Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| poor efficacy of residual chlorine disinfectant in drinking water to inactivate waterborne pathogens in distribution systems. | to evaluate the inactivating power of residual chlorine in a distribution system, test microorganisms (escherichia coli, clostridium perfringens, bacteriophage phi-x 170, and poliovirus type 1) were added to drinking water samples obtained from two water treatment plants and their distribution system. except for escherichia coli, microorganisms remained relatively unaffected in water from the distribution systems tested. when sewage was added to the water samples, indigenous thermotolerant colif ... | 1999 | 10528403 |
| reactive nitrogen and oxygen species ameliorate experimental cryptosporidiosis in the neonatal balb/c mouse model. | four-day-old balb/c mice were infected by the oral administration of 50,000 cryptosporidium parvum oocysts, and the resulting infection was scored histologically and by counting colonic oocysts. infection occurred in the ileum and proximal colon (but not duodenum and jejunum), peaked on days 14 to 18, and was cleared between days 24 and 30. nitric oxide (no) appeared to play a protective role in this model as evidenced by the facts that plasma nitrite and nitrate levels increased during the peri ... | 1999 | 10531244 |
| a comparison of the effects of two dinitroanilines against cryptosporidium parvum in vitro and in vivo in neonatal mice and rats. | the effects of two dinitroanilines, oryzalin and trifluralin, were compared against cryptosporidium parvum, in vitro using hct-8 cells and in vivo using neonatal swiss arc mice and wistar neonatal rats. in vitro, oryzalin and trifluralin exhibited ic(50) values (concentration necessary to cause a 50% inhibition) of 750 and 800 nm, respectively. a viability assay showed that neither compound produced a cytotoxic effect on the host cells at concentrations as high as 1 microm. the in vivo component ... | 1999 | 10536296 |
| supplementation with lactobacillus reuteri or l. acidophilus reduced intestinal shedding of cryptosporidium parvum oocysts in immunodeficient c57bl/6 mice. | the effect of l. acidophilus supplementation to reduce fecal shedding of cryptosporidium parvum oocysts was compared to l. reuteri using c57bl/6 female mice immunosuppressed by murine leukemia virus (strain lp-bm5) inoculation. after 12 weeks post lp-bm5 inoculation, 15 immunosuppressed mice each were randomly assinged to one of the following treatment groups: historical control (group a), lp-bm5 control (group b), c. parvum (group c), l. reuteri plus c. parvum (group d) or l. acidophilus plus c ... | 1999 | 10541481 |
| elimination of viruses, phages, bacteria and cryptosporidium by a new generation aquaguard point-of-use water treatment unit. | the elimination of human viruses, phages, bacteria and cryptosporidium oocysts by a new generation commercial aquaguard purifier for the domestic treatment of drinking water, has been evaluated. the unit basically consists of a candle prefilter, activated carbon filter and ultraviolet irradiation compartment. drinking water seeded with selected laboratory test strains of resistant micro-organisms was passed through the unit. similar tests were carried out with sewage-contaminated river water and ... | 1999 | 10546330 |
| 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 ... | 1999 | 10548585 |
| does cryptosporidium parvum have a clonal population structure? | cryptosporidiosis, the disease caused in humans by the opportunistic parasite cryptosporidium parvum, is the result of zoonotic or anthroponotic transmission. molecular characterization of different isolates from humans and other mammalian species has recently shown this species to be heterogeneous; this heterogeneity has been linked to the host of isolation, suggesting that the parasites causing zoonotic cryptosporidiosis and those propagated by anthroponotic transmission are genetically distin ... | 1999 | 10557152 |
| growth of toxoplasma gondii is inhibited by aryloxyphenoxypropionate herbicides targeting acetyl-coa carboxylase. | aryloxyphenoxypropionates, inhibitors of the plastid acetyl-coa carboxylase (acc) of grasses, also inhibit toxoplasma gondii acc. clodinafop, the most effective of the herbicides tested, inhibits growth of t. gondii in human fibroblasts by 70% at 10 microm in 2 days and effectively eliminates the parasite in 2-4 days at 10-100 microm. clodinafop is not toxic to the host cell even at much higher concentrations. parasite growth inhibition by different herbicides is correlated with their ability to ... | 1999 | 10557330 |
| 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. | 1999 | 10566807 |
| cryptosporidium infection in beech martens (martes foina). | temporary episodes of diarrhea in captive beech martens (martes foina) were accompanied by shedding of cryptosporidium oocysts. oocysts were detected in fecal samples by flotation and in acid-fast-stained smear preparations. the oocysts were 3-5 microns, which is consistent with c. parvum. the source of the cryptosporidium infection remained unknown. this is the first demonstration of cryptosporidium in beech martens. | 1999 | 10572868 |
