Table 3.
Current available data on the detection of Toxoplasma gondii oocysts in fresh fruit and vegetables, under non-experimental conditions
| References | Product | Origin | Sample size | Oocyst recovery method | Detection method | PCR target | T. gondii prevalence (%) | No. of oocysts | Sequence confirmation | Genotyping analysis |
|---|---|---|---|---|---|---|---|---|---|---|
| Al-Megrin (2010) [19] | Spinach, radish, leek, parsley, basil, green onion, dill, lettuce, cabbage, watercress, coriander, mint | Saudi Arabia |
n = 470 (250 g) |
Washing, centrifugation | Microscopy | na | 6.6 | nd | No | No |
| Lass et al. (2012) [20] | Lettuce, strawberries, carrots, radishes | Poland |
n = 216 One lettuce; 1000 g strawberries; 500 g carrots; 20 radishes |
Washing, centrifugation, flocculation (CaCO3) | Real-time qPCR | B1 gene | 9.7 | 1–20/sample | No | Yes (type I and II) |
| Haq et al. (2014) [21] | Cabbage, carrot, chili, coriander, cucumber, lettuce, mint, radish, tomato | Pakistan |
n = 500 (200–250 g) |
Washing, centrifugation, sedimentation or flotation | Microscopy | na | 1.9 | nd | No | No |
| Lalonde & Gajadhar (2016) [22] | Pre-packaged or bulk spinach, lettuce, chard, collards, dandelion greens, rapini, mixed salads | Canada |
n = 470 (250 g) |
Washing, centrifugation, flotation (Sheather’s sucrose solution) | Real-time PCR | 18S rDNA | 0.26 | nd | Yes | No |
| Marchioro et al. (2016) [23] | Organic and nonorganic: crisp lettuce, regular lettuce, chicory, rocket, parsley | Brazil |
n = 1171 (35 g) |
Washing, filtration (0.3 mm cellulose ester membrane), centrifugation | Conventional PCR | B1 gene/ 529 bp REP | 2.9/0.8 | nd | No | No |
| Caradonna et al. (2016) [24] | Ready-to-eat packaged salads | Italy |
n = 238 (50 g) |
Washing, centrifugation | Microscopy, qPCR, sequencing | B1 gene | 0.8 | 62–554/g | Yes | Yes (type I) |
| Ferreira et al. (2018) [25] | Crisp lettuce, arugula, chicory, chives, purple lettuce, spinach, chard | Brazil |
n = 470 (250 g) |
Washing, filtration (two layers of gauze), centrifugation | Conventional PCR | 529 bp REP | 12.9 | nd | No | No |
| Slany et al. (2019) [26] | Carrot, cucumber, lettuce | Czech Republic |
n = 648 (100 g) |
Washing, centrifugation | Triplex qPCR | B1 gene and 529 bp REP | 9.6 | 1–900/g | No | Type II |
| Present study | RTE/packaged and bulk (organic and nonorganic: lettuce, watercress, coriander, parsley, carrots, arugula, strawberries, raspberries, blueberries, mixed salads) | Portugal, Spain |
n = 35 (64–3600 g) |
IDEXX Filta-Max® filtration EPA method1623.1 | Microscopy, conventional PCR, qPCR, restriction enzyme, sequencing | 529 bp REP | 40.0 | 1–180/g | Yes | No |
Abbreviations: na, not applicable; nd, not determined; REP, repetitive region