鮑氏不動桿菌的生存之道

Fitness of Acinetobacter baumannii

鮑氏不動桿菌（Acinetobacter baumannii）是醫療照護相關感染的重要致病菌。它會造成伺機性感染，而且對碳青黴烯類、老虎黴素和多粘菌素抗生素的感受性持續下降，而使其成為全球公共衛生體系的嚴重威脅。在2017年世界衛生組織（WHO）將此菌列為優先一級病原體（top-priority pathogens），急需新型抗生素與替代藥物的開發需求。鮑氏不動桿菌可以在乾燥環境下長時間存活，並且對清潔劑、殺菌劑與抗生素有很強的耐受性。此菌利用菌體表面的莢膜多醣體保留水分而能在乾燥環境中存活，並且利用生物膜結構穩固附著醫療設施管路而不容易被清除。當環境毒物與抗生素進入菌體內時，鮑氏不動桿菌就會活化幫浦機制排出這些有害物質。過去十年的基因體研究逐步發現與揭示了這些調控機制，並且確認這些機制對於鮑氏不動桿菌在醫療機構環境中成長茁壯與抗生素抗藥性扮演重要角色。對鮑氏不動桿菌調控機制的近一步暸解，將幫助我們制定新的感控防治策略，以因應這難纏的威脅。因此，在這篇綜論，我們將探討鮑曼不動桿菌在惡劣的環境中的生存之道。

Acinetobacter baumannii is a major cause of healthcare-associated infections. It causes opportunistic infections with reduced susceptibility to carbapenems, tigecyclines, and polymyxins. In 2017, the World Health Organization (WHO) listed A. baumannii as a key pathogen and stated the urgent need to develop new antibiotics and alternative medicines accordingly. A. baumannii can survive on dry environmental surfaces for a long time and is highly resistant to cleaning agents and antibiotics. Capsular polysaccharides on their surface can retain water and help it survive in dry environments. The biofilm structure firmly attaches bacteria to surfaces in medical facilities. When environmental toxins and antibiotics enter this bacteria, the efflux pump activates and expels harmful substances. Within the past decade, many genomic studies have confirmed that these regulatory mechanisms play important roles in the survival of A. baumannii in healthcare settings. An in-depth understanding of the molecular mechanisms of this pathogen will aid in developing new infection control strategies to combat this intractable threat. Therefore, in this review article, we explore how A. baumannii survives in harsh environments.