| 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 ... | 1999 | 10574524 |
| prevalence of intestinal parasitic infections in patients with acquired immunodeficiency syndrome in brazil. | to evaluate the prevalence of intestinal parasitic infections and to investigate the possible associations of clinical status and laboratory findings with the different parasites found in stool samples. | 1999 | 10575149 |
| 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) ... | 1999 | 10576575 |
| 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 ... | 1999 | 10576576 |
| role of adult sheep in transmission of infection by cryptosporidium parvum to lambs: confirmation of periparturient rise. | in sheep farms, oocyst shedding by asymptomatic adult carriers is one of the mechanisms which may explain maintenance of infections by cryptosporidium parvum between lambing periods. the objective of this work was to investigate this hypothesis and the existence of a periparturient rise in oocyst shedding. fourteen pregnant sheep were randomly selected from two farms with a history of neonatal diarrhoea caused by c. parvum and samples were collected from the 6th week before birth until 2 weeks a ... | 1999 | 10576577 |
| 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 ... | 1999 | 10576578 |
| speculation on whether a vaccine against cryptosporidiosis is a reality or fantasy. | in this paper the authors question whether the development of a vaccine against cryptosporidiosis could be taken into consideration. the necessity and feasibility of such a vaccine for human and veterinary application is discussed. developmental stages within the life cycle of the parasite that might act as possible targets for vaccine development are summarised, as well as the target antigens offered by molecular biology and immunology studies. vaccination trials against cryptosporidiosis carri ... | 1999 | 10576579 |
| atypical outbreak of caprine cryptosporidiosis in the sultanate of oman. | an outbreak of cryptosporidiosis occurred in goats ranging in age from two days to adult, on a well-managed closed farm. none of the other animals on the farm, including sheep, cows and buffalo, were affected. morbidity approached 100 per cent in goats less than six months of age. despite intensive supportive care, 238 goats died, ranging in age from two days to over one year. cryptosporidia were detected in large numbers in the intestinal contents of dead animals and in faecal smears of animals ... | 1999 | 10576626 |
| cryptosporidium parvum: structural components of the oocyst wall. | cryptosporidium parvum, an enteropathogenic parasite, infects a wide range of mammals including man and constitutes a substantial veterinary and medical threat due to its ubiquitous distribution and the stability of the oocyst stage. the oocyst wall of c. parvum is known to be extremely resistant to chemical and mechanical disruption. isolated oocyst walls are shown by both thin sectioning and negative staining transmission electron microscopy to possess a filamentous array on the inner surface. ... | 1999 | 10577718 |
| oral dosing of neonatal mice with sucrose reduces infection with cryptosporidium parvum. | cryptosporidium parvum is a significant cause of diarrheal disease in humans and economically important livestock species. there is no effective treatment available for this protozoan parasite. mechanisms of intestinal colonization by c. parvum are not well understood, but it has been suggested that the parasite may utilize a lectin-like receptor. we used an infant mouse model to test whether high sugar concentrations in the intestine would affect in vivo colonization with c. parvum. we found th ... | 1999 | 10577733 |
| 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 ... | 1999 | 10577745 |
| managing gastrointestinal parasite infections in aids. | 1999 | 10578642 | |
| caspase-dependent apoptosis during infection with cryptosporidium parvum. | the protozoan parasite cryptosporidium parvum causes persistent diarrhea and malnutrition in children and the diarrhea-wasting syndrome in aids. no therapy exists for eliminating the parasite in the absence of a healthy immune response. although it had been reported that infection of intestinal cell lines with c. parvum leads to host cell death, the mechanisms of cytolysis have not been characterized. we show here that infection with c. parvum leads to typical apoptotic nuclear condensation and ... | 1999 | 10580271 |
| nosocomial infections in patients with hiv disease. | throughout the aids epidemic, nosocomial infection in the patient with hiv disease has presented a constant problem--not only for the hospitalized patient but also for the clinic attender. the nosocomial spread of multidrug-resistant tuberculosis has emphasized the need for effective control of infection measures in dealing with the immunodeficient. increased recognition of nosocomial bacterial pneumonias has raised questions about the place, if any, of antimicrobial prophylaxis in preventing gr ... | 1999 | 10582184 |
| 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 ... | 1999 | 10583987 |
