| increased stool sampling during a waterborne outbreak of cryptosporidiosis does not increase the detection of other faecal pathogens. | to ascertain the effect of enhanced surveillance following an outbreak of waterborne cryptosporidiosis on the number of faecal specimens submitted to the local microbiology laboratory and the number positive for common enteric pathogens. the outbreak provided an opportunity to estimate the extent of routine under ascertainment of common enteric pathogens. | 2002 | 11919210 |
| epidemiological survey of cryptosporidiosis in anhui province china. | to provide scientific evidence for prevention and controlling of cryptosporidiosis, the infection of cryptosporidium parvum and its epidemiological characteristics were studied in some areas of anhui province. | 2002 | 11925628 |
| survival of cryptosporidium parvum oocysts recovered from experimentally contaminated oysters (ostrea edulis) and clams (tapes decussatus). | samples of two species of shellfish that form part of the human food chain (the oyster ostrea edulis and the marine clam tapes decussatus) were experimentally contaminated with cryptosporidium parvum oocysts. changes in the viability of oocysts subsequently recovered from the shellfish were evaluated by means of an immunofluorescent antibody technique (ifat) and inclusion/exclusion of the fluorogenic vital dye propidium iodide. there was a sharp decrease in oocyst viability during the first 4 da ... | 2002 | 11936501 |
| cryptosporidium virulence determinants--are we there yet? | exposure to cryptosporidium parvum in healthy individuals results in transient infection that may be asymptomatic or can result in self-limited diarrhoea. in contrast, acquired immune deficiency syndrome patients with cryptosporidiosis can experience severe manifestations of disease. volunteer studies have demonstrated that as few as 10 oocysts can cause infection in otherwise healthy adults and that isolates from geographically diverse regions differ in infectivity and, perhaps, virulence. vari ... | 2002 | 11943224 |
| seasonal distribution of enteropathogens detected from diarrheal stool and water samples collected in kathmandu, nepal. | a total of 334 diarrheal fecal samples (from 210 males and 124 females) collected in kathmandu, nepal, were studied for various kinds of enteropathogens. overall, 33% (111/334) fecal samples were positive for one or more enteropathogens. there was no difference in detection rates between males and females. enteropathogen detection rates in summer, winter, spring, and autumn were 61% (40/66), 52% (45/87), 31% (25/81), and 25% (25/100), respectively. altogether eight species of bacteria, three gen ... | 2001 | 11944710 |
| specific bovine antibody response against a new recombinant cryptosporidium parvum antigen containing 4 zinc-finger motifs. | a cryptosporidium parvum sporozoite and oocyst lambda gt11 cdna library was screened with a hyperimmune rabbit serum that was developed against insoluble fragments of ultrasonicated oocysts. a clone named cp22.4.1 encoding a protein of 231 amino acids with 4 zinc-finger domains characterized by a cys-x2-cys-x4-his-x4-cys motif was isolated and characterized. there was a complete match between the sequencing data of the coding region of cp22.4.1 and the corresponding gene at chromosomal level. cl ... | 2002 | 11949214 |
| buparvaquone mucoadhesive nanosuspension: preparation, optimisation and long-term stability. | the poorly soluble drug buparvaquone is used in experimental clinics against the gastrointestinal persisting parasite cryptosporidium parvum. it was produced as nanosuspension by high pressure homogenisation. main advantages of nanosuspensions (amongst others) are their increase of saturation solubility and dissolution velocity, improving the bioavailability of drugs. the buparvaquone nanosuspension had a bulk population of about 600 nm (analysed by photon correlation spectroscopy (pcs)). the ad ... | 2002 | 11955813 |
| genetic complementation in apicomplexan parasites. | a robust forward genetic model for apicomplexa could greatly enhance functional analysis of genes in these important protozoan pathogens. we have developed and successfully tested a genetic complementation strategy based on genomic insertion in toxoplasma gondii. adapting recombination cloning to genomic dna, we show that complementing sequences can be shuttled between parasite genome and bacterial plasmid, providing an efficient tool for the recovery and functional assessment of candidate genes ... | 2002 | 11959921 |
| post-infective diarrhoea. | when diarrhoea caused by gastroenteritis persists for more than two weeks it is referred to as persistent diarrhoea in developing countries. whilst the control of diarrhoeal diseases programme has decreased mortality from acute diarrhoea, mortality from persistent diarrhoea has not been so responsive. a number of factors have been identified which are determinants for the progression of an acute episode to one which persists in developing communities. in one study from west africa, current infec ... | 2001 | 11964877 |
| parasitic infections of the intestine. | intestinal protozoal infections cause significant disease not only in the tropics but also in immunocompromised hosts and returning travellers in the developed world. precise diagnosis of protozoal intestinal infection by microscopy can be difficult. enzyme immunoassays for antigen detection are being used for some protozoal infections with some limitations which will, it is hoped, be overcome by molecular techniques. nucleic acid amplification techniques could help improve detection of microspo ... | 2001 | 11964880 |
| concentration of cryptosporidium, microsporidia and other water-borne pathogens by continuous separation channel centrifugation. | the aim of this study was to determine the effectiveness of continuous separation channel centrifugation for concentrating water-borne pathogens of various taxa and sizes. | 2002 | 11966905 |
| giardia and cryptosporidium removal from waste-water by a duckweed (lemna gibba l.) covered pond. | to determine the ability of duckweed ponds used to treat domestic waste-water to remove giardia and cryptosporidium. | 2002 | 11967063 |
| efficacy of common laboratory disinfectants on the infectivity of cryptosporidium parvum oocysts in cell culture. | nine liquid disinfectants were tested for their ability to reduce infectivity of cryptosporidium parvum oocysts in cell culture. a 4-min exposure to 6% hydrogen peroxide and a 13-min exposure to ammonium hydroxide-amended windshield washer fluid reduced infectivity 1,000-fold. other disinfectants tested (70% ethanol, 37% methanol, 6% sodium hypochlorite, 70% isopropanol, and three commercial disinfectants) did not reduce the infectivity after a 33-min exposure. the results indicate that hydrogen ... | 2002 | 11976138 |
