Parasitological analysis of green leaf lettuce cultivated in different production systems

Abstract

This study analysed parasite contamination in green leaf lettuce (Lactuca sativa), grown in different cultivation systems (conventional, organic, and hydroponic), from a family farmer cooperative in the municipality of Presidente Prudente, São Paulo, Brazil. Samples were collected at weekly intervals during five months, totalling 180 vegetable samples (60 samples of leaf lettuce from each cultivation system). Lettuce leaves were washed with 0.5% Extran MA 02, and the resulting fluid subjected to sedimentation and centrifugal flotation for recovery of parasite structures. Overall, 71 samples (39.4%) were contaminated with at least one parasite structure, 34 (47.9%) from lettuce grown in the hydroponic system, 20 (28.2%) from the organic system, and 17 (23.9%) from the conventional system. Entamoeba spp. cysts were the most common parasite structures found in the leafy vegetables, with the highest cyst counts found in the hydroponic system (p = 0.003). It is concluded that, regardless of the cultivation system (conventional, organic, or hydroponic), there is a possibility of green leaf lettuce contamination by intestinal parasites. Measures that improve sanitary conditions during production, as well as proper hygiene during the preparation of raw leafy vegetables, may be important to reduce contamination and consequent transmission of parasite diseases from raw leafy vegetable consumption. Key words: Enteroparasites. Cultivation systems. Leafy vegetables. Zoonoses. ResumoO presente estudo analisou a contaminação parasitológica em alfaces crespas (Lactuca sativa) cultivadas em diferentes sistemas de produção (convencional, orgânico e hidropônico), fornecidas por uma cooperativa de produtores da agricultura familiar, no município de Presidente Prudente, São Paulo. As coletas foram repetidas em intervalos semanais, durante um período cinco meses, totalizando 180 amostras de hortaliças (60 amostras de alface por tipo de produção). As folhas das alfaces foram lavadas com Extran MA 02 a 0.5% e o fluído resultante submetido às técnicas de sedimentação e de centrífugo-flutuação, para recuperação das estruturas parasitárias. Observou-se que do total de 180 amostras, 71 (39,4%) estavam contaminadas por pelo menos uma estrutura parasitária, sendo 34 (47,9%) das alfaces cultivadas no sistema hidropônico, 20 (28,2%) no orgânico e 17 (23,9%) no sistema convencional. Cistos de Entamoeba spp. foram as estruturas parasitárias mais frequentes nas hortaliças, com maior contagem de cistos naquelas produzidas no sistema hidropônico (p=0,003). Conclui-se que independentemente do sistema de cultivo (convencional, orgânico e hidropônico), existe a possibilidade de contaminação de alfaces por enteroparasitos. Medidas que propiciem a melhoria na qualidade higiênico-sanitária na produção, assim como a adequada higienização das verduras antes do consumo "in natura" podem ser importantes para a redução da contaminação e consequente transmissão de doenças parasitárias pelo consumo "in natura" de hortaliças. Palavras-chave: Enteroparasi...

Detection of enteroparasites in foliar vegetables commercialized in street- and supermarkets in Aparecida de Goiânia, Goiás, Brazil

“…An elevated number of intestinal parasites was detected in foliar vegetables commercialized in Aparecida de Goiânia, especially lettuce. The index of 70% positivity of lettuce samples is very high comparing with several others studies carried out in Brazil (Esteves and Figueirôa, 2009;Neres et al, 2011;Fernandes et al, 2015;Silva et al, 2015;Moura et al, 2016;Santos et al, 2017;Machado et al 2020); the nematode larvae were not included in statistics because they were not identified at the family, genus or species Occurrence of enteroparasites in foliar vegetables level, as they could be larvae of free-living non-parasitic nematodes. In addition, probable trematode eggs and Trypanoxyuris sp.…”

“…Despite the undeniable nutritional importance, raw or poorly washed vegetables contaminated with fecal residues or irrigated with water contaminated with parasitic forms have been reported as important vehicles for transmission of intestinal parasites to humans (Andrade et al, 2010;Fernandes et al, 2015). In Brazil, contamination of foliar vegetables is one of the main transmission routes of enteroparasites to humans (Soares and Cantos, 2005;Neres et al, 2011), and several studies have confirmed the presence of parasitic forms in vegetables commercialized in all regions of the country (Soares and Cantos, 2005;Esteves and Figueirôa, 2009;Neres et al, 2011;Gomes et al, 2014;Fernandes et al, 2015;Silva et al, 2015;Novacki et al, 2016;Santos et al, 2017;Maldonade et al, 2019;Machado et al, 2020;Rodrigues et al, 2020). However, in the State of Goiás there are still few reports on the occurrence of vegetables contaminated with parasitic forms.…”