| nasal immunization of mice with cryptosporidium parvum dna induces systemic and intestinal immune responses. | dna immunization offers a novel approach to inducing humoral and cellular immunity against infectious pathogens. we examined whether such an approach could be used against cryptosporiodiosis, an intestinal disease caused by the protozoan parasite cryptosporidium parvum. this infection is a major problem for young ruminants and immunosuppressed individuals in whom cryptosporidiosis causes life-threatening symptoms. the life cycle of c. parvum takes place in the enterocytes of the intestinal epith ... | 1999 | 10587377 |
| characterization of intracellular cryptosporidium parvum gene expression. | 1999 | 10589988 | |
| pathogenesis of cryptosporidium parvum infection. | cryptosporidium parvum can be regarded as a minimally invasive mucosal pathogen, since it invades surface epithelial cells that line the intestinal tract but does not invade deeper layers of the intestinal mucosa. nonetheless, infection can be associated with diarrhea and marked mucosal inflammation. this article briefly reviews in vitro and in vivo models useful for studying the pathogenesis of c. parvum infection and explores the role of innate and acquired immune responses in host defense aga ... | 1999 | 10594978 |
| the role of wild rats as a reservoir of some internal parasites in qalyobia governorate. | a total of one hundred and seventy two rats were trapped from different localities, rattus norvegicus and rattus r. alexandrinus. the overall infection-rate was 54% (93 out 172 rats). the infection rates of identified parasites were 28% cestodes (23.8% hymenolepis diminuta and 7% cysticercus fasciolaris), 8% acanthocephala species (moniliformis moniliformis) and 7% nematodes (strongyloides species). on the other hand, 40.7% were infected with protozoa (22.7% cryptosporidium parvum, 20.3% c. muri ... | 1999 | 10605500 |
| survey on equine cryptosporidiosis in poland and the possibility of zoonotic transmission. | the present study was undertaken to investigate the prevalence of cryptosporidium infection in horses used for recreational riding as well as in humans. a total of 106 faecal specimens from horses raised in 4 localities of western poland and 6 stool samples from 3 persons who had constant or sporadic contact with horses were screened microscopically for oocysts using modified ziehl-neelsen staining. enzyme immunoassay (eia) was additionally used for the detection of coproantigen in human stool s ... | 1999 | 10607998 |
| antimicrobial activity of polycationic peptides. | the in vitro activity of six polycationic peptides, buforin ii, cecropin p1, indolicidin, magainin ii, nisin, and ranalexin, were evaluated against several clinical isolates of gram-positive and gram-negative aerobic bacteria, yeasts, pneumocystis carinii and cryptosporidium parvum, by using microbroth dilution methods. the peptides exhibited different antibacterial activities and rapid time-dependent killing. the gram-negative organisms were more susceptible to buforin ii and cecropin p1, where ... | 1999 | 10612440 |
| 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. | 1999 | 10613218 |
| in vitro anticryptosporidial activity of ranalexin alone and in combination with other peptides and with hydrophobic antibiotics. | the in vitro activity of ranalexin alone and in combination with other cationic peptides, macrolides, rifampin, and rifabutin was investigated against a clinical isolate of cryptosporidium parvum. susceptibility tests were performed by inoculation of the isolate onto cell monolayers and determining the parasite count after 48 h of incubation at 37 degrees c. antibiotic-free cultures were used as controls in the study. ranalexin showed low anticryptosporidial activity: it suppressed the growth of ... | 1999 | 10614961 |
| evaluation of immunomagnetic separation for recovery of infectious cryptosporidium parvum oocysts from environmental samples. | two commercial immunomagnetic separation (ims) kits for cryptosporidium were compared for recovery of oocysts from environmental samples. oocyst recovery efficiencies with the dynal and crypto-scan kits ranged from 62 to 100% and 34 to 74%, respectively, for seeded environmental water concentrates (turbidity of 210 to 11,480 nephelometric turbidity units). recovery efficiencies were dependent on the mechanism of agitation during the magnetic capture procedure. an assay combining in vitro cell cu ... | 1999 | 9925626 |
| detection of cryptosporidium oocysts in wild mammals of mainland britain. | this paper combines the results from a preliminary survey of occurrence of cryptosporidium species in faecal samples from a range of wild mammal species inhabiting mainland britain with a tabulated literature review of world-wide reports of the parasite in those british mammals. in the literature, c. parvum was reported from 11 wild mammals found in britain and elsewhere, mainly in rodents but also in insectivores, lagomorphs and ungulates. c. muris has been reported only in wild rodents. the sa ... | 1999 | 9950333 |
