Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, VIC 3030, Australia.
Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, VIC 3030, Australia.
Vet Microbiol. 2023 Sep;284:109818. doi: 10.1016/j.vetmic.2023.109818. Epub 2023 Jun 19.
The MS-H vaccine strain (Vaxsafe MS®; Bioproperties Pty. Ltd., Australia) is a live attenuated temperature sensitive derivative of a virulent strain of M. synoviae, 86079/7NS, and is used to prevent diseases from M. synoviae challenges in poultry farms. The genome sequence of MS-H includes 32 single nucleotide polymorphisms (SNPs) compared to that of 86079/7NS. To investigate the nature of mutations responsible for temperature sensitivity, MS-H strain was subjected to thermal adaptation in vitro and in vivo. The only observed variation detected in the MS-H culture following sequential passages with incremental incubation temperature from 33 °C to 39.5 °C was an Ala210Val variation in Obg protein, associated with loss of temperature sensitivity phenotype. An identical variation was detected in the MS-H culture reisolated from one out of five bird 28 days after inoculation with MS-H. These findings suggest that M. synoviae is capable of thermoadaptive evolution and Obg plays a significant role in this trait.
MS-H 疫苗株（Vaxsafe MS®；Bioproperties Pty. Ltd.，澳大利亚）是一种活的、减毒的温度敏感型衍生物，源自一种毒力很强的滑液支原体菌株 86079/7NS，用于预防家禽养殖场中滑液支原体引起的疾病。与 86079/7NS 相比，MS-H 株的基因组序列包含 32 个单核苷酸多态性（SNP）。为了研究导致温度敏感性的突变性质，对 MS-H 株进行了体外和体内的热适应性研究。在将 33°C 至 39.5°C 的递增孵育温度连续传代后，仅在 MS-H 培养物中观察到 Obg 蛋白中的 Ala210Val 变异，与温度敏感性表型的丧失有关。在接种 MS-H 后 28 天的 5 只鸡中的 1 只鸡的 MS-H 再分离培养物中也检测到相同的变异。这些发现表明，滑液支原体能够进行热适应性进化，Obg 在这一特性中发挥了重要作用。