| efficacy of iodine water purification tablets against cryptosporidium oocysts and giardia cysts. | the ability to control water-borne diseases is critical for soldiers, hikers, and others who may need to drink directly from an outdoor source. water-borne protozoan parasites that are specifically of concern are giardia and cryptosporidium because of their resistance to halogen disinfection. the purpose of this study was to determine the effectiveness of iodine tablets against giardia and cryptosporidium under general- and worst-case water conditions that might be found in the field. giardia cy ... | 1997 | 11990150 |
| prevalence of and risk factors involved in the spread of neonatal bovine cryptosporidiosis in galicia (nw spain). | an epidemiological study was carried out on farms in galicia (nw spain) to investigate the prevalence of and the risk factors associated with the spread of infection by cryptosporidium parvum in calves of less than 3 weeks of age. a total of 22 cattle farms (10 beef herds and 12 dairy herds) were visited once every 21 days between january and december 2000. a faecal sample was collected directly from the rectum of each of the 844 calves born during the study period. each sample was studied macro ... | 2002 | 11992706 |
| a study of cryptosporidiosis in a cohort of neonatal calves. | during calving time on an experimental farm, 32 newborn calves were selected at random and monitored for infection with cryptosporidium parvum for the first 30 days of their lives. the animals were fed pooled colostrum for 2-3 days after birth and housed in individual pens, which were washed daily using a pressure hose. fecal smears were examined by microscopy after staining with carbol fuschin for visualization of oocysts. oocyst shedding was scored semiquantitatively according to the average n ... | 2002 | 11992707 |
| assessing the removal of inorganic colloids and cryptosporidium parvum from drinking water. | a new batch device that simulates the conditions in water and wastewater treatment plants and enables the study of low-concentration feeds is described. the application of this apparatus to the monitoring of the concentration of inorganic and/or biological contaminants is demonstrated, using kaolin particles and cryptosporidium parvum oocysts, respectively. the rate of inorganic particle attachment to the static medium is found to be directly proportional to the initial influent concentration. o ... | 2002 | 11993763 |
| disinfection of bacillus subtilis spores with chlorine dioxide: a bench-scale and pilot-scale study. | chlorine dioxide (clo2) inactivation of bacillus subtilis atcc 19659 spores was examined at pilot-scale during periods representative of winter and summer temperature extremes at the britannia water treatment plant in ottawa, canada. in addition, bench-scale experiments using the same source water (ottawa river, ontario, canada), as well as buffered and unbuffered laboratory waters were conducted using b. subtilis spores. bench-scale inactivation of b. subtilis spores by clo2 was similar to repo ... | 2002 | 11996351 |
| the effect of drinking water treatment on the spatial heterogeneity of micro-organisms: implications for assessment of treatment efficiency and health risk. | the effect of drinking water treatment (ferric coagulation, floc blanket clarification, rapid sand filtration) on the spatial heterogeneity of five species of micro-organism was studied at pilot scale. it was found that the spatial heterogeneity of vegetative bacteria (namely total coliform and heterotrophic (22 degrees c; 3 d) bacteria) was little affected by treatment. indeed, counts of total coliform bacteria within 500 l volumes of treated water were poisson distributed (i.e. showed minimum ... | 2002 | 11996352 |
| using flow cytometry to determine the viability of cryptosporidium parvum oocysts extracted from spiked environmental samples in chambers. | cryptosporidium parvum oocyst viability was determined by a dye permeability assay using a flow cytometric method. oocysts were inoculated into small chambers with soil and biosolids. oocysts extracted from soil and biosolids were then stained with propidium iodide (pi) and labeled with a fluorescein isothiocyanate (fitc)-conjugated monoclonal antibody. the oocyst population in each sample was determined using forward and side scatter plots, then further analyzed with fluorescence. a red and gre ... | 2002 | 11999019 |
| cattle near the bwindi impenetrable national park, uganda, as a reservoir of cryptosporidium parvum and giardia duodenalis for local community and free-ranging gorillas. | the prevalence and intensity of shedding of cryptosporidium parvum oocysts and giardia duodenalis cysts was investigated in cattle grazing in the vicinity of the bwindi impenetrable national park, uganda. the prevalence of cryptosporidiosis and giardiosis was 38% and 12%, respectively, with 10% concomitant infections. shedding intensity varied from 130 to 450 oocysts/g (mean of 215 oocysts/g) and from 110 to 270 cysts/g (mean of 156 cysts/g). significantly more pre-weaned than post-weaned cattle ... | 2002 | 11999029 |
| the effect of heating against cryptosporidium oocysts. | the effect of heat treatment was examined against oocysts of cryptosporidium parvum, cryptosporidium muris and chicken cryptosporidium sp. isolated in japan. the oocysts of these species were exposed at 50, 55, 60 and 70 degrees c for 5, 15, 30 and 60 sec in water bath, respectively. to determine the infectivity of heated oocysts, the nice and chickens were inoculated with the treated oocysts and the oocyst output in the feces after inoculation was examined. in c. parvum and chicken cryptosporid ... | 2002 | 11999437 |
| vitamin b12 and folic acid in children with intestinal parasitic infection. | to determine prospectively plasma levels of vitamin b12 and folic acid in children with intestinal parasitic infection before and three months after antiparasitic treatment. | 2002 | 11999537 |
| infectivity of a cryptosporidium parvum isolate of cervine origin for healthy adults and interferon-gamma knockout mice. | the infectivity of a cryptosporidium parvum isolate of cervine origin (type 2, moredun) propagated in calves was investigated simultaneously in healthy adult human volunteers and in interferon-gamma knockout (gko) mice. after exposure to 100-3000 oocysts, 16 volunteers recorded, for a duration of 6 weeks, the number and form of stools that they passed and any symptoms that they experienced. oocyst excretion was assessed by enzyme-linked immunosorbent assay and direct immunofluorescence assay. el ... | 2002 | 12001050 |
