| cryptosporidium hominis n. sp. (apicomplexa: cryptosporidiidae) from homo sapiens. | the structure and infectivity of the oocysts of a new species of cryptosporidium from the feces of humans are described. oocysts are structurally indistinguishable from those of cryptosporidium parvum. oocysts of the new species are passed fully sporulated, lack sporocysts. and measure 4.4-5.4 microm (mean = 4.86) x 4.4-5.9 microm (mean = 5.2 microm) with a length to width ratio 1.0-1.09 (mean 1.07) (n = 100). oocysts were not infectious for arc swiss mice, nude mice. wistar rat pups, puppies, k ... | 2002 | 12503676 |
| subgenotype analysis of cryptosporidium isolates from humans, cattle, and zoo ruminants in portugal. | cryptosporidium parvum and cryptosporidium hominis isolates from human immunodeficiency virus-infected patients, cattle, and wild ruminants were characterized by pcr and dna sequencing analysis of the 60-kda glycoprotein gene. seven alleles were identified, three corresponding to c. hominis and four corresponding to c. parvum. one new allele was found (iid), and one (iib) had only been found in portugal. isolates from cattle and wild ruminants clustered in two alleles. in contrast, human isolate ... | 2003 | 12791920 |
| phylogenetic classification of protozoa based on the structure of the linker domain in the bifunctional enzyme, dihydrofolate reductase-thymidylate synthase. | we have determined the crystal structure of dihydrofolate reductase-thymidylate synthase (dhfr-ts) from cryptosporidium hominis, revealing a unique linker domain containing an 11-residue alpha-helix that has extensive interactions with the opposite dhfr-ts monomer of the homodimeric enzyme. analysis of the structure of dhfr-ts from c. hominis and of previously solved structures of dhfr-ts from plasmodium falciparum and leishmania major reveals that the linker domain primarily controls the relati ... | 2003 | 14555647 |
| molecular surveillance of cryptosporidium spp. in raw wastewater in milwaukee: implications for understanding outbreak occurrence and transmission dynamics. | six cryptosporidium spp. were found in 50 of 179 milwaukee wastewater samples collected weekly over a year. of the eight subtypes of cryptosporidium hominis and cryptosporidium parvum present, allele ib was found in 14 of 16 samples, and its sequence was identical to that of the subtype in human samples from the 1993 milwaukee outbreak of cryptosporidiosis. | 2003 | 14605176 |
| microsatellite analysis of cryptosporidium hominis and c. parvum in portugal: a preliminary study. | | 2003 | 14736152 |
| cryptosporidium species and genotypes in hiv-positive patients in lima, peru. | cryptosporidium parasites from a cross-sectional study conducted in two national hospitals in lima, peru were genetically characterized to determine the diversity of cryptosporidium spp. in hiv-positive people. a total of 2,672 patients participated in this study and provided 13,937 specimens. cryptosporidium oocysts were detected by microscopy in 354 (13.3%) of the patients. analysis of 951 cryptosporidium-positive specimens from 300 patients using a small subunit rrna-based pcr-rflp tool ident ... | 2003 | 14736153 |
| the crystal structure of dihydrofolate reductase-thymidylate synthase from cryptosporidium hominis reveals a novel architecture for the bifunctional enzyme. | | 2003 | 14736160 |
| biology, persistence and detection of cryptosporidium parvum and cryptosporidium hominis oocyst. | cryptosporidium parvum and cryptosporidium hominis are obligate enteric protozoan parasites which infect the gastrointestinal tract of animals and humans. the mechanism(s) by which these parasites cause gastrointestinal distress in their hosts is not well understood. the risk of waterborne transmission of cryptosporidium is a serious global issue in drinking water safety. oocysts from these organisms are extremely robust, prevalent in source water supplies and capable of surviving in the environ ... | 2004 | 14769405 |
| detection and identification by real time pcr/rflp analyses of cryptosporidium species from human faeces. | to detect a wide range of cryptosporidium species from human faeces by analysis of the cryptosporidium oocyst wall protein gene by pcr. | 2004 | 14962043 |
| kinetic characterization of bifunctional thymidylate synthase-dihydrofolate reductase (ts-dhfr) from cryptosporidium hominis: a paradigm shift for ts activity and channeling behavior. | this study presents a kinetic characterization of the recently crystallized bifunctional thymidylate synthasedihydrofolate reductase (ts-dhfr) enzyme from the apicomplexa parasite, cryptosporidium hominis. our study focuses on determination of the c. hominis ts-dhfr kinetic mechanism, substrate channeling behavior, and domain-domain communication. unexpectedly, the unique mechanistic features of c. hominis ts-dhfr involve the highly conserved ts domain. at 45 s(-) (1), c. hominis ts activity is ... | 2004 | 14966126 |
| detection and molecular characterization of cryptosporidium spp. isolated from diarrheic children in switzerland. | the prevalence of cryptosporidium spp. in diarrheic immunocompetent children living in switzerland was 5.5% (15 of 273). infection rates increased significantly with age. anthroponotic cryptosporidium hominis was identified in 11 children, 9 with a travel history. the zoonotic cryptosporidium parvum bovine genotype was identified in 3 children (2 without travel history). hence transmission of cryptosporidium spp. is primarily of anthroponotic nature in the study area. | 2004 | 15071295 |
| a subgroup algorithm to identify cross-rotation peaks consistent with non-crystallographic symmetry. | molecular replacement (mr) often plays a prominent role in determining initial phase angles for structure determination by x-ray crystallography. in this paper, an efficient quaternion-based algorithm is presented for analyzing peaks from a cross-rotation function in order to identify model orientations consistent with proper non-crystallographic symmetry (ncs) and to generate proper ncs-consistent orientations missing from the list of cross-rotation peaks. the algorithm, crans, analyzes the rot ... | 2004 | 15159565 |
| infection with cryptosporidium hominis and reinfection with cryptosporidium parvum in a transplanted ileum. | a transplanted ileum was found to be infected with cryptosporidium hominis 6 days after transplantation. although the infection resolved, the ileum was later found to be infected with cryptosporidium parvum. the presence of the parasite was not always correlated with diarrhea. no other gastrointestinal symptom was ever detected. treatment with azithromycin and paromomycin apparently failed. | 2004 | 15233648 |
| genetic characterization and transmission cycles of cryptosporidium species isolated from humans in new zealand. | little is known about the genetic characteristics, distribution, and transmission cycles of cryptosporidium species that cause human disease in new zealand. to address these questions, 423 fecal specimens containing cryptosporidium oocysts and obtained from different regions were examined by the pcr-restriction fragment length polymorphism technique. indeterminant results were resolved by dna sequence analysis. two regions supplied the majority of isolates: one rural and one urban. overall, cryp ... | 2004 | 15240272 |
