Antiparasitic and immunomodulating effects of nitazoxanide, ivermectin and selenium on Cryptosporidium infection in diabetic mice.

The present work aims to investigate the antiparasitic and the immunomodulating effects of nitazoxanide (NTZ) and ivermectin (IVC) alone or combined together or combined with selenium (Se), on Cryptosporidium infection in diabetic mice. The results revealed that the combined NTZ and IVC therapy achieved the highest reduction of fecal oocysts (92%), whereas single NTZ showed the lowest reduction (63%). Also, adding Se to either NTZ or IVC resulted in elevation of oocyst reduction from 63% to 71% and from 82% to 84% respectively. All treatment regimens, with the exception of NTZ monotherapy, showed a significant improvement in the intestinal histopathology, the highest score was in combined NTZ and IVC therapy. The unique results of immunohistochemistry in this study showed reversal of the normal CD4/CD8 T cell ratio in the infected untreated mice, however, following therapy it reverts back to a normal balanced ratio. The combined (NTZ+ IVC) treatment demonstrated the highest level of CD4 T cell expression. Taken together, NTZ and IVC combined therapy showed remarkable anti-parasitic and immunostimulatory effects, specifically towards the CD4 population that seem to be promising in controlling cryptosporidiosis in diabetic individuals. Further research is required to explore other effective treatment strategies for those comorbid patients.

Antiparasitic and immunomodulating effects of nitazoxanide, ivermectin and selenium on Cryptosporidium infection in diabetic mice / Efeitos antiparasitários e imunomodulantes da nitazoxanida, ivermectina e selênio sobre a infecção por Cryptosporidium em camundongos diabéticos

Abstract The present work aims to investigate the antiparasitic and the immunomodulating effects of nitazoxanide (NTZ) and ivermectin (IVC) alone or combined together or combined with selenium (Se), on Cryptosporidium infection in diabetic mice. The results revealed that the combined NTZ and IVC therapy achieved the highest reduction of fecal oocysts (92%), whereas single NTZ showed the lowest reduction (63%). Also, adding Se to either NTZ or IVC resulted in elevation of oocyst reduction from 63% to 71% and from 82% to 84% respectively. All treatment regimens, with the exception of NTZ monotherapy, showed a significant improvement in the intestinal histopathology, the highest score was in combined NTZ and IVC therapy. The unique results of immunohistochemistry in this study showed reversal of the normal CD4/CD8 T cell ratio in the infected untreated mice, however, following therapy it reverts back to a normal balanced ratio. The combined (NTZ+ IVC) treatment demonstrated the highest level of CD4 T cell expression. Taken together, NTZ and IVC combined therapy showed remarkable anti-parasitic and immunostimulatory effects, specifically towards the CD4 population that seem to be promising in controlling cryptosporidiosis in diabetic individuals. Further research is required to explore other effective treatment strategies for those comorbid patients.

Resumo O presente trabalho tem como objetivo investigar os efeitos anti-parasitários e imunomodulantes da nitazoxanida (NTZ) e ivermectina (IVC), isoladas ou em associação, e do selênio (SE), associado à NTZ ou à IVC, sobre a infecção por Cryptosporidium em camundongos diabéticos. Os resultados revelaram que a terapia combinada com NTZ e IVC resultou em maior redução de oocistos fecais, enquanto a NTZ isolada mostrou a menor redução de oocistos fecais (63%). Além disso, a associação do SE com a NTZ ou IVC resultou em redução do número de oocistos fecais de 63% para 71% e de 82% para 84%, respectivamente. Todos os tratamentos, com exceção da monoterapia com NTZ, mostraram uma melhora significativa nos índices relacionados à histopatologia intestinal. Os resultados da imuno-histoquímica mostraram reversão da razão celular CD4/CD8 T normal nos camundongos infectados não tratados, no entanto, após a terapia, houve retorno à razão celular CD4/CD8 T normal. O tratamento combinado (NTZ+ IVC) demonstrou o mais alto nível de expressão celular CD4 T. Em conclusão, a terapia combinada com NTZ e IVC mostrou efeitos anti-parasitários e imunoestimuladores notáveis, especificamente para a população CD4, que parecem ser promissores para o controle da criptosporidiose em indivíduos diabéticos.

Probiotic Product Enhances Susceptibility of Mice to Cryptosporidiosis.

