66 research outputs found
Comparison of the Host Ranges and Antigenicity of Cryptosporidium parvum and Cryptosporidium wrairi from Guinea Pigs
Oocysts of a Cryptosporidium isolate from guinea pigs were not infectious for adult mice, but were infectious for two of three newborn calves and for suckling mice. However, oocysts isolated from calves or mice infected with guinea pig Cryptosporidium were not infectious for guinea pigs. Four isolates of C. parvum from calves were incapable of infecting weanling guinea pigs. Microscopic examination of tissue from the colon and cecum of suckling guinea pigs inoculated with C. parvum revealed sparse infection of some pups. These host range studies and previously described differences in 125 I-labeled oocyst surface protein profiles between Cryptosporidium sp. from guinea pigs and C. parvum suggest they are distinct species. We propose the name Cryptosporidium wrairi be retained. Studies with monoclonal antibodies indicate that C. wrairi and C. parvum are antigenically related.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75184/1/j.1550-7408.1992.tb01471.x.pd
Comparative genomics reveals Cyclospora cayetanensis possesses coccidia-like metabolism and invasion components but unique surface antigens
Assessment of the completeness of sequenced Toxoplasma gondii, Eimeria tenella and Cyclospora cayetanensis genomes based on core eukaryotic protein-encoding genes search using BUSCO. (DOCX 14 kb
Epidemiologic and Environmental Investigation of a Recreational Water Outbreak Caused by Two Genotypes of Cryptosporidium Parvum in Ohio in 2000
In August 2000, the Ohio Department of Health requested assistance to investigate a cryptosporidiosis outbreak with more than 700 clinical case-patients. An epidemiologic and environmental investigation was conducted. Stool specimens, pool water, and sand filter samples were analyzed. A community-based case-control study showed that the main risk factor was swimming in pool A (odds ratio [OR] = 42, 95% confidence interval [CI] = 12.3-144.9). This was supported by results of polymerase chain reaction (PCR) analysis, which showed the presence of both the human and bovine genotypes of Cryptosporidium parvum in case-patients and samples from the filter of pool A. A pool-based case-control study indicated that the highest risk was related to exposure to pool water via the mouth (OR = 5.1, 95% CI = 2.1-12.5) or to pool sprinklers (OR = 2.5, 95% CI = 1.3-4.7). Fecal accidents at the pool were documented. Records indicated that the pool met local health regulations. The outbreak, caused by co-infection with two C. parvum genotypes (human and bovine), underscores the need for concerted action to improve public health policies for recreational water facilities and enhanced education regarding the potential for disease transmission through pools
Prevalence and Molecular Characterization of Cyclospora cayetanensis, Henan, China
To determine prevalence of Cyclospora cayetanensis infection in Henan, China, we conducted a study of 11,554 hospital patients. Prevalence was 0.70% (95% confidence interval 0.70% ± 0.15%), with all age groups infected. Most cases were found in the summer. Minor sequence polymorphisms were observed in the 18S rRNA gene of 35 isolates characterized
Cryptosporidiosis Associated with Ozonated Apple Cider
We linked an outbreak of cryptosporidiosis to ozonated apple cider by using molecular and epidemiologic methods. Because ozonation was insufficient in preventing this outbreak, its use in rendering apple cider safe for drinking is questioned
New cryptosporidium genotypes in HIV-infected persons.
Using DNA sequencing and phylogenetic analysis, we identified four distinct Cryptosporidium genotypes in HIV-infected patients: genotype 1 (human), genotype 2 (bovine) Cryptosporidium parvum, a genotype identical to C. felis, and one identical to a Cryptosporidium sp. isolate from a dog. This is the first identification of human infection with the latter two genotypes
Intravenous Inoculation of a Bat-Associated Rabies Virus Causes Lethal Encephalopathy in Mice through Invasion of the Brain via Neurosecretory Hypothalamic Fibers
The majority of rabies virus (RV) infections are caused by bites or scratches from rabid carnivores or bats. Usually, RV utilizes the retrograde transport within the neuronal network to spread from the infection site to the central nervous system (CNS) where it replicates in neuronal somata and infects other neurons via trans-synaptic spread. We speculate that in addition to the neuronal transport of the virus, hematogenous spread from the site of infection directly to the brain after accidental spill over into the vascular system might represent an alternative way for RV to invade the CNS. So far, it is unknown whether hematogenous spread has any relevance in RV pathogenesis. To determine whether certain RV variants might have the capacity to invade the CNS from the periphery via hematogenous spread, we infected mice either intramuscularly (i.m.) or intravenously (i.v.) with the dog-associated RV DOG4 or the silver-haired bat-associated RV SB. In addition to monitoring the progression of clinical signs of rabies we used immunohistochemistry and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to follow the spread of the virus from the infection site to the brain. In contrast to i.m. infection where both variants caused a lethal encephalopathy, only i.v. infection with SB resulted in the development of a lethal infection. While qRT-PCR did not reveal major differences in virus loads in spinal cord or brain at different times after i.m. or i.v. infection of SB, immunohistochemical analysis showed that only i.v. administered SB directly infected the forebrain. The earliest affected regions were those hypothalamic nuclei, which are connected by neurosecretory fibers to the circumventricular organs neurohypophysis and median eminence. Our data suggest that hematogenous spread of SB can lead to a fatal encephalopathy through direct retrograde invasion of the CNS at the neurovascular interface of the hypothalamus-hypophysis system. This alternative mode of virus spread has implications for the post exposure prophylaxis of rabies, particularly with silver-haired bat-associated RV