| sporadic cryptosporidiosis case-control study with genotyping. | we report a case-control study of sporadic cryptosporidiosis with genotyping of isolates from case-patients. a postal questionnaire was completed by 427 patients and 427 controls. we obtained genotyping data on isolates from 191 patients; 115 were cryptosporidium hominis, and 76 were c. parvum. when all cryptosporidiosis cases were analyzed, three variables were strongly associated with illness: travel outside the united kingdom, contact with another person with diarrhea, and touching cattle. ea ... | 2004 | 15324544 |
| health sequelae of human cryptosporidiosis in immunocompetent patients. | there have been no systematic studies following up the longer term health effects of cases of cryptosporidiosis for which genotype data exist. | 2004 | 15356813 |
| the genome of cryptosporidium hominis. | cryptosporidium species cause acute gastroenteritis and diarrhoea worldwide. they are members of the apicomplexa--protozoan pathogens that invade host cells by using a specialized apical complex and are usually transmitted by an invertebrate vector or intermediate host. in contrast to other apicomplexans, cryptosporidium is transmitted by ingestion of oocysts and completes its life cycle in a single host. no therapy is available, and control focuses on eliminating oocysts in water supplies. two ... | 2004 | 15510150 |
| irreversible uv inactivation of cryptosporidium spp. despite the presence of uv repair genes. | ultraviolet light is being considered as a disinfectant by the water industry because it appears to be very effective for inactivating pathogens, including cryptosporidium parvum. however, many organisms have mechanisms for repairing ultraviolet light-induced dna damage, which may limit the utility of this disinfection technology. inactivation of c. parvum was assessed by measuring infectivity in cells of the human ileocecal adenocarcinoma hct-8 cell line, with an assay targeting a heat shock pr ... | 2004 | 15537090 |
| the response of cryptosporidium parvum to uv light. | ultraviolet (uv) light is being considered as a disinfectant by the water industry because it appears to be very effective for controlling potential waterborne pathogens, including cryptosporidium parvum. however, many organisms have mechanisms such as nucleotide excision repair and photolyase enzymes for repairing uv-induced dna damage and regaining preirradiation levels of infectivity or population density. genes encoding uv repair proteins exist in c. parvum, so the parasite should be able to ... | 2005 | 15664531 |
| detection of cryptosporidium and identification to the species level by nested pcr and restriction fragment length polymorphism. | cryptosporidiosis is an emerging protozoan disease associated with large waterborne outbreaks. diagnosis relies on microscopic examination of stools, but this method cannot identify the infecting species of cryptosporidium. we have developed a test based on nested pcr and restriction fragment length polymorphism (rflp) that offers simple identification of cryptosporidium hominis, cryptosporidium parvum, and most other human infective species in stool samples. purified c. parvum oocysts were used ... | 2005 | 15750054 |
| direct comparison of selected methods for genetic categorisation of cryptosporidium parvum and cryptosporidium hominis species. | a study was undertaken to compare the performance of five different molecular methods (available in four different laboratories) for the identification of cryptosporidium parvum and cryptosporidium hominis and the detection of genetic variation within each of these species. the same panel of oocyst dna samples derived from faeces (n=54; coded blindly) was sent for analysis by: (i) dna sequence analysis of a fragment of the hsp70 gene; (ii) dna sequence analysis and the ssrrna gene in laboratory ... | 2005 | 15777916 |
| risk of infection with cryptosporidium parvum and cryptosporidium hominis in dairy cattle in the new york city watershed. | to determine the risk posed by cryptosporidium parvum and cryptosporidium hominis from dairy cattle in the new york city watershed (nycw). | 2005 | 15822584 |
| uv inactivation of cryptosporidium hominis as measured in cell culture. | the cryptosporidium spp. uv disinfection studies conducted to date have used cryptosporidium parvum oocysts. however, cryptosporidium hominis predominates in human cryptosporidiosis infections, so there is a critical need to assess the efficacy of uv disinfection of c. hominis. this study utilized cell culture-based methods to demonstrate that c. hominis oocysts displayed similar levels of infectivity and had the same sensitivity to uv light as c. parvum. therefore, the water industry can be con ... | 2005 | 15870378 |
| natural cryptosporidium hominis infections in scottish cattle. | | 2005 | 15923554 |
| molecular characterization of cryptosporidium species and genotypes in chile. | knowledge of species and genotypes on cryptosporidium involved in human transmission is fundamental in studying the epidemiology of cryptosporidiosis. this is the first study in molecular epidemiology of cryptosporidiosis that has been made in chile. cryptosporidium parvum species and genotypes involved in human and bovine cryptosporidiosis were determined by pcr-rflp. low prevalence of cryptosporidium was found in humans and cattle. of the 127 cattle studied, only in one was c. parvum detected ... | 2005 | 15952040 |
| unique endemicity of cryptosporidiosis in children in kuwait. | to understand the transmission of cryptosporidium infection in children, fecal specimens from 62 kuwaiti children with gastrointestinal symptoms found to be positive by microscopy were genotyped and subtyped with a small subunit rrna-based pcr-restriction fragment length polymorphism analysis and a 60-kda glycoprotein-based dna sequencing tool. the median age of infected children was 4.5 years, and 77% of infections occurred during the cool season of november to april. fifty-eight of the childre ... | 2005 | 15956401 |
| infectivity of cryptosporidium hominis and cryptosporidium parvum genotype 2 isolates in immunosuppressed mongolian gerbils. | one-month-old dexamethasone-immunosuppressed mongolian gerbils were challenged with 1 oocyst to 2 x 10(5) oocysts from two isolates genotyped as cryptosporidium hominis and c. parvum (genotype 2), respectively. a similar dose-dependent gut infection was obtained, and the initial genotype maintained for 21 to 22 days. the data suggest that immunosuppressed gerbils provide a reliable rodent model of persistent c. hominis infection. | 2005 | 16041051 |
| sheep may not be an important zoonotic reservoir for cryptosporidium and giardia parasites. | little is known of the prevalence of cryptosporidium and giardia parasites in sheep and the genotypes that they harbor, although potentially sheep may contribute significantly to contamination of watersheds. in the present study, conducted in western australia, a total of 1,647 sheep fecal samples were screened for the presence of cryptosporidium and giardia spp. using microscopy, and a subset (n = 500) were screened by pcr and genotyped. analysis revealed that although both parasites were detec ... | 2005 | 16151078 |
