The effects of freezing, drying, ultraviolet irradiation (UV), chlorine, and a quaternary ammonium compound on the infectivity of the myxospore stage of Myxobolus cerebralis (the causative agent of whirling disease) for Tubifex tubifex were examined in a series of laboratory trials. Freezing at either -20 degrees C or -80 degrees C for a period of 7 d or 2 months eliminated infectivity as assessed by the absence of production of the actinospore stage (triactinomyxons [TAMs]) from T. tubifex cultures inoculated with treated myxospores over a 4-5-month period. Myxospores retained infectivity when held in well water at 5 degrees C or 22 degrees C for 7 d and when held at 4 degrees C or 10 degrees C d for 2 months. In contrast, no TAMs were produced from T. tubifex cultures inoculated with myxospores held at 20 degrees C for 2 months. Drying of myxospores eliminated any evidence of infectivity for T. tubifex. Doses of UV from 40 to 480 mJ/cm2 were all effective for inactivating myxospores of M. cerebralis, although a few TAMs were detected in one replicate T. tubifex culture at 240 mJ/cm2 and in one replicate culture at 480 mJ/cm2. Treatments of myxospores with chlorine bleach at active concentrations of at least 500 mg/L for 15 min largely inactivated myxospore infectivity for T. tubifex. Likewise, there was no evidence of TAMs produced by T. tubifex inoculated with myxospores treated with alkyl dimethyl benzyl ammonium chloride (ADBAC) at 1,500 mg/L for 10 min. Treatments of myxospores with 1,000-mg/L ADBAC for 10 min reduced TAM production in T. tubifex cultures sevenfold relative to that in cultures inoculated with an equal number of untreated myxospores. These results indicate that myxospores of M. cerebralis demonstrate a selective rather than broad resistance to selected physical and chemical treatments, and this selective resistance is consistent with conditions that myxospores are likely to experience in nature.

中文翻译：

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冷冻、干燥、紫外线照射、氯和季铵处理对 Tubifex tubifex 脑粘液孢子感染性的影响

在一系列实验室试验中，研究了冷冻、干燥、紫外线照射 (UV)、氯和季铵化合物对脑粘液菌（旋风病的病原体）粘孢子阶段感染性的影响。在 -20 摄氏度或 -80 摄氏度的温度下冷冻 7 天或 2 个月消除了传染性，通过从接种处理过的粘孢子的 T.tubifex 培养物中不产生放线孢子阶段（triactinomyxons [TAMs]）进行评估。 4-5 个月的时间。粘孢子在 5 摄氏度或 22 摄氏度的井水中保持 7 天和在 4 摄氏度或 10 摄氏度 d 下保持 2 个月时仍保持传染性。相比之下，T.tubifex 培养物接种了粘孢子，在 20 摄氏度下保持 2 个月，没有产生 TAM。干燥粘孢子消除了 T.tubifex 感染性的任何证据。40 至 480 mJ/cm2 的 UV 剂量均能有效灭活大脑分枝杆菌的粘孢子，尽管在 240 mJ/cm2 的一次重复培养中和 480 mJ/cm2 的一次重复培养中检测到一些 TAM。用活性浓度至少为 500 mg/L 的氯漂白剂处理粘孢子 15 分钟，很大程度上灭活了 T. tubifex 的粘孢子感染性。同样，没有证据表明 T.tubifex 接种了粘孢子，并用烷基二甲基苄基氯化铵 (ADBAC) 以 1,500 mg/L 的浓度处理 10 分钟。用 1,000 毫克/升 ADBAC 处理粘孢子 10 分钟后，T.tubifex 培养物中的 TAM 产量是接种等量未处理粘孢子的培养物中的 7 倍。