Cryptosporidiosis, a leading cause of diarrhea among infants, is caused by apicomplexan parasites classified in the genus Cryptosporidium The lack of effective drugs is motivating research to develop alternative treatments. With this aim, the impact of probiotics on the course of cryptosporidiosis was investigated. The native intestinal microbiota of specific pathogen-free immunosuppressed mice was initially depleted with orally administered antibiotics. A commercially available probiotic product intended for human consumption was subsequently added to the drinking water. Mice were infected with Cryptosporidium parvum oocysts. On average, mice treated with the probiotic product developed more severe infections. The probiotics significantly altered the fecal microbiota, but no direct association between ingestion of probiotic bacteria and their abundance in fecal microbiota was observed. These results suggest that probiotics indirectly altered the intestinal microenvironment or the intestinal epithelium in a way that favored proliferation of C. parvumIMPORTANCE The results of our study show that C. parvum responded to changes in the intestinal microenvironment induced by a nutritional supplement. This outcome paves the way for research to identify nutritional interventions aimed at limiting the impact of cryptosporidiosis.

Efficacy of nitazoxanide to treat natural Giardia infections in dogs.

BACKGROUND: Giardia parasites cause gastrointestinal disease in humans, dogs, and many other animals worldwide. The treatment of dogs for giardiasis requires further investigation to ascertain levels of drug efficacy and the possibility of adverse side effects. Nitazoxanide (NTZ) has shown good clinical anti-Giardia activity in humans, yet it has not been evaluated for the treatment of giardiasis in dogs. METHODS: Thirty-five dogs, naturally infected with Giardia were divided into five groups (n = 7): dogs in group NTZ1, NTZ2, and NTZ3 were treated with a single oral dose of 37.5 mg/kg, 75 mg/kg, and 150 mg/kg, respectively, of NTZ on days 0 and 14. The fourth group was treated with a commercially available regimen that includes a combination of pyrantel, praziquantel, and febantel (FEB) administered orally for three consecutive days. Additionally, an untreated control group was established. Giardia cysts from the stool of each dog were quantified on days -3, 0, 5, 7, 9, 11, 14, 18, 25, and 28. Biochemical parameters were evaluated in all dogs, before the first treatment and after concluding the experiment. RESULTS: Shedding of Giardia cysts was reduced in all treated groups when compared to untreated controls (P < 0.01). However, NTZ2, NTZ3, and FEB had a lower risk during the study. Furthermore, NTZ was also effective against another protozoan, Cryptosporidium spp. at doses of 75 mg/kg and 150 mg/kg, in contrast to the combination of febantel + pyrantel + praziquantel. Biochemical parameters of treated animals, namely, aspartate transaminase and alanine transaminase enzymes, remained within physiological ranges. CONCLUSIONS: Based on these results, the implementation of NTZ as a treatment for giardiasis in dogs is proposed. The administration of a single dose is an important advantage of NTZ because it reduces workload, particularly in animals placed in shelters and kennels, where handling of large numbers of animals is required, and personnel is frequently scarce.

Cryptosporidium canis in Two Mexican Toddlers.

Cryptosporidium canis is reported for the first time in 2 toddlers in Northwestern Mexico. The 2 toddlers (33 and 34 months old) were symptomatic at diagnosis, presenting diarrhea and fever, and 1 case presented chronic malnutrition. Both toddlers were HIV-negative. C. canis was identified by SspI and VspI restriction enzyme digestion of the 18S rRNA polymerase chain reaction products and confirmed by sequence analysis.

Effects of Enterococcus faecalis CECT 7121 on Cryptosporidium parvum infection in mice.

Cryptosporidium is an opportunistic protozoan parasite of humans and animals worldwide and causes diarrheal disease that is typically self-limiting in immunocompetent hosts but often life threatening to immunocompromised individuals. However, there is a lack of completely efficient therapy available. Probiotics have attracted the attention as potential antiparasite compounds against protozoa involved in intestinal infections. This study investigated the effects of administration of probiotic Enterococcus faecalis CECT 7121 on Cryptosporidium parvum infection in immunosuppressed mice. Effects on C. parvum infection at the intestinal mucosa were studied and scored at each portion of the gut. It was demonstrated that Ef CECT 7121 interfered with C. parvum infection when both probiotic and parasite were present in the same intestinal location suggesting that Ef CECT 7121 supplementation can alleviate the negative effects of C. parvum infection.

Early Life Antibiotic Exposure Is Not Associated with Growth in Young Children of Vellore, India.

