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hyperimmune bovine colostrum specific for recombinant cryptosporidium parvum antigen confers partial protection against cryptosporidiosis in immunosuppressed adult mice.preparturient cows were immunized three times over a six-week period with recombinant plasmid dna encoding the cryptosporidium parvum cp15/60 antigen by injecting the dna in the mammary gland. serum was collected at each immunization and first colostrum was collected after parturition; all were assayed for cryptosporidium-specific antibodies (ab). a serological response to c. parvum sporozoite and oocyst antigen was detected in cows immunized with pcp15/60 plasmid dna. colostrum from these cows, ...199910392628
risk factors associated with cryptosporidium parvum infection in dairy cattle in southeastern new york state.an observational analytical epidemiologic study was carried out to identify factors associated with the risk of infection with cryptosporidium parvum in dairy herds in southeastern new york state. a random sample of 2943 cattle on 109 farms was selected from the target population. fecal samples were collected from animals in three different age groups and examined for the presence of c. parvum using a quantitative centrifugation concentration flotation method. data on intrinsic, preweaning, post ...199910392763
evaluation of quantitative latex agglutination for detection of cryptosporidium parvum, e. coli k99, and rotavirus in calf feces.a new methodology for detection of rotavirus, escherichia coli k99, and cryptosporidium parvum in bovine fecal samples was developed based on a quantitative latex agglutination technique (qlat). calibrated microspheres coated with specific antibodies to 1 of the enteric pathogens are quantitatively agglutinated by the antigens present in diluted fecal sample. the test is performed in a 96-well flat-bottom plate. the samples were tested with a commercial enzyme-linked immunosorbent assay kit prio ...199910424645
characterization of cryptosporidium parvum in human and animal feces by single-tube nested polymerase chain reaction and restriction analysis.a dna isolation and purification method is described that produced dna free of inhibitory substances in 148 of the 159 analyzed fecal samples. the polymerase chain reaction (pcr) product from a sensitive single-tube nested pcr that amplifies a part of an oocyst protein was used to characterize cryptosporidium parvum genotypes by a simple restriction analysis. genotype 1 was solely detected in human-derived oocysts, genotype 2 was present in both animal and human-derived oocysts. the ratio betwee ...199910431737
chlorine disinfection of recreational water for cryptosporidium parvum.we examined the effects of chlorine on oocyst viability, under the conditions of controlled ph and elevated calcium concentrations required for most community swimming pools. we found that fecal material may alter the ct values (chlorine concentration in mg/l, multiplied by time in minutes) needed to disinfect swimming pools or other recreational water for cryptosporidium parvum.199910458969
the fate of cryptosporidium parvum oocysts ingested by dung beetles and their possible role in the dissemination of cryptosporidiosis.the fate of oocysts of cryptosporidium parvum ingested by dung beetles and the possible role these beetles serve in the dissemination of cryptosporidiosis were tested on the following species: anoplotrupes stercorosus, aphodius rufus, and onthophagus fracticornis. ten specimens of each species were offered cattle dung supplemented with 5.9 x 10(6) oocysts of c. purvum. after 24 hr of feeding, the beetles were examined for the presence of oocysts on their external surfaces, in their gastrointesti ...199910461948
serological differences in neospora caninum-associated epidemic and endemic abortions.a sandwich enzyme-linked immunosorbent assay (elisa) for the sensitive and specific detection of bovine antibodies to neospora caninum was developed and evaluated using sera from cattle experimentally infected with n. caninum, toxoplasma gondii, sarcocystis cruzi, sarcocystis hominis, sarcocystis hirsuta, eimeria bovis, cryptosporidium parvum, babesia divergens, and field sera from naturally exposed animals. field sera were classified using a gold standard that included the results from an indir ...199910461950
virulence of three distinct cryptosporidium parvum isolates for healthy adults.the infectivity of three cryptosporidium parvum isolates (iowa [calf], ucp [calf], and tamu [horse]) of the c genotype was investigated in healthy adults. after exposure, volunteers recorded the number and form of stools passed and symptoms experienced. oocyst excretion was assessed by immunofluorescence. the id50 differed among isolates: iowa, 87 (se, 19; 95% confidence interval [ci], 48.67-126); ucp, 1042 (se, 1000; 95% ci, 0-3004); and tamu, 9 oocysts (se, 2.34; 95% ci, 4.46-13.65); tamu vers ...199910479158
cryptosporidium parvum induces apoptosis in biliary epithelia by a fas/fas ligand-dependent mechanism.although the clinical features of sclerosing cholangitis from opportunistic infections of the biliary tree in patients with acquired immunodeficiency syndrome (aids) are well known, the mechanisms by which associated pathogens, such as cryptosporidium parvum, cause disease are obscure. using an in vitro model of biliary cryptosporidiosis, we observed that c. parvum induces apoptosis in cultured human biliary epithelia. both caspase protease inhibitors and neutralizing antibodies to either fas re ...199910484385
role of cryptosporidium parvum as a pathogen in neonatal diarrhoea complex in suckling and dairy calves in france.this study was carried out to find the importance of cryptosporidium parvum in diarrhoea of neonatal calves in two types of breeding - suckling and dairy calves - in france. different agents causing neonatal diarrhoea, e. coli, rotavirus, coronavirus, salmonella and cryptosporidium were systematically researched in faeces. 1. suckling calves: in 40 livestock farms selected for diarrhoea, 311 calves 4 to 10 days old which had diarrhoea for less than 24h or no diarrhoea, were included in the study ...199910488727
the norway rat as a reservoir host of cryptosporidium parvum.the potential of norway rats (rattus norvegicus) to spread the parasite cryptosporidium parvum was investigated by examining parasite prevalence in relation to the structure and movements of three permanent rat populations living on farmland in warwickshire (uk) from october 1994 to march 1997. one population lived among a group of farm buildings housing cattle, while the other two had no contact with livestock, one living around a pond and its outflowing stream and the other on a rubbish tip. o ...199910574524
the identification of cryptosporidium species and cryptosporidium parvum directly from whole faeces by analysis of a multiplex pcr of the 18s rrna gene and by pcr/rflp of the cryptosporidium outer wall protein (cowp) gene.a multiplex polymerase chain reaction (pcr) procedure to amplify 18s rrna gene fragments has been developed. amplified dna fragments of the expected size were obtained which were specific for cryptosporidium parvum and cryptosporidium wrairi (422 bp), cryptosporidium baileyi (11106 bp) and cryptosporidium muris (1346 bp). criptosporidium parvum and c. wrairi can be distinguished using a pcr/restriction fragment length polymorphism (rflp) analysis of the cryptosporidium outer wall protein (cowp) ...199910576575