| regional seroprevalence of cryptosporidium parvum-specific igg of cats in the united states. | the objective of this study was to determine the regional prevalence of cryptosporidium parvum-specific igg in the sera of cats in the united states. the continental united states was partitioned into eight regional areas. serum samples from 75 cats from each region were assayed for c. parvum-specific igg using an indirect enzyme-linked immunosorbent assay (elisa). age, sex, breed, and indoor/outdoor status were examined as possible risk factors for developing a positive c. parvum-specific igg a ... | 1999 | 9950343 |
| infectivity of cryptosporidium parvum in healthy adults with pre-existing anti-c. parvum serum immunoglobulin g. | a 50% infectious dose (id50) of 132 cryptosporidium parvum oocysts was previously determined in serologically negative individuals (elisa). in this study, 17 healthy adults with pre-existing anti-c. parvum serum igg were challenged with 500-50,000 oocysts. infection and diarrhea were associated with the higher challenge doses. the id50 was 1,880 oocysts, > 20-fold higher than in seronegative volunteers. fecal oocysts were detected in only seven (53.8%) of 13 individuals with clinical cryptospori ... | 1999 | 9988341 |
| cryptosporidium parvum infection in suckling rats: impairment of mucosal permeability and na(+)-glucose cotransport. | na(+)-glucose transport and transepithelial permeability were investigated during symptomatic acute cryptosporidiosis in newborn rats. the infection resulted in a significant (p < 0.01) decrease in the ileal short-circuit current and a nonsignificant fall in the transepithelial potential difference and conductance. in glucose-stimulated conditions, the rise in ileal short-circuit current and transepithelial permeability were significantly lower in cryptosporidium parvum-infected rats than in con ... | 1999 | 9990339 |
| 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. | 1999 | 10023403 |
| 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 ... | 1999 | 10024577 |
| declining cd4+ t-lymphocyte counts are associated with increased risk of enteric parasitosis and chronic diarrhea: results of a 3-year longitudinal study. | from january 1991 through september 1994, we observed people who were infected with hiv to assess the impact of enteric parasite-associated diarrhea. respondents answered comprehensive questionnaires covering clinical and epidemiologic information and provided stool specimens monthly, which were examined unstained as well as stained with trichrome, chromotrope 2r, and with kinyoun carbol-fuchsin, and with indirect immunofluorescence for cryptosporidium. in all, 602 participants, who were intervi ... | 1999 | 10048902 |
| 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 ... | 1999 | 10190862 |
| 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 ... | 1999 | 10190863 |
| the cryptosporidium "mouse" genotype is conserved across geographic areas. | a 298-bp region of the cryptosporidium parvum 18s rrna gene and a 390-bp region of the acetyl coenzyme a synthetase gene were sequenced for a range of cryptosporidium isolates from wild house mice (mus domesticus), a bat (myotus adversus), and cattle from different geographical areas. previous research has identified a distinct genotype, referred to as the "mouse"-derived cryptosporidium genotype, common to isolates from australian mice. comparison of a wider range of australian mouse isolates w ... | 1999 | 10203475 |
| detection by enzyme immunoassay of serum immunoglobulin g antibodies that recognize specific cryptosporidium parvum antigens. | human infection with cryptosporidium parvum usually elicits characteristic immunoglobulin g (igg), iga, and igm antibody responses against two sporozoite surface antigens with apparent molecular masses of approximately 27 and 17 kda. we have determined that these two antigens are actually complex families of related antigens. we have developed two new enzyme-linked immunosorbent assays (elisas) for the detection and quantitation of serum igg antibodies against both antigens. the assays utilize a ... | 1999 | 10203492 |
| biallelic polymorphism in the intron region of beta-tubulin gene of cryptosporidium parasites. | nucleotide sequencing of polymerase chain reaction amplified intron region of the cryptosporidium parvum beta-tubulin gene in 26 human and 15 animal isolates revealed distinct genetic polymorphism between the human and bovine genotypes. the separation of 2 genotypes of c. parvum is in agreement with our previous genotyping data based on the thrombospondin-related adhesion protein (trap-c2) gene, indicating these genotype characteristics are linked at 2 genetic loci. characterization of cryptospo ... | 1999 | 10207387 |
| age, geographic, and temporal distribution of fecal shedding of cryptosporidium parvum oocysts in cow-calf herds. | to evaluate fecal shedding of cryptosporidium parvum from california cow-calf herds with respect to age, geographic region, temporal effects, and association with watery feces. | 1999 | 10211683 |
| 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 ... | 1999 | 10219298 |
| 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 ... | 1999 | 10219300 |