OBJECTIVES: To estimate the effects of antibiotic exposures in the first 6 months of life on short- and long-term growth. STUDY DESIGN: In a prospective observational cohort study of 497 children from Vellore, India, we estimated short-term effects of antibiotics during the first 6 months using longitudinal general linear regression to model weight-for-age, height-for-age, and weight-for-height z-scores in monthly intervals. To estimate long-term effects, we modeled growth from 6 months to 3 years as a function of antibiotic use in the first 6 months. We also estimated the effects of antibiotics on the monthly relative risks of underweight, stunting, and wasting in the first 6 months and to 3 years. RESULTS: Underweight, stunting, and wasting were common in this population: 31%, 32%, and 15% on average after 6 months of age, respectively. There was no association between antibiotic exposures before 6 months and growth during that period. From 6 months to 3 years, adjusted absolute differences in weight and height were small (approximately -100 g and no more than -2 mm overall, respectively) and not statistically significant. CONCLUSIONS: Antibiotic exposures early in life were not associated with increased or decreased growth. The combination of malnutrition and recurrent illness likely complicate the relationship between antibiotic exposures and growth among children in low and middle-income countries.

Short report: Molecular insights for Giardia, Cryptosporidium, and soil-transmitted helminths from a facility-based surveillance system in Guatemala.

We molecularly characterized samples with Giardia, Cryptosporidium, and soil-transmitted helminths from a facility-based surveillance system for diarrhea in Santa Rosa, Guatemala. The DNA sequence analysis determined the presence of Giardia assemblages A (N = 7) and B (N = 12) and, Cryptosporidium hominis (N = 2) and Cryptosporidium parvum (N = 2), suggestive of different transmission cycles. All 41 samples with soil-transmitted helminths did not have the ß-tubulin mutation described for benzimidazole resistance, suggesting potential usefulness in mass drug administration campaigns.

[Intestinal cryptosporidiosis in HIV infected children]. / Criptosporidiosis intestinal en niños con HIV/Sida.

Cryptosporydium parvum is an intracellular parasite that infects gastrointestinal epithelium and produces diarrhea that is self-limited in immunocompetent persons but potentially life-threatening in immunocompromised, especially those with the acquired immunodeficiency syndrome (AIDS). C. parvum enteric infection's incidence in a pediatric HIV/AIDS cohort, during a 6 years period, was studied. Clinical and immunologic characteristics of the dual infection were also recorded. Highly active antiretroviral therapy (HAART) was started or continued by all the patients during follow-up. Azithromicyn was used as antiparasitic drug. Cryptosporidiosis incidence was 13.7%; 33 out 240 children showed chronic diarrhea lasting 14 days at least, or recurrent, without dehydration and electrolytic disturbance. Peripheral blood T CD4+ percentage levels of the patients were variable and without relationship with C. parvum presence. Viral load levels in 31 out 33 patients were over cut-off at the enteric episode time. Mild or moderate eosinophilia were recorded in 23% of the patients and other intestinal parasites were present in 11 children. When the number of enteric episodes were compared with the clinical and immunological patient's status, not significant differences were recorded. HAART is the best treatment to improve immune function in HIV patients avoiding potentially fatal complications that accompany acute diarrhea during concomitant infection with C. parvum.

Criptosporidiosis intestinal en niños con HIV/SIDA / Intestinal cryptosporidiosis in HIV infected children

El Cryptosporidium parvum, protozoo parásito intracelular, infecta el epitelio gastrointestinal produciendo diarrea autolimitada en individuos inmunocompetentes pero potencialmente grave en pacientes inmunocomprometidos, especialmente en aquellos con Sida. En este trabajo se evaluó, durante un lap-so de 6 años, la incidencia de infección intestinal por C. parvum en una población pediátrica con HIV/Sida analizando las características clínicas e inmunológicas de la coinfección. Todos los pacientes iniciaron o continuaron el tratamiento antirretroviral de alta eficacia HAART durante el período de estudio, mientras que la infección intestinal fue tratada con azitromicina. La incidencia de criptosporidiosis fue de 13.7%. 33 de los 240 niños en seguimiento presentaron diarrea crónica de más de 14 días de evolución o recurrente, sin complicaciones hidroelectrolíticas. Los pacientes evaluados presentaron niveles porcentuales variables de células T CD4+ en sangre periférica, y la presencia del parásito no estuvo en relación con el compromiso inmunitario. Al momento del cuadro entérico 31 de los 33 pacientes tuvieron niveles plasmáticos de carga viral que superaban el límite de detección. Se observó eosinofilia leve o moderada en el 23% de los pacientes y la coinfección con otros parásitos fue detectada en 11 niños. No se obtuvieron diferencias significativas al relacionar el número de episodios intestinales con los estadios clínico-inmunológicos de los pacientes. La correcta implementación del HAART con la subsecuente restauración de la función inmune se relacionaría con la ausencia de cuadros diarreicos agudos y de las complicaciones hidroelectrolíticas derivadas de la coinfección con C. parvum.

