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No effective approved drug therapy exists for Cryptosporidium infection of immunocompromised patients.Here we investigated the nonabsorbed anthelmintic drug pyrvinium pamoate for inhibition of the growth of the intestinal protozoan parasite Cryptosporidium parvum. The concentration of pyrvinium that effected 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was 354 nM. For comparison, in the same assay, 50% growth inhibition was obtained with 711 M paromomycin or 27 M chloroquine. We used a neonatal mouse model to measure the anti-Cryptosporidium activity of pyrvinium pamoate in vivo. Beginning 3 days after infection, pyrvinium at 5 or 12.5 mg/kg of body weight/day was administered to the treatment group mice for 4 or 6 consecutive days. Nine days after infection, the mice were sacrificed, and drug efficacy was determined by comparing the numbers of oocysts in the fecal smears of treated versus untreated mice. The intensities of trophozoite infection in the ileocecal intestinal regions were also compared using hematoxylin-and-eosin-stained histological slides. We observed a >90% reduction in infection intensity in pyrvinium-treated mice relative to that in untreated controls, along with a substantial reduction in tissue pathology. Based on these results, pyrvinium pamoate is a potential drug candidate for the treatment of cryptosporidiosis in both immunocompetent and immunocompromised individuals.Cryptosporidium is an important apicomplexan protozoan pathogen that contributes significantly to diarrheal disease in both humans and animals throughout the world (9, 10, 21). In immunocompetent hosts, infections are generally restricted to the intestinal epithelium, causing an acute, self-limiting gastroenteritis. However, in AIDS patients and other immunocompromised individuals, infection can result in life-threatening, chronic diarrhea and may spread to extraintestinal locations (16,26). Although the efficacies of numerous antimicrobial agents against Cryptosporidium infection have been tested using animal and cell culture models, there is currently no reliably effective therapeutic for the treatment of chronic cryptosporidiosis in immunocompromised patients (30).Recently, nitazoxanide (NTZ), a nitrothiazole benzamide, was approved by the FDA for the treatment of cryptosporidiosis in immunocompetent adults and children aged Ͼ1 year (2). However, while clinical studies are ongoing, the efficacy of NTZ for the treatment of Cryptosporidium infection in immunocompromised patients has not yet been demonstrated (1). A 50% inhibitory concentration (IC 50 ) of 3.8 M has been reported for NTZ in cell culture (12). In a neonatal mouse model, oral administration of NTZ at 150 mg/kg of body weight reduced oocyst output to less than 5% of that seen in controls (6); however, NTZ at 100 or 200 mg/kg was ineffective at reducing parasite burdens in a SCID mouse model (24).Prior to the FDA approval of NTZ as an anti-Cryptosporidium therapeutic, the glycoside antibiotic paromomyc...

Cognitive impairment, including clinical Alzheimer's-type dementia (CATD), mild cognitive impairment (MCI), or age-related cognitive decline (ARCD), affects many older adults. Although much remains unknown about preventing, delaying onset, or slowing progression of these conditions, a growing body of research is emerging that may inform decision making by consumers, patients, clinicians, and public health practitioners.

ABSTRACTEnvironmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (Bacillus cereus) and Gram-negative (Burkholderia thailandensisandEscherichia coli) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.

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Numerous studies have documented the presence of Cryptosporidium parvum, an anthropozoonotic enteric parasite, in molluscan shellfish harvested for commercial purposes. Getting accurate estimates of Cryptosporidium contamination levels in molluscan shellfish is difficult because recovery efficiencies are dependent on the isolation method used. Such estimates are important for determining the human health risks posed by consumption of contaminated shellfish. In the present study, oocyst recovery was compared for multiple methods used to isolate Cryptosporidium parvum oocysts from oysters (Crassostrea virginica) after exposure to contaminated water for 24 h. The immunomagnetic separation (IMS) and immunofluorescent antibody procedures from Environmental Protection Agency method 1623 were adapted for these purposes. Recovery efficiencies for the different methods were also determined using oyster tissue homogenate and hemolymph spiked with oocysts. There were significant differences in recovery efficiency among the different treatment groups (P < 0.05). We observed the highest recovery efficiency (i.e., 51%) from spiked samples when hemolymph was kept separate during the homogenization of the whole oyster meat but was then added to the pellet following diethyl ether extraction of the homogenate, prior to IMS. Using this processing method, as few as 10 oocysts could be detected in a spiked homogenate sample by nested PCR. In the absence of water quality indicators that correlate with Cryptosporidium contamination levels, assessment of shellfish safety may rely on accurate quantification of oocyst loads, necessitating the use of processing methods that maximize oocyst recovery. The results from this study have important implications for regulatory agencies charged with determining the safety of molluscan shellfish for human consumption.

Pyrvinium is a potential gut lumen agent for treatment of intestinal amoebiasis, but possibly not for giardiasis. SYBR Green I is an alternative screening method for E. histolytica, but not G. intestinalis.