Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.
Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China; Department of Laboratory Medicine, Shaanxi Provincial People's Hospital, Xi'an, China.
Microb Pathog. 2021 Jun;155:104922. doi: 10.1016/j.micpath.2021.104922. Epub 2021 Apr 28.
Acinetobacter baumannii is an important pathogen in clinical. The factors of biofilm formation, antibiotic resistance and motility contribute great to A. baumannii in persisting in stressed environment, and further leads to nosocomial infections. 70 A. baumannii clinical isolates were investigated for their clinical characteristics of infection. Among the tested strains, 54 (77.1%) isolates were obtained from ICUs, with the frequency of multidrug-resistance (MDR) at 55.7%, and that of extensively drug-resistance (XDR) at 31.4%. 97.1% of the clinical isolates could form biofilms, in which 4.3% possessed weak biofilm formation ability, while 41.4% and 51.4% were moderate and strong biofilm producers, respectively. A strong correlation between antibiotic resistance and biofilm formation ability was found that all the resistant strains could form biofilms, with the majority in moderate and strong levels, but 2.9% sensitive isolates had no such ability. However, the sensitive strains that could produce biofilms showed stronger biofilm formation capacity in the early stage before 24 h compared to the resistant isolates, though they became weaker afterwards. 24 biofilm-related genes and two bla genes were found in both biofilm-forming and non-biofilm-forming strains, but with higher prevalence in the strains that could produce biofilms. No correlation was detected between twitching motility with antibiotic susceptibility or biofilm formation. These results raised a viewpoint that examining timepoint is a key factor for determining the biofilm formation ability, and further highlighted the importance of the appropriate surveillance and control measures in preventing the emergence and transmission of MDR and XDR A. baumannii.
鲍曼不动杆菌是临床中的一种重要病原体。生物膜形成、抗生素耐药性和运动性等因素有助于鲍曼不动杆菌在应激环境中存活，并进一步导致医院感染。我们调查了 70 株鲍曼不动杆菌临床分离株的感染临床特征。在检测的菌株中，54 株（77.1%）分离株来自 ICU，其中多药耐药（MDR）的频率为 55.7%，广泛耐药（XDR）的频率为 31.4%。97.1%的临床分离株可以形成生物膜，其中 4.3%具有较弱的生物膜形成能力，而 41.4%和 51.4%分别为中度和强生物膜生产者。发现抗生素耐药性和生物膜形成能力之间存在很强的相关性，所有耐药菌株都可以形成生物膜，大多数处于中度和强水平，但 2.9%的敏感分离株没有这种能力。然而，能够产生生物膜的敏感菌株在 24 小时之前的早期表现出比耐药菌株更强的生物膜形成能力，尽管随后它们变得较弱。在形成生物膜和不形成生物膜的菌株中都发现了 24 个生物膜相关基因和两个 bla 基因，但在能够产生生物膜的菌株中更为普遍。抖动运动性与抗生素敏感性或生物膜形成之间没有相关性。这些结果提出了一个观点，即检查时间点是确定生物膜形成能力的关键因素，并进一步强调了适当监测和控制措施在预防 MDR 和 XDR 鲍曼不动杆菌的出现和传播方面的重要性。
