Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK.
J Appl Microbiol. 2022 Jun;132(6):4252-4265. doi: 10.1111/jam.15517. Epub 2022 Apr 4.
To develop an optimized solid culture medium for improved growth of Mycobacterium avium subsp. paratuberculosis (MAP).
Seven medium constituents (factors) were assessed at various concentrations for their ability to positively affect MAP growth. The factors tested were Tween 80, egg yolk, casitone, taurocholic acid, Mycobactin J, agar and either OADC or ADC supplement. After an initial screening of individual factors, a fractional factorial design and a response surface methodology (RSM) central composite design were used to assess the effects of multiple factors simultaneously and design a new solid culture medium. MAP growth became visible on streak plates of the optimized solid medium 2 weeks earlier than on Herrold's egg yolk medium (HEYM).
MAP grew faster on the optimized solid medium than on HEYM. It consisted of Middlebrook 7H9 broth with 1.0% Tween 80, 0.019% casitone, 1.4% bacteriological agar, 10% egg yolk, 10% ADC and 1.65 μg ml Mycobactin J.
This is the first study to use an RSM approach to optimize the composition of a solid medium for MAP culture. The new medium could improve MAP culture in future by reducing incubation times and increasing MAP colony numbers.
开发一种优化的固体培养基，以促进禽分枝杆菌副结核亚种（MAP）的生长。
评估了七种培养基成分（因素）在不同浓度下对 MAP 生长的积极影响能力。测试的因素包括吐温 80、蛋黄、酪蛋白胨、牛胆酸钠、Mycobactin J、琼脂以及 OADC 或 ADC 补充剂。在对单个因素进行初步筛选后，使用分阶实验设计和响应面法（RSM）中心组合设计同时评估多个因素的影响并设计新的固体培养基。与 Herrold 的蛋黄培养基（HEYM）相比，优化后的固体培养基上的 MAP 生长在划线平板上更早可见，早了 2 周。
与 HEYM 相比，MAP 在优化的固体培养基上生长更快。它由 Middlebrook 7H9 肉汤组成，含有 1.0%吐温 80、0.019%酪蛋白胨、1.4%细菌学琼脂、10%蛋黄、10%ADC 和 1.65μg/ml Mycobactin J。
这是首次使用 RSM 方法优化 MAP 培养的固体培养基组成的研究。新的培养基可以通过缩短孵育时间和增加 MAP 菌落数量来改善未来的 MAP 培养。
