Department of Pathophysiology of Reproduction and Mammary Gland, National Veterinary Research Institute, Powstańców Wlkp. 10, 85-090 Bydgoszcz, Poland.
Mycopathologia. 2011 Mar;171(3):177-82. doi: 10.1007/s11046-010-9365-7. Epub 2010 Sep 18.
Bovine mastitis caused by the yeast-like alga Prototheca zopfii represents a serious veterinary problem and may result in heavy economic losses to particular dairy farms. The purpose of this study was to evaluate the survival of 50 isolates of P. zopfii in milk subjected to different heat treatments and the survival of further 106 P. zopfii isolates after exposure to three classes of teat disinfectants: iodine (Dipal), quaternary ammonium compounds (Teat), and dodecylbenzenesulphonic acid (Blu-gard). Of the 50 isolates tested for thermal tolerance, 29 (58%) survived heat treatment at 62 °C for 30 s and 13 (26% of all isolates) of those survived after heat treatment at 72 °C for 15 s. None of the 106 isolates were able to withstand the in-use concentrations of the three disinfectants tested. The highest disinfectant concentrations that permitted survival of at least one isolate were dilutions: 1:1,000 for Dipal (survival rate of 52.8-57.5%), 1:100 for Teat (88.7-90.6%), and 1:10 for Blu-gard (100%). No differences in the survival rates of P. zopfii were observed with respect to the duration of exposure to disinfectant. The results of this study support the previous findings that P. zopfii may resist high-temperature treatments, including that applied in the high-temperature, short-time (HTST) pasteurization process. The obtained data also demonstrate the efficacy of the three classes of teat disinfectants against P. zopfii, with the efficacy of iodine being most pronounced. The study emphasizes the necessity of using higher temperatures in the pasteurization of raw milk to kill the Prototheca algae, as well as the particular suitability of the iodine for the control procedures of protothecal mastitis.
由酵母样藻类——产朊假丝酵母引起的牛乳腺炎是一个严重的兽医问题，可能会给特定的奶牛场造成巨大的经济损失。本研究的目的是评估 50 株产朊假丝酵母在不同热处理牛奶中的存活情况，以及另外 106 株产朊假丝酵母在暴露于 3 类乳头消毒剂后的存活情况：碘（Dipal）、季铵化合物（Teat）和十二烷基苯磺酸（Blu-gard）。在耐热性测试的 50 株分离株中，有 29 株（58%）在 62°C 下 30 秒的热处理中存活下来，其中 13 株（所有分离株的 26%）在 72°C 下 15 秒的热处理后存活下来。在测试的三种消毒剂的实际使用浓度下，没有一种分离株能够存活。至少有一种分离株能够存活的消毒剂最高浓度稀释度为：Dipal 为 1:1000（存活率为 52.8-57.5%）、Teat 为 1:100（88.7-90.6%）和 Blu-gard 为 1:10（100%）。产朊假丝酵母的存活率与接触消毒剂的时间长短无关。本研究结果支持先前的研究结果，即产朊假丝酵母可能耐受高温处理，包括高温短时间（HTST）巴氏消毒过程中应用的高温处理。所得数据还证明了三种类型的乳头消毒剂对产朊假丝酵母的有效性，其中碘的效果最为显著。该研究强调了在巴氏消毒生奶时需要使用更高的温度来杀死产朊假丝酵母藻类，以及碘在控制产朊假丝酵母乳腺炎方面的特别适用性。
