Calf Clinical Model of Cryptosporidiosis for Efficacy Evaluation of Therapeutics.

Cryptosporidiosis, caused by the apicomplexan parasite Cryptosporidium parvum, is a moderate-to-severe diarrheal disease now recognized as one of the leading causes of morbidity and mortality in livestock globally, and in humans living in resource-limited parts of the world, particularly those with AIDS or malnourished individuals. This recognition has fueled efforts for the discovery of effective therapeutics. While recent progress in drug discovery has been encouraging, there are presently no acceptably effective parasite-specific drugs for the disease. The urgent need for new drug discovery or drug repurposing has also increased the need for refined animal models of clinical disease for therapeutic efficacy evaluation. Here, we describe an acute model of cryptosporidiosis using newborn calves to evaluate well-defined clinical and parasitological parameter outcomes, including the effect on diarrhea severity and duration, oocyst numbers produced, and multiple measures of clinical health. The model is highly reproducible and provides unequivocal direct measures of treatment efficacy on diarrhea severity and parasite replication.

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: areas with many higher socioeconomic status individuals, many individuals aged less than 4 years, areas with a high estimate of Cryptosporidium applied to land from manure, and areas with poorer water treatment. For C. hominis cases, the strongly significant risk factors were areas with many higher socioeconomic status individuals, areas with many young children and urban areas. Socioeconomic status and areas with many individuals aged less then 4 years had a greater impact for infection with C. hominis than for C. parvum. Policy implications are discussed.

Evaluation of Cryptosporidium parvum oocyst recovery efficiencies from various filtration cartridges by electrochemiluminescence assays.

AIMS: To evaluate four types of filtration cartridges for their capacities, efficiency for capture and release of Cryptosporidium parvum oocysts for detection. METHODS AND RESULTS: Filtration cartridges included in this evaluation were IDEXX Filta-Max, Gelman Envirochek HV, Corning CrypTest, and Filterite Sigma+. Various dosages of C. parvum oocysts were spiked into water samples with a wide range of turbidity (10-50 NTU). Electrochemiluminescence assays were employed to enumerate viable or total number of C. parvum oocysts in these eluates. Among the cartridges tested, Filta-Max consistently showed higher oocyst recovery efficiency, especially with large volume, highly turbid water samples. CONCLUSIONS: Filta-Max filter is the best performer because of its higher oocyst recovery efficiency. SIGNIFICANCE AND IMPACT OF THE STUDY: The overall sensitivities of various C. parvum oocyst detection assays in water samples can be improved if highly efficient oocyst recovery filtration cartridges such as Filta-Max are incorporated in sample preparation.

Host intestinal epithelial response to Cryptosporidium parvum.

Cryptosporidium parvum is an obligate intracellular protozoan parasite that is a well-recognized cause of diarrhea in humans and animals throughout the world, and is associated with a substantial degree of morbidity and mortality in patients with the acquired immunodeficiency syndrome (AIDS). C. parvum primarily infects epithelial cells of the gastrointestinal tract, resulting in acute watery diarrhea for which there is no effective therapy. During infection, all parasite development, sexual or asexual, occurs within epithelial cells of the host. This requires a unique and complex association between two distinct eukaryotic organisms. Conversely, due to the intracellular nature of C. parvum, epithelial cells appear to play a key role in activating and communicating with the host immune system. Delineation of the biochemical processes that are regulated within infected epithelial cells is crucial for understanding the pathology of C. parvum infection, the process by which the host clears and ultimately develops resistance to infection, and the development of chemotherapeutic strategies to intercede infections.

Anticryptosporidial activity of furan derivative G1 and its inclusion complex with beta-cyclodextrin.

The capacity of beta-cyclodextrin (betaCD) to form a complex with a new furanic derivative, G1, was investigated. Interactions of the drug and betaCD in solution and in the solid state were studied using phase solubility techniques, thermal methods, X-ray, and IR spectroscopy. Preparation of a kneaded mix of G1/betaCD increased both the aqueous solubility and the dissolution rate of the furan derivative. The anticryptosporidial efficacies of the drug and of the inclusion complex were evaluated using a suckling murine model. Oral administration of G1 considerably decreased the intensity of the infection, but betaCD showed similar anticryptosporidial activity to that of the betaCD-G1 complex and higher activity than G1 alone.

Is drinking water a risk factor for endemic cryptosporidiosis? A case-control study in the immunocompetent general population of the San Francisco Bay Area.