| the zoonotic transmission of giardia and cryptosporidium. | the molecular characterisation of giardia and cryptosporidium has given rise to a more epidemiological meaningful and robust taxonomy. importantly, molecular tools are now available for 'typing' isolates of the parasites directly from clinical and environmental samples. as a consequence, information on zoonotic potential has been obtained although the frequency of zoonotic transmission is still poorly understood. analysis of outbreaks and case-control studies, especially when coupled with genoty ... | 2005 | 16159658 |
| capillary electrophoretic analysis of fragment length polymorphism in ribosomal markers of cryptosporidium from humans. | cryptosporidium oocyst dna samples (n=80) from humans with cryptosporidiosis in australia and the uk were characterized genetically and categorized by capillary electrophoretic (ce) analysis of part of the small subunit gene (pssu; approximately 300bp) and second internal transcribed spacer (pits-2; approximately 230bp) of nuclear ribosomal dna. the amplicons were heat denatured and subjected to capillary electrophoresis in lpa matrix (amersham) in a megabacetrade mark 1000 system (amersham). th ... | 2005 | 16169706 |
| short report: asymptomatic cryptosporidium hominis infection among human immunodeficiency virus-infected patients in tanzania. | few data exist on the relative importance of individual cryptosporidium species in acquired immunodeficiency syndrome cryptosporidiosis. we characterized 127 inpatients infected with human immunodeficiency virus (hiv) in tanzania for their cd4 cell count and by stool analysis, including cryptosporidium immunofluorescence and polymerase chain reaction-restriction fragment length polymorphism. cryptosporidium was detected in patients both with and without diarrheal symptoms (defined as > or = 3 li ... | 2005 | 16172475 |
| patterns of cryptosporidium oocyst shedding by eastern grey kangaroos inhabiting an australian watershed. | the occurrence of cryptosporidium oocysts in feces from a population of wild eastern grey kangaroos inhabiting a protected watershed in sydney, australia, was investigated. over a 2-year period, cryptosporidium oocysts were detected in 239 of the 3,557 (6.7%) eastern grey kangaroo fecal samples tested by using a combined immunomagnetic separation and flow cytometric technique. the prevalence of cryptosporidium in this host population was estimated to range from 0.32% to 28.5%, with peaks occurri ... | 2005 | 16204534 |
| identification and determination of the viability of giardia lamblia cysts and cryptosporidium parvum and cryptosporidium hominis oocysts in human fecal and water supply samples by fluorescent in situ hybridization (fish) and monoclonal antibodies. | in the present study, fluorescent in situ hybridization (fish) and monoclonal antibodies (mabs) were evaluated for species-specific detection and viability determination of giardia lamblia, cryptosporidium parvum, and cryptosporidium hominis in human fecal and water supply samples. a total of 50 fecal human samples positive for g. lamblia cysts, 38 positive for c. parvum, and 23 positive for c. hominis were studied. also, 18 water supply samples positive for giardia spp. and cryptosporidium spp. ... | 2005 | 16261356 |
| interaction of cryptosporidium hominis and cryptosporidium parvum with primary human and bovine intestinal cells. | cryptosporidiosis in humans is caused by the zoonotic pathogen cryptosporidium parvum and the anthroponotic pathogen cryptosporidium hominis. to what extent the recently recognized c. hominis species differs from c. parvum is unknown. in this study we compared the mechanisms of c. parvum and c. hominis invasion using a primary cell model of infection. cultured primary bovine and human epithelial intestinal cells were infected with c. parvum or c. hominis. the effects of the carbohydrate lectin g ... | 2006 | 16368962 |
| cryptodb: a cryptosporidium bioinformatics resource update. | the database, cryptodb (http://cryptodb.org), is a community bioinformatics resource for the aids-related apicomplexan-parasite, cryptosporidium. cryptodb integrates whole genome sequence and annotation with expressed sequence tag and genome survey sequence data and provides supplemental bioinformatics analyses and data-mining tools. a simple, yet comprehensive web interface is available for mining and visualizing the data. cryptodb is allied with the databases plasmodb and toxodb via apidb, an ... | 2006 | 16381902 |
| an outbreak of cryptosporidium hominis infection at an illinois recreational waterpark. | cryptosporidium has become increasingly recognized as a pathogen responsible for outbreaks of diarrhoeal illness in both immunocompetent and immunocompromised persons. in august 2001, an illinois hospital reported a cryptosporidiosis cluster potentially linked to a local waterpark. there were 358 case-patients identified. we conducted community-based and waterpark-based case-control studies to examine potential sources of the outbreak. we collected stool specimens from ill persons and pool water ... | 2006 | 16409662 |
| intestinal parasitism in peruvian children and molecular characterization of cryptosporidium species. | intestinal parasitism was studied in children of trujillo (peru) to create a prevention and control program. fecal samples of 489 children were examined. the general prevalence of intestinal parasitosis was found to be 68%. the most frequent pathogenic enteroparasites were giardia lamblia (26.4%), cyclospora cayetanensis (13%), hymenolepis nana (2%), hymenolepis diminuta (1.6%), and cryptosporidium spp. (1%). all these parasites appeared both in diarrheic and nondiarrheic children, except crypto ... | 2006 | 16432755 |
| identification of cpgp40/15 type ib as the predominant allele in isolates of cryptosporidium spp. from a waterborne outbreak of gastroenteritis in south burgundy, france. | cryptosporidium sp. isolates from a waterborne outbreak of diarrhea in france were analyzed by pcr-restriction fragment length polymorphism analysis and sequencing of the cpgp40/15 locus. ninety-one percent of the isolates were cryptosporidium hominis type ib. the results of this study and those of studies of other outbreaks suggest that the type ib allele is the predominant allele associated with waterborne cryptosporidiosis. | 2006 | 16455918 |
| multilocus genotyping of cryptosporidium sp. isolates from human immunodeficiency virus-infected individuals in south india. | this study characterized cryptosporidial infections in 48 human immunodeficiency virus-infected individuals in india by multilocus genotyping. cryptosporidium hominis, c. parvum, c. felis, c. muris, and c. meleagridis were identified. cpgp40/15 pcr-restriction fragment length polymorphism identified six subgenotypes. cryptosporidial diarrhea was associated with decreased cd4 counts, below 200 (p = 0.009), but not high viral loads. | 2006 | 16455931 |