Cathelicidin-like Helminth Defence Molecules (HDMs) Absence of Cytotoxic, Anti-microbial and Anti-protozoan Activities Imply a Specific Adaptation to Immune Modulation
Host defence peptides (HDPs) are expressed throughout the animal and plant kingdoms. They have multifunctional roles in the defence against infectious agents of mammals, possessing both bactericidal and immune-modulatory activities. We have identified a novel family of molecules secreted by helminth parasites (helminth defence molecules; HDMs) that exhibit similar structural and biochemical characteristics to the HDPs. Here, we have analyzed the functional activities of four HDMs derived from Schistosoma mansoni and Fasciola hepatica and compared them to human, mouse, bovine and sheep HDPs. Unlike the mammalian HDPs the helminth-derived HDMs show no antimicrobial activity and are non-cytotoxic to mammalian cells (macrophages and red blood cells). However, both the mammalian- and helminth-derived peptides suppress the activation of macrophages by microbial stimuli and alter the response of B cells to cytokine stimulation. Therefore, we hypothesise that HDMs represent a novel family of HDPs that evolved to regulate the immune responses of their mammalian hosts by retaining potent immune modulatory properties without causing deleterious cytotoxic effects. © 2013 Thivierge et al
Recommended from our members
Cryptosporidium: Oocyst production and hybridoma generation for examining colostrum and monoclonal antibody roles in cryptosporidial infections.
Techniques for the large-scale isolation of Cryptosporidium oocysts and sporozoites, obtained from the feces of experimentally infected Holstein calves, were developed employing discontinuous sucrose gradients and isopycnic Percoll gradients. The three step oocyst recovery method utilized two sequential discontinuous sucrose gradients followed by one Percoll gradient. Recovered oocysts were essentially free of debris and bacteria and represented 34% of the original oocyst suspension. Sporozoites were recovered from excystation mixtures on a single Percoll gradient. Sixty-three percent of the original sporozoites were recovered with 2.2% contamination by intact oocysts and virtually no oocyst walls. Eight anti-oocyst hybridomas were derived from oocyst-immunized mice: five from BALB/c mice and three from RBF/Dn mice. The monoclonal antibody (Mab) OW3 reacted specifically with C. parvum oocysts in immunofluorescent assays (IFA) and was shown to be superior to conventional stains for detecting oocysts in fecal smears from infected individuals. Sixteen anti-sporozoite hybridomas were derived from sporozoite-immunized BALB/c mice. The Mabs appeared to react with cell surface and cytoplasmic antigens by IFA. Two anti-sporozoite Mabs (C8C5, C6B6) reacted with a 20 kDa sporozoite antigen in western blots while the Mab C4A1 reacted with multiple antigens in western blots. These three Mabs (C8C5, C6B6, C4A1) were examined for potential modulation of cryptosporidial infections in vivo by oral Mab administration to oocyst-inoculated neonatal mice. The role for colostrum and breast milk in controlling cryptosporidial infections was examined by immunizing mouse dams and experimentally infecting their neonatal offspring. Colostrum and Mab-treated neonatal mice were sacrificed four days post infection. No difference in infection rates was observed among the treatment groups. Suckling mice treated daily with orally administered mixtures of Mabs (purified or ascitic fluid) showed significantly reduced parasite loads compared to control mice at four days post infection. In vitro cultivation of C. parvum was successful through asexual stages in human fetal lung, bovine turbinate and murine L929 cells. Parasite numbers that developed in the cell cultures varied from infection run to infection run
In Vitro Cultivation of Cryptosporidium Species
The in vitro cultivation of protozoan parasites of the genus Cryptosporidium has advanced significantly in recent years. These obligate, intracellular parasites colonize the epithelium of the digestive and respiratory tracts, are often difficult to obtain in significant numbers, produce durable oocysts that defy conventional chemical disinfection methods, and are persistently infectious when stored at refrigerated temperatures (4 to 8°C). While continuous culture and efficient life cycle completion (oocyst production) have not yet been achieved in vitro, routine methods for parasite preparation and cell culture infection and assays for parasite life cycle development have been established. Parasite yields may be limited, but in vitro growth is sufficient to support a variety of research studies, including assessing potential drug therapies, evaluating oocyst disinfection methods, and characterizing life cycle stage development and differentiation
- …