Cystoisospora belli infection in an AIDS patient in China: Need for cautious interpretation of mNGS.

Cystoisospora belli (C. belli) is an opportunistic coccidian parasite. This case is the first reported C. belli infection associated with AIDS in China. C. belli infection of this case was diagnosed with the presence of oocysts using direct wet mount and Ziehl-Neelsen acid-fast stain method, and confirmed by polymerase chain reaction (PCR) and Sanger sequencing, ruling out the result of metagenomic next-generation sequencing (mNGS). This case demonstrates that C. belli infection in AIDS could be a potential risk factor for persistent diarrhea, and should not be neglected in non-endemic area and emphaise the necessity of accurate mNGS databases.

Case Report: Molecular Diagnosis of Cystoisospora belli in a Severely Immunocompromised Patient with HIV and Kaposi Sarcoma.

Diarrhea in an immunocompromised patient has a broad infectious differential. Diagnosis is difficult despite advances in diagnostic modalities. We report a case of a 45-year-old Nigerian woman who immigrated to the United States 2 years ago. She presented to the hospital with gastrointestinal bleeding, newly diagnosed HIV, and disseminated Kaposi sarcoma. During hospitalization, the patient had an onset of watery diarrhea and high eosinophilia. Subsequent stool analysis using multi-parallel real-time quantitative polymerase chain reaction for 13 parasites was positive for Cystoisospora belli. The patient was treated with trimethoprim-sulfamethoxazole, but had relapsed disease when her antibiotics were stopped prematurely. After restarting trimethoprim-sulfamethoxazole, her diarrhea and eosinophilia improved, and she had undetectable Cystoisospora belli DNA on repeat stool quantitative polymerase chain reaction. This case highlights the importance of a thorough workup for diarrhea, including parasites, especially for immunocompromised patients. Antibiotic prophylaxis is recommended in patients with Cystoisospora belli and HIV/AIDS.

Molecular detection of Cystoisospora belli by single-run polymerase chain reaction in stool samples.

INTRODUCTION: Cystoisospora belli (C. belli) is the only pathogenic species of the Cystoisospora genus responsible for severe diarrhea in immunocompromised patients. Most common microscopic method of diagnosis is less sensitive due to intermittent shedding of oocysts. We developed a new single-run polymerase chain reaction (PCR)-based diagnostic assay for C. belli. METHODS: A new single-run PCR-based diagnostic assay was standardized for the detection of C. belli. Diagnostic reproducibility and repeatability of the PCR assay were evaluated. A cross-sectional analytical study was done on a total of 354 stool samples collected from 331 immunocompromised patients with diarrhea. All the stool samples were tested for the presence of oocysts of C. belli and were also tested by our new PCR assay for C. belli. Three of the representative PCR products were confirmed by sequencing. Fisher's exact test was used to compare the two proportions. RESULTS: Microscopy detected C. belli in 11/354 (3.1%) of stool samples, and the new PCR-based assay detected C. belli in 16/354 (4.5%). The new single-run PCR-based assay detected C. belli in all the stool samples which were tested positive by microscopy and additionally detected C. belli in five stool samples. The developed PCR assay detected statistically significant proportion of C. belli (p < 0.001) as compared to microscopy. The 795 base pair PCR product from one microscopy positive stool sample and two microscopy negative stool samples were confirmed by sequencing. CONCLUSION: Our newly developed single-run PCR-based detection assay for C. belli is robust and reproducible. It may be used for molecular diagnosis of cystoisosporiasis especially in transplant, pediatrics, and human immunodeficiency virus (HIV) positive patients.

Cystoisospora belli infection in a renal transplant recipient: a case report and review of literature.

Cystoisospora belli is a coccidian parasite that causes prolonged watery diarrhea especially among immunocompromised patients. Herein, we report a renal transplant patient who complaints of alternating diarrhea and review of literature related to cystoisosporiasis amongst the transplant recipients.

Chronic cystoisosporiasis in an immunocompetent adult: A case report.