ultrastructure, fractionation and biochemical analysis of cryptosporidium parvum sporozoites.sporozoites of the apicomplexan parasite cryptosporidium parvum were subjected to cell disruption and subcellular fractionation using a sucrose density step gradient. with this procedure, highly enriched preparations of the parasite membrane, the micronemes, dense granules and amylopectin granules were produced. no separate fraction containing rhoptries was obtained, however this organelle was found in defined fractions of the gradient, still associated with the apical tip of the sporozoites. us ...199910576576
a review of the importance of cryptosporidiosis in farm animals.cryptosporidium species are coccidian parasites with a large capacity to reproduce and to disseminate. several species are known to infect farm animals, although the economic importance of cryptosporidiosis is highly host species dependent. this paper reviews the impact of cryptosporidial infections in livestock and poultry. for different farm animals, the cryptosporidium spp. that occur, as well as their clinical and pathological features, and their interactions with other pathogens, are descri ...199910576578
molecular analysis of the 18s rrna gene of cryptosporidium serpentis in a wild-caught corn snake (elaphe guttata guttata) and a five-species restriction fragment length polymorphism- based assay that can additionally discern c. parvum from c. wrairi.an adult wild-caught corn snake (elaphe guttata guttata) was presented for humane euthanasia and necropsy because of severe cryptosporidiosis. the animal was lethargic and >5% dehydrated but in good flesh. gastric lavage was performed prior to euthanasia. histopathologic findings included gastric mucosal hypertrophy and a hemorrhagic erosive gastritis. numerous 5- to 7-microm-diameter round extracellular organisms were associated with the mucosal hypertrophy. a pcr, acid-fast stains, giemsa stai ...199910583987
association of herd composition, stocking rate, and duration of calving season with fecal shedding of cryptosporidium parvum oocysts in beef herds.to evaluate the association of herd demographics, parturition variables, stocking rate, and rotational grazing practices with the probability of fecal shedding of cryptosporidium parvum from beef cow-calf herds in california.199910613218
comparison of fecal samples collected per rectum and off the ground for estimation of environmental contamination attributable to beef cattle.to determine whether sampling feces off the ground replicates prevalence estimates for specific pathogens obtained from fecal samples collected per rectum of adult cows, and to determine characteristics of feces on the ground (fecal pats) that are associated with subsequent identification of campylobacter spp, cryptosporidium parvum, and giardia duodenalis.199910566807
cloning and expression of a dna sequence encoding a 41-kilodalton cryptosporidium parvum oocyst wall protein.this study was conducted to produce a recombinant species-specific oocyst wall protein of cryptosporidium parvum. antigens unique to c. parvum were identified by gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting of oocyst proteins from several different cryptosporidium species. antiserum was then prepared against a 41-kda antigen unique to c. parvum and used to identify a recombinant dna clone, designated rcp41. expression of cp41 mrna in c. parvum oocysts was ...199910548585
assessment of drugs against cryptosporidium parvum using a simple in vitro screening method.a rapid semi-quantitative screening method was devised for assessing the anticryptosporidial and cytotoxic effects of putative chemotherapeutic compounds. the method is suitable as an initial rapid screening procedure from which compounds demonstrating anticryptosporidial activity can be identified for further analysis. it has the advantages of speed, low cost and concurrent assessment of anticryptosporidial and cytotoxic effects and allows accurate determination of minimum lethal concentrations ...199910499272
house flies (musca domestica) as transport hosts of cryptosporidium parvum.refuse and promiscuous-landing synanthropic filth flies, such as house flies (musca domestica), are recognized as transport hosts for a variety of protozoan and metazoan parasites in addition to viral and bacterial pathogens of public health importance. exposure of adult m. domestica to 20 ml of bovine diarrheal feces containing cryptosporidium parvum oocysts (2.0 x 10(5) oocysts/ml) resulted in intense deposition of the oocysts through fly feces on the surfaces visited by the flies (mean = 108 ...199910497998
mechanisms of attachment and internalization of cryptosporidium parvum to biliary and intestinal epithelial cells.although infection of the intestinal and biliary tracts by cryptosporidium parvum is a major problem in patients with the acquired immunodeficiency syndrome, the specific microbial and host molecules involved in c. parvum infection are unknown. we tested the hypothesis that lectin-carbohydrate interactions and cytoskeleton reorganization are involved in the infection of biliary and intestinal epithelia by c. parvum.200010648465
cryptosporidium andersoni n. sp. (apicomplexa: cryptosporiidae) from cattle, bos taurus.a new species of cryptosporidium is described from the feces of domestic cattle, bos taurus. oocysts are structurally similar to those of cryptosporidium muris described from mice but are larger than those of cryptosporidium parvum. oocysts of the new species are ellipsoidal, lack sporocysts, and measure 7.4 x 5.5 microm (range, 6.0-8.1 by 5.0-6.5 microm). the length to width ratio is 1.35 (range, 1.07-1.50). the colorless oocyst wall is < 1 microm thick, lacks a micropyle, and possesses a longi ...200010651302
accumulation of mucosal t lymphocytes around epithelial cells after in vitro infection with cryptosporidium parvum.we had previously shown that ileal intraepithelial lymphocytes isolated from calves with cryptosporidiosis include significantly increased numbers of cd8+ t lymphocytes and activated cd4+ cells. these increases could result from redistribution of resident mucosal lymphocytes or from homing of peripheral t cells to ileal mucosa. to determine whether resident mucosal lymphocytes can redistribute to cryptosporidium parvum-infected epithelium, oocysts were inoculated in vitro onto ileum explants tak ...199910461968
molecular characterization of cryptosporidium isolates obtained from human immunodeficiency virus-infected individuals living in switzerland, kenya, and the united states.a total of 22 cryptosporidium isolates from human immunodeficiency virus-infected patients from kenya, switzerland, and the united states were examined at three genetic loci: the 18s ribosomal dna, hsp-70, and acetyl coenzyme a synthetase genes. four distinct cryptosporidium genotypes were identified: (i) the cryptosporidium parvum "human" genotype, (ii) the c. parvum "cattle" genotype, (iii) cryptosporidium felis, and (iv) cryptosporidium meleagridis. this is the first report of c. meleagridis ...200010699017
environmental and geographical factors contributing to watershed contamination with cryptosporidium parvum oocysts.cryptosporidium parvum is a waterborne parasite which infects cattle and produces life-threatening zoonosis in people with impaired immune systems. digital maps of 100-year floodplain boundaries, land use/cover, and livestock operations were used to select and characterize cattle farms in the floodplain area in lancaster county, pennsylvania, u.s.a. over 21% of the cattle farms were located within 100-year floodplain boundaries. on average, a single farm comprised 12.8 ha of pasture (including b ...200010702335