| the role of cytokines in the pathogenesis of cryptosporidium infection. | first described in 1912, the importance of the coccidian parasite cryptosporidium parvum as an enteropathogen in humans was not recognized until the early 1980s, when it was found to be a common opportunistic infection in aids. infection with this organism triggers a complex array of innate and cell-mediated immune responses within the intestinal mucosa. how cytokines and chemokines interact to regulate these responses in order to achieve clearance of the parasite yet preserve the integrity of t ... | 2002 | 12015455 |
| cryptosporidium dose response studies: variation between isolates. | the infectivity of three different isolates of the waterborne protozoan parasite cryptosporidium parvum has been tested in human feeding studies. these three isolates (iowa, tamu, and ucp) have different id50s, indicating substantial variation in their infectivity for humans. this finding is of great importance for quantitative risk assessment as it provides strong evidence for heterogeneity in infectivity among isolates of the same species. | 2002 | 12017359 |
| epidemiologic differences between cyclosporiasis and cryptosporidiosis in peruvian children. | we compared the epidemiologic characteristics of cyclosporiasis and cryptosporidiosis in data from a cohort study of diarrhea in a periurban community near lima, peru. children had an average of 0.20 episodes of cyclosporiasis/year and 0.22 episodes of cryptosporidiosis/year of follow-up. the incidence of cryptosporidiosis peaked at 0.42 for 1-year-old children and declined to 0.06 episodes/child-year for 5- to 9-year-old children. in contrast, the incidence of cyclosporiasis was fairly constant ... | 2002 | 12023913 |
| cryptosporidium oocysts in a water supply associated with a cryptosporidiosis outbreak. | an outbreak of cryptosporidiosis occurred in and around clitheroe, lancashire, in northwest england, during march 2000. fifty-eight cases of diarrhea with cryptosporidium identified in stool specimens were reported. cryptosporidium oocysts were identified in samples from the water treatment works as well as domestic taps. descriptive epidemiology suggested that drinking unboiled tap water in a single water zone was the common factor linking cases. environmental investigation suggested that conta ... | 2002 | 12023920 |
| three drinking-water-associated cryptosporidiosis outbreaks, northern ireland. | three recent drinking-water-associated cryptosporidiosis outbreaks in northern ireland were investigated by using genotyping and subgenotyping tools. one cryptosporidium parvum outbreak was caused by the bovine genotype, and two were caused by the human genotype. subgenotyping analyses indicate that two predominant subgenotypes were associated with these outbreaks and had been circulating in the community. | 2002 | 12023922 |
| evaluation of three flocculation methods for the purification of cryptosporidium parvum oocysts from water samples. | evaluation of three flocculation methods for the purification of cryptosporidium parvum oocysts from tap water. | 2002 | 12028427 |
| an ic-pcr method for detection of cryptosporidium and giardia in natural surface waters in finland. | we developed an immunocapture-based polymerase chain reaction (pcr) assay for simultaneous detection of cryptosporidium parvum oocysts and giardia intestinalis cysts in surface water. using primer pairs cry9/cry15 and laxa/laxb for cryptosporidium and gdh1/gdh4 for giardia, the sensitivity of the entire detection procedure (dealing with concentration, separation, dna purification and pcr amplification) was at the level of 50-100 oocysts and cysts. of 54 surface water samples, 4 were positive for ... | 2002 | 12031580 |
| the development of a real-time quantitative-pcr method for characterisation of a cryptosporidium parvum in vitro culturing system and assessment of drug efficacy. | | 2002 | 12034463 |
| disease reporting from an automated laboratory-based reporting system to a state health department via local county health departments. | the authors assessed the completeness of disease reporting from a managed care organization's automated laboratory-based reporting system to the california department of health services (cdhs) via local public health departments. | 2001 | 12034915 |
| immunomagnetic separation (ims)-fluorescent antibody detection and ims-pcr detection of seeded cryptosporidium parvum oocysts in natural waters and their limitations. | detection and enumeration of cryptosporidium parvum in both treated and untreated waters are important to facilitate prevention of future cryptosporidiosis incidents. immunomagnetic separation (ims)-fluorescent antibody (fa) detection and ims-pcr detection efficiencies were evaluated in two natural waters seeded with nominal seed doses of 5, 10, and 15 oocysts. ims-fa detected oocysts at concentrations at or below the three nominal oocyst seed doses, illustrating that ims-fa is sensitive enough ... | 2002 | 12039759 |
| molecular identification of food-borne and water-borne protozoa. | cryptosporidium and giardia can be transmitted to humans by contaminated food and water, resulting in large outbreaks of diarrheal disease. sensitive methods for detecting these parasites are needed to control and prevent infection. however, this issue is complicated by the fact that there is still uncertainty about the role played by different species/genotypes with respect to human disease. we are in the process of collecting samples from clinical cases (both sporadic and outbreak-related huma ... | 2001 | 12041581 |
| inactivation of cryptosporidium parvum oocysts in field soil. | cryptosporidium parvum oocysts from dairy calves are believed to regularly contaminate watersheds. identifying oocysts and measuring their viability in the natural environment are important elements in estimating the risk posed by this resistant organism. a 152 day field study was conducted to measure the viabilities of oocysts inoculated into 25 sampling points. water potential, ph, and ammonium content were also measured at the same 25 sampling sites. a three-dimensional mapping program (surfe ... | 2001 | 12041587 |
| testing methods for detection of cryptosporidium spp in water samples. | a large waterborne outbreak of cryptosporidiosis in milwaukee, wisconsin, usa in 1993 prompted a search for ways to prevent large-scale waterborne outbreaks of protozoan parasitoses. methods for detecting cryptosporidium parvum play an integral role in strategies that lead to appropriate treatment of surface water, but are criticized because they produce results that are highly variable. the us environmental protection agency developed a set of criteria to evaluate detection methods for protozoa ... | 2001 | 12041588 |
| role of the enteric nervous system in the pathophysiology of secretory diarrhea. | details of the physiology and pathophysiology of epithelial secretion in the gastrointestinal tract are becoming clear, leading to new models of the mechanisms underlying diarrhea. the enteric nervous system is a critical component of the mechanism regulating fluid secretion in the normal gut and a key element in the pathophysiology of diarrhea. neural reflex pathways increase epithelial fluid secretion in response to several enteric pathogens of veterinary importance such as salmonella spp., cr ... | 2002 | 12041649 |