BACKGROUND: Cryptosporidiosis, caused by Cryptosporidium, is an enteric illness that has received much attention as an infection of immunocompromised persons as well as in community outbreaks (frequently waterborne). There are, however, no studies of the risk factors for sporadic community-acquired cryptosporidiosis in the immunocompetent US population. We undertook a case-control study in the San Francisco Bay Area as part of a national study sponsored by the Centers for Disease Control and Prevention to ascertain the major routes of transmission for endemic cryptosporidiosis, with an emphasis on evaluating risk from drinking water. METHODS: Cases were recruited from a population-based, active surveillance system and age-matched controls were recruited using sequential random-digit dialing. Cases (n = 26) and controls (n = 62) were interviewed by telephone using a standardized questionnaire that included information about the following exposures: drinking water, recreational water, food items, travel, animal contact, and person-to-person fecal contact, and (for adults) sexual practices. RESULTS: In multivariate conditional logistic regression analyses no significant association with drinking water was detected. The major risk factor for cryptosporidiosis in the San Francisco Bay Area was travel to another country (matched odds ratio [95% confidence interval]: 24.1 [2.6, 220]). CONCLUSION: The results of this study do not support the hypothesis that drinking water is an independent risk factor for cryptosporidiosis among the immunocompetent population. These findings should be used to design larger studies of endemic cryptosporidiosis to elucidate the precise mechanisms of transmission, whether waterborne or other.

Respuesta inmune en niños con infección intestinal por giardia lamblia, Cryptosporidium parvum y enterobius vermicularis / Inmune response in children with intestinal parasitic infection for Giardia lamblia, Cryptosporidium parvum and Enterobious vermicularis

El objetivo de este estudio es determinar la respuesta inmune sérica en niños con parasitosis intestinal al diagnóstico y tres meses después sin infección. Fueron recogidas 3036 muestras de 1959 niños y 939 pruebas de cello de 688 niños para investigación parasitaria. De los 155 niños con parásitos, 86 con un único parásito fueron seguidos en este estudio. Veintiséis con Giardia lamblia fueron tratados con tinidazol y metranidazol, cuarente con Enterobius vermicularis con palmoato de prantel y veinte con Cryptosporidium parvum sólo con tratamiento sintomático. Las inmunoglobulinas séricas fueron determinadas mediante nefelometria cinética CD4+ y CD8+ por citometria de flujo y anticuerpos monocionales marcados con fluorescencia. Existe un incremento signficativo de IgA en pacientes con Giardia lamblia y de IgG para Cryptosporidium parvum, entre la fase aguda de parasitación y tres meses después sin infección. No existen diferencias para IgM. Hay un descenso significativo en los tres tipos de parasitación para IgE entre el diagnóstico y tres meses después sin infección. No hemos encontrado diferencias significativas para CD4+, CD8+ y CD4+ / CD8+. Los pacientes con parasitosis intestinal presentan modificaciones inmunológicas significativas en la fase aguda de parasitación. Actualmente, el mecanismo mediante el cual el sistema inmune responde en las personas inmunocompetes es escasamente conocido. La respuesta inmunológica podría reflejar las alteraciones surgidas en la mucosa intestinal en contacto con el parásito (AU)

To determine prospectively plasma levels of immunes response in children with intestinal parasitic infection and three months after without infection. Three thousand thirty-six faecal stool samples were collected form 1959 children, and 939 cello-tape anal swabs form 688 children, were performed for intestinal parasite searching. From 155 children with parasitic infection, 86 were followed during this study. Twenty-six children with Giardi lamblia infection were treated with tinidazoie and metronidazole. Pyrantel palmoate symptomatic treatment. Serum inmune globulin, were determined for kinetic nephelometric, CD4+ and CD8+ for cytometric of flow and monoclonal atibodies marked with fluorescence. There were significant increases of IgA for Giardi lamblia and of IgG for Cryptosporidium parvum. No statistical difference was found for IgM. There were significant differences among the three types of parasites for IgE. There were a decrease significant of IgE among diagnosis and three months without infection for all types of parasites. No statistical difference was found for CD4+ CD8+ and C4/CD8. Patients with intestinal parasitic infection have alteration immunology´s significances. The mechanism with which the immune system of an inmunocompetent host responds to intestinal parasitic infection is still poorly understood. the immune response should reflect he pathology at the intestinal mucous site (AU)

Endemic cryptosporidiosis and exposure to municipal tap water in persons with acquired immunodeficiency syndrome (AIDS): a case-control study.

