Sartory D P, Waldock R, Davies C E, Field A M
Severn Trent Water, Quality and Environmental Assurance, Shrewsbury, UK.
Lett Appl Microbiol. 2006 Apr;42(4):418-24. doi: 10.1111/j.1472-765X.2006.01867.x.
To evaluate testing for acid phosphatase as an alternative method for the confirmation of Clostridium perfringens isolated from water.
Sixty-two reference strains of Clostridium were tested for their ability to produce acid phosphatase, as well as reduction of sulfite on tryptose sulfite cycloserine agar (TSC) and production of fluorescence in TSC supplemented with 4-methylumbelliferylphosphate (MUP). Additionally 155 environmental presumptive C. perfringens isolates from TSC incubated at 44 degrees C were identified and tested for acid phosphatase production and by the conventional MNLG (testing for motility, nitrate reduction, lactose fermentation and gelatin liquefaction) confirmation procedure. Twenty-seven strains from 15 species of Clostridium-reduced sulfite to some extent on TSC incubated at 44 degrees C, with a significant number of species being able to grow well at this temperature, indicating that a confirmation step is needed for the enumeration of C. perfringens on this medium. All 10 strains of C. perfringens tested, together with one strain each of Clostridium baratii and Clostridium rectum produced acid phosphatase. These also produced fluorescence on MUP supplemented TSC, as did 13 strains of acid phosphatase negative, sulfite-reducing clostridia, representing nine species. Of the environmental isolates, 114 were identified as C. perfringens of which 108 (94.7%) were confirmed by the acid phosphatase test compared with 104 (91.2%) by the MNLG tests.
Testing for acid phosphatase production is at least as reliable, and much simpler to perform, than the current standard confirmation MNLG procedure. Incorporation of MUP into TSC does not reliably improve the identification of presumptive C. perfringens.
Application of testing for acid phosphatase as a confirmation test for C. perfringens would substantially simplify the analysis for this bacterium from water samples, and reduce the analysis time to confirmed counts.
评估酸性磷酸酶检测作为确认从水中分离出的产气荚膜梭菌的替代方法。
对62株梭菌参考菌株进行检测，以评估它们产生酸性磷酸酶的能力，以及在胰蛋白胨亚硫酸盐环丝氨酸琼脂（TSC）上还原亚硫酸盐的能力和在添加4-甲基伞形酮基磷酸酯（MUP）的TSC上产生荧光的能力。此外，对155株从44℃孵育的TSC上分离出的环境中产气荚膜梭菌疑似菌株进行鉴定，并检测其酸性磷酸酶的产生情况，同时采用传统的MNLG（检测运动性、硝酸盐还原、乳糖发酵和明胶液化）确认程序进行检测。15种梭菌属的27株菌株在44℃孵育的TSC上能在一定程度上还原亚硫酸盐，并且有大量菌株能在该温度下良好生长，这表明在此培养基上对产气荚膜梭菌进行计数时需要一个确认步骤。所有测试的10株产气荚膜梭菌菌株，以及巴氏梭菌和直肠梭菌各1株均产生酸性磷酸酶。这些菌株在添加MUP的TSC上也产生荧光，13株酸性磷酸酶阴性、能还原亚硫酸盐的梭菌（代表9个种）同样如此。在环境分离株中，114株被鉴定为产气荚膜梭菌，其中108株（94.7%）通过酸性磷酸酶检测得到确认，而通过MNLG检测的为104株（91.2%）。
检测酸性磷酸酶的产生至少与当前标准的MNLG确认程序一样可靠，且操作更简单。将MUP加入TSC并不能可靠地改进对产气荚膜梭菌疑似菌株的鉴定。
应用酸性磷酸酶检测作为产气荚膜梭菌的确认试验将极大地简化水样中该细菌的分析，并减少分析时间至确认计数。