| differential evolution of repetitive sequences in cryptosporidium parvum and cryptosporidium hominis. | cryptosporidium parvum and cryptosporidium hominis are two morphologically identical species of apicomplexan protozoa infecting humans. although the genomes of these species are 97% identical, their host range is strikingly different. c. parvum infects humans and animals and is primarily a zoonotic infection, whereas c. hominis is typically not detected in animals. the extent of genetic polymorphism in both species has been surveyed locally, but not on a larger geographical scale. herein, a coll ... | 2006 | 16503512 |
| two crystal structures of dihydrofolate reductase-thymidylate synthase from cryptosporidium hominis reveal protein-ligand interactions including a structural basis for observed antifolate resistance. | cryptosporidium hominis is a protozoan parasite that causes acute gastrointestinal illness. there are no effective therapies for cryptosporidiosis, highlighting the need for new drug-lead discovery. an analysis of the protein-ligand interactions in two crystal structures of dihydrofolate reductase-thymidylate synthase (dhfr-ts) from c. hominis, determined at 2.8 and 2.87 a resolution, reveals that the interactions of residues ile29, thr58 and cys113 in the active site of c. hominis dhfr provide ... | 2005 | 16511011 |
| partial purification and characterization of an aminopeptidase from eimeria tenella. | our previous investigation demonstrated the expression in eimeria tenella sporulated oocysts of an aminopeptidase (ap) with strong homology to ap n. to further understand the role of proteases during development, we investigated the molecular and biochemical properties of e. tenella ap. greater than 95% ap activity was present in a soluble extract during sporulation of oocysts with highest activity in fully sporulated oocysts. the ap activity was inhibited by the ap inhibitors bestatin and 1,6-p ... | 2005 | 16539006 |
| distribution of cryptosporidium subtypes in humans and domestic and wild ruminants in portugal. | to investigate the transmission of cryptosporidiosis in portugal, cryptosporidium hominis and cryptosporidium parvum from hiv-infected patients, cattle, and wild ruminants were characterized by sequence analysis of the 60-kda glycoprotein (gp60) gene. fourteen subtypes within nine subtype families were identified, and three of the subtype families (if, iib, and iid) were restricted or largely limited to portugal. parasites from cattle from various regions in portugal and wild ruminants in lisbon ... | 2006 | 16552512 |
| genotype and subtype analyses of cryptosporidium isolates from dairy calves and humans in ontario. | to assess the importance of dairy cattle as a source of human cryptosporidium infections in ontario, canada, 44 cryptosporidium isolates from neonatal dairy calves and 11 from sporadic human cases of cryptosporidiosis in the province were genotyped by pcr-rflp analyses of the cryptosporidium oocyst wall protein (cowp) and 18s rrna genes. isolates were also subtyped by sequence analysis of the 60-kda glycoprotein (gp60) gene. all bovine isolates successfully subtyped belonged to cryptosporidium p ... | 2006 | 16565813 |
| multilocus genotyping of cryptosporidium hominis associated with diarrhea outbreak in a day care unit in são paulo. | a number of species of cryptosporidium are associated with diarrhea worldwide. little data exists regarding the genotypes and species of cryptosporidium associated with cases of infections in brazil. | 2006 | 16680328 |
| genetic analysis of cryptosporidium from 2414 humans with diarrhoea in england between 1985 and 2000. | the characterization of cryptosporidium using dna extracted from whole faecal samples collected from 2414 humans with diarrhoea in england between 1985 and 2000 where cryptosporidial oocysts were detected using conventional methods is described. characterization was achieved by pcr/rflp and dna sequencing of fragments of the cryptosporidium oocyst wall protein and the 18s rdna genes. cryptosporidium parvum was detected in 56.1 % of cases, cryptosporidium hominis in 41.7 % and a mixture of c. par ... | 2006 | 16687587 |
| bile acids enhance invasiveness of cryptosporidium spp. into cultured cells. | bile salts such as sodium taurocholate (natc) are routinely used to induce the excystation of cryptosporidium oocysts. here we show that natc significantly enhanced the invasion of several cultured cell lines by freshly excysted cryptosporidium parvum and cryptosporidium hominis sporozoites. a variety of purified bile salts or total bile from bovine also enhanced the invasion of cultured cells by c. parvum. further studies demonstrated that natc increased protein secretion and gliding motility o ... | 2006 | 16714562 |
| failure to propagate cryptosporidium spp. in cell-free culture. | the successful propagation of cryptosporidium parvum in cell-free culture medium was recently reported. to investigate whether this phenomenon could be broadened to include other c. parvum isolates, as well as cryptosporidium hominis, we attempted to propagate 3 isolates in cell-free medium under reported culture conditions. cryptosporidium oocysts from c. parvum strains moredun (md) or iowa or c. hominis strain tu502 were added to media containing coagulated newborn calf serum. the cultures wer ... | 2006 | 16729703 |
| analysis of complexes of inhibitors with cryptosporidium hominis dhfr leads to a new trimethoprim derivative. | cryptosporidiosis, an opportunistic infection affecting immunocompromised patients, the elderly, and children, is still an untreatable disease since the causative agent, cryptosporidium hominis, is essentially resistant to all clinically used antimicrobial agents. in order to accelerate the design of new potent and selective inhibitors targeting dihydrofolate reductase of c. hominis (chdhfr), we determined the structural basis for the potency of existing dhfr inhibitors using superpositions of t ... | 2006 | 16750361 |
| molecular characterisation of cryptosporidium isolates from humans in slovenia. | twenty-nine faecal specimens from slovenian patients in which cryptosporidium oocysts had been identified were studied. a fragment of the cryptosporidium 18s rrna gene and a fragment of the cryptosporidium cowp gene were amplified by pcr and sequenced. cryptosporidium parvum was identified in 26 of the 29 specimens, cryptosporidium hominis in two, and cryptosporidium cervine genotype in one. the fact that c. parvum, which is associated traditionally with animals, was identified in the majority o ... | 2006 | 16882299 |
| characterisation of small double stranded rna molecule in cryptosporidium hominis, cryptosporidium felis and cryptosporidium meleagridis. | coding regions of double stranded rna molecules from 3 human faecal samples containing cryptosporidium hominis, c. felis and c. meleagridis were characterised by sequencing and compared with that previously obtained for c. parvum. sequences outside the coding regions were also obtained. overall similarities of between 86% and 92% and between 86% and 93% were observed in the nucleotide and amino acid sequences respectively between these species. these larger sequences will allow further molecular ... | 2006 | 16890010 |
