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Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits

BACKGROUND: Toxoplasma gondii is the third most important contributor to health burden caused by food-borne illness. Ingestion of tissue cysts from undercooked meat is an important source of horizontal transmission to humans. However, there is an increasing awareness of the consumption of fresh frui...

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Autores principales: Marques, Cláudia S., Sousa, Susana, Castro, António, da Costa, José Manuel Correia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7140358/
https://www.ncbi.nlm.nih.gov/pubmed/32268915
http://dx.doi.org/10.1186/s13071-020-04040-2
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author Marques, Cláudia S.
Sousa, Susana
Castro, António
da Costa, José Manuel Correia
author_facet Marques, Cláudia S.
Sousa, Susana
Castro, António
da Costa, José Manuel Correia
author_sort Marques, Cláudia S.
collection PubMed
description BACKGROUND: Toxoplasma gondii is the third most important contributor to health burden caused by food-borne illness. Ingestion of tissue cysts from undercooked meat is an important source of horizontal transmission to humans. However, there is an increasing awareness of the consumption of fresh fruit and vegetables, as a possible source for oocyst transmission, since this stage of the parasite can persist and remain infective in soil and water for long time. Herein, we outline findings related with detection of T. gondii oocysts in vegetables and berry fruits, which are usually raw consumed. The procedure includes the estimation of the number of oocysts. METHODS: Food samples were collected from local producers and supermarket suppliers. Toxoplasma gondii oocysts were concentrated after washing the samples by applying high resolution water filtration and immunomagnetic separation (method 1623.1: EPA 816-R-12-001-Jan 2012), in order to (i) remove potential Cryptosporidium spp. oocysts and Giardia spp. cysts present in the samples; and (ii) select T. gondii oocysts. Toxoplasma gondii oocyst detection and an estimation of their numbers was performed by conventional PCR and real time qPCR, using specific primers for a 183-bp sequence of the T. gondii repetitive DNA region. All PCR-positive DNA samples were purified and sequenced. Restriction enzyme digestion with EcoRV endonuclease confirmed the presence of the T. gondii DNA fragment. In addition, the presence of the parasite was observed by fluorescent microscopy, taking advantage of the oocysts autofluorescence under UV light. RESULTS: Forty percent of the analysed samples (95% CI: 25.5–56.5%) presented the expected PCR and digested DNA fragments. These fragments were confirmed by sequencing. Microscopic autofluorescence supported the presence of T. gondii-like oocysts. The estimated mean (± SE) oocyst concentration was 23.5 ± 12.1 oocysts/g, with a range of 0.6–179.9 oocysts/g. CONCLUSIONS: Our findings provide relevant evidence of contamination of fresh vegetables and berry fruits with T. gondii oocysts. [Image: see text]
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spelling pubmed-71403582020-04-14 Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits Marques, Cláudia S. Sousa, Susana Castro, António da Costa, José Manuel Correia Parasit Vectors Research BACKGROUND: Toxoplasma gondii is the third most important contributor to health burden caused by food-borne illness. Ingestion of tissue cysts from undercooked meat is an important source of horizontal transmission to humans. However, there is an increasing awareness of the consumption of fresh fruit and vegetables, as a possible source for oocyst transmission, since this stage of the parasite can persist and remain infective in soil and water for long time. Herein, we outline findings related with detection of T. gondii oocysts in vegetables and berry fruits, which are usually raw consumed. The procedure includes the estimation of the number of oocysts. METHODS: Food samples were collected from local producers and supermarket suppliers. Toxoplasma gondii oocysts were concentrated after washing the samples by applying high resolution water filtration and immunomagnetic separation (method 1623.1: EPA 816-R-12-001-Jan 2012), in order to (i) remove potential Cryptosporidium spp. oocysts and Giardia spp. cysts present in the samples; and (ii) select T. gondii oocysts. Toxoplasma gondii oocyst detection and an estimation of their numbers was performed by conventional PCR and real time qPCR, using specific primers for a 183-bp sequence of the T. gondii repetitive DNA region. All PCR-positive DNA samples were purified and sequenced. Restriction enzyme digestion with EcoRV endonuclease confirmed the presence of the T. gondii DNA fragment. In addition, the presence of the parasite was observed by fluorescent microscopy, taking advantage of the oocysts autofluorescence under UV light. RESULTS: Forty percent of the analysed samples (95% CI: 25.5–56.5%) presented the expected PCR and digested DNA fragments. These fragments were confirmed by sequencing. Microscopic autofluorescence supported the presence of T. gondii-like oocysts. The estimated mean (± SE) oocyst concentration was 23.5 ± 12.1 oocysts/g, with a range of 0.6–179.9 oocysts/g. CONCLUSIONS: Our findings provide relevant evidence of contamination of fresh vegetables and berry fruits with T. gondii oocysts. [Image: see text] BioMed Central 2020-04-08 /pmc/articles/PMC7140358/ /pubmed/32268915 http://dx.doi.org/10.1186/s13071-020-04040-2 Text en © The Author(s) 2020 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
spellingShingle Research
Marques, Cláudia S.
Sousa, Susana
Castro, António
da Costa, José Manuel Correia
Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits
title Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits
title_full Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits
title_fullStr Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits
title_full_unstemmed Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits
title_short Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits
title_sort detection of toxoplasma gondii oocysts in fresh vegetables and berry fruits
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7140358/
https://www.ncbi.nlm.nih.gov/pubmed/32268915
http://dx.doi.org/10.1186/s13071-020-04040-2
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