| role of intraepithelial lymphocytes in mucosal immune responses of mice experimentally infected with cryptosporidium parvum. | in order to investigate the role of intestinal intraepithelial lymphocytes (iels) in host defense against cryptosporidium parvum infection, conventionally bred immunocompetent (imct) icr mice and immunosuppressed (imsp) littermates were infected orally with 10(6) c. parvum oocysts. then fecal oocyst excretion, the number and location of iels, and their t lymphocyte subsets were observed on days 4, 7, 10, 13, 16, and 20 postinfection (pi). uninfected imct and imsp mice were used as controls. the ... | 1999 | 10219301 |
| use of a sentinel system for field measurements of cryptosporidium parvum oocyst inactivation in soil and animal waste. | a small-volume sentinel chamber was developed to assess the effects of environmental stresses on survival of sucrose-percoll-purified cryptosporidium parvum oocysts in soil and animal wastes. chambers were tested for their ability to equilibrate with external chemical and moisture conditions. sentinel oocysts were then exposed to stresses of the external environment that affected their viability (potential infectivity), as indicated by results of a dye permeability assay. preliminary laboratory ... | 1999 | 10223991 |
| 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 ... | 1999 | 10228259 |
| [an evaluation of the relationship between intestinal parasitoses and the risk factors for hiv in aids patients]. | we conducted a cohort survey on 200 aids patients in são paulo, sp, brazil, to verify if the presence of enteroparasites is associated with the various risk factors for hiv infection. diarrhea was significantly more frequent in the group of patients presenting enteroparasitosis (p < 0.00001). giardia lamblia, found in 32 (16%) cases, was the most prevalent parasite. the presence of parasites in the stool samples was not significantly associated with risk factors for hiv infection, mainly when co ... | 1999 | 10228369 |
| fast and reliable extraction of protozoan parasite dna from fecal specimens. | polymerase chain reaction (pcr) detection of intestinal protozoa in fecal specimens is hampered by poor recovery of dna and by the presence of pcr inhibitors. in this study we describe a novel method for dna extraction from such specimens containing spores and oocysts of enterocytozoon bieneusi and cryptosporidium parvum, respectively. | 1999 | 10229775 |
| cryptosporidiosis in a black bear in virginia. | cryptosporidiosis has not been previously reported in black bears in north america, either free-roaming or captive. however, oocysts have been documented in two captive malayan sun bears (helarctos malayanus) located in zoological parks in taiwan. developmental stages of cryptosporidium parvum were observed in tissue sections from the small intestine of a black bear cub found dead in virginia (usa). | 1999 | 10231767 |
| opportunism and aids: walking the tightrope. | 1999 | 10234182 | |
| cpabc, a cryptosporidium parvum atp-binding cassette protein at the host-parasite boundary in intracellular stages. | the intracellular parasite cryptosporidium parvum develops inside a vacuole at the apex of its epithelial host cell. the developing parasite is separated from the host cell cytoplasm by a zone of attachment that consists of an extensively folded membranous structure known as the feeder organelle. it has been proposed that the feeder organelle is the site of regulation of transport of nutrients and drugs into the parasite. in this report, we localize an approximately 200-kda integral membrane pro ... | 1999 | 10318953 |
| sacroiliitis associated with cryptosporidium parvum in an hla-b27-negative patient. | 1999 | 10325675 | |
| [a new trichromic safranin stain for the detection of cryptosporidium parvum, cyclospora cayetanensis, species of microsporidia and isospora belli in fecal material]. | cryptosporidium parvum, isospora belli, cyclospora cayetanensis and microsporidia are frequent pathogens in the immunodeficient host, which may cause multiple infections. the above mentioned parasites are found in feces by the application of different specific tintorial techniques. the objective of this work was the development of a stain for the simultaneous detection of these parasites, reducing costs as well as the time taken to make the diagnosis. the safranin-trichrome stain is simple, chip ... | 1999 | 10932763 |
| immunodetection of the microvillous cytoskeleton molecules villin and ezrin in the parasitophorous vacuole wall of cryptosporidium parvum (protozoa: apicomplexa). | microvilli - actin - villin - ezrin - cryptosporidium parvum the sporozoites and merozoites of the apicomplexan protozoan cryptosporidium parvum (c. parvum) invade the apical side of enterocytes and induce the formation of a parasitophorous vacuole which stays in the brush border area and disturbs the distribution of microvilli. the vacuole is separated from the apical cytoplasm of the cell by an electron-dense layer of undetermined composition. in order to characterize the enterocyte cytoskelet ... | 1999 | 10604656 |
| case of cryptosporidiosis in an iraqi woman with ulcerative colitis. | 1999 | 10793796 | |