| heavy cryptosporidial infections in children in northeast brazil: comparison of cryptosporidium hominis and cryptosporidium parvum. | cryptosporidium is an important cause of infectious diarrhoea worldwide, but little is known about the course of illness when infected with different species. over a period of 5 years, cryptosporidium was identified in the stools of 58 of 157 children prospectively followed from birth in an urban slum (favela) in northeast brazil. forty isolates were available for quantification and 42 for speciation (24 cryptosporidium hominis and 18 c. parvum). children with c. hominis shed significantly more ... | 2007 | 16934303 |
| evidence supporting zoonotic transmission of cryptosporidium spp. in wisconsin. | cryptosporidium hominis and cryptosporidium parvum are the primary species of cryptosporidium that infect humans. c. hominis has an anthroponotic transmission cycle, while c. parvum is zoonotic, infecting cattle and other ruminants, in addition to humans. most cryptosporidiosis outbreaks in the united states have been caused by c. hominis, and this species is often reported as the primary cause of cryptosporidiosis in this country. however, outbreaks account for only 10% of the overall cryptospo ... | 2006 | 17005736 |
| multilocus sequence typing and genetic structure of cryptosporidium hominis from children in kolkata, india. | endemicity of cryptosporidiosis in india has been documented with little genetic characterization of the parasites. fifty cryptosporidium-positive specimens collected between 2001 and 2004 from pediatric patients in kolkata, india were analyzed for parasite genetic structure using multilocus sequence typing (mlst). genotype analyses showed the presence of cryptosporidium hominis, cryptosporidium meleagridis and cryptosporidium felis in 49, 2 and 1 patients, respectively (two patients had mixed i ... | 2007 | 17010677 |
| detection of uv-induced thymine dimers in individual cryptosporidium parvum and cryptosporidium hominis oocysts by immunofluorescence microscopy. | to investigate the effect of uv light on cryptosporidium parvum and cryptosporidium hominis oocysts in vitro, we exposed intact oocysts to 4-, 10-, 20-, and 40-mj x cm-2 doses of uv irradiation. thymine dimers were detected by immunofluorescence microscopy using a monoclonal antibody against cyclobutyl thymine dimers (anti-tdmab). dimer-specific fluorescence within sporozoite nuclei was confirmed by colocalization with the nuclear fluorogen 4',6'-diamidino-2-phenylindole (dapi). oocyst walls wer ... | 2007 | 17012589 |
| proteolytic processing of the cryptosporidium glycoprotein gp40/15 by human furin and by a parasite-derived furin-like protease activity. | the apicomplexan parasite cryptosporidium causes diarrheal disease worldwide. proteolytic processing of proteins plays a significant role in host cell invasion by apicomplexan parasites. in previous studies, we described gp40/15, a cryptosporidium sp. glycoprotein that is proteolytically cleaved to yield two surface glycopeptides (gp40 and gp15), which are implicated in mediating infection of host cells. in the present study, we showed that biosynthetically labeled gp40/15 is processed in crypto ... | 2007 | 17043102 |
| towards in silico lead optimization: scores from ensembles of protein/ligand conformations reliably correlate with biological activity. | accurately ranking protein/ligand interactions and distinguishing subtle differences between homologous compounds in a virtual focused library in silico is essential in a structure-based drug discovery program. in order to establish a predictive model to design novel inhibitors of dihydrofolate reductase (dhfr) from the parasitic protozoa, cryptosporidium hominis, we docked a series of 30 dhfr inhibitors with measured inhibition constants against the crystal structure of the protein. by includin ... | 2007 | 17078091 |
| cryptosporidium hominis: experimental challenge of healthy adults. | cryptosporidium hominis causes diarrhea in humans and has been associated with community outbreaks. this study describes the infectivity, illness, and serologic response after experimental challenge of 21 healthy adult volunteers with 10-500 c. hominis (tu502) oocysts. sixteen subjects (76.2%) had evidence of infection; the 50% infectious dose (id(50)) was estimated to be 10-83 oocysts using clinical and microbiologic definitions of infection, respectively. diarrhea occurred in 40% of subjects r ... | 2006 | 17123976 |
| [investigation of cryptosporidium spp. oocysts in tap water, well water, sewage water and sea water in mersin, turkey.] | cryptosporidium spp. are protozoa which only live in a host cell and may cause an infection that may result in the death of people with immune deficiency. it is known that cryptosporidium parvum and cryptosporidium hominis infections may be spread by contaminated well and tap waters. the facts that there is no certain and reliable cure and that the organisms may be found asymptomatically in the healthy people increases the importance of cryptosporidiosis. our study has been performed in the city ... | 2005 | 17124673 |
| subtype analysis of cryptosporidium isolates from children in uganda. | cryptosporidium hominis and cryptosporidium parvum isolates from children in uganda were characterized by dna sequence analysis of the gp60 gene. eight alleles were identified, 4 c. hominis and 4 c. parvum, of which 3 represent new c. parvum families. the data show that it is highly likely that the route of transmission is anthroponotic. | 2006 | 17152957 |
| development of a multilocus sequence typing tool for cryptosporidium hominis. | | 2006 | 17169064 |
| [cryptosporidium hominis diarrhea outbreak and transmission linked to diaper infant use]. | on the basis of several cases of cryptosporidiosis detected in a child day-care center, we stablished the extent of the outbreak and investigated causes of parasite transmission. | 2006 | 17169283 |
| a survey of cryptosporidiosis among 2,541 residents of 25 coastal islands in jeollanam-do (province), republic of korea. | in order to determine the distribution and prevalence of human cryptosporidiosis on western and southern coastal islands of jeollanam-do (province), fecal samples were collected from 2,541 people residing on 25 islands, 13 in the western coasts and 12 in the southern coasts, during july and august 2000. fecal smears were prepared following formalin-ether sedimentation of the samples and stained by a modified acid-fast procedure. the presence of cryptosporidium oocysts was determined by light mic ... | 2006 | 17170579 |
| highly efficient ligands for dihydrofolate reductase from cryptosporidium hominis and toxoplasma gondii inspired by structural analysis. | the search for effective therapeutics for cryptosporidiosis and toxoplasmosis has led to the discovery of novel inhibitors of dihydrofolate reductase (dhfr) that possess high ligand efficiency: compounds with high potency and low molecular weight. detailed analysis of the crystal structure of dihydrofolate reductase-thymidylate synthase from cryptosporidium hominis and a homology model of dhfr from toxoplasma gondii inspired the synthesis of a new series of compounds with a propargyl-based linke ... | 2007 | 17269758 |
