Temperature and the development and survival of infective Toxocara canis larvae
Temperature and the development and survival of infective Toxocara canis larvae
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DOI：
10.1007/s00436-011-2536-8
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发表时间：
2012-02-01
影响因子：
2
通讯作者：
Morgan, Eric Rene
中科院分区：
文献类型：
--
作者：
Azam, Dena;Ukpai, Onyinye M.;Morgan, Eric Rene
在实验室条件下，在 15、20、25、30 和 35A 摄氏度的水中以及在 22A +/- 1A 摄氏度的室温下，研究了温度对犬弓蛔虫幼虫发育和存活的影响。在所有测试温度下，犬弓蛔虫卵都能够发育到幼虫阶段。显影速率随温度升高而增加。发育速率与温度的线性回归预测发育阈值较低，为 11.8A 摄氏度。卵在冷却至 1 和 -2A 摄氏度下可存活 6 周，当转移到更高温度时可以发育到感染性幼虫阶段，但与非冷藏卵相比，其发育速率会延迟。在测试的温度范围内孵化 7 周后，幼虫卵仍能保持活力，其中在 25°C 时存活率最高 (47%)。在 20°C 至 30°C 之间，卵发育到感染性幼虫阶段平均需要 121 天。结果为预测不同气候下环境中卵的感染性随时间的变化提供了基础。
The influence of temperature on the development and survival of Toxocara canis larvae was investigated under laboratory conditions, in water at 15, 20, 25, 30 and 35A degrees C and at room temperature 22A degrees C A +/- 1A degrees C. T. canis eggs were able to develop to the larvated stage at all the tested temperatures. Development rate increased with temperature. Linear regression of development rate against temperature predicted a lower development threshold of 11.8A degrees C. Eggs survived cooling to 1 and -2A degrees C for 6 weeks, and could develop to the infective, larvated stage when transferred to higher temperatures, but their development rates were then retarded compared with non-chilled eggs. Larvated eggs remained viable after 7 weeks of incubation across the tested temperature range, with the highest percentage viability (47%) obtained at 25A degrees C. Development of eggs to the infective larval stage required, on average, 121 degree days between 20A degrees C and 30A degrees C. Results provide a basis for predicting variation in the infectivity of eggs in the environment over time in different climates.