Molecular Detection and Genotyping of Enteric Protists in Asymptomatic Schoolchildren and Their Legal Guardians in Madrid, Spain

Pamela Carolina Köster,Aly Salimo Muadica,Lucia Reh,Marta Hernández-De-Mingo,Begoña Bailo,Alejandro Dashti,David Carmena

doi:10.3390/parasitologia1020010

Pamela Carolina Köster, Aly Salimo Muadica + Show 5 more

Open Access

https://doi.org/10.3390/parasitologia1020010

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Abstract

Asymptomatic carriage of diarrhoea-causing enteric protist parasites in the general population is poorly understood, particularly in medium- to high-income countries. This molecular epidemiological survey investigates the presence, molecular diversity, and household transmission of Giardia duodenalis, Cryptosporidium spp., Blastocystis sp., and Enterocystozoon bieneusi in schoolchildren aged 2–13 years (n = 74) and their legal guardians (n = 6) in Madrid, Spain. Enteroparasite detection and genotyping was conducted in stool samples by molecular (PCR and Sanger sequencing) methods. Potential associations linked to infections were investigated through epidemiological questionnaires. Giardia duodenalis was the most prevalent enteric parasite found (14%, 95% CI: 7.1–23), followed by Blastocystis sp. (10%, 95% CI: 6.2–22) and Cryptosporidium spp. (3.8%, 95% CI: 0.78–11). None of the participants tested positive for E. bieneusi. Sequence analyses revealed the presence of G. duodenalis assemblage B, sub-assemblage BIV in a single child. The three Cryptosporidium isolates obtained were assigned to C. hominis, two of them belonging to the gp60 subtype IbA10G2. Four Blastocystis subtypes were identified including ST2 (38%, 3/8), ST3 (25%, 2/8), ST4 (25%, 2/8), and ST8 (12%, 1/8). All G. duodenalis and Cryptosporidium isolates were detected in children only. Blastocystis ST3 and ST4 were circulating in members of the same household. Blastocystis carriage rates increased with the age of the participants. Presence of diarrhoea-causing enteric protists was common in apparently healthy children.

Highlights

Several enteric protistan species contribute to the burden of diarrhoeal illness globally.Those considered of higher public health relevance include the protozoa Cryptosporidium spp., Entamoeba histolytica, Giardia duodenalis, and Cyclospora cayetanensis, and the microsporidia Enterocytozoon bieneusi [1,2,3,4]
A total of 80 stool samples and associated questionnaires were collected from asymptomatic schoolchildren (n = 74) and their legal guardians (n = 6)
The main findings of the study are the confirmation that the protist enteroparasites G. duodenalis, Cryptosporidium spp., and Blastocystis sp. are a common finding in the stools of apparently healthy schoolchildren, and to a lesser extent, in their legal guardians

Summary

Introduction

Several enteric protistan species contribute to the burden of diarrhoeal illness globally Those considered of higher public health relevance include the protozoa Cryptosporidium spp., Entamoeba histolytica, Giardia duodenalis, and Cyclospora cayetanensis, and the microsporidia Enterocytozoon bieneusi [1,2,3,4]. Infections by these well-recognized pathogens affect primarily young children and immunocompromised individuals in poor-resource settings characterised by insufficient access to safe drinking water and sanitation [5]. In contrast with the relative abundance of data existing in endemic areas, a comparatively much lower amount of information is currently available on the epidemiology of diarrhoea-causing protistan pathogens in medium- 4.0/).

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