| human enteropathogen load in activated sewage sludge and corresponding sewage sludge end products. | this study demonstrated a significant reduction in the concentrations of cryptosporidium parvum and cryptosporidium hominis oocysts, giardia lamblia cysts, and spores of human-virulent microsporidia in dewatered and biologically stabilized sewage sludge cake end products compared to those of the respective pathogens in the corresponding samples collected during the sludge activation process. | 2007 | 17277215 |
| quantitative tracking of cryptosporidium infection in cell culture with cfse. | immunofluorescence-based assays have been developed to detect and quantitate cryptosporidium parvum infection in cell culture. here, we describe a method that tracks and quantifies the early phase of attachment and invasion of c. parvum sporozoites using a fluorescent dye. newly excysted sporozoites were labeled with the amine-reactive fluorescein probe carboxyfluorescein diacetate succinimidyl esters (cfse) using an optimized protocol. the initial invasion of cells by labeled parasites was dete ... | 2006 | 17304819 |
| temporal occurrence of cryptosporidium in the manila clam ruditapes philippinarum in northern adriatic italian lagoons. | in order to evaluate the temporal occurrence of cryptosporidium oocysts in ruditapes philippinarum clams bred along the northeastern italian adriatic coast and molecularly characterize the isolates, 2,160 specimens (180 clams per month) were collected from three clam farms from january to december 2004. two farms (sites a and b) were located in venice (chioggia, veneto region) and one (site c) in the marano lagoons (friuli venezia giulia region). clams from 36 pools (i.e., one pool of 60 clams p ... | 2007 | 17340889 |
| subtypes of cryptosporidium parvum in humans and disease risk. | the 2 main species of cryptosporidium that infect humans are cryptosporidium hominis and c. parvum. here, multilocus fragment analysis of 3 microsatellite loci (ml1, ml2, and gp60) was used to subtype strains from sporadic cases of cryptosporidiosis in wales and northwest england. of 72 strains of c. parvum, 63 were typeable at all 3 loci, forming 31 subtypes. these strains formed 3 broad clusters, representing 74.6%, 20.6%, and 4.8% of typeable strains. of 118 c. hominis strains, 106 were typea ... | 2007 | 17370519 |
| genetic characterization of cryptosporidium species from humans in spain. | several species of cryptosporidium have been associated with infection. cryptosporidium parvum and cryptosporidium hominis are the main agents of cryptosporidiosis in humans. stool samples from 108 cryptosporidium-infected patients were submitted to pcr-rflp analysis for a 553-bp fragment of cryptosporidium oocyst wall protein (cowp) gene and an 826-864 bp fragment of the small-subunit ribosomal rna (ssu-rrna) gene. ninety-two patients were immunocompetent children and 16 were hiv-infected adult ... | 2007 | 17383227 |
| [worldwide human zoonotic cryptosporidiosis caused by cryptosporidium felis]. | cryptosporidium is an important enteric pathogen worldwide distributed causing diarrhoeal illness in humans and animals. identifying cryptosporidium species using conventional criteria, such as oocyst morphology, is inadequate. the advent of molecular techniques has conducted to characterize different species and genotypes of cryptosporidium infecting humans. the vast majority of human cases of cryptosporidiosis in the world are caused by both species, cryptosporidium hominis and cryptosporidium ... | 2007 | 17432054 |
| [investigation of cryptosporidium oocysts in elementary school students in mersin]. | cryptosporidium parvum, a protozoon, is an obligate intracellular parasite which can cause fatal diarrheal disease in immunocompromised individuals. cryptosporidium parvum and cryptosporidium hominis are usually known to be transmitted from fecally contaminated drinking and tap waters. because oocysts can be detected in asymptomatic healthy individuals and no safe and effective therapy for cryptosporidial enteritis is available, the importance of cryptosporidiosis is increased. in this study, st ... | 2007 | 17471406 |
| cryptosporidium hominis infection of the human respiratory tract. | cryptosporidium oocysts, observed in a natural sputum sample of a patient with hiv, were further studied by using dna markers to determine the species of the parasite. c. hominis was identified as the species infecting the patient's respiratory tract, a finding that strengthens evidence regarding this pathogen's role in human disease. | 2007 | 17552101 |
| nonconserved residues ala287 and ser290 of the cryptosporidium hominis thymidylate synthase domain facilitate its rapid rate of catalysis. | cryptosporidium hominis ts-dhfr exhibits an unusually high rate of catalysis at the ts domain, at least 10-fold greater than those of other ts enzymes. using site-directed mutagenesis, we have mutated residues ala287 and ser290 in the folate-binding helix to phenylalanine and glycine, respectively, the corresponding residues in human and most other ts enzymes. our results show that the mutant a287f, the mutant s290g, and the double mutant all have reduced affinities for methylene tetrahydrofolat ... | 2007 | 17580969 |
| rapid microsphere assay for identification of cryptosporidium hominis and cryptosporidium parvum in stool and environmental samples. | cryptosporidium hominis and cryptosporidium parvum are associated with massive disease outbreaks worldwide. because these two species have different transmission cycles, identification of these parasites to the species level in clinical samples may provide laboratory data of crucial importance in epidemiologic investigations. to date, the most reliable way to differentiate c. hominis and c. parvum is based on dna sequencing analysis of pcr amplicons. although this approach is very effective for ... | 2007 | 17652477 |
| molecular basis of cryptosporidium-host cell interactions: recent advances and future prospects. | host-parasite interactions mediating attachment of cryptosporidium spp. to host cells and invasion of the cell membrane are complex processes that involve multiple parasite and host molecules. knowledge of the molecular basis of these processes is crucial for understanding the pathogenic mechanisms underlying infection and for designing strategies to combat cryptosporidiosis. recent progress in this field has been greatly facilitated by the completion of the genome sequences of cryptosporidium p ... | 2006 | 17661665 |
| multilocus analysis of cryptosporidium hominis and cryptosporidium parvum isolates from sporadic and outbreak-related human cases and c. parvum isolates from sporadic livestock cases in the united kingdom. | cryptosporidium parvum and cryptosporidium hominis isolates from sporadic, drinking water-associated, and intrafamilial human cases together with c. parvum isolates from sporadic cases in livestock were collected in the united kingdom between 1995 and 1999. the isolates were characterized by analysis of three microsatellite markers (ml1, gp15, and ms5) using pcr amplification. within c. hominis, four alleles were detected within the gp15 and ms5 loci, and a single type was detected with ml1. c. ... | 2007 | 17687021 |
