这项研究开发并评估了一种体外瘤胃孵育(IVRI)方法,以描述瘤胃液(RL)中的三期感染幼虫(L3)的出鞘动力学。具体目标是(i)标准化IVRI方法,以促进L3和RL之间的接触以及幼虫恢复,和(ii)应用IVRI方法描述H.contortus的出鞘动力学并选择最佳拟合的非线性模型。根据IVRI技术在牛RL或PBS中孵育含有H.contortus幼虫的孵育装置。孵育条件包括RL与富氮培养基混合,保持在39°C,pH=7.0,用CO2排出并手动搅拌。在0、1、3、6、9、12和24小时后恢复幼虫。计数出鞘和入鞘的幼虫以估计RL或PBS中的出鞘(%)。用非线性回归模型分析RL中的出鞘:指数,Gompertz,物流,日志-物流,还有Weibull.比较了拟合模型,以选择最能描述出鞘动力学的模型。RL的出鞘率达到6.52%,20.65%,58.22%,69.24%,73.08%,在1、3、6、9、12和24小时内占77.20%,分别。虽然Gompertz,威布尔,Logistic模型足以描述观察到的出鞘,Log-Logistic模型拟合效果最佳。使用牛RL的IVRI方法代表了研究H.contortusL3的体外鞘鞘动力学的合适工具。
This study developed and evaluated an in vitro rumen incubation (IVRI) method to describe the
exsheathment kinetics of Haemonchus contortus third-stage infective larvae (L3) in ruminal liquor (RL). The specific objectives were (i) to standardize the IVRI method to facilitate the contact between L3 and RL as well as the larval recovery, and (ii) to apply the IVRI method to describe the exsheathment kinetics of H. contortus and to select the best fitting nonlinear model. Incubation devices containing H. contortus larvae were incubated according to the IVRI technique in cattle RL or PBS. The incubation conditions included RL mixed with a nitrogen-rich media, maintained at 39 °C, with pH = 7.0, vented with CO2 and manual agitation. The larvae were recovered after 0, 1, 3, 6, 9, 12, and 24 h. The exsheathed and ensheathed larvae were counted to estimate the
exsheathment (%) in RL or PBS. Exsheathment in RL was analyzed with nonlinear regression models: Exponential, Gompertz, Logistic, Log-Logistic, and Weibull. The models\' fit was compared to select the one that best described the
exsheathment kinetics. The
exsheathment in RL reached 6.52%, 20.65%, 58.22%, 69.24%, 73.08%, and 77.20% in 1, 3, 6, 9, 12, and 24 h, respectively. Although the Gompertz, Weibull, and Logistic models were adequate to describe the observed exsheathment, the Log-Logistic model had the best fit. The IVRI method using bovine RL represents a suitable tool for the study of the in vitro
exsheathment kinetics of H. contortus L3.