Occurrence and diversity of ciliated protozoa in the most commonly consumed leafy greens in Brazil: a qualitative study

Abstract

Ciliated protozoa are an ubiquitous group of eukaryotes that have been poorly reported on leafygreens. The present study aimed to verify the occurrence and diversity of ciliated protozoa in theleaves and roots of three of the most commonly consumed leafy greens in Brazil – lettuce, rocket andcoriander. The vegetable samples were washed by manual agitation (3 minutes) in two different media(mineral water and Page´s Amoeba Saline solution). After washing, the contents were incubatedin Petri dishes and aliquots were removed for microscopic identification and in vivo observation.A total of 21 ciliated protozoa species were found, most of which were bacterivorous. Leafy greenshave commonly been associated with foodborne outbreaks and ciliated protozoa, which althoughthey are not a Public Health concern, can act as “Trojan Horses” harboring bacteria, viruses andother protozoa cysts and oocysts and can suggest a new route towards microbiological quality relatedto the food chain. This is the first report of ciliated protozoa on leafy greens consumed in Brazil.