inhibition of cryptosporidium parvum in vitro by 9-(alkylthio)acridine derivatives.the synthesis of several acridinic thioethers is described. compounds prepared were tested in vitro as potential drugs against the opportunistic infection known as cryptosporidiosis. with a view to predict activity, the quantitative structure-activity relationships were investigated. correlations between experimental data and either log p or pka are discussed.200010719621
specific pcr primers for cryptosporidium parvum with extra high sensitivity.one pair of high-sensitive polymerase chain reaction (pcr) primers for cryptosporidium parvum was constructed based on the sequence of random amplified polymorphic dna. pcr with this primer pair amplified only the dna of c. parvum, not the control dna including cryptosporidium muris. this primer pair had most advantageous in its sensitivity over the six pairs of primers reported elsewhere. the minimum amount of template dna required to produce visible bands after gel electrophoresis and ethidium ...200010722790
immunomagnetic separation of cryptosporidium parvum oocysts using macs microbeads and high gradient separation columns.we evaluated the macs immunomagnetic separation (ims) system for concentrating cryptosporidium parvum. oocysts were first labeled with fluorescein isothiocyanate (fitc) or rabbit anti-c. parvum antibodies, then linked to microbeads coated with anti-fitc or anti-rabbit igg, and separated through a high gradient separation column. results indicated that over 95% of oocysts were recovered and their fluorescence and infectivity were retained. the presence of microbeads showed no effect on genomic dn ...200010739338
a microsatellite marker reveals population heterogeneity within human and animal genotypes of cryptosporidium parvum.isolates of the protozoan parasite cryptosporidium parvum have been differentiated into 2 genotypes: genotype 'h', which is associated only with human infections, and genotype 'c', which is associated with both human and animal infections. to date, the analysis of polymorphisms of genes and of the small subunit ribosomal dna have revealed no heterogeneity within the 2 genotypes. in the present study, a locus containing simple sequence repeats (microsatellites) was pcr amplified and sequenced fro ...200010759081
presence of double-stranded rnas in human and calf isolates of cryptosporidium parvum.we examined the occurrence of 2 virus-like double-stranded (ds)rnas in human and calf isolates of cryptosporidium parvum senso latu and other microorganisms, including 7 other members of the genus. a total of 32 isolates of c. parium, 16 from humans (5 from acquired immune deficiency syndrome patients) and 16 from calves, were analyzed. ethidium bromide staining, or northern blot analysis, or reverse transcription/polymerase chain reaction, or all 3 methods, revealed that both genotype 1 and gen ...200010780545
viability and infectivity of two cryptosporidium parvum bovine isolates from different geographical location.the viability of two cryptosporidium parvum bovine isolates from spain and colombia was evaluated by in vitro excystation, inclusion/exclusion of two fluorogenic vital dyes (dapi and pi) and infectivity assay in a suckling murine model. excystation percentages were similar for both spain and colombia isolates (83% and 87%, respectively). the total viability of the spain isolate, measured by inclusion/exclusion of two fluorogenic vital dyes, was 71% in comparison with that detected for oocysts of ...200010799839
activity of decoquinate against cryptosporidium parvum in cell cultures and neonatal mice.cryptosporidium parvum is an apicomplexan parasite that is an important cause of diarrhea in neonatal calves and humans. no treatment is currently available for neonatal calves. we have recently learned from colleagues in the pharmaceutical industry that dairy practitioners are sometimes using decoquinate for the treatment of neonatal bovine cryptosporidiosis. therefore, the present study was undertaken to determine whether the clinical observations in calves can be substantiated by laboratory i ...200010799844
association of rna polymerase complexes of the parasitic protozoan cryptosporidium parvum with virus-like particles: heterogeneous system.rna polymerase complexes were purified from cryptosporidium parvum, a parasitic protozoan known to infect many species of mammals including humans. western blot analysis revealed the association of the complexes with two different proteins, encoded by large and small segments of viral double-stranded rnas. each complex was found to contain only double-stranded rna, both double- and single-stranded rna, or only single-stranded rna. maximum rna-dependent rna polymerase activity was observed within ...200010846057
a random survey of the cryptosporidium parvum genome.cryptosporidium parvum is an obligate intracellular pathogen responsible for widespread infections in humans and animals. the inability to obtain purified samples of this organism's various developmental stages has limited the understanding of the biochemical mechanisms important for c. parvum development or host-parasite interaction. to identify c. parvum genes independent of their developmental expression, a random sequence analysis of the 10.4-megabase genome of c. parvum was undertaken. tota ...199910417162
long-term survival of cryptosporidium parvum oocysts in seawater and in experimentally infected mussels (mytilus galloprovincialis).transmission of infectious oocysts of cryptosporidium parvum via surface- and drinking-water supplies has been reported and many surface waters flow into the sea, potentially causing runoff of animal-infected faeces. eating raw mussels is a common practice in many countries, increasing the public's risk of acquiring enteric pathogens. the aims of the present study were to estimate how long c. parvum oocysts remain infectious in artificial seawater, to determine if the oocysts are retained in mus ...199910404265
successful hyperimmune bovine colostrum treatment of savanna monitors (varanus exanthematicus) infected with cryptosporidium sp.therapy based on the protective passive immunity of hyperimmune bovine colostrum (hbc) (raised against cryptosporidium parvum in cows) was applied to 4 savanna monitors (varanus exanthematicus) with gastric cryptosporidium sp. infections. all lizards were moderately emaciated, and their fecal and gastric lavage samples contained moderate numbers of cryptosporidium sp. oocysts. the first 3 of 7 gastric hbc treatments at 1-wk interval each decreased the numbers of oocysts in the fecal and gastric ...200010864270
development of a novel, rapid integrated cryptosporidium parvum detection assay.the aim of this study was to develop a reverse transcription-pcr assay and lateral flow detection protocol for specific identification of cryptosporidium parvum. the method which we developed is sensitive and specific and has a low limit of detection. in our protocol a solid phase material, the xtra bind capture system, was used for extraction and purification of double-stranded rna (dsrna) specific for c. parvum. the xtra bind capture system interfaced with pellets concentrated from water sampl ...200010877759
