Cystoisospora belli, liver disease and hypothesis on the life cycle.

Cystoisospora belli causes chronic diarrhoea, acalculous cholecystitis, cholangiopathy and disseminated cystoisosporosis in patients with AIDS. Clinical manifestations and histological stages during C. belli infection in a patient with AIDS and liver disease were described. It was possible to identify sporozoite-like structures in the villus epithelium of the duodenum, close to the vascularization that underlies the basal membrane and unizoite tissue cysts near to the vascularization in the lamina propria. Unizoite tissue cysts were found inside of sinusoids in the liver communicating with the central vein and with a bile canaliculus and portal spaces. Based on these findings a hypothesis on C. belli life cycle could consider that the route of migration of unizoite tissue cysts up the liver is via the portal blood. The unizoite tissue cysts located in hepatic portal vein could migrated via sinusoid to central vein and general circulation through the venous system. The unizoite tissue cysts could also return via bile canaliculus to bile duct to portal triad. This hypothesis allows to understand the presence of unizoite stages in blood, the pathway by which the bile ducts become infected and unizoites in the liver being able to behave like hypnozoites that favour relapses and treatment failures.

Multimethodological Approach to Gastrointestinal Microsporidiosis in HIV-Infected Patients.

PURPOSE: Microsporidiosis is an opportunistic infection that produces chronic diarrhoea and cholangiopathy in patients with AIDS, mainly caused by two species of microsporidia, Enterocytozoon bieneusi and Encephalitozon intestinalis. The aim of this work was to develop an integral system for the diagnosis of microsporidiosis of the intestine and biliary tract in HIV-infected patients, comprising microscopic and molecular techniques. METHODS: The study population comprised 143 adult patients of both sexes with diagnosis of HIV infection, with chronic diarrhoea, and with or without HIV-associated cholangiopathy. Stool studies for microsporidia identification of spores were performed on each patient. A video esofagogastroduodenoscopy with biopsy collection was also carried out for routine histology and semi-thin sections stained with Azure II. Species identification was carried out by transmission electron microscopy and/or polymerase chain reaction for the species E. bieneusi and E. intestinalis. RESULTS: Out of the 143 patients a total of 12.6% (n = 18) were infected with microsporidia. Microsporidia species identified in most cases was E. bieneusi (16/18 cases), followed by E. intestinalis (4/18), all of these last ones in coinfection with E. bieneusi. CONCLUSIONS: Clinical, imaging, microscopic and molecular analyses, when applied in a systematic and integrated approach, allow diagnosis and identification of microsporidia at species level in AIDS patients with chronic diarrhoea, and with or without HIV-associated cholangiopathy.

First report of Cystoisospora belli parasitemia in a patient with acquired immunodeficiency syndrome.

Cystoisospora belli in patients with the acquired immunodeficiency syndrome (AIDS) has been described as cause of chronic diarrhea and disseminated cystoisosporosis. Diagnosis of intestinal cystoisosporosis can be achieved at the tissue level in the villus epithelium of the small bowel. Disseminated cystoisosporosis is diagnosed by microscopy identification of unizoite tissue cysts in the lamina propria of the intestine. We report a case of disseminated cystoisosporosis in a human immunodeficiency virus (HIV)-infected patient with detection of parasitemia. We studied a 39-year old patient with AIDS and chronic diarrhea by analysis of stool and duodenal biopsy samples. Blood samples were also collected and examined by light microscopy and molecular techniques for C. belli DNA detection. The unizoite tissue cyst stages were present in the lamina propria, with unsporulated oocysts in feces. Zoites were present in blood smears and DNA of C. belli was detected in blood samples. Our study identified a new stage in the life cycle of C. belli. Detection of parasitemia is a novel and noninvasive tool for diagnosis of disseminated cystoisosporosis.

Effects of two commonly found strains of influenza A virus on developing dopaminergic neurons, in relation to the pathophysiology of schizophrenia.

Influenza virus (InfV) infection during pregnancy is a known risk factor for neurodevelopment abnormalities in the offspring, including the risk of schizophrenia, and has been shown to result in an abnormal behavioral phenotype in mice. However, previous reports have concentrated on neuroadapted influenza strains, whereas increased schizophrenia risk is associated with common respiratory InfV. In addition, no specific mechanism has been proposed for the actions of maternal infection on the developing brain that could account for schizophrenia risk. We identified two common isolates from the community with antigenic configurations H3N2 and H1N1 and compared their effects on developing brain with a mouse modified-strain A/WSN/33 specifically on the developing of dopaminergic neurons. We found that H1N1 InfV have high affinity for dopaminergic neurons in vitro, leading to nuclear factor kappa B activation and apoptosis. Furthermore, prenatal infection of mothers with the same strains results in loss of dopaminergic neurons in the offspring, and in an abnormal behavioral phenotype. We propose that the well-known contribution of InfV to risk of schizophrenia during development may involve a similar specific mechanism and discuss evidence from the literature in relation to this hypothesis.

First case report of infection caused by Encephalitozoon intestinalis in a domestic cat and a patient with AIDS.

Microsporidia are eukaryotic, intracellular obligate parasites that infect invertebrate and vertebrate animals, and have emerged as important opportunistic parasites in AIDS patients. We used light microscopy to detect microsporidial spores in stool samples of a domestic cat confirmed as Encephalitozoon intestinalis by PCR, owned by an AIDS patient with chronic diarrhea and E. intestinalis infection. Cats can be considered hosts of E. intestinalis.

Molecular identification of protozoa causing AIDS-associated cholangiopathy in Buenos Aires, Argentina.