| an enterotoxic activity of 18-20 kda cryptosporidium parvum secretory coproantigen (cca 18-20 kda). | an 18-20 kda cryptosporidum coproantigen (18-20 cca), had been detected in the stool of infected humans and calves. a purified, electroeluted and concentrated 18-20 kda antigen was tested in ussing chamber, and electric parameters were tested before and after the addition of this antigen. a significant increase in the short circuit current (isc) was detected. the enterotoxic effectof 18-20 kda cca, was time and dose dependent, heat labile, and cl- dependent. the detected change in the short circ ... | 1999 | 12561907 |
| immunofluorescent detection of both giardia lamblia and cryptosporidium parvum using anti-cryptosporidium oocyst antibodies. | giardia lamblia and cryptosporidium parvum are two protozoal parasites proved to have a major role in gastroenteritis in humans. both are documented to coexist in many waterborne parasitic transmission, as well as in outbreaks. in the present work, a polyspecific anti-cryptosporidium oocyst antibodies were used for simultaneous detection of both parasites in human stool. known positive formalinized human stool specimens of giardia sp. (n = 10), cryptosporidium sp. (n = 7), mixed infection (n = 3 ... | 1999 | 12561917 |
| evaluation of five stains in diagnosing human intestinal coccidiosis. | three hundreds cases over the year 1998 complaining of diarrhoea were examined. the stools were examined by the traditional diagnostic methods and confirmed to be free from intestinal parasites. cryptosporidium parvum, isospora belli and cyclospora cayetanensis were detected by using different types of faecal stains namely modified ziehl-neelsen, kinyoun acid-fast, auramine-rhodamine, gomori's trichrome and giemsa. the number of positive cases were 87 c. parvum (29%), 5 cases l. belli (1.7%) and ... | 1999 | 12561927 |
| opportunistic intestinal protozoal infections in immunocompromised children. | hundred immunocompromised children and 100 house contact controls were chosen. patients included: 52 nephrotic syndrome children receiving corticosteroids for more than one month (age 5.28 +/- 2.32 years), 14 protein-calorie malnutrition (pcm) patients (8 cases of marasmus aged 6 +/- 2.27 months and 6 cases of marasmic kwashiorkor aged 1.39 +/- 0.88 years) and 34 lymphomas patients (22 cases of hodgkin's disease and 12 cases of non-hodgkin's lymphoma; age 4.5 +/- 3.54 years). examination of conc ... | 1999 | 12561933 |
| [studies on immunoprotection of monoclonal antibodies against cryptosporidium parvum]. | to explore the immune protection of the monoclonal antibody (mcab) against cryptosporidium parvum. | 1999 | 12563792 |
| [preparation of dna probe for cryptosporidium parvum]. | to prepare a probe with high specificity and sensitivity for the detection of cryptosporidium parvum. | 1999 | 12563795 |
| [advances in researches on anti-cryptosporidium parvum hyperimmune bovine colostrum]. | 1999 | 12563798 | |
| enhanced detection of cryptosporidium parvum in the acid-fast stain. | 1999 | 12968749 | |
| [cryptosporidiosis in hiv-positive patients]. | cryptosporidium parvum is a coccidian parasite that affects millions of people worldwide. clinical outcome of human cryptosporidiosis differs between immunocompetent and immnunodeficient individuals. c. parvum is responsible for causing protracted and life-threatening diarrhea, biliary, and pulmonary infections in immunocompromised persons, especially in patients with aids. though no effective treatment has been found so far, early diagnosis may be useful in controlling the infection. thirty-eig ... | 1999 | 16886452 |
| everyday and exotic foodborne parasites. | everyday foodborne parasites, which are endemic in canada, include the protozoans entamoeba histolytica, giardia lamblia and cryptosporidium parvum. however, these parasites are most frequently acquired through unfiltered drinking water, homosexual activity or close personal contact such as in daycare centres and occasionally via a food vehicle. it is likely that many foodborne outbreaks from these protozoa go undetected. transmission of helminth infections, such as tapeworms, is rare in canada ... | 2000 | 18159283 |
| a nmri suckling mouse model for the evaluation of infectivity of cryptosporidium parvum oocysts. | to evaluate the infectivity of cryptosporidium parvum oocysts in nmri suckling mouse. | 2000 | 12567724 |
| characterization of a major sporozoite surface glycoprotein of cryptosporidum parvum. | we have identified s60, a new cryptosporidium parvum sporozoite surface glycoprotein. s60 was cleaved into two subunits, s16 and s45, approximately 16-18 and 45-47 kda respectively, with cleavage occurring at an srsrr motif likely to be sensitive to trypsin in vivo. analysis by surface biotinylation, lectins and monoclonal antibodies suggests s60 is an abundant sporozoite surface glycoprotein that is shed by migrating sporozoites. the major glycosylation on s60 was identified as single o-linked ... | 2000 | 11793239 |
| detection of cryptosporidium parvum antigen by co-agglutination test and elisa. | confirmation of the presence of cryptosporidium in environmental samples is laborious, costly and often difficult. we report here a simple and economic slide agglutination test (co-agglutination test) for detecting cryptosporidial antigen in stool, serum and water. the results show that as a screening method co-agglutination is clearly superior to enzyme-linked immunosorbent assay (elisa) and modified ziehl-neelsen staining, although elisa is more accurate. the co-agglutination test is recommend ... | 2000 | 12197347 |