aging of cryptosporidium parvum oocysts in river water and their susceptibility to disinfection by chlorine and monochloramine.cryptosporidium parvum oocysts were aged in waters from both the st. lawrence river and the ottawa river. in situ survival experiments were carried out by incubating the oocysts in either dialysis cassettes or microtubes floated into an overflow tank. a significant portion of the oocysts survived in the test waters for several weeks. oocyst survival in the st. lawrence river was better in membrane-filtered (0.2 microm-pore diameter) water than in unfiltered water, suggesting that biological anta ...199810383227
extensive polymorphism in cryptosporidium parvum identified by multilocus microsatellite analysis.restriction fragment length polymorphism and dna sequence analysis discern two main types of cryptosporidium parvum. we present a survey of length polymorphism at several microsatellite loci for type 1 and type 2 isolates. a total of 14 microsatellite loci were identified from c. parvum dna sequences deposited in public databases. all repeats were mono-, di-, and trinucleotide repeats of a, at, and aat, reflecting the high at content of the c. parvum genome. several of these loci showed signific ...200010919789
recovery and viability of cryptosporidium parvum oocysts and giardia intestinalis cysts using the membrane dissolution procedure.previously, the cellulose acetate membrane filter dissolution method was reported to yield cryptosporidium parvum oocyst recoveries of 70.5%, with recovered oocysts retaining their infectivity. in contrast, high spike doses (approximately 1 x 10(5) cryptosporidium parvum oocysts and giardia intestinalis cysts) yielded recoveries ranging from 0.4% to 83.9%, and 3.2% to 90.3%, respectively, in this study. recoveries with low spike doses (approximately 100 (oo)cysts) continued to demonstrate high v ...200010941515
inactivation of cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.cryptosporidium parvum is a common cause of self-limited gastroenteritis in the normal host but may cause severe disease in immunocompromised persons. person-to-person transmission has been well documented in households, child care centers, and hospitals. because contaminated environmental surfaces and medical devices such as endoscopes may play a role in disease transmission, we studied the susceptibility of c parvum to chemical agents commonly used for disinfection and evaluated the efficacy o ...199910228259
an immunoglobulin g1 monoclonal antibody highly specific to the wall of cryptosporidium oocysts.the detection of cryptosporidium oocysts in drinking water is critically dependent on the quality of immunofluorescent reagents. experiments were performed to develop a method for producing highly specific antibodies to cryptosporidium oocysts that can be used for water testing. balb/c mice were immunized with six different antigen preparations and monitored for immunoglobulin g (igg) and igm responses to the surface of cryptosporidium oocysts. one group of mice received purified oocyst walls, a ...200010973448
isoenzyme activities of different strains of cryptosporidium parvum.different isoenzyme activities have been assayed in three strains of cryptosporidium parvum, c1 (c. parvum from infected calves, uk), c2 (c. parvum from infected calves, egypt) and c3 (c. parvum from infected goats, egypt). the electrophoretic variations of five enzymes; lactate dehydrogenase (ldh), glucose phosphate isomerase (gpi), hexokinase (hk), malate dehydrogenase (mdh) and glutamate dehydrogenase (gldh) were compared among the three different isolates using native polyacrylamide gel-elec ...199910190863
prevalence of giardia sp. cryptosporidium parvum and cryptosporidium andersoni (syn. c. muris) [correction of cryptosporidium parvum and cryptosporidium muris (c. andersoni)] in 109 dairy herds in five counties of southeastern new york.a cross-sectional study was undertaken to determine the prevalence of giardia sp. (g. duodenalis group), cryptosporidium parvum and cryptosporidium andersoni (c. muris) [corrected] in dairy cattle in three different age groups, and to evaluate the association of age and season with prevalence. one hundred and nine dairy farms, from a total of 212 farms, in five counties of southeastern new york volunteered to participate. on these farms, 2943 fecal samples were collected from three defined age g ...200011027856
oocysts, igg levels and immunoblot patterns determined for cryptosporidium parvum in bovine examined during a visit to a farm (northeastern spain).single fecal and serum samples were individually collected from 101 bovines selected at random during a visit to a farm in northeastern spain (group i, 26 animals aged 2-36 days; group ii, 34 animals aged 1.5-4.5 months; group iii, 41 animals aged 20-24 months). testing for the presence of cryptosporidium parvum oocysts in feces (monofluo kit cryptosporidium, diagnostics pasteur, france) indicated that 26% animals were infected (81% of group i, 15% of group ii and 0% of group iii). serological t ...199910190862
prevalence of cryptosporidium parvum infection and pattern of oocyst shedding in calves in japan.cryptosporidium parvum infection and the pattern of oocyst shedding were observed in calves. a total of 480 fecal samples were collected from 30 calves (age, < or =30 days) over a period of 10 months from june 1998 to march 1999. a sucrose centrifugal flotation technique revealed 28/30 (93%) calves were passing cryptosporidium oocysts. oocyst shedding was first detected on the sixth day after birth, with 8% of the calves testing positive. this rate increased day by day and reached approximately ...200011078941
efficacies of lipophilic inhibitors of dihydrofolate reductase against parasitic protozoa.competitive inhibitors of dihydrofolate reductase (dhfr) are used in chemotherapy or prophylaxis of many microbial pathogens, including the eukaryotic parasites plasmodium falciparum and toxoplasma gondii. unfortunately, point mutations in the dhfr gene can confer resistance to inhibitors specific to these pathogens. we have developed a rapid system for testing inhibitors of dhfrs from a variety of parasites. we replaced the dhfr gene from the budding yeast saccharomyces cerevisiae with the dhfr ...200111120964
cryptosporidium parvum sporozoite pellicle antigen recognized by a neutralizing monoclonal antibody is a beta-mannosylated glycolipid.the protozoan parasite cryptosporidium parvum is an important cause of diarrhea in humans, calves, and other mammals worldwide. no approved vaccines or parasite-specific drugs are currently available for the control of cryptosporidiosis. to effectively immunize against c. parvum, identification and characterization of protective antigens are required. we previously identified cps-500, a conserved, neutralization-sensitive antigen of c. parvum sporozoites and merozoites defined by monoclonal anti ...199910024577
unexpected activity of beta-cyclodextrin against experimental infection by cryptosporidium parvum.an unexpected activity of beta-cyclodextrin, an excipient used in pharmaceutical technology, was observed against cryptosporidium parvum. the viability and infectivity of purified oocysts, exposed for 24 hr to beta-cyclodextrin (2.5% suspension), were evaluated by inclusion/exclusion of 2 fluorogenic vital dyes and a suckling murine model, respectively. results of the viability assay showed a high proportion of nonviable oocysts (81.5%). the intensity of experimental infection, determined 7 days ...200011128490
