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.

Investigating arsenic bioavailability and bioaccumulation by the freshwater oligochaete Lumbriculus variegatus.

The complex and variable composition of natural sediments makes it difficult to predict the bioavailability and bioaccumulation of sediment-bound contaminants. Several approaches, including an experimental model using artificial particles as analogues for natural sediments, have been proposed to overcome this problem. For this work, we applied this experimental device to investigate the uptake and bioaccumulation of As(III) by the freshwater oligochaete Lumbriculus variegatus. Five different particle systems were selected, and particle-water partition coefficients for As(III) were calculated. The influence of different concentrations of commercial humic acids was also investigated, but this material had no effect on bioaccumulation. In the presence of particulate matter, the bioaccumulation of As(III) by the oligochaetes did not depend solely on the levels of chemical dissolved but also on the amount sorbed onto the particles and the strength of that binding. This study confirms that the use of artificial particles may be a suitable experimental model for understanding the possible interactions that may occur between contaminants and particulate matter. In addition, it was found that the most hydrophobic resin induced an increase in arsenic bioavailability, leading to the highest bioaccumulation to L. variegatus compared with animals that were exposed to water only.

[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.

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.

Aluminum exposure affects transferrin-dependent and -independent iron uptake by K562 cells.

Aluminum (Al) and iron (Fe) share several physicochemical characteristics and they both bind to transferrin (Tf), entering the cell via Tf receptors (TfR). Previously, we found similar values of affinity constant for the binding of TfR to Tf carrying either Al or Fe. The competitive interaction between both metals prevented normal Fe incorporation into K562 cells and triggered the upregulation of Fe transport. In the present work we demonstrated that Al modified Fe uptake without affecting the expression of Tf receptors. Both TfR and TfR2 mRNA levels, evaluated by RT-PCR, and TfR antigenic sites, analyzed by flow cytometry, were found unchanged after Al exposure. In turn, Al did induce upregulation of non-Tf bound Fe (NTBI) uptake. This modulation was not due to intracellular Fe decrease since NTBI transport proved not to be regulated by Fe depletion. Unlike its behavior in the presence of Tf, Al was unable to compete with NTBI uptake, suggesting that both metals do not share the same alternative transport pathway. We propose that Al interference with TfR-mediated Fe incorporation might trigger the upregulation of NTBI uptake, an adaptation aimed at incorporating the essential metal required for cellular metabolism without allowing the simultaneous access of a potentially toxic metal.

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.

[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.

Direct, immunological and molecular techniques for a fasciolosis survey in a rural area of San Luis, Argentina.

Fasciolosis is a zoonosis caused by the trematode Fasciola hepatica, prevalent in cattle, that is actually emerging as a cause of disease in humans. The goal of this work was to describe the characteristics of fasciolosis in arroyo El Juncal region, La Toma, San Luis province, Argentina. In order to get this objective, a transversal, quantitative study was carried out by a fieldwork that allowed the collection of data, human, animal, and environmental samples. The materials were processed by direct, immunological and/or molecular diagnostic techniques. According to the geographical characteristics and in presence of all the definitive and intermediate hosts, reservoirs, and sources of infection, it was possible to describe the persistence of fasciolosis in the area. The prevalence was 11.90 % in humans (by serology), 5.26 % in cattle (by coprological analysis) and 61.76 % in snails (by PCR). The situation that was found for this area indicates that any measure of intervention for the control of this zoonosis should be adopted by multidisciplinary teams.

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.

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.

Experiencia inicial en estudios videocolonoscópicos en un Servicio de Cirugía General y médicos en formación / Initial experience in videocolonoscopic studies in a general surgery service and doctors in training

Introducción: la Videocolonoscopía (VCC) es cada vez más utilizada en los servicios de cirugía. Objetivo: estimar el rédito diagnóstico y terapéutico de todas las videocolonoscopías, y la efectividad de los médicos en formación. Material y Métodos: se revisaron los estudios videocolonoscópicos realizados en el servicio de cirugía, entre julio de 2009 y julio de 2011. Resultados: se efectuaron 221 VCC con sedación. El género de los pacientes fue: masculino 117 (53%) y femenino 104 (47%). El motivo del estudio fue: hematoquecia 54 pacientes (24%), sospecha de cáncer colorrectal 20 (9%), reconstrucción del tránsito intestinal 19 (9%), dolor abdominal 13 (6%), cambio del ritmo evacuatorio 9 (4%), anemia 8 (4%), screening 9 (4%), tumor anexial 8 (4%), SOMF positiva 4 (2%), diarrea crónica 6 (3%) y Colitis ulcerosa 1 (0,50%). Se realizaron 179 (81%) VCC completas y 42 (19%) VCC incompletas. Los diagnósticos fueron: examen normal 53 (24%), lesiones polipóideas sésiles 43 (20%), lesiones polipóideas pediculadas 17 (8%), más de 2 a 3 lesiones polipóides 10 (5%), patología hemorroidaria 44 (20%), diverticulosis 37 (17%), rectosigmoiditis ulcerosa idiopática 2 (1%), tumor del canal anal 2 (1%), lipoma 1 (0.50%). Con relación al hallazgo de lesiones neoplásicas, hubo 3 lesiones neoplásicas tempranas tipo IIa de la Clasificación de Paris (1%), y 23 lesiones avanzadas (10%). De éstas 18 (8%) eran lesiones infranqueables, lo que impidió que el estudio fuera completo. Además de estos casos hubo otras 24 VCC incompletas (11%). El 100% de las lesiones polipóideas fueron extirpadas durante la VCC. Conclusiones: el 90% de los estudios fueron VCC completas, con lesiones tumorales infranqueables en el 8%. En las lesiones polipoideas se realizó terapéutica endoscópica en el 100% de los casos. Los médicos en formación cumplieron adecuadamente con los objetivos.