| coccidial infection in immunosuppressed mice: prophylaxis and treatment with dehydroepiandrosterone. | cryptosporidiosis and toxoplasmosis are diseases caused by opportunistic coccidial parasites that can lead to life-threatening infection in immunocompromised patients. we evaluated dehydroepiandrosterone as prophylaxis and therapy in immunosuppressed mice infected with cryptosporidium parvum and avirulent toxoplasma gondii. mice were infected with either cryptosporidium oocysts or toxoplasma cysts. assessment was by mortality rates, parasitic counts and electron microscopic studies. mortality ra ... | 2000 | 12197348 |
| [giardiasis: a parasitic disease of continued topicality. study of prevalence among a selected adult population] | we studied the prevalence of giardia intestinalis in five patients risk groups including institutionalised psychiatric of elderly subjects, hiv-positive immunocompromised patients, immigrants from developing countries and travellers to tropical countries. stool specimens of 1319 subjects were studied. stools were collected in triplicate from each subject. the presence of bacteria, viruses and parasites was evaluated. a direct smear examination from fresh faecal specimens and after concentration ... | 2000 | 12709600 |
| effect of antiretroviral therapy on cryptosporidiosis and microsporidiosis in patients infected with human immunodeficiency virus type 1. | to better understand whether potent antiretroviral therapies can modify the natural history of hiv-1-associated microsporidiosis and cryptosporidiosis, the response to antimicrobial treatment of these opportunistic infections was evaluated in patients with or without antiretroviral treatment. fifty patients with diarrhoea, all positive for cryptosporidium parvum or enterocytozoon bieneusi, were included in the study. retrospective data were collected concerning demographics, clinical and microbi ... | 2000 | 10795595 |
| in vitro anti-cryptosporidial activity of cationic peptides alone and in combination with inhibitors of ion transport systems. | the anti-cryptosporidial activity of four cationic peptides alone and in combination with five ion transport system (its) inhibitors was investigated for six clinical isolates of cryptosporidium parvum recovered from stools of aids patients. the susceptibility tests were performed by inoculating the protozoa on to cell monolayers and determining the parasite count after 48 h incubation at 37 degrees c. the culture medium was supplemented with serial dilutions of cecropin p1, magainin ii, indolic ... | 2000 | 10797088 |
| quantitative polymerase chain (qpcr) reaction using the mimic approach to estimate cryptosporidium parvum oocysts, an intestinal pathogen, in municipal water treatment sludge samples. | an accurate estimation of the number of cryptosporidium parvum oocysts in water treatment plant sludge was determined using the quantitative polymerase chain reaction (qpcr) method. approximately 8x10(6)purified viable oocysts were spiked into raw water and treated by conventional water treatment methods. the settled sludge was collected and the dna extracted. the qpcr mimic produced two competing products that were 300 and 435 base pairs in size. the log ratio of the products were used in the s ... | 2000 | 10799274 |
| study of the combined influence of environmental factors on viability of cryptosporidium parvum oocysts in water evaluated by fluorogenic vital dyes and excystation techniques. | using a factorial experimental design, the combined effect of salinity, temperature and storage time on the viability of cryptosporidium parvum oocysts in water was evaluated by fluorogenic vital dyes (4',6-diamidino-2-phenylindole and propidium iodide) and an excystation technique. salinity, storage time and their interaction seemed to be the most influential factors, whereas temperature was not a significant factor. under unfavourable conditions (salinity 35 per thousand, storage time 40 days) ... | 2000 | 10799838 |
| 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 ... | 2000 | 10799839 |
| 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 ... | 2000 | 10799844 |
| rotifers ingest oocysts of cryptosporidium parvum. | six genera of rotifers including philodina, monostyla, epiphanes, euchlanis, brachionus, and asplanchna were exposed to oocysts of cryptosporidium parvum cleaned of fecal debris. unstained oocysts and those stained with fluorescein-conjugated monoclonal antibody were added to suspensions of viable rotifers and were examined by phase-contrast, differential interference contrast, and fluorescence microscopy. rotifers of all six genera were observed ingesting oocysts. a maximum of 25 oocysts was ob ... | 2000 | 10750844 |
