and domestic animals in several rural areas of korea. | the present study was undertaken to investigate the infection status of cryptosporidium parvum in the villagers and the reservoir hosts in several rural areas in korea. a total 5,262 fecal samples were collected from the inhabitants residing at gangwon-do, chungcheongbuk-do, jeollanam-do, and gyeongsangnam-do between the dates of september, 2001 to june, 2002. in addition, 1,453 fecal samples were collected from livestock reared in gokseong-gun, jeollanam-do and chungju-si, chungcheongbuk-do. al ... | 2004 | 15060334 |
| infection status of pigs with cryptosporidium parvum. | to investigate the infection status of pigs with cryptosporidium parvum, 589 fecal samples were collected from pigs raised at farm in chungcheongbuk-do and chungcheongnam-do. of the 589 pig fecal samples, 62 (10.5%) were positive for c. parvum. the area showing the highest positive rate was dangjin-gun, chungcheongnam-do (14.0%), and the lowest (0%) salmi-myon, chungcheongbuk-do. the positive rate of c. parvum in judok-eup increased from 12.7% in the winter to 22.1% in the summer. the results of ... | 2004 | 15060340 |
| host intestinal epithelial response to cryptosporidium parvum. | cryptosporidium parvum is an obligate intracellular protozoan parasite that is a well-recognized cause of diarrhea in humans and animals throughout the world, and is associated with a substantial degree of morbidity and mortality in patients with the acquired immunodeficiency syndrome (aids). c. parvum primarily infects epithelial cells of the gastrointestinal tract, resulting in acute watery diarrhea for which there is no effective therapy. during infection, all parasite development, sexual or ... | 2004 | 15063595 |
| evaluation of five membrane filtration methods for recovery of cryptosporidium and giardia isolates from water samples. | we evaluated the efficiency of five membrane filters for recovery of cryptosporidium parvum oocysts and giardia lamblia cysts. these filters included the pall life sciences envirochek (ec) standard filtration and envirochek high-volume (ec-hv) membrane filters, the millipore flatbed membrane filter, the sartorius flatbed membrane filter (smf), and the filta-max (fm) depth filter. distilled and surface water samples were spiked with 10 oocysts and 10 cysts/liter. we also evaluated the recovery ef ... | 2004 | 15066827 |
| the sensitivity of pcr detection of cryptosporidium oocysts in fecal samples using two dna extraction methods. | the implementation of cost-effective intervention strategies for zoonotic protozoa relies on the development of sensitive and accurate diagnostic methods. we carried out a study to evaluate the accuracy of a pcr method for the detection of cryptosporidium spp. oocysts in fecal samples from cattle. | 2003 | 15068384 |
| detection and molecular characterization of cryptosporidium spp. isolated from diarrheic children in switzerland. | the prevalence of cryptosporidium spp. in diarrheic immunocompetent children living in switzerland was 5.5% (15 of 273). infection rates increased significantly with age. anthroponotic cryptosporidium hominis was identified in 11 children, 9 with a travel history. the zoonotic cryptosporidium parvum bovine genotype was identified in 3 children (2 without travel history). hence transmission of cryptosporidium spp. is primarily of anthroponotic nature in the study area. | 2004 | 15071295 |
| cryptosporidium parvum and giardia intestinalis in calf diarrhoea in sweden. | the objective of this study conducted in 75 herds was to investigate the presence and significance of criptosporidium parvum and giardia intestinalis in swedish dairy calves in comparison with rotavirus, coronavirus and escherichia coli k99+. the farmers were asked to collect faecal samples from each heifer calf that had diarrhoea between birth and 90 days of age, and also from a healthy calf of the same age. in total, 270 samples were collected and analysed. c. parvum, either alone or together ... | 2003 | 15074627 |
| amylopectin: a major component of the residual body in cryptosporidium parvum oocysts. | amylopectin is used for carbohydrate storage in different life-stages of a number of apicomplexan parasites. we have performed an ultrastructural analysis of amylopectin granules from the oocyst residual body and sporozoites of cryptosporidium parvum. amylopectin granules were studied in situ and after isolation from 'french' press disrupted parasites, by conventional transmission electron microscopy (tem) of sectioned oocysts and various negative staining and cryoelectron microscopy techniques. ... | 2004 | 15074876 |