RATIONALE: Cystoisosporiasis is an intestinal infectious disease caused by a coccidian protozoa, Cystoisospora belli (C. belli). It can cause prolonged and refractory diarrhea most commonly in immunocompromised patients, while immunocompetent individuals usually exhibit no symptoms or self-limited diarrhea. PATIENT CONCERNS: We herein report a case of chronic cystoisosporiasis in an immunocompetent patient. A 62-year-old man, who had been first diagnosed with cystoisosporiasis 15 years ago and had been treated with oral administration of trimethoprim-sulfamethoxazole (TMP-SMX), complained of persistent watery diarrhea. He was negative for anti-human immunodeficiency virus antibody and anti-human T-cell leukemia virus type 1 (HTLV-1) antibody. DIAGNOSIS: Biopsy specimens from the duodenum revealed oocysts in the atrophic absorptive epithelium and protozoa were detected through stool examination, indicating the recurrence of cystoisosporiasis. Capsule endoscopy showed diffuse atrophic mucosa with white villi in the entire small intestine. We diagnosed him with chronic cystoisosporiasis that occurred in an immunocompetent adult. INTERVENTIONS: Since oral administration of TMP-SMX and ciprofloxacin were ineffective, the intravenous administration of TMP-SMX was initiated. OUTCOMES: Intravenous TMP-SMX exhibited a significant improvement. LESSONS: This case indicates that even immunocompetent individuals may develop recurrent and refractory cystoisosporiasis. Furthermore, intravenous treatment of antibiotic agents should be considered when the impaired absorptive ability from the small intestine is suspected.

Pitfalls in Morphologic Diagnosis of Pathogens: Lessons Learned From the Pseudo-Cystoisospora Epidemic.

Multiple groups have recently reported involvement of the gallbladder mucosa of immunocompetent patients by cystoisospora organisms. However, this has recently been disproved with the support of molecular and ultrastructural studies. Here we present a summary of these events, recounting how this pseudo-Cystoisospora epidemic began and ended. This review also highlights the important role played by ancillary techniques in supplementing the morphologic diagnosis of pathogens.

Cystoisospora belli associated persistent diarrhea in an AIDS patient.

Cystoisospora belli infection is regarded as an indicator disease of AIDS in Japan; however, only a few case reports showing this association are present. Our case study involved a 49-year-old Thai woman living in Japan since her marriage to a Japanese man. She was repeatedly hospitalized owing to persistent diarrhea. Considering her native country, she was suggested of having AIDS. Serological examination for HIV-1 tested positive, and C. belli infection was diagnosed on detection of oocysts in her stool samples. She was treated successfully for the parasitic infection with oral trimethoprim-sulphamethoxazole therapy for 10 days. No AIDS-associated opportunistic infections other than cystoisosporiasis were detected. Thus, this study suggests that an immunocompromised individual with persistent and recurrent diarrhea should be examined to confirm for C. belli infection. Moreover, it is possible that a person in a high-latitude region will develop a parasitic infection common in tropical areas because of globalization.

Ocorrência de parasitos gastrointestinais de gatos domésticos (Felis catus domesticus) em amostras fecais recebidas no hospital veterinário da Universidade Estadual de Santa Cruz no período de 2018-2019 / Occurrence of gastrointestinal parasites of domestic cats (Felis catus domesticus) in fecal samples received at the veterinary hospital at the State University of Santa Cruz in the 2018-2019 period / Incidencia de parásitos gastrointestinales en gatos domésticos (Felis catus domesticus) muestras fecales recibidas en el hospital veterinario de la Universidad Estatal de Santa Cruz en el período 2018-2019

O objetivo deste trabalho é avaliar a ocorrência de parasitos gastrointestinais em 20 amostras fecais de gatos domésticos recebidas no Laboratório de Parasitologia Veterinária da Universidade Estadual de Santa Cruz. As amostras foram recebidas no período de 19 de abril de 2018 a 09 de agosto de 2019, sendo de animais de diferentes raças e ambos os sexos. Dessas amostras (15/20) foram negativas e (5/20) foram positivas, onde o foram encontrados com maior frequência ovos de Ancylostoma spp. (4/20) além de uma amostra positiva para oocistos de Cystisospora spp (1/20). Os animais com amostras positivas eram animais com idade inferior a um ano e nunca tinham passado por acompanhamento veterinário. Enquanto o alto número de amostras negativas pode ser justificado por serem animais cuidados por membros da comunidade acadêmica e que já tinham passado por atendimento no Hospital Veterinário, realizando de tratamentos antiparasitários.(AU)

