Lee H-W, Koh Y M, Kim J, Lee J-C, Lee Y-C, Seol S-Y, Cho D-T, Kim J
Department of Microbiology, Kyungpook National University, School of Medicine, Daegu, Korea.
Clin Microbiol Infect. 2008 Jan;14(1):49-54. doi: 10.1111/j.1469-0691.2007.01842.x. Epub 2007 Nov 13.
This study evaluated the capacity of 23 multidrug-resistant (MDR) clinical isolates of Acinetobacter baumannii to adhere to respiratory epithelial cell surfaces and to form biofilm on a polystyrene surface. All 23 A. baumannii isolates were capable of adhering efficiently to respiratory epithelial cells, and biofilm production was positively associated with epithelial cell adhesiveness (r 0.80, p <0.0001). In the presence of the chelating agent EDTA, biofilm formation was markedly reduced. Cell adhesiveness and biofilm formation were significantly higher in isolates carrying the bla(PER-1) gene as compared with isolates without this extended-spectrum beta-lactamase gene (p <0.005 and p <0.001, respectively). Further examination by RT-PCR showed a positive correlation between the level of expression of the bla(PER-1) gene and the level of biofilm formation (r 0.89, p <0.0001) and cell adhesiveness (r 0.74, p <0.006). Overall, the study demonstrated a high capacity of clinical isolates of MDR A. baumannii to form biofilm and to adhere to respiratory epithelial cells. This feature, combined with multidrug resistance, might contribute to the survival of these organisms and their dissemination in the hospital environment.
本研究评估了23株鲍曼不动杆菌多重耐药（MDR）临床分离株黏附于呼吸道上皮细胞表面以及在聚苯乙烯表面形成生物膜的能力。所有23株鲍曼不动杆菌分离株均能有效黏附于呼吸道上皮细胞，且生物膜形成与上皮细胞黏附性呈正相关（r = 0.80，p <0.0001）。在螯合剂乙二胺四乙酸（EDTA）存在的情况下，生物膜形成明显减少。与不携带这种超广谱β-内酰胺酶基因的分离株相比，携带bla(PER-1)基因的分离株的细胞黏附性和生物膜形成显著更高（分别为p <0.005和p <0.001）。通过逆转录聚合酶链反应（RT-PCR）进一步检测发现，bla(PER-1)基因的表达水平与生物膜形成水平（r = 0.89，p <0.0001）和细胞黏附性（r = 0.74，p <0.006）之间呈正相关。总体而言，该研究表明多重耐药鲍曼不动杆菌临床分离株具有很高的形成生物膜和黏附于呼吸道上皮细胞的能力。这一特性，再加上多重耐药性，可能有助于这些微生物的存活及其在医院环境中的传播。