| [comparison between the modified ziehl-neelsen and acid-fast-trichrome methods for fecal screening of cryptosporidium parvum and isospora belli]. | due to the importance of cryptosporidium parvum, cyclospora cayetanensis and isospora belli as opportunistic parasites, it is essential for laboratories to morphologically differentiate these coccidia. among the recommended methods for diagnosis of c. parvum and i. belli is the modified ziehl-neelsen stain (mzn) and recently a new technique, the acid-fast-trichrome (aft) was proposed. the purpose of this study was to compare the aft and mzn techniques regarding the detection of c. parvum and i. ... | 2002 | 12045812 |
| survey of faecal parasites in patients from western kenya. | faecal specimens were collected from patients complaining of diarrhoea and abdominal or epigastric discomfort at two hospitals. information obtained by questionnaires completed at the time of specimens collection, included demographic and clinical data. specimens were preserved in 10% formalin and polyvinyl alcohol (pva) and examined, as wet mounts and stained with wheatley's trichrome, weber, modified acid-fast and hot safranin stains. one hundred patients were examined, in 30 of them parasites ... | 2002 | 12049246 |
| the use of ziehl-neelsen stain, enzyme-linked immunosorbent assay and nested polymerase chain reaction in diagnosis of cryptosporidiosis in immuno-competent, -compromised patients. | in the present study, cryptosporidium parvum was diagnosed in stool by z-n stain, elisa and pcr. the detected cases were 5.3%, 8.3% and 9.6% by the previous three methods, respectively. the sensitivity, specificity and accuracy of the different techniques were evaluated. the z-n stain showed the lowest sensitivity and accuracy in relation to either elisa or pcr. moreover, the study revealed that the sensitivity, specificity and accuracy of elisa detection of cryptosporidium in relation to detect ... | 2002 | 12049251 |
| efficacy of beta-cyclodextrin against experimental cryptosporidiosis in neonatal lambs. | the efficacy of beta-cyclodextrin against experimental cryptosporidium parvum infection was evaluated in neonatal lambs. the animals were treated by oral administration of the drug at 1 g/kg of body weight during 3 consecutive days. preventive treatment was started within 1 day of birth, and therapeutic treatment was initiated at the onset of diarrhea following confirmation of infection. disease development and drug efficacy were evaluated by monitoring the presence or absence of diarrhea and oo ... | 2002 | 12053962 |
| association of il-10 expression by mucosal lymphocytes with increased expression of cryptosporidium parvum epitopes in infected epithelium. | the objective of this study was to determine whether changes in the ileal intraepithelial lymphocyte (tel) phenotype and function occurred prior to development of diarrhea in cryptosporidium parvum-infected calves. calves were orally inoculated with 10(8) oocysts and maintained in enteric pathogen-free conditions until their use in experiments. age-matched uninfected calves were used for comparisons. ileal iels were isolated and phenotyped to determine whether changes in lymphocyte population dy ... | 2002 | 12053998 |
| microbial risk assessment of source-separated urine used in agriculture. | a screening-level quantitative microbial risk assessment (qmra) was undertaken for a urine separating sewerage system. exposures evaluated included the handling of stored and unstored urine as well as consumption of crops fertilised with urine. faecal cross-contamination was the source of risk and campylobacter jejuni, cryptosporidium parvum and rotavirus were the organisms chosen to represent different groups of enteric pathogens. accidental ingestion of unstored urine implied a high risk (pinf ... | 2002 | 12058821 |
| characterisation of a novel transporter from cryptosporidium parvum. | p-atpases are transmembrane proteins that hydrolyse atp to drive cations or other substances across biomembranes. in this study we present the characterisation of a novel p-atpase from the apicomplexan parasite cryptosporidium parvum (cpatpase3), an opportunistic pathogen in autoimmune deficiency syndrome patients, for which no treatment is available. the single copy gene encodes 1488 amino acids, predicting a protein of 169.7 kda. primary sequence analysis, as well as an extensive phylogenetic ... | 2002 | 12062559 |
| analysis of sequence diversity at the highly polymorphic cpgp40/15 locus among cryptosporidium isolates from human immunodeficiency virus-infected children in south africa. | cryptosporidium sp. is a significant cause of diarrheal disease, particularly in human immunodeficiency virus (hiv)-infected patients in developing countries. we recently cloned and sequenced several alleles of the highly polymorphic single-copy cryptosporidium parvum gene cpgp40/15. this gene encodes a precursor protein that is proteolytically cleaved to yield mature cell surface glycoproteins gp40 and gp15, which are implicated in zoite attachment to and invasion of enterocytes. the most-strik ... | 2002 | 12065532 |
| requirement for tnf-tnfrsf1 signalling for sclerosing cholangitis in mice chronically infected by cryptosporidium parvum. | an increase in mrna levels for tnf and tnfrsf1 in the bile ducts of tnfsf5-/-(cd40 ligand or cd154 knockout) mice developing cholangitis following infection by cryptosporidium parvum (cp) is accompanied by staining for tnfalpha in areas of inflammation. to determine whether tnf contributed to the bile duct damage seen in chronically-infected animals, we bred b6 mice with disrupted genes for tnfrsf1a, tnfrsf1b and tnfsf5. following cp infection, the tnfsf5-/- tnfrsf1a & 1b-/- mice were spared fro ... | 2002 | 12067295 |
| contamination of water supplies with cryptosporidium parvum and giardia lamblia and diarrheal illness in selected russian cities. | cryptosporidium parvum and giardia lamblia are important agents of waterborne diarrheal illness worldwide. while giardiasis is routinely diagnosed in russia with a chemical staining technique, data on the prevalence of cryptosporidiosis are scarce. monitoring of the respective parasites in water supplies in russia is very limited. a health survey conducted in the city of cherepovets and three other cities in the european part of russia using enzyme-linked immunosorbent assays (elisa) demonstrate ... | 2002 | 12068747 |