BACKGROUND: In persons with acquired immunodeficiency syndrome (AIDS), Cryptosporidium parvum causes a prolonged, severe diarrheal illness to which there is no effective treatment, and the risk of developing cryptosporidiosis from drinking tap water in non-outbreak settings remains uncertain. To test the hypothesis that drinking tap water was associated with developing cryptosporidiosis, we conducted a matched case-control study among persons with AIDS in San Francisco. METHODS: Among patients reported to the San Francisco AIDS Registry from May 1996 through September 1998, we compared patients who developed cryptosporidiosis to those who did not. Cases were individually matched to controls based on age, sex, race/ethnicity, CD4+ T lymphocyte count, date of CD4+ count, and date of case diagnosis. Population attributable fractions (PAFs) were calculated. RESULTS: The study consisted of 49 cases and 99 matched controls. In the multivariable analysis with adjustments for confounders, tap water consumption inside and outside the home at the highest exposure categories was associated with the occurrence of cryptosporidiosis (inside the home: odds ratio (OR), 6.76; 95% CI 1.37-33.5, and outside the home: OR 3.16; 95% CI 1.23-8.13). The PAF was 85%; that is, the proportion of cases of cryptosporidiosis in San Francisco AIDS patients attributable to tap water consumption could have been as high as 85%. CONCLUSIONS: Although the results from this observational study cannot be considered definitive, until there is more data, we recommend persons with AIDS, especially those with compromised immune systems, consider avoiding tap water.

Supplementation with Lactobacillus reuteri or L. acidophilus reduced intestinal shedding of cryptosporidium parvum oocysts in immunodeficient C57BL/6 mice.

The effect of L. acidophilus supplementation to reduce fecal shedding of Cryptosporidium parvum oocysts was compared to L. reuteri using C57BL/6 female mice immunosuppressed by murine leukemia virus (strain LP-BM5) inoculation. After 12 weeks post LP-BM5 inoculation, 15 immunosuppressed mice each were randomly assinged to one of the following treatment groups: historical control (group A), LP-BM5 control (group B), C. parvum (group C), L. reuteri plus C. parvum (group D) or L. acidophilus plus C. parvum (group E). Mice were pre-fed the L. reuteri or L. acidophilus bacteria strains daily for 13 days, challenged with C. parvum oocysts and thereafter fed the specified Lactobacillus regimens daily during the experimental period. Animals supplemented with L. reuteri shed fewer (p<0.05) oocysts on day-7 post C. parvum challenge compared to controls. Mice supplemented with L. acidophilus also shed fewer (p<0.05) oocysts on days 7 and 14 post-challenge compared to controls. Overall, Lactobacillus supplementation reduced C. parvum shedding in the feces but failed to suppress the production of T-helper type 2 cytokines [interleukin-4 (IL-4), IL-8)] which are associated with immunosuppression. Additionally, Lactobacillus supplementation did not restore T-helper type 1 cytokines (interleukin-2 (IL-2) and gamma interferon (IFN-gamma), which are required for recovery from parasitic infections. Altered T-helper types 1 and 2 cytokine production as a consequence of immunodysfunction permitted the development of persistent cryptosporidiosis while mice with intact immune system were refractory to infection with C. parvum. Reduction in shedding of oocysts observed in the Lactobacillus supplemented mice during deminished IL-2 and IFN-gamma production may be mediated by factors released into the intestinal lumen by the Lactobacillus and possibly other host cellular mechanisms. These observations suggest that L. reuteri or L. acidophilus can reduce C. parvum parasite burdens in the intestinal epithelium during cryptosporidiosis and may serve potential benefits as probiotics for host resistance to intestinal parasitic infections. L. acidophilus was more efficacious in reducing fecal shedding than L. reuteri and therefore may also have implication in the therapy of cryptosporidiosis during immunosuppressive states including human AIDS.

A comparison of the effects of two dinitroanilines against Cryptosporidium parvum in vitro and in vivo in neonatal mice and rats.

The effects of two dinitroanilines, oryzalin and trifluralin, were compared against Cryptosporidium parvum, in vitro using HCT-8 cells and in vivo using neonatal Swiss ARC mice and Wistar neonatal rats. In vitro, oryzalin and trifluralin exhibited IC(50) values (concentration necessary to cause a 50% inhibition) of 750 and 800 nM, respectively. A viability assay showed that neither compound produced a cytotoxic effect on the host cells at concentrations as high as 1 microM. The in vivo component of this study consisted of inoculation of neonatal mice and neonatal rats with 10(5) viable oocysts of C. parvum per animal and the subsequent treatment of this infection with trifluralin and oryzalin administered via gastric intubation. At doses of 100 mg kg(-1) body weight administered twice daily for 3 consecutive days, trifluralin had no statistically significant effect on the number of oocysts recovered from the gut of either rats or mice compared with controls, whereas at the same concentration, oryzalin caused 90 and 79% inhibition of oocysts recovered from mice and rats, respectively.

