Quantification of viable protozoan parasites on leafy greens using molecular methods

Protozoan contamination in produce is of growing importance due to their capacity cause illnesses consumers fresh leafy greens. Viability assays are essential accurately estimate health risk caused by viable parasites that contaminate food. We evaluated the efficacy reverse transcription quantitative PCR (RT-qPCR), propidium monoazide coupled with (q)PCR, and viability staining using iodide through systematic laboratory spiking experiments for selective detection Cryptosporidium parvum , Giardia enterica Toxoplasma gondii . In presence only protozoa, RT-qPCR could detect two nine (oo)cysts/g spinach (in 10 g processed). When different proportions inactivated parasite were spiked, mRNA concentrations correlated increasing (oo)cysts, although low levels false-positive signals detectable high amounts protozoa. Our study demonstrated among methods tested, performed more effectively discriminate from C. parvum, G. T. on spinach. This application greens can be adopted industry regulatory agencies charged protection human public screen protozoan pathogen contamination. • Viable protozoa quantified experiments. when present together. better compared PMA-(q)PCR DFA/PI staining.