molecular characterization of a cryptosporidium isolate from a black bear.to further validate the observation of the existence of host-adapted strains of cryptosporidium parvum, we genetically characterized an isolate of cryptosporidium parasite from a black bear. sequence analysis of the ribosomal rna small subunit and the 70-kda heat shock protein (hsp70) showed that this parasite represents a new genotype of c. parvum and is related to the c. parvum dog genotype. this finding is helpful for clarifying cryptosporidium taxonomy.200011128505
host cell apoptosis impairs cryptosporidium parvum development in vitro.the absence of a self-sustaining in vitro propagation method for cryptosporidium parvum is a major obstacle for research on this parasite. conventional cell monolayers are unsuitable for long-term parasite propagation because the level of infection decreases over time and few oocysts, if any, are produced. the interaction between parasite and host cell was studied to identify factors limiting parasite development in vitro. loss of substrate adherence and death of parasitized host cells was obser ...200011128511
duration of naturally acquired giardiosis and cryptosporidiosis in dairy calves and their association with diarrhea.to determine duration of infection and association of infection with diarrhea for dairy calves with naturally acquired cryptosporidiosis and giardiosis.199910023403
antibody reactivity to cryptosporidium parvum in saliva of calves after experimental infection.antibodies against cryptosporidium parvum in the saliva and sera of three calves experimentally infected with this parasite were examined by an indirect immunofluorescence antibody test and immunoblotting. salivary anti-c. parvum iga antibody appeared on day 12 post-challenge and had a tendency to increase transiently between days 15 and 30 post-challenge. salivary anti-c. parvum igg antibody levels showed a gradual increase along with the change in iga antibody levels during the infection. in c ...200011129874
identification of 5 types of cryptosporidium parasites in children in lima, peru.cryptosporidium parvum is usually considered to be the pathogen responsible for human cryptosporidiosis. we genotyped cryptosporidium in 132 stool specimens from 80 peruvian children, representing 85 infection episodes, using techniques that differentiate cryptosporidium species and c. parvum genotypes. five types of cryptosporidium were identified: c. parvum human (67), bovine (8), and dog (2) genotypes, c. meleagridis (7), and c. felis (1). twenty-five (29%) of the 85 infection episodes were a ...200111133382
ultrastructural details of cryptosporidium parvum development in calf intestine.cryptosporidium parvum and c. muris appear to be different species found in calves, with different oocysts size and distribution on the gastrointestinal tract. this work presents new images of c. parvum ultrastructure in calf intestine, mainly its development in nonmicrovillous cells and the presence of microtubular structures in the membrane enveloping the macrogamonts and immature oocysts.19989921314
infectivity of cryptosporidium parvum oocysts stored in water at environmental temperatures.oocysts of cryptosporidium parvum obtained from calves were cleaned of fecal debris by density gradient centrifugation and suspended in deionized water in microcentrifuge tubes. the tubes were placed in circulating water baths at temperatures of -10, -5, 0, 5, 10, 15, 20, 25, 30, or 35 c, and 2 tubes were removed from each water bath 1, 2, 4, 8, 12, 16, 20, and 24 wk later. oocysts from 1 tube were administered at the rate of 1.5 x 10(5) oocysts per mouse to 2 litters of neonatal balb/c mice and ...19989920307
morphologic, host specificity, and genetic characterization of a european cryptosporidium andersoni isolate.this study was undertaken in order to characterize a cryptosporidium muris-like parasite isolated from cattle in hungary and to compare this strain with other cryptosporidium species. to date, the large-type oocysts isolated from cattle were considered as c. muris described from several mammals. the size, form, and structure of the oocysts of the hungarian strain were identical with those described by others from cattle. an apparent difference between the morphometric data of c. muris-like paras ...200011191899
detection of mucosally delivered antibody to cryptosporidium parvum p23 in infected calves.we have developed an assay to detect mucosally delivered antibody to cryptosporidium parvum sporozoite antigens. we absorbed a recombinant 23-kd sporozoite protein to polystyrene microspheres, and used flow cytometry to detect, titer, and determine the isotype of antibody to p23 that was shed in the feces of experimentally infected calves. noninoculated calves have low levels of mucosal antibody to p23, with igg1 as the predominant isotype. antibody titers rise in inoculated calves as the animal ...200011193650
sedimentation of free and attached cryptosporidium oocysts and giardia cysts in water.experimental analysis of the sedimentation velocity of cryptosporidium parvum oocysts and giardia lamblia cysts was compared with mathematical description of their sedimentation velocities by using measurements of (oo)cyst size and density and the density and viscosity of the sedimentation medium to determine if the sedimentation kinetics of freely suspended oocysts of c. parvum and cysts of g. lamblia can be described by stokes' law. the theoretically calculated sedimentation kinetics showed a ...19989797307
cryptosporidium parvum infection involving novel genotypes in wildlife from lower new york state.cryptosporidium, an enteric parasite of humans and a wide range of other mammals, presents numerous challenges to the supply of safe drinking water. we performed a wildlife survey, focusing on white-tailed deer and small mammals, to assess whether they may serve as environmental sources of cryptosporidium. a pcr-based approach that permitted genetic characterization via sequence analysis was applied to wildlife fecal samples (n = 111) collected from september 1996 to july 1998 from three areas i ...200111229905
cryptosporidium parvum: an attempt at experimental infection in rainbow trout oncorhynchus mykiss.a study was carried out on rainbow trout oncorhynchus mykiss fed with a commercial feed contaminated with bovine-isolated cryptosporidium parvum oocysts whose viability and infectivity were previously tested by inoculation of oocysts to neonatal swiss cd-1 mice. histological examination of hematoxylin-eosin-stained gastrointestinal sections from control and c. parvum-exposed fish revealed no life-cycle stages of cryptosporidium in any part of the apical border of the digestive tract. however, se ...19989794634
establishing the cryptosporidium parvum karyotype by noti and sfii restriction analysis and southern hybridization.the molecular karyotype of the coccidian parasite cryptosporidium parvum has proven difficult to study because chromosomes of similar sizes migrate together when submitted to pulsed-field gel electrophoresis (pfge). in the present work, the karyotype was studied by restriction of chromosome-sized dna with the rare-cutting enzymes noti and sfii, followed by pfge separation of the restriction fragments and southern hybridization. these experiments showed that the c. parvum karyotype is formed by e ...19989757000
bovine milk antibodies for health.the immunoglobulins of bovine colostrum provide the major antimicrobial protection against microbial infections and confer a passive immunity to the newborn calf until its own immune system matures. the concentration in colostrum of specific antibodies against pathogens can be raised by immunising cows with these pathogens or their antigens. immune milk products are preparations made of such hyperimmune colostrum or antibodies enriched from it. these preparations can be used to give effective sp ...200011242458