Background: the use of Videocolonoscopy is increasingly growing in surgical units. Objective: To estimate the diagnostic and therapeutic yield of colonoscopy and the effectiveness of training operators. Material and Methods: we reviewed all the colonoscopic exams from July 2009 to July 2011. Results: we performed 221 colonoscopies: 117 males (53%) and 104 females (47%). The indication was: hematochezia 54 (24%), suspected colorectal cancer 20 (9%), reconstruction of bowel transit: 19 (9%), abdominal pain: 13 (6%), change of bowel movement habits 9 (4%), anemia 8 (4%), screening 9 (4%), ovarian tumor 8 (4%), positive FOBT 4 (2%), chronic diarrhea 6 (3%) and ulcerative colitis 1 (0.50%). There were 179 (81%) complete exams and 42 (19%) incomplete. The diagnosis were: abscence of pathology 53 (24%), sessile polypoid lesions 43 (20%), pedunculated polypoid lesions 17 (8%), more than 2-3 sessile polypoid lesions 10 (5%), pathologic hemorrhoids 44 (20%), diverticulosis 37 (17%), idiopathic ulcerative rectosigmoiditis 2 (1%), anal canal tumor 2 (1%) and lipoma 1 (0.50%). Regarding neoplasic lesions there were 3 Paris type IIa (1%), and 23 advanced tumors (10%). Of them, 18 (8%) impaired a complete examination. There were other incomplete colonoscopies 24 (11%), mainly due to a bad preparation. Conclusions: complete colonoscopy was achieved in 90% of the studies, with obstructive tumors in 8% which did not allow a complete exam. Regarding polypoid lesions endoscopic therapy was performed in 100% of cases. Training operators adequately met the objectives.

Estudio morfologico de Enterocytozoon bieneusi en pacientes con SIDA y diarrhea cronica / Morphological study of Enterocytozoon bineousi in patients with AIDS and chronic diarrhea

Microsporidia are protozoan parasites responsible for significant gastrointestinal disease in patients infected with the human inmunodeficiency virus. We reporte the clinical features of three patients with chronic diarrhea and intestinal microsporidiosis caused by Enterocytozoon bieneusi. The average value for CD4 in these patients was ó 50 cells/mm3. The spores were detected in smears from stool samples and duodenal aspirates stained with trichrome blue in all patiens. Light microscopy of semithin plastic sections revealed parasites and spores in the enterocytes and were associated with villous atrophy (2 out of 3). Thin section-electron microscopy showed a variety of developmental stages of the microsporidio. Patients treated with Albendazole had an unsatisfactory clinical response to therapy. Enterocytozzon bieneusi infection may be an important cause of diarrhea in patiens with AIDS in our country.

Estrategias clasicas para el dignostico de criptosporidiosis en pacientes con SIDA y diarrea cronica / Classic estrategies for diagnosis of cryptosporidiosis in patients with AIDS and chronic diarrhea

El protozoario Cryptosporidium sp. ha sido reconocido crecientemente en asociación con enteritis grave en paceintes con el síndrome de immunodeficiencia. Los individuos estudiados comprendieron 84 adultos com SIDA y diarrea crónica. En este trabajo se describen 14 pacientes con infección intestinal causada por Cryptosporidium sp. La media del recuerdo de CD4 en estos pacientes fue (300 células/mm3 (en 7 de los 14). El examen de aspirados duodenales y heces incluyó preparaciones de muestras concentradas coloreadas con Kinjoun, Dimetilsulfóxido y Auramina. Se realizaron videoesofagogastroduodenoscopías (VEDA) para inspeccionar visualmente la mucosa y obtener biopsias. La VEDA reveló duodeno granular en 10 pacientes y jaspeado en uno de ellos. Las biopsias duodenales fueron coloreadas con hematoxilina-eosina, Giemsa y Azur II. Los acambios histológicos incluyeron atrofia (3/14), duodenitis (2/14) a ambos (3/14). La microscopía eletrónica de transmisión fue usada para la identificación de estadíos de desarrollo de Cryptosporidium sp.