| cryptosporidium andersoni from a danish cattle herd: identification and preliminary characterisation. | in november 1997, cryptosporidium andersoni, for the first time, was isolated from a danish heifer. the isolate was characterised morphologically, molecularly, and furthermore inoculated into mice and one calf. data on the distribution of cryptosporidia in the herd of origin were obtained at two separate visits in december 1997 and april 1998. c. andersoni was detected in 27 (19.0%) of 142 cattle examined at the first visit, whereas c. parvum was found in six (4.2%). at the following visit 42 (2 ... | 2002 | 12072212 |
| [the current status of infectious enteritis in japan--reports of the "research group for infectious enteric diseases, japan" in the last 5 years (1996-2000)]. | the patients or carriers with infectious enteritis admitted to the hospitals for infectious diseases in the last 5 years (1996-2000) were studied. the total number of cases admitted in each year were 969, 1,113, 981, 637 and 573 respectively. a total of 1,527 shigella spp. strains including 1,078 strains from overseas travelers' cases were isolated. the isolates of salmonella spp. excluding s. typhi and s. paratyphi a were 562 in number. a total of 61 vibrio cholerae o1 strains including 44 stra ... | 2002 | 12073571 |
| uv disinfection of giardia lamblia cysts in water. | the human and animal pathogen giardia lamblia is a waterborne risk to public health because the cysts are ubiquitous and persistent in water and wastewater, not completely removed by physical-chemical treatment processes, and relatively resistant to chemical disinfection. given the recently recognized efficacy of uv irradiation against cryptosporidium parvum oocysts, the inactivation of g. lamblia cysts in buffered saline water at ph 7.3 and room temperature by near monochromatic (254 nm) uv irr ... | 2002 | 12075814 |
| [detection of cryptosporidium parvum in fecal samples using polymerase chain reaction combined with non-radioactive labeled dna probe hybridization]. | to develop a non-radioactive labeled probe hybridization technique for the detection of the pcr products of cryptosporidium parvum dna in fecal samples and evaluate its specificity and sensitivity. | 1998 | 12078251 |
| [preparation and characterization of monoclonal antibodies against cryptosporidium parvum]. | to develop and characterize the monoclonal antibodies(mcabs) against cryptosporidium parvum (c. parvum). | 1998 | 12078258 |
| in vitro effect of short-term exposure to two synthetic peptides, alone or in combination with clarithromycin or rifabutin, on cryptosporidium parvum infectivity. | the viability of cryptosporidium parvum after exposure to peptide antibiotics was studied by two different methods, a cell culture system and a double fluorogenic staining. the peptides kffkffkff and ikflkflkfl exerted high cytotoxic effects on sporozoites, as demonstrated by cell cultures (complete inhibition after 60 min at 100 microg/ml) and flow cytometry (30% after 20 min at 100 microg/ml), but did not affect consistently the oocysts. clarithromycin and rifabutin demonstrated less activity ... | 2002 | 12084535 |
| cryptosporidium dose-response studies: variation between hosts. | the issue of variation is highly important in dose-response analysis: variation among genetically related pathogens infecting the same host, but also variation among hosts, in susceptibility to infection by the same pathogen. this latter issue is addressed here for the protozoan parasite cryptosporidium parvum, the causative agent for many outbreaks of water-borne gastrointestinal illness. in human feeding studies, infectivity has been shown to be low in subjects with high preexisting anti-crypt ... | 2002 | 12088227 |
| cryptosporidiosis stimulates an inflammatory intestinal response in malnourished haitian children. | the mechanisms by which cryptosporidium parvum cause persistent diarrhea and increased morbidity and mortality are poorly understood. three groups of haitian children <18 months old were studied: case patients, children with diarrhea not due to cryptosporidium, and healthy control subjects. compared with both control groups, children with acute cryptosporidiosis were more malnourished (including measures of stunting [p=.03] and general malnutrition [p=.01]), vitamin a deficient (p=.04), and less ... | 2002 | 12089667 |
| invasion of different cell types by sporozoites of eimeria species and effects of monoclonal antibody 1209-c2 on invasion of cells by sporozoites of several apicomplexan parasites. | sporozoites of avian eimeria species differed markedly in their ability to invade cells in vitro. invasion by e. tenella and e. adenoeides was significantly greater in baby hamster kidney (bhk) and chicken cecal cell (cc) cultures than in primary chicken (pck) or turkey kidney (ptk) cell cultures. moreover, invasion of bhk cell cultures by e. adenoeides was significantly greater than that of other eimeria species, and invasion by e. acervulina sporozoites was significantly lower. monoclonal anti ... | 2001 | 12095105 |
| influence of temperature on cryptosporidium parvum oocyst infectivity in river water samples as detected by tissue culture assay. | cryptosporidium parvum oocysts were stored in 1-ml aliquots of filtered river water at -20, 4, 10, and 21-23 c in the dark. oocysts were also added to filter-sterilized river water samples and stored at 21-23 c. the infectivity of oocysts stored under different conditions was assayed at weekly intervals through infection of human adenocarcinoma ileocecal (hct-8) cell monolayers. wells containing between 10 and 100 foci of infection were enumerated by immunofluorescent microscopy, and the number ... | 2002 | 12099446 |
| pcr detection of specific pathogens in water: a risk-based analysis. | the relative concentration of pathogens in water samples collected from storm drains and adjacent surfaces was evaluated using established pcr-based protocols. out of the 58 samples collected from 21 different storm drains, 22% were pcr positive for escherichia coli etec, salmonella, or adenovirus. the risk of swimming related illnesses associated with detection of e. coli etec and salmonella ranged from 0.39 to 30:100 000 and 0.3-25:1000, respectively. the detection limit corresponding to a neg ... | 2002 | 12099475 |
| [importance of the different species and genotypes of cryptosporidium in public health]. | until recently, only the bovine and human genotypes of cryptosporidium parvum had been considered to infect man and to be potential pathogens. lately, symptomatic infections with c. felis, c. meleagridis, and dog c. parvum-like genotype have been described in immunocompetent and immunosuppressed individuals. these findings suggest that zoonotic parasites could also play an important role in public health. | 2002 | 12108027 |