genotypic and phenotypic characterization of cryptosporidium parvum isolates from people with aids.genotypic analysis of cryptosporidium parvum has demonstrated the presence of two subgroups within the species, whereas biochemical and antigenic characterization have shown more heterogeneity. the clinical relevance of these observations is unknown. c. parvum isolates from people with aids were studied with respect to parasite genotypes and virulence in cell monolayers and laboratory animals. ten of 13 oocyst samples had a characteristic human-associated (h) genotype; 3 had a genotype typical o ...19989728554
effect of salinity, temperature and storage time on mouse experimental infection by cryptosporidium parvum.cryptosporidium parvum oocysts collected from a naturally infected calf were exposed to different salinity and temperature for 2, 21 and 40 days, and then inoculated intragastrically into coccidium-free neonatal mice. the intensity of infection as determined seven days later by examination of intestinal homogenates were statistically analysed. salinity, time and salinity-time interaction were the only factors with significant effect on the infection intensity.199910628695
tracking cryptosporidium parvum by sequence analysis of small double-stranded rna.we sequenced a 173-nucleotide fragment of the small double-stranded viruslike rna of cryptosporidium parvum isolates from 23 calves and 38 humans. sequence diversity was detected at 17 sites. isolates from the same outbreak had identical double-stranded rna sequences, suggesting that this technique may be useful for tracking cryptosporidium infection sources.200111266306
antigen incorporation on cryptosporidium parvum oocyst walls.cryptosporidium parvum oocysts are the infective stages responsible for transmission and survival of the organism in the environment. in the present work we show that the oocyst wall, far from being a static structure, is able to incorporate antigens by a mechanism involving vesicle fusion with the wall, and the incorporation of the antigen to the outer oocyst wall. using immunoelectron microscopy we show that the antigen recognized by a monoclonal antibody used for diagnosis of cryptosporidiosi ...200111285502
inactivation of cryptosporidium parvum oocysts in cider by flash pasteurization.cryptosporidium parvum is a well-recognized pathogen of significant medical importance, and cider (apple juice) has been associated with foodborne cryptosporidiosis. this study investigated the effect of flash pasteurization on the viability of contaminant c. parvum oocysts. cider inoculated with oocysts was heated at 70 or 71.7 degrees c for 5, 10, or 20 s, and oocyst viability was measured by a semiquantitative in vitro infectivity assay. by infecting multiple wells of confluent madin-darby bo ...200111307890
polymorphisms in the beta-tubulin gene of cryptosporidium parvum differentiate between isolates based on animal host but not geographic origin.polymerase chain reaction primers were designed to target a region of the cryptosporidium parvum beta-tubulin gene spanning an intron. amplification products contained 11 polymorphic positions, representing a sequence divergence of 1.8%, which discriminated between isolates of c. parvum found solely in humans (genotype 1) and those found in humans and animals (genotype 2). seven of the polymorphic sites were located outside of the intron and the polymorphism between isolates was readily demonstr ...199910577745
cryptosporidium sp. and giardia sp. infections in mountain gorillas (gorilla gorilla beringei) of the bwindi impenetrable national park, uganda.for conservation purposes and because of growing ecotourism, some mountain gorilla (gorilla gorilla beringei) populations have been habituated to humans. fecal specimens (n = 100) of nonhabituated and human-habituated gorillas (5 populations; 6 age classes) were tested for cryptosporidium sp. oocysts and giardia sp. cysts by conventional staining and immunofluorescent antibody (ifa). cryptosporidium sp. infections (prevalence 11%) were not restricted to very young gorillas but were observed in 3 ...199910647041
[isolation and incidence of cryptosporidium and giardia from river water].a study was conducted during the period from july to october in 1999, surface water samples were collected from 13 rivers in hyogo prefecture serving as tap water sources and examined for cryptosporidium oocysts and giardia cysts using the immunomagnetic separation method. in 9 (69%) of the 13 rivers, cryptosporidium oocyst was detected. giardia cyst was detected in 5 (38%) of the 13 rivers. the cryptosporidium oocyst positive rate was comparable to that of fecal bacteriological indicators, whic ...200111321780
quantitative shedding of two genotypes of cryptosporidium parvum in california ground squirrels (spermophilus beecheyi).sixteen percent of california ground squirrels (spermophilus beecheyi) were found to be shedding an average of 53,875 cryptosporidium parvum oocysts/g of feces. male squirrels had a higher prevalence and higher intensity of shedding than did female squirrels. the majority of c. parvum isolates matched a bovine-murine genotype, with a few isolates resembling a porcine genotype. higher intensities of shedding by males may enhance dissemination and genotypic mixing of this protozoa given males' pro ...200111375204
cryptosporidium parvum-induced inflammatory bowel disease of tcr-beta- x tcr-delta-deficient mice.experimental inoculation of neonatal immunocompetent strains of mice with cryptosporidium parvum results in a transient, noninflammatory enteric infection. in the present study, we show that inoculation of mice deficient in alphabeta and gammadelta t cells (tcr-beta- x tcr-delta-deficient mice) with c. parvum results in persistent infection and severe inflammatory bowel disease-like lesions. the most severe lesions in these mice were in the cecum with similar yet less severe lesions in the ileum ...199910647043
phylogenetic relationships among isolates of cryptosporidium: evidence for several new species.isolates of cryptosporidium were characterized using nucleotide sequence analysis of the 18s rrna and dihydrofolate reductase genes and also random-amplified polymorphic dna analysis. phylogenetic analysis confirmed the validity of the species of cryptosporidium examined in this study such as cryptospordium muris and cryptosporidium baileyi, and also reinforced evidence from numerous researchers worldwide suggesting that cryptosporidium parvum is not a single uniform species. the data obtained p ...199910647047
inhibition of cryptosporidium infection in mice treated with a cyclodextrin inclusion complex with diloxanide furoate.the efficacies of diloxanide furoate, beta-cyclodextrin and a cyclodextrin inclusion complex against cryptosporidium parvum were evaluated in a suckling murine model. efficacy was established by numbers of oocysts recovered from the intestinal tract of mice on day 7 postinfection. the level of infection in treated mice was significantly lower than in control mice and, surprisingly, the most efficacious treatment was beta-cyclodextrin, an excipient used in pharmaceutical technology.200111411943