| cryptosporidium parvum mitochondrial-type hsp70 targets homologous and heterologous mitochondria. | a mitochondrial hsp70 gene (cp-mthsp70) is described for the apicomplexan cryptosporidium parvum, an agent of diarrhea in humans and animals. mitochondrial hsp70 is known to have been acquired from the proto-mitochondrial endosymbiont. the amino acid sequence of cp-mthsp70 shares common domains with mitochondrial and proteobacterial homologues, including 34 amino acids of an nh2-terminal mitochondrion-like targeting presequence. phylogenetic reconstruction places cp-mthsp70 within the mitochondr ... | 2004 | 15075277 |
| update on cryptosporidium and giardia infections in cattle. | | 2004 | 15099558 |
| differential regulation of beta-defensin gene expression during cryptosporidium parvum infection. | invasion of enterocytes by pathogenic microbes evokes both innate and adaptive immune responses, and microbial pathogens have developed strategies to overcome the initial host immune defense. beta-defensins are potentially important endogenous antibiotic-like effectors of innate immunity expressed by intestinal epithelia. in this study, the interplay between the enteric protozoan parasite cryptosporidium parvum and host epithelial beta-defensin expression was investigated. using human and murine ... | 2004 | 15102787 |
| cdc42 and the actin-related protein/neural wiskott-aldrich syndrome protein network mediate cellular invasion by cryptosporidium parvum. | cryptosporidium parvum invasion of epithelial cells involves host cell membrane alterations which require a remodeling of the host cell actin cytoskeleton. in addition, an actin plaque, possibly associated with the dense-band region, forms within the host cytoplasm at the host-parasite interface. here we show that cdc42 and rhoa, but not rac1, members of the rho family of gtpases, are recruited to the host-parasite interface in an in vitro model of human biliary cryptosporidiosis. interestingly, ... | 2004 | 15102814 |
| [inactivation of cryptosporidium parvum oocysts by copper ions]. | | 2004 | 15103905 |
| an outbreak of cryptosporidium parvum in a surrey pool with detection in pool water sampling. | | 2004 | 15109091 |
| scavengers beware! | | 2004 | 15109941 |
| simultaneous prediction of cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of synthetic waters. | a model was developed to simultaneously assess cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of synthetic solutions in batch and flow-through reactors. the model incorporated 65 elementary chemical reactions involved in the decomposition of ozone and the oxidation of bromine species and their corresponding rate or equilibrium constants reported in the literature. ozonation experiments were performed with a laboratory-scale batch reactor to evaluate the model w ... | 2004 | 15112829 |
| allogeneic hematopoietic stem cell transplantation for seven children with x-linked hyper-igm syndrome: a single center experience. | x-linked hyper-igm syndrome (xhim), or hyper-igm syndrome type 1 (higm1), is a rare primary immunodeficiency disorder susceptible to recurrent bacterial infection and opportunistic infection such as pneumocystis carinii and cryptosporidium parvum. the long-term outcome is quite poor, and allogeneic hematopoietic stem cell transplantation (hsct) offers the only cure. seven patients with xhim, from age 3 to 19 years (mean 11.3 years), underwent allogeneic hsct in our institution. details of pre- a ... | 2004 | 15114594 |
| preliminary foodnet data on the incidence of infection with pathogens transmitted commonly through food--selected sites, united states, 2003. | in the united states, an estimated 76 million persons contract foodborne and other acute diarrheal illnesses each year. cdc's emerging infections program foodborne diseases active surveillance network (foodnet) collects data on diseases caused by enteric pathogens transmitted commonly through food in nine u.s. sites. foodnet quantifies and monitors the incidence of these infections by conducting active surveillance for laboratory-diagnosed illness. this report describes preliminary surveillance ... | 2004 | 15123986 |
| influence of temperature and salinity on the viability and infectivity of giardia lamblia and cryptosporidia parvum. | the present work was designed to assess the effect of different degrees of temperature and salinity on the viability and infectivity of g. lamblia and c. parvum at different storage time. the results revealed that boiling of protozoa for one minute minimized their viability to less than 1% and rendered them non-infectious, while exposure to 4 degrees c and -4 degrees c up to seven days preserved their viability and infectivity. whereas it was found that salinity was effective at high concentrati ... | 2004 | 15125524 |
| reduction and compaction in the genome of the apicomplexan parasite cryptosporidium parvum. | the complete genome of the apicomplexan parasite cryptosporidium parvum reveals many new insights into apicomplexan biology and evolution, as well as the general process of genome reduction in parasites. the genome is globally compacted, but gene loss seems to be focused, in particular in relation to organelles. massive losses of mitochondrial genes have taken place and there is no evidence of any plastid-related genes, providing a useful tool for examining putative plastid proteins in plasmodiu ... | 2004 | 15130487 |