| detection of diarrhoea-causing protozoa in general practice patients in the netherlands by multiplex real-time pcr. | the diagnostic value of a multiplex real-time pcr for the detection of entamoeba histolytica, giardia lamblia and cryptosporidium parvum/cryptosporidium hominis was evaluated by comparing the pcr results obtained with those of routinely performed microscopy of faecal samples from patients consulting their general practitioner (gp) because of gastrointestinal complaints. analysis of 722 faecal dna samples revealed that the prevalence of g. lamblia was 9.3% according to pcr, as compared to 5.7% by ... | 2007 | 17714523 |
| cryptosporidium and giardia as foodborne zoonoses. | cryptosporidium and giardia are major causes of diarrhoeal disease in humans, worldwide and are major causes of protozoan waterborne diseases. both cryptosporidium and giardia have life cycles which are suited to waterborne and foodborne transmission. there are 16 'valid'cryptosporidium species and a further 33+ genotypes described. parasites which infect humans belong to the giardia duodenalis "type", and at least seven g. duodenalis assemblages are recognised. cryptosporidium parvum is the maj ... | 2007 | 17728067 |
| seropositive human subjects produce interferon gamma after stimulation with recombinant cryptosporidium hominis gp15. | cryptosporidiosis is an important cause of diarrhea worldwide. in normal hosts, infection is self-limited and associated with seroconversion and partial immunity to reinfection. immunity is associated with interferon gamma (ifngamma) production. cryptosporidium surface proteins gp15 and gp40 are among the immunodominant proteins in terms of antibody responses. we asked the question of whether these antigens also stimulate production of ifngamma in patients who have serologic evidence of prior in ... | 2007 | 17827383 |
| case-control study of environmental and social factors influencing cryptosporidiosis. | we report on the first case-control study to investigate the role of wider environmental and socioeconomic factors upon human cryptosporidiosis. using gis the detailed locations of 3368 laboratory-confirmed cases were compared to the locations of an equal number of controls. all cases were genotyped enabling cryptosporidium hominis and cryptosporidium parvum to be examined separately. when all cryptosporidiosis cases were analyzed, several location variables were strongly associated with illness ... | 2007 | 17891460 |
| cryptosporidium p30, a galactose/n-acetylgalactosamine-specific lectin, mediates infection in vitro. | cryptosporidium sp. cause human and animal diarrheal disease worldwide. the molecular mechanisms underlying cryptosporidium attachment to, and invasion of, host cells are poorly understood. previously, we described a surface-associated gal/galnac-specific lectin activity in sporozoites of cryptosporidium parvum. here we describe p30, a 30-kda gal/galnac-specific lectin isolated from c. parvum and cryptosporidium hominis sporozoites by gal-affinity chromatography. p30 is encoded by a single copy ... | 2007 | 17905738 |
| a practical and cost-effective mutation scanning-based approach for investigating genetic variation in cryptosporidium. | in the present study, we used a mutation scanning-targeted sequencing approach to assess variation in part (pgp60) of the 60 kda glycoprotein (gp60) gene among cryptosporidium samples from humans in victoria, australia. two nuclear ribosomal loci (the small subunit rrna gene and the second internal transcribed spacer) were used to identify the samples as cryptosporidium hominis (n = 74), cryptosporidium parvum (n = 23) or cryptosporidium meleagridis (n = 1). in total, nine distinct pgp60 sequenc ... | 2007 | 17960838 |
| molecular epidemiology of cryptosporidium in humans and cattle in the netherlands. | the protozoan parasite cryptosporidium is found world-wide and can cause disease in both humans and animals. to study the zoonotic potential of cryptosporidium in the netherlands we isolated this parasite from the faeces of infected humans and cattle and genotyped those isolates for several different markers. the overall genotyping results showed: for humans isolates, 70% cryptosporidium hominis, 19% cryptosporidium parvum, 10% a combination of c. hominis and c. parvum, and 1% cryptosporidium fe ... | 2008 | 18054936 |
| genotyping of cryptosporidium isolates from human clinical cases in poland. | cryptosporidium spp. infection is usually self-limited in immunocompetent hosts but can be severe and life threatening in children and in immunocompromised individuals including those with primary or acquired immunodeficiencies. one hundred and three faecal samples were collected from 35 hospitalised patients with different symptoms and tested for the presence of the parasite. cryptosporidium oocysts were found in four of 35 patients (11.4%) using ziehl-neelsen staining of faecal smears and immu ... | 2008 | 18301922 |
| geographic linkage and variation in cryptosporidium hominis. | uk cryptosporidium hominis isolates have previously shown slight pcr fragment length polymorphism at multiple loci. to further investigate transmission, we conducted a case-control study and sequenced the gp60 locus from 115 isolates. nine subtypes were identified; iba10g2 predominated. having a non-iba10g2 subtype was significantly linked to recent travel outside europe. | 2008 | 18325272 |
| evidence supporting zoonotic transmission of cryptosporidium in rural new south wales. | cryptosporidium hominis, which has an anthroponotic transmission cycle and cryptosporidium parvum, which is zoonotic, are the primary species of cryptosporidium that infect humans. the present study identified the species/genotypes and subgenotypes of cryptosporidium in 7 human and 15 cattle cases of sporadic cryptosporidiosis in rural western nsw during the period from november 2005 to january 2006. the species/genotype of isolates was determined by pcr sequence analysis of the 18s rrna and c. ... | 2008 | 18343369 |
| antigenic differences within the cryptosporidium hominis and cryptosporidium parvum surface proteins p23 and gp900 defined by monoclonal antibody reactivity. | the biological basis for the specificity of host infectivity patterns of cryptosporidium spp., in particular c. hominis and c. parvum, has yet to be fully elucidated. comparison of the c. parvum and c. hominis p23 and gp900 predicted amino acid sequences revealed 3 differences in p23 and 4 and 17 differences in gp900 domains 1 and 5, respectively. using monoclonal antibodies developed against the surface (glyco)proteins p23 and gp900 of the c. parvum iowa isolate, solubilized glycoprotein from t ... | 2008 | 18400317 |
| unique cryptosporidium population in hiv-infected persons, jamaica. | a cryptosporidiosis survey showed the presence of cryptosporidium hominis, c. parvum, c. canis, and c. felis in 25, 7, 1, and 1 hiv-positive persons from jamaica, respectively; 1 person had both c. hominis and c. felis. multilocus sequence typing indicated the presence of a homogeneous but geographically distinct c. hominis population in jamaica. | 2008 | 18439378 |