serological response to cryptosporidium parvum in adult cattle from the andean region of colombia.single faecal and serum samples were individually collected from 135 asymptomatic adult cows on seven farms in cundinamarca (colombian andean region). tests for the presence of oocysts of cryptosporidium parvum (carbol fuchsin stain) and eimeria spp (flotation in saturated saline solution) revealed that none of the animals had coccidia in their faeces. the igg antibody levels to c. parvum were measured by an enzyme-linked immunosorbent assay (elisa) technique and the reactivity to c. parvum anti ...200111411953
morphologic, host specificity, and molecular characterization of a hungarian cryptosporidium meleagridis isolate.this study was undertaken in order to characterize cryptosporidium meleagridis isolated from a turkey in hungary and to compare the morphologies, host specificities, organ locations, and small-subunit rna (ssu rrna) gene sequences of this organism and other cryptosporidium species. the phenotypic differences between c. meleagridis and cryptosporidium parvum hungarian calf isolate (zoonotic genotype) oocysts were small, although they were statistically significant. oocysts of c. meleagridis were ...200010653744
phenotypic and genotypic characterization of cryptosporidium species and isolates.recent outbreaks of cryptosporidiosis from contaminated water supplies have led to a need for the detection of cryptosporidium oocysts from various hosts and contaminating sources. the presence of nonpathogenic species or strains of cryptosporidium is important for diagnostic purposes as there is a potential for false- positive detection of pathogenic parasites. the present review focuses on phenotypic differences and recent advances in genotypic analyses of the genus cryptosporidium with an emp ...200111420647
[prevalence and importance of endoparasites in calves raised in swiss cow-calf farms].a longitudinal study was performed to establish estimates of prevalence of selected endoparasites in swiss cow-calf operations and to investigate the importance of an infection with endoparasites on diarrhea and weight gain until weaning. three hundred and eighty-six calves raised in 67 larger cow-calf herds were included in the study. faecal samples were collected during the first three months of life and at weaning. parasitological analyses were performed according to standard procedures inclu ...199910481370
natural transmission of cryptosporidium parvum between dams and calves on a dairy farm.the transmission of cryptosporidium parvum between dams and their respective calves was studied. for this purpose, fecal specimens taken from the rectum of preparturient, parturient, and postparturient dams were analyzed for c. parvum oocysts. fecal specimens were taken from the newborn calf 4 hr after birth. because the environment can be a source of contamination to the animals, specimens taken from inside and outside the barn were analyzed. the sucrose concentration method together with the z ...200010864245
dna fingerprinting of cryptosporidium parvum isolates using amplified fragment length polymorphism (aflp).the genetic variability of 10 cryptosporidium parvum isolates of human and animal origin was investigated using amplified fragment length polymorphism (aflp). analysis of fluorescent dye-labeled amplified products was carried out using an abi prisms 377 dna sequencer and abi prisms genescan software. one-hundred and twelve primer combinations were evaluated using a single c. parvum isolate. the patterns generated were highly reproducible. for subsequent study, a subset of 9 primer pairs that yie ...200010958466
constitutive expression of small subunit ribosomal rna transcripts in cryptosporidium parvum oocysts and intracellular stages.as in other apicomplexan protozoa, the ribosomal genes of cryptosporidium parvum are present in small number and dispersed on several chromosomes. two types of ribosomal small subunit genes have been identified in bovine isolates by sequencing and sequence-specific polymerase chain reaction. using denaturing gradient gel electrophoresis, ribosomal gene expression was investigated in c. parvum oocysts and intracellular stages grown in tissue culture. in a calf-propageted c. parvum isolate, extra ...199910219300
large sequence variation at two microsatellite loci among zoonotic (genotype c) isolates of cryptosporidium parvum.the genetic polymorphism among 57 cryptosporidium parvum isolates belonging to genotype 'c' was studied by pcr amplification and the sequencing of two microsatellite loci (ml1 and ml2). a comparative analysis of dna sequences showed the presence of three (ml1-238, ml1-226, and ml1-220) and seven (ml2-231, ml2-229, ml2-227, ml2-213, ml2-193, ml2-191, and ml2-187) different alleles at these two loci. alleles differed by expansions/contractions of the microsatellite repeats that generated length po ...200111429171
differential mrna display cloning and characterization of a cryptosporidium parvum gene expressed during intracellular development.differential mrna display was used to detect differences in gene expression between mock-infected and cryptosporidium parvum-infected human adenocarcinoma cells. a reproducible band present only in c. parvum-infected cells, ddhc-10 was isolated and cloned. northern blot analysis was used to confirm the differential expression of the hc-10 mrna. as differential mrna display does not differentiate between parasite and host mrnas, southern blot analysis was used to demonstrate that ddhc-10 represen ...199910219298
genetic and biological diversity among isolates of neospora caninum.neospora caninum is a protozoan parasite that causes bovine abortion. the epidemiology of n. caninum is poorly understood and little is known about the genetic diversity of the parasite, or whether individual isolates differ in virulence. such diversity may, among other factors, underlie the range of pathologies seen in cattle. in this study we analysed biological and genetic variation in 6 isolates of n. caninum originating from canine and bovine hosts by measurement of growth rate in vitro, we ...200111467779
excretion patterns of mucosally delivered antibodies to p23 in cryptosporidium parvum infected calves.fecal samples obtained at intervals from six calves with acute cryptosporidiosis contained antibodies of multiple isotypes to p23. igm-, iga-, and igg(1)-isotype anti-p23 appeared before igg(2)-isotype antibodies. all anti-p23 antibodies had declined by 2 months after infection. one calf that failed to shed oocysts following initial exposure developed igg(1)-isotype anti-p23 antibodies. one calf that died following exposure to cryptosporidium parvum oocysts lacked detectable anti-p23 antibodies. ...200011044562
calves as a potential reservoir of cryptosporidium parvum and giardia sp.studies on cryptosporidiosis and giardiosis were carried out between march and april 1997 on 75 calves from 9 selected farms of wielkopolska macroregion. faecal specimens from calves, 3-13 days old, were screened for oocysts of c. parvum using ziehl-neelsen staining and both for oocysts of c. parvum and cysts of giardia sp. using direct immunofluorescent (merifluor cryptosporidium/giardia) assay. the oocysts of c. parvum assessed by ziehl-neelsen staining were revealed on 6 (67%) of 9 farms exam ...19989860815