Cryptosporydium parvum is an intracellular parasite that infects gastrointestinal epithelium and produces diarrhea that is self-limited in immunocompetent persons but potentially life-threatening in immunocompromised, especially those with the acquired immunodeficiency syndrome (AIDS). C. parvum enteric infection's incidence in a pediatric HIV/AIDS cohort, during a 6 years period, was studied. Clinical and immunologic characteristics of the dual infection were also recorded. Highly active antiretroviral therapy (HAART) was started or continued by all the patients during follow-up. Azithromicyn was used as antiparasitic drug. Cryptosporidiosis incidence was 13.7%; 33 out 240 children showed chronic diarrhea lasting 14 days at least, or recurrent, without dehydration and electrolytic disturbance. Peripheral blood T CD4+ percentage levels of the patients were variable and without relationship with C. parvum presence. Viral load levels in 31 out 33 patients were over cut-off at the enteric episode time. Mild or moderate eosinophilia were recorded in 23% of the patients and other intestinal parasites were present in 11 children. When the number of enteric episodes were compared with the clinical and immunological patient's status, not significant differences were recorded. HAART is the best treatment to improve immune function in HIV patients avoiding potentially fatal complications that accompany acute diarrhea during concomitant infection with C. parvum.

AIDS-associated diarrhea and wasting in Northeast Brazil is associated with subtherapeutic plasma levels of antiretroviral medications and with both bovine and human subtypes of Cryptosporidium parvum.

Advanced HIV infection is frequently complicated by diarrhea, disruption of bowel structure and function, and malnutrition. Resulting malabsorption of or pharmacokinetic changes in antiretroviral agents might lead to subtherapeutic drug dosing and treatment failure in individual patients, and could require dose adjustment and/or dietary supplements during periods of diarrheal illness. We determined the plasma levels of antiretroviral medications in patients that had already been started on medication by their physicians, in an urban infectious diseases hospital in northeast Brazil. We also obtained blood samples from patients hospitalized for diarrhea or AIDS-associated wasting, and we found reduced stavudine and didanosine levels in comparison with outpatients without diarrhea or wasting who had been treated at the same hospital clinic. There was a predominance of the protozoal pathogens Cryptosporidium and Isospora belli, typical opportunistic pathogens of AIDS-infected humans, in the stool samples of inpatients with diarrhea. We conclude that severe diarrhea and wasting in this population is associated with both protozoal pathogens and subtherapeutic levels of antiretroviral medications.

AIDS-associated diarrhea and wasting in northeast Brazil is associated with subtherapeutic plasma levels of antiretroviral medications and with both bovine and human subtypes of Cryptosporidium parvum

Advanced HIV infection is frequently complicated by diarrhea, disruption of bowel structure and function, and malnutrition. Resulting malabsorption of or pharmacokinetic changes in antiretroviral agents might lead to subtherapeutic drug dosing and treatment failure in individual patients, and could require dose adjustment and/or dietary supplements during periods of diarrheal illness. We determined the plasma levels of antiretroviral medications in patients that had already been started on medication by their physicians in an urban infectious diseases hospital in northeast Brazil. We also obtained blood samples from patients hospitalized for diarrhea or AIDS-associated wasting, and we found reduced stavudine and didanosine levels in comparison with outpatients without diarrhea or wasting who had been treated at the same hospital clinic. There was a predominance of the protozoal pathogens Cryptosporidium and Isospora belli, typical opportunistic pathogens of AIDS-infected humans, in the stool samples of inpatients with diarrhea. We conclude that severe diarrhea and wasting in this population is associated with both protozoal pathogens and subtherapeutic levels of antiretroviral medications

Some aspects of protozoan infections in immunocompromised patients- a review.

