Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, People's Republic of China.
Foodborne Pathog Dis. 2010 Aug;7(8):879-85. doi: 10.1089/fpd.2009.0445.
In many countries, the method of choice in inspecting meat for Trichinella spiralis infection is artificial digestion. We conducted a study of the sensitivity of the artificial digestion method recommended by the International Commission on Trichinellosis for detecting T. spiralis larvae in meat and of the effect of modifications of some procedures used in the method on its sensitivity. As part of this, we evaluated the effects on larval recovery of the vessels used for larval settling, sieve sizes, and temperatures at which larvae passed through the sieves, using larvae from T. spiralis-infected mice. We observed the effects on larval recovery of digestion duration and of modified artificial digestion by using 10-g samples of infected mouse muscle alone or mixed with uninfected pork. The percentages of larvae recovered with the respective use of separatory funnels and conical cylinders were 51.20% and 98.70%. The rates of recovery of T. spiralis larvae at 4 degrees C after passage through sieves of 425-microm mesh (No. 40), 250-microm mesh (No. 60), and 180-microm mesh (No. 80) were 98.42%, 90.59%, and 81.63%, which exceeded the 97.79%, 85.10%, and 61.12% rates of recovery of motile larvae at 40 degrees C and the 95.12%, 78.60%, and 44.16% rates of recovery of dead larvae at 90 degrees C. The larval recovery rate after digestion for 2 hours (96.18%) was greater than that after 0.5 hours (88.00%). We then examined a modified digestion method in which 10-g samples of pork mixed with 300 mL of digestive solution were digested for 2 hours at 43 degrees C followed by chilling of digest solution to 4 degrees C before passing it through a 425-microm mesh (No. 40) sieve and allowing it to settle in a 1-L conical cylinder. With this procedure, the modified method detected T. spiralis in samples of pork meat weighing 10 g and containing either 1 larva per gram or 0.1 larva per gram. Further validation of digestion method incorporating these modifications is required with the use of larger samples of infected muscle from species such as swine, which are routinely tested for T. spiralis for the purpose of food safety.
在许多国家，检查旋毛虫感染的首选方法是人工消化。我们研究了国际旋毛虫委员会推荐的人工消化方法检测肉中旋毛虫幼虫的灵敏度，以及方法中一些步骤的修改对其灵敏度的影响。为此，我们使用来自感染旋毛虫的小鼠的幼虫，评估了用于幼虫沉淀的容器、筛网尺寸以及幼虫通过筛网的温度对幼虫回收的影响。我们观察了消化时间和改良人工消化对幼虫回收的影响，方法是使用单独或混合感染小鼠肌肉的 10 克样本。分别使用分离漏斗和锥形圆柱的幼虫回收率为 51.20%和 98.70%。在 4°C 下，通过 425 微米筛网（40 号）、250 微米筛网（60 号）和 180 微米筛网（80 号）的旋毛虫幼虫回收率分别为 98.42%、90.59%和 81.63%，超过了在 40°C 下运动幼虫的 97.79%、85.10%和 61.12%回收率，以及在 90°C 下死亡幼虫的 95.12%、78.60%和 44.16%回收率。消化 2 小时（96.18%）后的幼虫回收率大于消化 0.5 小时（88.00%）后的回收率。然后，我们检查了一种改良的消化方法，其中将 10 克猪肉样本与 300 毫升消化液混合，在 43°C 下消化 2 小时，然后将消化液冷却至 4°C，再通过 425 微米筛网（40 号），并让其在 1 升锥形圆柱中沉淀。通过这种方法，改良的方法可以检测到重量为 10 克、每克含有 1 条幼虫或每克含有 0.1 条幼虫的猪肉样本中的旋毛虫。需要进一步验证包含这些改进的消化方法，使用来自猪等物种的更大感染肌肉样本进行验证，这些物种通常为食品安全目的检测旋毛虫。