| phosphatidylinositol 3-kinase and frabin mediate cryptosporidium parvum cellular invasion via activation of cdc42. | cryptosporidium parvum invades target epithelia via a mechanism that involves host cell actin reorganization. we previously demonstrated that c. parvum activates the cdc42/neural wiskott-aldrich syndrome protein network in host cells resulting in actin remodeling at the host cell-parasite interface, thus facilitating c. parvum cellular invasion. here, we tested the role of phosphatidylinositol 3-kinase (pi3k) and frabin, a guanine nucleotide exchange factor specific for cdc42 in the activation o ... | 2004 | 15133042 |
| intron-containing beta-tubulin transcripts in cryptosporidium parvum cultured in vitro. | the genome of cryptosporidium parvum contains a relatively small number of introns, which includes the beta-tubulin gene with only a single intron. recently, it was observed that the intron was not removed from some of the beta-tubulin transcripts in the late life cycle stages cultured in vitro. although normally spliced beta-tubulin mrna was detected in all parasite intracellular stages by rt-pcr (e.g. hct-8 or caco-2 cells infected with c. parvum for 12-72 h), at 48-72 h post-infection unproce ... | 2004 | 15133080 |
| functional characterization of replication protein a2 (rpa2) from cryptosporidium parvum. | replication protein a (rpa) is a heterotrimeric complex of single-stranded dna-binding proteins that play multiple roles in eukaryotic dna metabolism. the rpa complex is typically composed of heterologous proteins (termed rpa1, rpa2 and rpa3) in animals, plants and fungi, which possess different functions. previously, two distinct, short-type rpa large subunits (cprpa1 and cprpa1b) from the apicomplexan parasite cryptosporidium parvum were characterized. here are reported the identification and ... | 2004 | 15133081 |
| differential expression and interaction of transcription co-activator mbf1 with tata-binding protein (tbp) in the apicomplexan cryptosporidium parvum. | all gene-specific transcriptional activators initiate gene transcriptions by binding to promoter sequences and recruiting general transcription factors including tata-binding protein (tbp) to upstream of targeted genes. some of them require multiprotein bridging factors (mbfs); for example, the type 1 mbf (mbf1) which interconnects the gene activator with tbp. in this study, the properties of a previously cloned type 1 multiprotein bridging factor (cpmbf1) and a newly identified tbp (cptbp1) fro ... | 2004 | 15133082 |
| strength in diversity. | | 2004 | 15134078 |
| microbial contamination of drinking water and disease outcomes in developing regions. | drinking water is a major source of microbial pathogens in developing regions, although poor sanitation and food sources are integral to enteric pathogen exposure. gastrointestinal disease outcomes are also more severe, due to under-nutrition and lack of intervention strategies in these regions. poor water quality, sanitation and hygiene account for some 1.7 million deaths a year world-wide (3.1% of all deaths and 3.7% of all daly's), mainly through infectious diarrhoea. nine out of 10 such deat ... | 2004 | 15138046 |
| survival of cryptosporidium species in environments relevant to foods and beverages. | to provide data on the survival of cryptosporidium oocysts in a range of conditions relevant to foods and beverages. | 2004 | 15139913 |
| effects of pesticides on sporulation of cyclospora cayetanensis and viability of cryptosporidium parvum. | disease outbreaks caused by the coccidian parasite cyclospora cayetanensis in food have been linked to consumption of raspberries that may have been contaminated through exposure to water mixed with insecticides and fungicides that may have been sprayed onto the berries. three different fungicides (captan 50% w.p., benomyl 50% w.p., and zineb 75% w.p.) and two different insecticides (malathion 25% w.p. and diazinon 4e 47.5%) were evaluated at five different concentrations and for exposure times ... | 2004 | 15151249 |
| nitric oxide synthase stimulates prostaglandin synthesis and barrier function in c. parvum-infected porcine ileum. | cell culture models implicate increased nitric oxide (no) synthesis as a cause of mucosal hyperpermeability in intestinal epithelial infection. no may also mediate a multitude of subepithelial events, including activation of cyclooxygenases. we examined whether no promotes barrier function via prostaglandin synthesis using cryptosporidium parvum-infected ileal epithelium in residence with an intact submucosa. expression of no synthase (nos) isoforms was examined by real-time rt-pcr of ileal muco ... | 2004 | 15155179 |