Protozoa are among the most important pathogens that can cause infections in immunocompromised hosts. These microorganisms particularly infect individuals with impaired cellular immunity, such as those with hematological neoplasias, renal or heart transplant patients, patients using high doses of corticosteroids, and patients with acquired immunodeficiency syndrome. The protozoa that most frequently cause disease in immunocompromised patients are Toxoplasma gondii, Trypanosoma cruzi, different Leishmania species, and Cryptosporidium parvum; the first two species cause severe acute meningoencephalitis and acute myocarditis, Leishmania sp. causes mucocutaneous or visceral disease, and Cryptosporidium can lead to chronic diarrhea with hepatobiliary involvement. Various serological, parasitological, histological and molecular methods for the diagnosis of these infections are currently available and early institution of specific therapy for each of these organisms is a basic measure to reduce the morbidity and mortality associated with these infections.

Cyclospora cayetanensis in sputum and stool samples

We report the observation of acid-fast Cyclospora cayetanensis oocysts in a sputum sample. The patient, a 60 year-old, HIV negative man, was successfully treated for pulmonary tuberculosis during 1997. On February 1998, he was admitted to our center due to loss of weight, cough with purulent expectoration, dysphonia and a radiological picture of pulmonary fibrosis. Bacilloscopic study of sputum (negative for acid-fast bacilli) stained with Ziehl-Neelsen technique showed large (8-10 µm) spherical, acid-fast Cyclospora cayetanensis oocysts. No other pathogens were isolated on cultures from this sample or from laryngeal biopsy. Serial parasitologic studies showed C. cayetanensis and also eggs of Trichuris trichiura, Ascaris lumbricoides and Hymenolepis nana and of Entamoeba coli cysts. The patient lives in the outskirts of Buenos Aires in a brick-made house with potable water and works as builder of sewers. He travelled in several occasions to the rural area of province of Tucumán which has poor sanitary conditions. C. cayetanensis is an emergent agent of diarrhea and as far as we know this is the first time the parasite is observed in respiratory samples.

Diarreas parasitarias no amebianas / Non amoebian parasitary diarrheas

Se analiza un conjunto de infecciones parasitarias que se traducen por diarreas agudas altas, hipersecretoras, de evolución más arrastrada que las bacterianas; de curso inicialmente febril y que comprometen el estado general debido a alteraciones hidroelectrolíticas y trastornos de la absorción intestinal. Estos cuadros, producidos por protozoos esporulados (Isospora belli, Sarcocystis hominis, Cryptosporidium, Cyclosporidium y Mycrosporidium), afecta de preferencia los pacientes inmunodeprimidos y no tienen tratamiento reconocidamente eficaces. En los sujetos no inmunodeprimidos son autolimitados

AIDS-related cryptosporidial diarrhoea: an open study with roxithromycin.

In immunocompromised patients, cryptosporidial diarrhoea is a debilitating and potentially life-threatening infection for which no effective specific therapy exists. In an uncontrolled study of 24 AIDS patients with diarrhoea exclusively due to Cryptosporidium spp., treatment with roxithromycin, 300 mg bd for 4 weeks, produced symptomatic improvement of diarrhoea in 79% of cases, with 50% of patients achieving complete response. The response rate was 100% in a subgroup of five patients with no previous or concomitant opportunistic infections. In complete responders, improvement was rapid, occurring within 3-5 days, and the duration of response was at least 6 months. Response did not appear to be correlated with the degree of immunodeficiency. The most limiting adverse effects were abdominal pain (two patients), elevated hepatic enzymes (two patients) and abdominal pain with elevated hepatic enzymes (one patient). Minor symptoms, such as gastrointestinal upset, occurred in nine patients. We conclude that roxithromycin is relatively well tolerated and effective against cryptosporidial diarrhoea in AIDS patients. Further studies to optimize dosing regimens are required.

Roxithromycin treatment for diarrhoea caused by Cryptosporidium spp. in patients with AIDS.

In view of the action of newer macrolide antibiotics on intracellular protozoa, we have investigated the efficacy of roxithromycin in the treatment of cryptosporidiosis in 26 patients with AIDS. Cryptosporidiosis was confirmed either by faecal examination for parasites (modified Kinyoun method) or by detection of the parasite in biopsy material obtained by colonoscopy. Patients received oral roxithromycin (300 mg bd) for 4 weeks. Twenty-two patients completed the study. At the end of the study, 15 patients (68%) were considered to be cured and six patients (27%) improved, and treatment failed in one patient (5%). We conclude that roxithromycin is a useful treatment for diarrhoea caused by Cryptosporidium spp. associated with AIDS.