Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
Institute for Infectious Diseases and Infection Control and Center for Sepsis Care and Control (CSCC), Jena University Hospital, Jena, Germany.
BMC Microbiol. 2024 Apr 4;24(1):118. doi: 10.1186/s12866-024-03246-z.
Q fever, a worldwide-occurring zoonotic disease, can cause economic losses for public and veterinary health systems. Vaccines are not yet available worldwide and currently under development. In this regard, it is important to produce a whole cell antigen, with preserved structural and antigenic properties and free of chemical modifications. Thus, inactivation of Coxiella burnetii with ultraviolet light C (UVC) was evaluated. C. burnetii Nine Mile phase I (NMI) and phase II (NMII) were exposed to decreasing intensities in a time-dependent manner and viability was tested by rescue cultivation in axenic medium or cell culture. Effects on the cell structure were visualized by transmission electron microscopy and antigenicity of UVC-treated NMI was studied by immunization of rabbits. NMI and NMII were inactivated at UVC intensities of 250 µW/cm for 5 min or 100 µW/cm for 20 min. Reactivation by DNA repair was considered to be unlikely. No morphological changes were observed directly after UVC inactivation by transmission electron microscopy, but severe swelling and membrane degradation of bacteria with increasing severity occurred after 24 and 48 h. Immunization of rabbits resulted in a pronounced antibody response. UVC inactivation of C. burnetii resulted in a structural preserved, safe whole cell antigen and might be useful as antigen for diagnostic purposes or as vaccine candidate.
Q 热是一种全球性的人畜共患病，可导致公共卫生和兽医卫生系统的经济损失。目前全球尚未开发出疫苗，正在开发中。在这方面，生产具有保存结构和抗原性且无化学修饰的完整细胞抗原非常重要。因此，评估了用紫外线 C（UVC）灭活柯克斯体。用时间依赖性方式以递减强度使牛布鲁氏菌九英里一期（NMI）和二期（NMII）菌株暴露，并通过在无菌培养基或细胞培养中进行挽救培养来测试其活力。通过透射电子显微镜观察细胞结构的变化，并通过免疫接种兔来研究经 UVC 处理的 NMI 的抗原性。NMI 和 NMII 在 UVC 强度为 250 µW/cm2 时失活 5 分钟或在 100 µW/cm2 时失活 20 分钟。认为 DNA 修复后的再激活不太可能。透射电子显微镜观察未直接观察到 UVC 失活后的形态变化，但在 24 和 48 小时后，细菌出现严重肿胀和膜降解。免疫接种兔可引起明显的抗体反应。UVC 灭活牛布鲁氏菌可产生结构保存的安全全细胞抗原，可作为诊断目的的抗原或疫苗候选物有用。
