Boşgelmez-Tinaz Gülgün, Ulusoy Seyhan, Aridoğan Buket, Eroğlu Füsun, Kaya Selçuk
Department of Biology, Suleyman Demirel University, 32260 Isparta, Turkey.
Microbiol Res. 2005;160(4):399-403. doi: 10.1016/j.micres.2005.03.005.
Acylated homoserine lactones (AHLs) are self-generated diffusible signal molecules that mediate population density dependent gene expression (quorum sensing) in a variety of Gram-negative bacteria, and several virulence genes of human pathogens are known to be controlled by AHLs. In this study, strains of Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae, isolated from intensive care patients, were screened for AHL production by using AHL responsive indicator strains of Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NT1. Positive reactions were recorded for all 50 isolates of P. aeruginosa and 10 isolates of Acinetobacter baumannii with Agrobacterium tumefaciens NT1. Surprisingly, most P. aeruginosa isolates gave negative results with C. violaceum CV026 in contrast to previous reports. This suggests that the new isolates of P. aeruginosa either failed to make short chain AHLs or the level of the signal molecule is very low.
酰化高丝氨酸内酯（AHLs）是一类自身产生的可扩散信号分子，可介导多种革兰氏阴性菌中群体密度依赖性基因表达（群体感应），并且已知人类病原体的几种毒力基因受AHLs调控。在本研究中，使用紫色色杆菌CV026和根癌农杆菌NT1的AHL响应指示菌株，对从重症监护患者中分离出的铜绿假单胞菌、鲍曼不动杆菌、大肠杆菌和肺炎克雷伯菌菌株进行了AHL产生的筛选。所有50株铜绿假单胞菌分离株和10株鲍曼不动杆菌分离株与根癌农杆菌NT1反应呈阳性。令人惊讶的是，与之前的报道相反，大多数铜绿假单胞菌分离株与紫色色杆菌CV026反应呈阴性。这表明新分离的铜绿假单胞菌要么无法产生短链AHLs，要么信号分子水平非常低。