an examination of risk factors associated with beef cattle shedding pathogens of potential zoonotic concern.the prevalence of three waterborne zoonotic pathogens (campylobacter sp., giardia sp. and cryptosporidium parvum) in rectal faecal samples from a random sample of adult beef cattle was determined. management factors that may be associated with shedding of these organisms were examined. for campylobacter sp. prevalence was 5.0%, and the number of females on the farm was positively associated with the proportion that tested positive. for giardia sp. prevalence was 6.5%, and none of the management ...200111561967
molecular characterization of cryptosporidium isolates obtained from humans in france.cryptosporidium parvum is usually considered the agent of human cryptosporidiosis. however, only in the last few years, molecular biology-based methods have allowed the identification of cryptosporidium species and genotypes, and only a few data are available from france. in the present work, we collected samples of whole feces from 57 patients from france (11 immunocompetent patients, 35 human immunodeficiency virus [hiv]-infected patients, 11 immunocompromised but non-hiv-infected patients) in ...200111574558
detection of cryptosporidium parvum oocysts in environmental water in hokkaido, japan.control of cryptosporidiosis is important in public health. rivers that are polluted with cryptosporidium and drinking water that is treated for drinking water production from polluted rivers could result in the waterborne disease of cryptosporidiosis. we carried out an epidemiological study of natural water supplies in hokkaido, one of the largest dairy prefectures in japan. to detect cryptosporidium oocysts in environmental water, the filtration method was used for 28 samples, which were colle ...200111307921
number of cryptosporidium parvum oocysts or giardia spp cysts shed by dairy calves after natural infection.to determine the total number of cryptosporidium parvum oocysts and giardia spp cysts shed by dairy calves during the period when they are most at risk after natural infection.200111592328
infectivity to experimental rodents of cryptosporidium parvum oocysts from siberian chipmunks (tamias sibiricus) originated in the people's republic of china.we isolated cryptosporidium parvum-type oocysts from naturally infected siberian chipmunks which originated in the people's republic of china and examined the infectivity to rodents as experimental animals. the naturally infected chipmunks did not show any clinical symptoms. the oocysts were 4.8 x 4.2 microm on average in size. they were ovoid and morphologically similar to the c. parvum oocysts isolated from human and cattle. experimental rodents were inoculated with 1.6 x 10(6) original oocyst ...200010852396
transforming growth factor beta1 ameliorates intestinal epithelial barrier disruption by cryptosporidium parvum in vitro in the absence of mucosal t lymphocytes.exposure to oocysts of the protozoan cryptosporidium parvum causes intestinal epithelial cell dysfunction in vivo and in vitro, but effective means by which mucosal injury might be prevented remain unclear. we examined the ability of transforming growth factor beta1 (tgf-beta1)-a cytokine synthesized and released by cells in the intestine-to preserve the barrier function of human colonic epithelia when challenged with c. parvum oocysts and then studied the mechanisms involved. epithelial barrier ...200010992464
epidemiology of cryptosporidium spp. and giardia duodenalis on a dairy farm.prevalences of cryptosporidium spp. and giardia duodenalis in relation to age and season were investigated on a dairy farm in the netherlands over the course of 1year. the whole herd was sampled five times, whereas calves younger than about 2 months were sampled every 2-3 weeks. associations between diarrhoea and presence of one or more pathogens (cryptosporidium spp., g. duodenalis, rotavirus) were investigated. potential transmission routes of cryptosporidium spp. were evaluated and positive s ...200111705652
cryptosporidium parvum and mucosal immunity in neonatal cattle.cryptosporidium parvum is an important zoonotic protozoan pathogen that causes acute infection and self-limiting gastrointestinal disease in neonatal calves. there are currently no consistently effective antimicrobials available to control cryptosporidiosis. therefore, immunotherapeutic and vaccination protocols offer the greatest potential for long-term control of the disease. in order to devise effective control measures, it is important to better define mucosal immunity to c. parvum in young ...200011706841
dicyclic and tricyclic diaminopyrimidine derivatives as potent inhibitors of cryptosporidium parvum dihydrofolate reductase: structure-activity and structure-selectivity correlations.a structurally diverse library of 93 lipophilic di- and tricyclic diaminopyrimidine derivatives was tested for the ability to inhibit recombinant dihydrofolate reductase (dhfr) cloned from human and bovine isolates of cryptosporidium parvum (j. r. vásquez et al., mol. biochem. parasitol. 79:153-165, 1996). in parallel, the library was also tested against human dhfr and, for comparison, the enzyme from escherichia coli. fifty percent inhibitory concentrations (ic(50)s) were determined by means of ...200111709300
[cryptosporidium spp. in farms in the eastern region of venezuela].cryptosporidiosis is caused by the coccidian protozoa cryptosporidium. it is the most worldwide prevalent pathogen associated with diarrhea in young cattle and usually is caused by c. parvum which is also responsible of infections in humans, specially in immunocompromised patients. faecal samples from 75 young cattle aged between 2 to 20 weeks, were collected in four western dairy farms of venezuela and screened for the presence of cryptosporidium oocysts. positive samples were detected in 22 an ...200011155766
characterization of an intestinal epithelial cell receptor recognized by the cryptosporidium parvum sporozoite ligand csl.the protozoan parasite cryptosporidium parvum is a leading cause of diarrhea in humans and neonatal calves. the absence of approved parasite-specific drugs, vaccines, and immunotherapies for cryptosporidiosis relates in part to limited knowledge on the pathogenesis of zoite attachment and invasion. we recently reported that the c. parvum apical complex glycoprotein csl contains a zoite ligand for intestinal epithelial cells which is defined by monoclonal antibody (mab) 3e2. in the present study, ...200111179341
molecular characterization of cryptosporidium isolates obtained from human and bovine infections in japan.cryptosporidium oocysts, morphologically identified as cryptosporidium parvum, were isolated from 22 human and 14 bovine cases in japan, and were genotyped by means of a pcr/rflp analysis of the polythreonine gene. dna profiles of human isolates gave three distinct genotypes, namely an anthroponotic genotype 1, zoonotic genotype 2 and a new genotype. isolates from bovine samples gave zoonotic genotype 2. the unusual genotype of cryptosporidium was isolated from the feces of three immunologically ...200111728022
sequential inactivation of cryptosporidium parvum using ozone and chlorine.inactivation of bovine-derived c. parvum oocysts was studied at bench-scale in oxidant demand free 0.05 m phosphate buffer using free chlorine alone or ozone followed by free chlorine at temperatures of 1 degrees c, 10 degrees c and 22 degrees c at ph 6. animal infectivity using neonatal cd-1 mice was used for evaluation of oocyst viability after treatment. kinetic models based on the linear chick-watson model were developed for free chlorine inactivation and ozone/free chlorine sequential inact ...200111763036
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