| some aspects of protozoan infections in immunocompromised patients- a review. | protozoa are among the most important pathogens that can cause infections in immunocompromised hosts. these microorganisms particularly infect individuals with impaired cellular immunity, such as those with hematological neoplasias, renal or heart transplant patients, patients using high doses of corticosteroids, and patients with acquired immunodeficiency syndrome. the protozoa that most frequently cause disease in immunocompromised patients are toxoplasma gondii, trypanosoma cruzi, different l ... | 2002 | 12118272 |
| variability among cryptosporidium parvum genotype 1 and 2 immunodominant surface glycoproteins. | published genomic differences between cryptosporidium parvum genotype 1 (human-derived) and genotype 2 (animal and human-derived) isolates suggest that these may belong to two distinct species. this is of significant interest since genotype 1 isolates are associated with sporadic cases of human cryptosporidiosis in 30-40 % of cases in contrast to 60-70 % of cases caused by genotype 2. the lower genetic sequence similarity between genotype 1 and 2 surface glycoproteins (gp40/15) suggests that ant ... | 2002 | 12120593 |
| in vitro effect of nitazoxanide against entamoeba histolytica, giardia intestinalis and trichomonas vaginalis trophozoites. | nitazoxanide, a 5-nitrothiazolyl derivative, is effective in the treatment of a broad range of parasitic infections. in vitro, it is active against several protozoa, including cryptosporidium parvum, blastocystis hominis, and giardia intestinalis. the objective of this study was to determine the in vitro effect of nitazoxanide on the growth and morphology of three anaerobic protozoa (entamoeba histolytica, giardia intestinalis, and trichomonas vaginalis) and to compare these effects with those o ... | 2002 | 12120985 |
| alpha-proteobacterial relationship of apicomplexan lactate and malate dehydrogenases. | we have cloned and sequenced a lactate dehydrogenase (ldh) gene from cryptosporidium parvum (cpldh1). with this addition, and that of four recently deposited alpha-proteobacterial malate dehydrogenase (mdh) genes, the phylogenetic relationships among apicomplexan ldh and bacterial mdh were re-examined. consistent with previous studies, our maximum likelihood (ml) analysis using the quartet-puzzling method divided 105 ldh/mdh enzymes into five clades, and confirmed that mitochondrial mdh is a sis ... | 2002 | 12120991 |
| cryptosporidiosis and the challenges of chemotherapy. | cryptosporidium parvum is a protozoan parasite that infects the epithelial cells of the small intestine causing diarrheal illness in humans. cryptosporidium has a worldwide distribution and is considered an emerging zoonosis. despite intensive efforts to develop workable experimental models, and the evaluation of over 200 chemotherapeutic agents, adequate therapies to clear the host of these parasites are still lacking. the reasons for the lack of drug efficacy are probably manifold and may incl ... | 2002 | 12127863 |
| comparison of in vitro cell culture and a mouse assay for measuring infectivity of cryptosporidium parvum. | in vitro cell cultures were compared to neonatal mice for measuring the infectivity of five genotype 2 isolates of cryptosporidium parvum. oocyst doses were enumerated by flow cytometry and delivered to animals and cell monolayers by using standardized procedures. each dose of oocysts was inoculated into up to nine replicates of 9 to 12 mice or 6 to 10 cell culture wells. infections were detected by hematoxylin and eosin staining in cd-1 mice, by reverse transcriptase pcr in hct-8 and caco-2 cel ... | 2002 | 12147476 |
| inactivation of cryptosporidium parvum oocysts in fresh apple cider by uv irradiation. | this study evaluated the efficacy of uv irradiation on the inactivation of cryptosporidium parvum oocysts in fresh apple cider. cider was inoculated with oocysts and exposed to 14.32 mj of uv irradiation/cm(2). oocyst viability was assessed with the gamma interferon gene knockout (gko) mouse and infant balb/cbyj mouse models. all gko mice challenged with uv-treated cider demonstrated no morbidity or mortality, and infant balb/c mice challenged with treated cider were negative for the presence of ... | 2002 | 12147528 |
| low incidence of concurrent enteric infection associated with sporadic and outbreak-related human cryptosporidiosis in northern ireland. | | 2002 | 12149394 |
| comparison of fluorescence, antigen and pcr assays to detect cryptosporidium parvum in fecal specimens. | to optimize routine screening for cryptosporidiosis, 198 stool samples from patients at risk and from calves were examined by enzyme immunoassay (eia), a direct fluorescent-antibody (dfa) and a modified immunofluorescence assay. ninety-nine samples were positive in at least one assay, whereas 99 were negative in all three assays. sensitivity of antigen eia and dfa were similar (94%, 95% ci: 88-98%, and 91%, 95% ci: 84-95%). the modified immunofluorescence was significantly less sensitive (64%, 9 ... | 2002 | 12151188 |
| cryptosporidiosis in people sharing habitats with free-ranging mountain gorillas (gorilla gorilla beringei), uganda. | cryptosporidiosis, a zoonotic diarrheal disease, significantly contributes to the mortality of people with impaired immune systems worldwide. infections with an animal-adapted genotype (genotype 2) of cryptosporidium parvum were found in a human population in uganda that shares habitats with free-ranging gorillas, from which the same genotype of c. parvum had been recovered previously. a high prevalence of disease was found in park staff members (21%) who frequently contact gorillas versus 3% di ... | 2002 | 12164303 |
| prevalence and abundance of cryptosporidium parvum and giardia spp. in wild rural rodents from the mazury lake district region of poland. | prevalence and abundance of cryptosporodium parvum and giardia spp. were studied in 3 species of rodents from forests and abandoned agricultural fields in n.e. poland (clethrionomys glareolus n = 459; microtus arvalis n = 274; apodemus flavicollis n = 209). overall prevalence was consistently higher in the voles compared with a. flavicollis (70.6, 73.0 and 27.8% respectively for c. parvum and 93.9, 96.3 and 48.3% respectively for giardia spp.). prevalence and abundance of infection also varied m ... | 2002 | 12166517 |
| a multiplex allele specific polymerase chain reaction (mas-pcr) on the dihydrofolate reductase gene for the detection of cryptosporidium parvum genotypes 1 and 2. | a multiplex allele specific polymerase chain reaction (mas-pcr) based on the cryptosporidium parvum dihydrofolate reductase (dhfr) gene sequence differentiates genotype 1 ('human') from 2 ('cattle') in a 1-step reaction. the mas-pcr was validated on a panel of 34 microscopically positive c. parvum faecal samples of human and animal origin in comparison with 2 published pcr-restriction fragment length polymorphism (rflp) methods targeting dhfr and the oocyst wall protein (cowp) genes. a validatio ... | 2002 | 12166518 |
