Detection of Toxoplasma gondii oocysts in fresh vegetables and berry fruits.
Parasit Vectors
; 13(1): 180, 2020 Apr 08.
Article
em En
| MEDLINE
| ID: mdl-32268915
ABSTRACT
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.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Toxoplasma
/
Verduras
/
Parasitologia de Alimentos
/
Oocistos
/
Frutas
Tipo de estudo:
Diagnostic_studies
País/Região como assunto:
Europa
Idioma:
En
Revista:
Parasit Vectors
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Portugal