人工消化法检验肉类中旋毛虫优化方案的研究

The optimized protocol of artificial digestion method for inspection of Trichinella spiralis in meat

为了观察ICT人工消化法检验肉类中旋毛虫敏感性的影响因素与优化方案的检验效果,将120只小鼠随机分为3组(每组40只),分别经口感染300条、20条、5条旋毛虫感染性肌幼虫,42d后剖杀,肌肉剪碎后经ICT-消化法消化,收集肌幼虫,观察不同沉淀容器、温度、过滤筛及消化时间对幼虫回收效果的影响。结果表明,幼虫回收率随筛孔径的增大而升高(p<0.01),随温度升高而降低(p<0.01)。肉样消化2h的幼虫回收率(96.18%)明显高于消化0.5h(88%)(p<0.05)。ICT-消化法与改良消化法用于5条旋毛虫感染小鼠肌肉检验时的阳性率均为100%,但后者收集的幼虫数(68.70条)明显多于前者(55.90条)(p<0.01);改良消化法对每克肌肉虫荷(lpg)为0.1lpg和1lpg的肉样检验时,敏感性与幼虫回收率均为100%。消化法检验肉类中旋毛虫的最佳方案为肉样43℃消化2h、消化液冷却至4℃时40目(425μm孔径)筛过滤及锥形量杯沉淀。

To identify the major factors affecting the artificial digestion method for detection of Trichinella spiralis in meat and to optimize the method for increased sensitivity, groups of mice were orally inoculated with T.spiralis muscle larvae at various dosages, and were slaughtered at 42 days post-infection. Larvae were collected from the mouse muscles using the method recommended by International Commission on Trichinellosis （ICT-digestion）. Different settling vessels, temperatures, sieves and digestion time were examined for effect on the recovery of T. spiralis larvae from muscle tissue. The larval recovery rate by conical cylinders was significantly higher than separatory funnels （t=33.090, p〈0.05）, and optomal larval recovery was obtained with #40 （425 μm mesh） sieve at a reduced temperature （43 ℃, p〈0.01）. Higher larval recovery rate was obtained with a longer digestion time （2 h）. The improved digestion protocol was applied to test the meat samples containing 0.1 or 1 lpg and showed 100 % larval recovery.