CpABC, a Cryptosporidium parvum ATP-binding cassette protein at the host-parasite boundary in intracellular stages.

The intracellular parasite Cryptosporidium parvum develops inside a vacuole at the apex of its epithelial host cell. The developing parasite is separated from the host cell cytoplasm by a zone of attachment that consists of an extensively folded membranous structure known as the feeder organelle. It has been proposed that the feeder organelle is the site of regulation of transport of nutrients and drugs into the parasite. In this report, we localize an approximately 200-kDa integral membrane protein, CpABC, from Cryptosporidium parvum to the host-parasite boundary, possibly the feeder organelle. The predicted amino acid sequence of CpABC has significant structural similarity with the cystic fibrosis conductance regulator and the multidrug resistance protein subfamily of ATP-binding cassette proteins. This is an example of a parasite-encoded transport protein localized at the parasite-host interface of an intracellular protozoan.

Identificación de Cryptosporidium en cerdos con enteritis / Identification of Cryptosporidium in pigs with enteritis in Mexico

Se observaron numerosos Cryptosporidium en el borde ciliado de las células epiteliales del intestino delgado, en tres lechones de 10 semanas de edad. Estos hallazgos se asociaron con una severa atrofia de vellosidades y moderada infiltración linfoide en la lámina propia. Además, en todos estos casos hubo una severa neumonía intersticial y linfoproliferativa compatible con una infección por Mycoplasma. Los estudios bacteriológicos fueron negativos a cepas enteropatógenas de Salmonella y Pasteurella. Estos cerdos pertenecían a una piara con mala higiene y sujetos a masivos tratamientos con varios antibióticos. Aunque el principal papel patológico de Cryptosporidium no puede ser atribuido en éste, la infección por este protozoario podría estar involucrada en el desarrollo de las lesiones. La cryptosporidiosis ha sido previamente notificada en becerros en México, pero este constituye el primer informe en cerdos

Diagnóstico sorológico da criptosporidiose humana / Serological diagnosis of human cryptosporidiosis

Para verificar a prevalência de Cryptosporidium em indivíduos humanos, através da Reação de Imunofluorescência Indireta, foram examinados 74 soros de imunodeficientes com um percentual de ocorrência de 55,40 pôr cento de IgC. Em 210 soros de crianças examinados verificou-se uma prevalência global extimada de 9,05 pôr cento. O antígeno utilizado foi obtido da porção distal do terço posterior do íleo de bezerros inoculados experimentalmente com C. parvum. A sensibilidade da Reação de Imunofluorescência Indireta (RIFI) tomanto como padrão os esfregaços fecais, foi 79,27 pôr cento. Em 44 soros de vaqueiros examinados foram encontrados 3 casos (6,81 pôr cento) positivos em uma diluição de 1:40

Prevalência de Cryptosporidium parvum em bezerros procedentes da microrregião de Goiânia-Go / Prevalence of Cryptosporidium parvim in calves proceeding from the micro-region of Goiânia-Go

Foi verificada a prevalência de Cryptosporidium em bezerros na faixa etária de 0 a 30 dias na microrregião de Goiânia. Examinou-se 499 bezerros na faixa etária acima referida, oriundos de 87 propriedades. Foram examinados através de esfregaços fecais corados pela técnica de Ziehl-Neelsen modificado. A prevalência global estimada do Cryptosporidium para a microrregião de Goiânia, foi de 12,02 pôr cento

Prevalance of cryptosoporidium oocysts in livestock in Trinidad and Tobago

Faecal samples from 683 diarrhoeic and non-diarrhoeic piglets, calves, lambs and goat kids were examined for Crytosporidium occysts. The prevalence of infection in piglets and lambs was 19.6 percent and 20 percent, respectively, and these rates were significantly higher that those detected in calves (8.7 percent). Amongst the four animal species studied, the detection rates were higher in diarrhoeic than in non-diarrhoeic animals and in animals under extensive and semi-intensive husbandry systems. However, these differences were not statistically significant(AU)