| prevalence of giardia and cryptosporidium and characterization of cryptosporidium spp. isolated from wildlife, human, and agricultural sources in the north saskatchewan river basin in alberta, canada. | the environmental distribution of giardia spp. and cryptosporidium spp. is dependent upon human, agricultural, and wildlife sources. the significance of each source with regard to the presence of parasites in the environment is unknown. this 2-year study examined parasite prevalence in human sewage influent, wildlife, and agricultural sources associated with the north saskatchewan river basin in alberta, canada. fecal samples were collected from cow-calf, dairy, and hog operations in the watersh ... | 2002 | 12166680 |
| hollow-fiber ultrafiltration of cryptosporidium parvum oocysts from a wide variety of 10-l surface water samples. | an optimized hollow-fiber ultrafiltration system (50 000 mwco) was developed to concentrate cryptosporidium oocysts from 10-l samples of environmental water. seeded experiments were conducted using a number of surface-water samples from the southwestern u.s.a. and source water from four water districts with histories of poor oocyst recovery. ultrafiltration produced a mean recovery of 47.9% from 19 water samples (55.3% from 39 individual tests). we also compared oocyst recoveries using the hollo ... | 2002 | 12166681 |
| development of a ct equation for the inactivation of cryptosporidium oocysts with ozone. | cryptosporidium parvum, a protozoan parasite, has been implicated in a number of waterborne disease outbreaks. it is difficult to inactivate using free chlorine, but appears to be easily inactivated by ozone. therefore, the us epa has promulgated the interim enhanced surface water treatment rule, which for the first time, addresses the control of c. parvum in drinking water. the use of ct (concentration of disinfectant in mg/l times, time in minutes) values is being considered as one of the opti ... | 2002 | 12171413 |
| serological detection of exposure to cryptosporidium parvum in cattle by elisa and its evaluation in relation to coprological tests. | we evaluated serum examination as an alternative to fecal analysis for the diagnosis of exposure to cryptosporidium parvum in cattle. the accuracy of the serum elisa was compared to the combined results of concentration flotation microscopy and fecal enzyme immunoassay. the expected performance of the serum elisa at different levels of infection with c. parvum was evaluated using the predicative values positive and negative. optimal conditions for the serum elisa can be achieved by diluting the ... | 2002 | 12172810 |
| direct detection of cryptosporidium parvum oocysts by immunomagnetic separation-polymerase chain reaction in raw milk. | cryptosporidium parvum is an emerging protozoan parasite responsible for several serious outbreaks of cryptosporidiosis, an enteric infection characterized by severe intestinal distress. this parasite can be transmitted through contaminated water and raw food in the oocyst form, which is resistant to many environmental stresses and food processes. c. parvum is also commonly found on dairy farms and could be transmitted to humans through contaminated raw milk and dairy products. thus, an immunoma ... | 2002 | 12182493 |
| optimised immunofluorescence procedure for enumeration of cryptosporidium parvum oocyst suspensions. | the aim of this study was to evaluate an optimised immunofluorescence assay in terms of the variability of sets of counts for cryptosporidium parvum oocyst suspensions and data recovery and the reliability of the procedure. a coefficient of variation (cv) of 10% was determined to be the maximum value acceptable for count variability. it was found that the optimised ifa tested provided a high precision for the sets of enumerations for suspensions containing 800-20,000 oocysts/ml. the procedure wa ... | 2002 | 12188126 |
| a prevalence of cryptosporidium infections among thai hiv-infected patients. | the prevalence of cryptosporidium in 156 hiv-infected thai patients who had acute diarrheal illness at bamrasnaradura infectious diseases hospital, was studied. this cross-sectional study was performed from march to august in year 2001. the patients ranged in age from 1 month-65 years old. a stool sample from each subject was stained to find the oocysts by modified ziehl nelson carbolfuchsin staining. according to the present study, a diagnosis of cryptosporidium parvum infection was found in 20 ... | 2002 | 12188446 |
| recent advances in cryptosporidiosis: the immune response. | an increased understanding of host immune responses to cryptosporidium parvum which are responsible for clearance of primary infection and resistance to reinfection, and characterization of the parasite molecules to which they are directed, are essential for discovery of effective active and passive immunization strategies against cryptosporidiosis. in this article, recent advances in knowledge of humoral and cellular immune responses to c. parvum, their antigen specificities, and mechanisms of ... | 2002 | 12191657 |
| genomics and genetics of cryptosporidium parvum: the key to understanding cryptosporidiosis. | this paper focuses on recent advances in the genetics and genomics of cryptosporidium parvum. the approach to and the relevance of sequencing the genomes of c. parvum type 1 and type 2 are discussed, as well as new insights into the genetic heterogeneity of this species. | 2002 | 12191658 |
| enteric pathogens, intestinal permeability and nitric oxide production in acute gastroenteritis. | aboriginal children hospitalized with diarrheal disease in northern australia have high rates of acidosis, hypokalemia and osmotic diarrhea, as well as abnormal small bowel permeability and elevated nitric oxide (no) production. | 2002 | 12192160 |
| house fly (musca domestica) as a transport vector of cryptosporidium parvum. | | 2002 | 12194490 |
| prevalence of intestinal parasitic pathogens in hiv-seropositive individuals in northern india. | to assess the prevalence of intestinal parasitic infections in human immunodeficiency virus (hiv)-seropositive subjects, fecal samples were collected from 120 hiv-seropositive patients and were analyzed for various intestinal parasites. thirty-six patients (30%) were found to harbor an intestinal parasite. cryptosporidium parvum was the most common (10.8%), followed by giardia lamblia (8.3%). cyclospora cayetanensis and blastocystis hominis each were detected in 3.3% of the patients, while isosp ... | 2002 | 12195048 |
| pathogenesis of human and bovine cryptosporidium parvum in gnotobiotic pigs. | to compare the pathogenesis of human genotype 1 (hug1) and bovine genotype 2 (bog2) cryptosporidium parvum, neonatal gnotobiotic pigs were given 1-10 hug1 or bog2 oocysts. the prepatent and patent periods were significantly longer for hug1 than for bog2 c. parvum (prepatent, 8.6 vs. 5.6 days; patent, 16.6 vs. 10.3 days). bog2-infected pigs developed significantly more severe disease than did hug1-infected pigs. bog2 parasites were seen microscopically throughout the intestines during the prepate ... | 2002 | 12195362 |