BACKGROUND: Several species of microsporidia and coccidia are protozoa parasites responsible for cholan-giopathy disease in patients infected with human immunodeficiency virus (HIV). The goals of this work were to identift opportunistic protozoa by molecular methods and describe the clinical manifestations at the gastrointestinal tract and the biliary system in patients with AIDS-associated cholangiopathy from Buenos Aires, Argentina. MATERIAL AND METHODS: This study included 11 adult HIV-infected individuals with diagnosis ofAIDS- associated cholangiopathy. An upper gastrointestinal endoscopy with biopsy specimen collection and a stool analysis for parasites were performed on each patient. The ultrasound analysis revealed bile ducts compromise. An endoscopic retrograde cholangiopancreatography and a magnetic resonance cholangiography were carried out. The identification to the species level was performed on biopsy specimens by molecular methods. RESULTS: Microorganisms were identified in 10 cases. The diagnosis in patients with sclerosing cholangitis was cryptosporidiosis in 3 cases, cystoisosporosis in 1 and microsporidiosis in 1. In patients with sclerosing cholangitis and papillary stenosis the diagnosis was microsporidiosis in 2 cases, cryptosporidiosis in 2 and cryptosporidiosis associated with microsporidiosis in 1. In 3 cases with cryptosporidiosis the species was Cryptosporidium hominis, 1 of them was associated with Enterocytozoon bieneusi, and the other 2 were coinfected with Cryptosporidium parvum. In the 4 cases with microsporidiosis the species was Enterocytozoon bieneusi. CONCLUSIONS: These results suggest that molecular methods may be useful tools to identify emerging protozoa in patients with AIDS-associated cholangiopathy.

Molecular characterization of Cystoisospora belli and unizoite tissue cyst in patients with Acquired Immunodeficiency Syndrome.

Cystoisospora belli is a coccidian protozoan that can cause chronic diarrhoea, acalculous cholecystitis and cholangiopathy in AIDS patients. We applied molecular methods to identify Cystoisospora at species level in AIDS patients presenting with and without the presence of unizoites in lamina propria. Coprological and histological analyses were performed in stool and/or biopsy samples from 8 Cystoisospora-infected patients. DNA from the same samples was used to amplify 2 fragments of the SSU-rRNA gene and the ITS-1 region. Sequencing of the resulting amplicons identified C. belli infections in all cases, independent of the presence or absence of unizoite tissue cysts. Further work should be considered in order to find molecular targets related to strain variations in C. belli.

[Identification of Cryptosporidium hominis in a patient with sclerosing cholangitis and AIDS]. / Identificación de Cryptosporidium hominis en un paciente con colangitis esclerosante y SIDA.

Cryptosporidium hominis (C hominis) is the most common protozoan parasite recognized in human patients with AIDS. We report the clinical features of a patient with chronic diarrhea and AIDS-related sclerosing cholangitis. The imaging studies with ultrasonography and endoscopic retrograde cholangiopancreatography disclosed intrahepatic and extrahepatic bile duct changes identical to those seen in sclerosing cholangitis. C hominis was detected in the duodenum and peri-papillary duodenum by means of light microscopy and confirmed by nested polymerase chain reaction (PCR) amplification from fresh biopsy specimens followed by restriction length polymorphism analysis. Chominis infection should be suspected in our country in patients with advanced immunodeficiency and AIDS-related sclerosing cholangitis.

Systemic sarcocystosis in a patient with acquired immune deficiency syndrome.

Sarcocystis sp is a tissue coccidian parasite in humans that causes intestinal and muscular sarcocystosis in immunocompetent patients. Intestinal sarcocystosis can be diagnosed at the tissue level in the lamina propria of the small bowel and by fecal examination. Muscular sarcocystosis is diagnosed by microscopic examination of muscle biopsies. This report describes a case of systemic sarcocystosis in an HIV-infected patient. We studied a 31-year-old patient with AIDS, chronic diarrhea, cholestatic hepatitis, and musculoskeletal pain by stool analysis and endoscopy with duodenal and liver biopsy specimens that were processed for routine histology. The microgamete and macrogamete stages of Sarcocystis sp were present in the lamina propria, with sporulated oocysts in feces. Schizont stages of the protozoa were found in liver biopsy. In summary, sarcocystosis should be considered another opportunistic infection in HIV-infected patients.

[Cyclospora cayetanensis in patients with AIDS and chronic diarrhea]. / Cyclospora cayetanensis en pacientes con SIDA y diarrea crónica.

Cyclospora spp. is a protozoan parasite responsible for significant gastrointestinal disease in patients infected with the human immunodeficiency virus. We report the clinical features of two patients with chronic diarrhea and intestinal cyclosporosis caused by Cyclospora cayetanensis. The average value for CD4 count in these patients was lower than or equal to 100 cells/mm3. The oocysts were detected in smears from stool samples stained with modified acid-fast or safranin technique. Light microscopy revealed parasites in the enterocytes and these parasites were associated with villous atrophy. Cyclospora cayetanensis infection might be an important cause of diarrhea in patients with AIDS in Argentina.

Cyclospora cayetanensis en pacientes con SIDA y diarrea crónica. / [Cyclospora cayetanensis in patients with AIDS and chronic diarrhea]

Cyclospora spp. is a protozoan parasite responsible for significant gastrointestinal disease in patients infected with the human immunodeficiency virus. We report the clinical features of two patients with chronic diarrhea and intestinal cyclosporosis caused by Cyclospora cayetanensis. The average value for CD4 count in these patients was lower than or equal to 100 cells/mm3. The oocysts were detected in smears from stool samples stained with modified acid-fast or safranin technique. Light microscopy revealed parasites in the enterocytes and these parasites were associated with villous atrophy. Cyclospora cayetanensis infection might be an important cause of diarrhea in patients with AIDS in Argentina.