Dámek Filip, Fremaux Bastien, Aubert Dominique, Thoumire Sandra, Delsart Maxime, Martin Jean-Luc, Vuillermet Sandra, Opsteegh Marieke, Jokelainen Pikka, Le Roux Delphine, Boireau Pascal, Villena Isabelle, Blaga Radu
Anses, INRAE, Ecole Nationale Vétérinaire d'Alfort, Laboratoire de Santé Animale, BIPAR, Maisons-Alfort, France.
IFIP - Institut du Porc, Ecole Nationale Vétérinaire d'Alfort, Maisons-Alfort, France.
Food Waterborne Parasitol. 2023 May 16;31:e00194. doi: 10.1016/j.fawpar.2023.e00194. eCollection 2023 Jun.
is an important zoonotic foodborne parasite. Meat of infected animals appears to be a major source of infection in Europe. Pork is the most consumed meat in France, with dry sausages well represented. The risk of transmission via consumption of processed pork products is largely unknown, mainly since processing will affect viability but may not entirely inactivate all parasites. We investigated the presence and concentration of DNA in the shoulder, breast, ham, and heart of pigs orally inoculated with 1000 oocysts ( = 3) or tissue cysts (n = 3) and naturally infected pigs ( = 2), by means of magnetic capture qPCR (MC-qPCR). Muscle tissues of experimentally infected pigs were further used to evaluate the impact of manufacturing processes of dry sausages, including different concentrations of nitrates (0, 60, 120, 200 ppm), nitrites (0, 60, 120 ppm), and NaCl (0, 20, 26 g/kg), ripening (2 days at 16-24 °C) and drying (up to 30 days at 13 °C), by a combination of mouse bioassay, qPCR and MC-qPCR. DNA of was detected in all eight pigs, including in 41.7% (10/24) of muscle samples (shoulder, breast and ham) and 87.5% (7/8) of hearts by MC-qPCR. The number of parasites per gram of tissue was estimated to be the lowest in the hams (arithmetic mean (M) = 1, standard deviation (SD) = 2) and the highest in the hearts (M = 147, SD = 233). However, the burden estimates varied on the individual animal level, the tissue tested and the parasitic stage used for the experimental infection (oocysts or tissue cysts). Of dry sausages and processed pork, 94.4% (51/54) were positive for by MC-qPCR or qPCR, with the mean burden estimate equivalent to 31 parasites per gram (SD = 93). Only the untreated processed pork sample collected on the day of production was positive by mouse bioassay. The results suggest an uneven distribution of in the tissues examined, and possibly an absence or a concentration below the detection limit in some of them. Moreover, the processing of dry sausages and processed pork with NaCl, nitrates, and nitrites has an impact on the viability of from the first day of production. Results are valuable input for future risk assessments aiming to estimate the relative contribution of different sources of human infections.
是一种重要的人畜共患食源性寄生虫。在欧洲，受感染动物的肉似乎是主要感染源。猪肉是法国消费最多的肉类，干香肠很有代表性。通过食用加工猪肉产品传播的风险很大程度上未知，主要是因为加工会影响其生存能力，但可能不会完全灭活所有寄生虫。我们通过磁捕获定量聚合酶链反应（MC-qPCR）研究了经口接种1000个卵囊（n = 3）或组织包囊（n = 3）的猪以及自然感染猪（n = 2）的肩部、胸部、火腿和心脏中该寄生虫DNA的存在情况和浓度。实验感染猪的肌肉组织进一步用于评估干香肠制造工艺的影响，包括不同浓度的硝酸盐（0、60、120、200 ppm）、亚硝酸盐（0、60、120 ppm）和氯化钠（0、20、26 g/kg），成熟（16 - 24°C下2天）和干燥（13°C下长达30天），采用小鼠生物测定、定量聚合酶链反应和磁捕获定量聚合酶链反应相结合的方法。通过MC-qPCR在所有8头猪中均检测到该寄生虫的DNA，包括41.7%（10/24）的肌肉样本（肩部、胸部和火腿）和87.5%（7/8）的心脏。每克组织中的寄生虫数量估计在火腿中最低（算术平均值（M）= 1，标准差（SD）= 2），在心脏中最高（M = 147，SD = 233）。然而，该寄生虫的负荷估计在个体动物水平、检测的组织以及用于实验感染的寄生虫阶段（卵囊或组织包囊）上有所不同。在干香肠和加工猪肉中，94.4%（51/54）通过MC-qPCR或定量聚合酶链反应检测为阳性，平均该寄生虫负荷估计相当于每克31个寄生虫（SD = 93）。仅生产当天采集的未处理加工猪肉样本通过小鼠生物测定呈阳性。结果表明在所检查的组织中该寄生虫分布不均，并且在其中一些组织中可能不存在或浓度低于检测限。此外，用氯化钠、硝酸盐和亚硝酸盐加工干香肠和加工猪肉从生产第一天起就对该寄生虫的生存能力有影响。这些结果是未来风险评估的宝贵输入，旨在估计不同来源对人类感染该寄生虫的相对贡献。
