Investigation of Parasite Contamination in Raw Vegetables Consumed in Çorum by Microscopic and Molecular Methods

Abstract

Aim: Intestinal parasitic infections can be transmitted via the fecal-oral way by eating intrinsically contaminated food or via uptake of free-living parasitic stages from the environment. In this study, the prevalence of parasitic contamination on raw consumed vegetables which are sold in bazaar and used as salad material was determined

it was aimed to see the status of important potential parasitic infections caused from raw vegetables in Corum province by molecular and microscopic methods. Methods: A total of 80 samples of raw vegetables, including tomatoes (10), peppers (10), cucumbers (10), lettuce (10), parsley (10), green onions (10), arugula (10) and carrots (10), which grow on the field were collected randomly from sellers in public bazaar of Corum, Turkey. The samples were transported to the laboratory for analysis in sterile nylon bags. Each raw vegetable sample was weighted (100 g) into sterile plastic bags and washed with physiological saline solution (250 ml) and the washing water/saline was left for about 24 h for sedimentation. The top water was discarded and 12 ml of the remaining washing water centrifuged at 2,000g for 15 min. The supernatant was discarded and the sediment carefully collected. Half of the samples were agitated gently by hand for dispersion of cysts and eggs, and then examined in native, Lugol and modified Kinyoun’s stain by light microscopy. The rest of samples were used for DNA extraction and the presence of Cryptosporidium, Giardia, Entamoeba and Blastocystis sp. in these samples was investigated by molecular methods. Results: A total of 80 raw vegetables were examined, of which 27.5% (22/80) were contaminated with different intestinal parasites. Parasitic contamination was detected on raw lettuce, parsley, arugula, green onions, carrots, cucumber and tomatoes. Lettuce (7/10) was the most commonly contaminated vegetable while peppers were not contaminated. The identified protozoans and helminthes were Eimeria spp. 8.75% (7), Nematodes larvae 7.5% (6), Blastocystis sp. 7.5% (6), Strongyloides larvae 2.5% (2), Ascaris egg 1.25% (1) and Dicrocoelium egg 1.25% (1) by light microscopy. Blastocystis hominis ST1 15% (12), Cryptosporidium parvum 3.75% (3) and Giardia intestinalis Assemblages A 1.25% (1) were detected by nested PCR and confirmed by sequencing while Entamoeba was not detected. Conclusion: There are few studies on parasitic contamination in vegetables in Turkey. However, no study has been conducted on this subject in Çorum. This study is the first study to illuminate the situation of the region. In this study, it was stated that the potential of carrying disease from raw consumed salads emerged. The results of this study showed that vegetables in the Çorum bazaars are contaminated with some parasites and may be a health risk to raw vegetable consumers. Washing procedures before eating raw vegetables regardless of the humans sanitation should be performed to avoid transmission of intestinal parasites.