Evaluation of real-time PCR assay for the detection of Ascaris suum contamination in meat and organ meats

Ascarid larva migrans syndrome (ascarid LMS) is caused by ascarid roundworms including Ascaris suum. In East Asia, ascarid LMS has been considered as a food-borne disease in adulthood who has the dietary habitat of consuming raw or lightly cooked meat and organ meats. To evaluate the potential risk of A. suum infection from these foods, Ascaris specific real-time PCR was developed. The assay could constantly detect A. suum DNA up to 10 fg. Its specificity was confirmed by non-amplification with Toxocara canis and Toxocara cati DNA. A. suum DNA could be amplified from not only a single larva but also mouse liver spiked with a larva. Moreover, the assay could detect A. suum DNA in experimentally infected mouse liver, and showed higher sensitivity than a conventional digestion method. This real-time PCR assay would be useful for detecting the A. suum larval contamination in meat and organ meats. Practical applications It has been considered that one of the most important risk factors for ascarid LMS in humans is the consumption of raw or undercooked meat or organ meats of domestic animals infected with Ascaris suum. Thus, we developed the novel real-time PCR with the high sensitivity and specificity in order to specifically detect A. suum DNA from animal tissues. This assay can be applied to the meat inspection procedure for the identification of parasite larval contamination that may adversely impact on public health as well as on animal health and welfare.