The objective of this work is to evaluate the occurrence of gastrointestinal parasites in 20 fecal samples from domestic cats received in the Laboratory of Veterinary Parasitology at the State University of Santa Cruz. The samples were received from April 19, 2018 to August 9, 2019 and were from animals of different breeds and both genders. From these samples, (15/20) were negative and (5/20) were positive. Eggs of Ancylostoma spp. were found more frequently, in 4 of the samples, and one (1) sample tested positive for oocysts of Cystisospora spp (1/20). The animals with positive samples were animals aged less than one year old and had never been through veterinary follow-up. The high number of negative samples can be justified because they were animals cared for by members of the academic community and that had already been seen by the staff at the Veterinary Hospital, performing antiparasitic treatments.(AU)

El objetivo de este estudio es evaluar la presencia de parásitos gastrointestinales en 20 muestras fecales de gatos domésticos recibidas en el Laboratorio de Parasitología Veterinaria de la Universidad Estatal de Santa Cruz. Las muestras se recibieron desde el 19 de abril de 2018 hasta el 9 de agosto de 2019, y procedían de animales de diferentes razas y ambos sexos. De esas muestras (15/20) fueron negativas y (5/20) fueron positivas, donde los óvulos de Ancylostoma spp. se encontraron con más frecuencia. (4/20) y una muestra positiva para ooquistes de Cystisospora spp (1/20). Los animales con muestras positivas eran animales de menos de un año de edad y nunca habían sido acompañados por un veterinario. Si bien el elevado número de muestras negativas puede justificarse por tratarse de animales cuidados por miembros de la comunidad académica y que ya habían pasado por la asistencia en el Hospital Veterinario, realizando tratamientos antiparasitarios.(AU)

A QPCR ASSAY AND TESTING GUIDELINES FOR THE MOLECULAR DIAGNOSIS OF SYSTEMIC ISOSPOROSIS (FORMERLY ATOXPLASMOSIS) IN PASSERINE BIRDS.

Systemic isosporosis (formerly atoxoplasmosis), is a protozoal infection that causes death in nestling and fledgling passerine birds impacting ex situ breeding and reintroduction programs. Because current antemortem diagnostic tests lack sensitivity, a qPCR was developed for detection of Isospora spp. using primers and a fluorescent-tagged MGB probe targeting the large subunit (28s) ribosomal RNA gene (assay efficiency = >100%; sensitivity = <1 dsDNA copy). The assay was used to screen postmortem frozen or formalin-fixed paraffin-embedded tissue samples from passerine birds (n = 24; 12 with confirmed systemic isosporosis), whole blood and feces (n = 38) from live passerines, and other tissues infected with phylogenetically similar protozoa. The qPCR identified Isospora sp. DNA in tissues from 21/24 birds including 12/12 birds with cytologically-histologically confirmed infection (100% sensitivity) and 9/12 birds lacking microscopic organisms. The assay also amplified Eimeria sp. DNA; however, sequence analysis ruled out infection in the passerine cases. Blood and/or feces were positive in 30/38 birds, and in only 7/38 birds, blood and feces both contained Isospora sp. DNA. Finally, the qPCR was utilized to screen 30 consecutive daily fecal samples from live passerines (n = 20) to determine optimal sampling protocols. One or more of the daily fecal samples were positive in all 20 birds. In individual birds, the interval between positive qPCR amplification results ranged from 0 to 23 days, with an average of 5.85 days. Simulated application of 13 potential sample collection schedules was used to identify the sensitivity of repeated testing for identification of infected birds. Increased sampling days resulted in higher sensitivity but increased both cost and animal handling requirements. Based on statistical analysis and clinical considerations, the testing recommendation for detection of fecal shedding was collection and assay of five consecutive daily fecal samples, which had an average diagnostic sensitivity of 0.86.