| balancing the risks and benefits of drinking water disinfection: disability adjusted life-years on the scale. | to evaluate the applicability of disability adjusted life-years (dalys) as a measure to compare positive and negative health effects of drinking water disinfection, we conducted a case study involving a hypothetical drinking water supply from surface water. this drinking water supply is typical in the netherlands. we compared the reduction of the risk of infection with cryptosporidium parvum by ozonation of water to the concomitant increase in risk of renal cell cancer arising from the productio ... | 2000 | 10753089 |
| 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 ... | 2000 | 10759081 |
| malaria, intestinal parasites, and schistosomiasis among barawan somali refugees resettling to the united states: a strategy to reduce morbidity and decrease the risk of imported infections. | in 1997, enhanced health assessments were performed for 390 (10%) of approximately 4,000 barawan refugees resettling to the united states. of the refugees who received enhanced assessments, 26 (7%) had malaria parasitemia and 128 (38%) had intestinal parasites, while only 2 (2%) had schistosoma haematobium eggs in the urine. mass therapy for malaria (a single oral dose of 25 mg/kg of sulfadoxine-pyrimethamine) was given to all barawan refugees 1-2 days before resettlement. refugees >2 years of a ... | 2000 | 10761735 |
| characterization and formulation of multiple epitope-specific neutralizing monoclonal antibodies for passive immunization against cryptosporidiosis. | the coccidian parasite cryptosporidium parvum causes diarrhea in humans, calves, and other mammals. neither immunization nor parasite-specific pharmaceuticals that are consistently effective against this organism are available. while polyclonal antibodies against whole c. parvum reduce infection, their efficacy and predictability are suboptimal. we hypothesized that passive immunization against cryptosporidiosis could be improved by using neutralizing monoclonal antibodies (mabs) targeting funct ... | 2000 | 10768951 |
| eradication of cryptosporidium parvum infection by mice with ovalbumin-specific t cells. | cd154 is necessary for mice to clear a cryptosporidium parvum infection, but whether this ligand has to be expressed on t cells with specificity for c. parvum has not been determined. we infected do11.10 (ovalbumin specific) t-cell receptor transgenic mice that had been bred to a rag(-/-) background with c. parvum and found that the infection was cleared within 6 weeks, while rag(-/-) controls were unable to clear c. parvum infection. recovery was accompanied by an increase in the number of sple ... | 2000 | 10768958 |
| estimating viability of cryptosporidium parvum oocysts using reverse transcriptase-polymerase chain reaction (rt-pcr) directed at mrna encoding amyloglucosidase. | the purpose of the present study was to determine if reverse transcriptase-polymerase chain reaction (rt-pcr) directed at mrna encoding the enzyme amyloglucosidase (cpag) could serve as a indicator for c. parvum oocyst viability. oocysts were stored for 1-11 months in the refrigerator and at monthly intervals extracted for total rna for rt-pcr analysis. an aliquot of these c. parvum oocysts was inoculated into neonatal mice which were necropsied 4 days later for ileal tissue that was analyzed by ... | 2000 | 11121608 |
| b cells are required for the induction of intestinal inflammatory lesions in tcralpha-deficient mice persistently infected with cryptosporidium parvum. | mice with targeted disruptions in the t-cell receptor alpha gene (tcralpha-/-) spontaneously develop inflammatory intestinal lesions with extensive b-cell lamina propria infiltrates. cryptosporidium parvum infection accelerates intestinal lesion formation in tcralpha-/- mice. in the present study, tcralpha-/- mice were crossed with jh-/- (b-cell-deficient) mice and challenged with c. parvum to determine if b cells are required for intestinal lesion development. tcralpha-/- x jh-/- mice challenge ... | 2000 | 11128483 |
| 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 ... | 2000 | 11128490 |
| 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. | 2000 | 11128505 |
| 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 ... | 2000 | 11128511 |
| a factor derived from adult rat and cow small intestine reduces cryptosporidium parvum infection in infant rats. | cryptosporidium parvum is an intracellular protozoan parasite of the mammalian intestine. in rats, c. parvum infection is age related; infants are susceptible, whereas adults are resistant. the transition from susceptibility to resistance usually takes place around the age of weaning. in the present study, infant rats were orally inoculated with a preparation of intestinal scrapings taken from adult rats or cows. infant rats received the scrapings daily from 3 to 14 days of age, were inoculated ... | 2000 | 11128521 |
| 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 ... | 2000 | 11129874 |
| 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 ... | 2000 | 10941515 |
| laboratory diagnosis of cryptosporidium parvum infection. | 2000 | 10943506 | |
| clinical aspects of human cryptosporidiosis. | 2000 | 10943507 | |
| host immune responses against cryptosporidium. | 2000 | 10943508 | |
| gene discovery in cryptosporidium parvum: expressed sequence tags and genome survey sequences. | 2000 | 10943509 |