| effects of freeze-thaw events on the viability of cryptosporidium parvum oocysts in soil. | the effects of freeze-thaw events on the inactivation of cryptosporidium parvum oocysts in soil were examined. oocysts were inoculated into distilled water in microcentrifuge tubes or into chambers containing soil the water content of which was maintained at 3%, 43%, or 78% of the container capacity. the chambers and tubes were then embedded in 3 soil samples from different aspects of a hillside landscape (experiments 1 and 2) and in 3 distinct soil types (experiment 3) and frozen at -10 c. cont ... | 2002 | 12197120 |
| 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 |
| epstein-barr virus encoded nuclear protein ebna-3 binds a novel human uridine kinase/uracil phosphoribosyltransferase. | epstein-barr virus (ebv) infects resting b-lymphocytes and transforms them into immortal proliferating lymphoblastoid cell lines (lcls) in vitro. the transformed immunoblasts may grow up as immunoblastic lymphomas in immuno-suppressed hosts. | 2002 | 12199906 |
| detection and genotyping of oocysts of cryptosporidium parvum by real-time pcr and melting curve analysis. | several real-time pcr procedures for the detection and genotyping of oocysts of cryptosporidium parvum were evaluated. a 40-cycle amplification of a 157-bp fragment from the c. parvum beta-tubulin gene detected individual oocysts which were introduced into the reaction mixture by micromanipulation. sybr green i melting curve analysis was used to confirm the specificity of the method when dna extracted from fecal samples spiked with oocysts was analyzed. because c. parvum isolates infecting human ... | 2002 | 12202559 |
| development of a taqman quantitative pcr assay specific for cryptosporidium parvum. | a rapid detection method that is both quantitative and specific for the water-borne human parasite cryptosporidium parvum is reported. real-time polymerase chain reaction (pcr) combined with fluorescent taqman technology was used to develop this sensitive and accurate assay. the selected primer-probe set identified a 138-bp section specific to a c. parvum genomic dna sequence. the method was optimized on a cloned section of the target dna sequence, then evaluated on c. parvum oocyst dilutions. q ... | 2002 | 12204366 |
| efficacy of oryzalin and associated histological changes in cryptosporidium-infected neonatal rats. | this paper reports the anti-cryptosporidial effects of, and concomitant amelioration of the histological changes in the gut of neonatal rats with intestinal cryptosporidiosis treated with the dinitroaniline, oryzalin. the ed50 was determined to be 7 mg/kg using twice daily doses administered for 3 consecutive days. a maximum inhibition of 85.5% was achieved at 25 mg/kg and this inhibition remained constant despite increasing the oryzalin dose to 200 mg/kg. cryptosporidiosis significantly decreas ... | 2002 | 12211604 |
| [utility of studying feces for the diagnosis and management of infants and preschool children with acute diarrhea]. | to analyze the results of a stool work-up protocol in a series of infants and preschoolers with acute diarrhea. | 2002 | 12216520 |
| diarrhea, cd4 counts and enteric infections in a community-based cohort of hiv-infected adults in uganda. | to examine relationships between diarrhoea, cd4 cell counts and stool pathogens in a community-based cohort of hiv-infected adults in uganda. | 2002 | 12217712 |
| outbreak of diarrheal illness in attendees at a ukrainian dance festival, dauphin, manitoba--may 2001. | | 2002 | 12219577 |
| magnesium precipitate hot start method for pcr. | for the amplification of hiv-1 gag gene, and other challenging targets, a simple new hot start pcr protocol is presented which consists simply and entirely of the buffer system. this novel buffer composition and reaction assembly protocol for pcr includes magnesium and phosphate combined at high concentration in addition to standard buffer reagents. the resulting magnesium-containing precipitate provides a hot start for pcr, since the magnesium in the precipitate is unavailable to dna polymerase ... | 2002 | 12219733 |
| intra-familial and extra-familial risk factors associated with cryptosporidium parvum infection among children hospitalized for diarrhea in goiânia, goiás, brazil. | a cross-sectional study was conducted for assessing the prevalence of and risk factors associated with cryptosporidium parvum in diarrheic children who were hospitalized in goiânia, capital of goiás state in brazil. a crude prevalence of 14.4% (64 of 445) was observed using a direct immunfluorescent assay (dfa), but the true prevalence was 18.7% (83 of 445) when a gold standard of immunomagnetic separation was used in combination with the dfa. infection was more predominant in children less than ... | 2002 | 12224593 |
| seasonal prevalence of intestinal parasites in the united states during 2000. | one-third of 5,792 fecal specimens from 2,896 patients in 48 states and the district of columbia tested positive for intestinal parasites during the year 2000. multiple infections with 2-4 parasitic species constituted 10% of 916 infected cases. blastocystis hominis infected 662 patients (23% or 72% of the 916 cases). its prevalence appears to be increasing in recent years. eighteen other species of intestinal parasites were identified. cryptosporidium parvum and entamoeba histolytica/e. dispar ... | 2002 | 12224595 |
| evaluation of an immunochromatographic dip-strip test for the detection of cryptosporidium oocysts in stool specimens. | the study presented here examined the efficacy of a commercially available qualitative immunochromatographic assay for detecting cryptosporidium oocysts in stool samples. a total of 75 samples were tested, including 50 positive for cryptosporidium spp. by acid-fast stain, 20 positive for other parasites ( blastocystis hominis, endolimax nana, entamoeba coli, giardia lamblia, ascaris lumbricoides, strongyloides stercoralis and trichuris trichiura), and five negative samples. the observed sensitiv ... | 2002 | 12226697 |
| genetic analysis of a cryptosporidium parvum human genotype 1 isolate passaged through different host species. | cryptosporidium parvum tu502, a genotype 1 isolate of human origin, was passaged through three different mammalian hosts, including humans, pigs, and calves. it was confirmed to be genotype 1 by pcr-restriction fragment length polymorphism analysis of the cryptosporidium oocyst wall protein gene, direct sequencing of pcr fragments of the small subunit rrna and beta-tubulin genes, and microsatellite analysis. this isolate was shown to be genetically stable when passaged through the three mammalia ... | 2002 | 12228296 |