Horiuchi Ayaka, Kubota Noriko, Hidaka Eiko, Shimabukuro Atsuya, Yasukochi Satoshi, Nakamura Tomohiko, Oana Kozue, Kawakami Yoshiyuki
Department of Laboratory Medicine, Nagano Children's Hospital, Azumino 399-8288, Japan.
Department of Laboratory Medicine, Nagano Children's Hospital, Azumino 399-8288, Japan; Department of Life Science Research Center, Nagano Children's Hospital, Azumino 399-8288, Japan.
J Infect Chemother. 2015 Sep;21(9):680-6. doi: 10.1016/j.jiac.2015.06.004. Epub 2015 Jun 19.
This study was the first to describe the hitherto deficiently evaluated alkaline tolerance of Kocuria marina isolate from a pediatric patient with continuous intravenous epoprostenol dosing therapy. Our isolate from blood of a 7-year-old Japanese boy was finally identified as K. marina by the morphological, cultural, and biochemical properties together with the comparative sequence analyses of the 16S rRNA genes. The K. marina isolate, the causative agent of catheter-related blood-stream infection, was not only revealed to be salt tolerant (NaCl 15%), but also demonstrated to be stably survived with no apparent decrease of cell counts for long periods (120 h) in an alkaline environment (pH 8, 9, 10, and 11) at 35 °C. Its remarkable tolerance to the stresses of high alkalinity compared with a clinical Staphylococcus aureus strain should provide consistent interpretation that the environment of high alkalinity (pH 10.2-10.8) measures should be insufficient to inactivate almost all the causative agents including K. marina strains in the solution of epoprostenol (pH 10.4) (Flolan(®), GlaxoSmithKline, Ltd., Tokyo, Japan.). To the best of our knowledge, the first description of the property of being tolerant to high alkalinity that the K. marina isolate exhibited was noteworthy and a useful piece of information. In conclusion, we believe that the present study should be a notification regarding the potential risk of catheter-related blood-stream infections due to K. marina, suggestive of an alkalophile, especially in patients receiving continuous intravenous epoprostenol dosing therapy.
本研究首次描述了从一名接受持续静脉注射依前列醇治疗的儿科患者中分离出的海科克氏菌（Kocuria marina）的碱性耐受性，此前对其评估不足。通过形态学、培养和生化特性以及16S rRNA基因的比较序列分析，我们从一名7岁日本男孩的血液中分离出的菌株最终被鉴定为海科克氏菌。该海科克氏菌分离株是导管相关血流感染的病原体，不仅被证明耐盐（15%氯化钠），而且在35°C的碱性环境（pH 8、9、10和11）中能长时间（120小时）稳定存活，细胞计数无明显下降。与临床金黄色葡萄球菌菌株相比，其对高碱胁迫具有显著耐受性，这应能提供一致的解释，即高碱环境（pH 10.2 - 10.8）措施可能不足以灭活依前列醇溶液（pH 10.4）（Flolan(®)，葛兰素史克有限公司，东京，日本）中包括海科克氏菌菌株在内的几乎所有病原体。据我们所知，海科克氏菌分离株所表现出的耐高碱性特性的首次描述值得关注，是一条有用的信息。总之，我们认为本研究应是关于海科克氏菌导致导管相关血流感染潜在风险的一项通报，提示存在嗜碱菌，尤其是在接受持续静脉注射依前列醇治疗的患者中。