| classification of cryptosporidium species from patients with sporadic cryptosporidiosis by use of sequence-based multilocus analysis following mutation scanning. | in the present study, we analyzed genetic variation in cryptosporidium species from humans (n = 62) with clinical cryptosporidiosis in south australia. sequence variation was assessed in regions within the small subunit of nuclear rrna (p-ssu), the 70-kda heat shock protein (p-hsp70), and the 60-kda glycoprotein (p-gp60) genes by employing single-strand conformation polymorphism analysis and sequencing. based on the analyses of p-ssu and p-hsp70, cryptosporidium hominis (n = 38) and cryptosporid ... | 2008 | 18448696 |
| molecular characterization of cryptosporidium isolates from human and bovine using 18s rrna gene in shahriar county of tehran, iran. | cryptosporidiosis is a widespread cause of diarrheal diseases of humans, young calves, and many mammals. although in recent years molecular investigations on cryptosporidium have increased, no data are available on iran in this regard. two species of cryptosporidium are known to infect human beings; cryptosporidium hominis which shows anthroponotic transmission among humans and cryptosporidium parvum which shows zoonotic transmission between animals and humans. cryptosporidium oocysts, morpholog ... | 2008 | 18478266 |
| cryptosporidium species causing acute diarrhoea in children in antananarivo, madagascar. | a 13-month study of children presenting with acute diarrhoeal disease at hospitals and rehydration clinics in antananarivo, madagascar, was undertaken between may 2004 and may 2005. cryptosporidiosis accounted for diarrhoea in 12 (5.6%) of the 215 children investigated. cases of cryptosporidiosis were detected only in the rainy season, and the median age of cases was 13.5 months (range=1 day-27 months). as 11 of the cases of cryptosporidiosis were caused by cryptosporidium hominis and only one b ... | 2008 | 18510811 |
| genotypic identification of cryptosporidium spp. isolated from hiv-infected patients and immunocompetent children of são paulo, brazil. | cryptosporidium isolates identified in fourteen stool samples, collected from five hiv-infected patients and nine immunocompetent children, living in the state of são paulo, brazil, were submitted to a molecular analysis using a nested pcr followed of restriction fragment length polymorphism (rflp), for genetic characterization. the analysis was based on digestion with rsai restriction enzyme of a dna fragment amplified from the cryptosporidium oocyst wall protein (cowp) gene. based on this anal ... | 2008 | 18516466 |
| contribution of treated wastewater to the contamination of recreational river areas with cryptosporidium spp. and giardia duodenalis. | samples of the influent and final effluent from 12 wastewater treatment plants from galicia (nw, spain) were analyzed for the presence of cryptosporidium spp. oocysts and giardia duodenalis cysts. all of the plants discharge effluent to a hydrographic basin in which there are numerous recreational areas and fluvial beaches. the samples (25-50 liters) were collected in spring, summer, autumn and winter of 2007. a total of 96 samples were analyzed using techniques included in the us environmental ... | 2008 | 18538816 |
| assessment of cryptodiag for diagnosis of cryptosporidiosis and genotyping cryptosporidium species. | the performance of a new commercial pcr-enzyme-linked immunosorbent assay (elisa) (cryptodiag; bio advance, france) for the diagnosis of cryptosporidiosis and the identification of cryptosporidium hominis and c. parvum from stool samples was examined. this test is based on pcr amplification of cryptosporidium dna extracted from stools, followed by an elisa based on hybridization with cryptosporidium sp.-, c. hominis-, or c. parvum-specific probes. in spiking experiments, approximately five oocys ... | 2008 | 18550739 |
| protein coding gene nucleotide substitution pattern in the apicomplexan protozoa cryptosporidium parvum and cryptosporidium hominis. | cryptosporidium parvum and c. hominis are related protozoan pathogens which infect the intestinal epithelium of humans and other vertebrates. to explore the evolution of these parasites, and identify genes under positive selection, we performed a pairwise whole-genome comparison between all orthologous protein coding genes in c. parvum and c. hominis. genome-wide calculation of the ratio of nonsynonymous versus synonymous nucleotide substitutions (dn/ds) was performed to detect the impact of pos ... | 2008 | 18551181 |
| prevalence and genetic characterization of cryptosporidium isolates from common brushtail possums (trichosurus vulpecula) adapted to urban settings. | the common brushtail possum (trichosurus vulpecula) is one of the most abundant native marsupials in urban australia, having successfully adapted to utilize anthropogenic resources. the habituation of possums to food and shelter available in human settlements has facilitated interaction with people, pets, and zoo animals, increasing the potential for transmission of zoonotic cryptosporidium pathogens. this study sought to examine the identity and prevalence of cryptosporidium species occurring i ... | 2008 | 18641156 |
| explaining an unusually fast parasitic enzyme: folate tail-binding residues dictate substrate positioning and catalysis in cryptosporidium hominis thymidylate synthase. | the essential enzyme ts-dhfr from cryptosporidium hominis undergoes an unusually rapid rate of catalysis at the conserved ts domain, facilitated by two nonconserved residues, ala287 and ser290, in the folate tail-binding region. mutation of these two residues to their conserved counterparts drastically affects multiple steps of the ts catalytic cycle. we have determined the crystal structures of all three mutants (a287f, s290g, and a287f/s290g) in complex with active site ligands dump and cb3717 ... | 2008 | 18672899 |
| rare cryptosporidium hominis subtype associated with aquatic center use. | | 2008 | 18680673 |
| analysis of sir2e in the cellular slime mold dictyostelium discoideum: cellular localization, spatial expression and overexpression. | it has been reported that dictyostelium discoideum encodes four silent information regulator 2 (sir2) proteins (sir2a-d) showing sequence similarity to human homologues of sir2 (sirt1-3). further screening in a database revealed that d. discoideum encodes an additional sir2 homologue (sir2e). the amino acid sequence of sir2e is not similar to those of sirts but is similar to those of proteins encoded by giardia lamblia, cryptosporidium hominis and cryptosporidium parvum. fluorescence of sir2e-gr ... | 2008 | 18707607 |
| cryptosporidiosis in children in sub-saharan africa: a lingering challenge. | hospital- and community-based studies in sub-saharan africa document a high prevalence of cryptosporidiosis in children aged 6-36 months, particularly among those who are malnourished or positive for human immunodeficiency virus (hiv) infection and during rainy seasons. this is despite advances in developed countries that have curbed the incidence of cryptosporidiosis in the general and hiv-positive populations. transmission in sub-saharan africa appears to occur predominantly through an anthrop ... | 2008 | 18715159 |