Ultrastructural Characteristics of Gallbladder Epithelial Inclusions Mimicking Cystoisospora.

OBJECTIVES: There is recently reported increased prevalence of Isospora organisms in cholecystectomy specimens from immunocompetent patients, especially in acalculous cholecystectomies. We performed an ultrastructural and molecular evaluation of these specimens. METHODS: From 28 gallbladders with intraepithelial inclusions, two specimens with diffuse involvement of the gallbladder epithelium were analyzed by electron microscopy. Polymerase chain reaction was performed on five samples for the ITS2 region of C belli and eukaryotic 18S region. The 18S products were sequenced by next-generation sequencing. RESULTS: Electron microscopic analysis showed cytoplasmic condensations leading to vacuole formation. In contrast with true C belli, there were no identifiable organelles or organization. None of these cases showed amplified products other than human on molecular analysis. CONCLUSIONS: Electron microscopic analysis demonstrates that the inclusions are condensed cytoplasmic material and not true organisms.

A rare diarrheic parasite in a kidney transplant patient: Cystoisospora belli.

Cystoisospora belli colitis is a rare complication of immunosuppression in solid organ transplant recipients. We describe a case of Cystoisospora belli infection with colitis following renal transplantation.

Chronic Cystoisospora belli infection in an HIV/AIDS patient treated at the specialized assistance service in Porto Velho County - Rondônia.

Cystoisospora belli infection manifests as diarrhea, and can potentially progress to malabsorption in HIV patients. Here, we report a case of C. belli infection in an HIV/AIDS patient with chronic diarrhea symptoms for at least 2 years. Coproscopic analyses based on direct technique and modified Ziehl-Neelsen technique without a commercial kit were performed. The current case report highlights the protocol to be adopted in coproscopic analyses applied to HIV patients. The importance of including the appropriate parasitological testing of patients with chronic intestinal isosporiasis in parasitological test routines must be considered.

Chronic Cystoisospora belli infection in an HIV/AIDS patient treated at the specialized assistance service in Porto Velho County - Rondônia

Abstract Cystoisospora belli infection manifests as diarrhea, and can potentially progress to malabsorption in HIV patients. Here, we report a case of C. belli infection in an HIV/AIDS patient with chronic diarrhea symptoms for at least 2 years. Coproscopic analyses based on direct technique and modified Ziehl-Neelsen technique without a commercial kit were performed. The current case report highlights the protocol to be adopted in coproscopic analyses applied to HIV patients. The importance of including the appropriate parasitological testing of patients with chronic intestinal isosporiasis in parasitological test routines must be considered.

A review of Cystoisospora felis and C. rivolta-induced coccidiosis in cats.

Until the discovery of Toxoplasma gondii oocysts in cat feces in 1970, little was known of coccidiosis in cats. Until 1970, three coccidian parasites based on different sized oocysts were recognized, the parasite with large oocysts (∼40 µm long and called Isospora felis), medium sized oocysts (∼25 µm long, called Isospora rivolta), and small sized oocysts (14 µm or less, called Isospora bigemina) were known and they were considered not host-specific. Later, it was demonstrated that these parasites were host-specific and had also extra-intestinal stages. The Isospora bigemina turned out to be more than 25 organisms belonging to T. gondii, Hammondia spp., Sarcocystis spp., Besnoitia spp., and Neospora spp.; these subjects have been reviewed previously in detail. The present paper summarizes biology of Isospora felis, and I. rivolta (now transferred to genus Cystoisospora), including taxonomy, life cycle, diagnosis, and treatment. Re-excretion of T. gondii oocysts from chronically infected cats after superinfection with Cystoisospora felis oocysts is discussed. There are only two species of Cystoisospora species in cats, C. felis and C. rivolta; Isospora novocati and Cystoisospora frenkeli named for I. rivolta-like parasites of cats are considered synonym of C. rivolta. Clinical coccidiosis occurs more commonly in recently weaned kittens and C. felis infections are more prevalent than C. rivolta.