Genetic analysis of surface motility in Acinetobacter baumannii
Genetic analysis of surface motility in Acinetobacter baumannii
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DOI：
10.1099/mic.0.049791-0
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发表时间：
2011-09-01
期刊：
影响因子：
2.8
通讯作者：
Rather, Philip N.
中科院分区：
文献类型：
--
作者：
Clemmer, Katy M.;Bonomo, Robert A.;Rather, Philip N.
发现革兰氏阴性病原体鲍曼不动杆菌菌株M2在低百分比（0.2-0.4%）琼脂平板上表现出稳健的表面运动性。这些运动模式显着不同，这取决于是否使用Difco或Eiken琼脂。在许多（但不是所有）临床和环境分离株中观察到运动性。使用液滴塌陷试验证明表面活性剂的生产是不成功的，表面活性剂在A。鲍曼不动杆菌M2的运动性仍不清楚。表面运动性受损的插入pilT，编码的基因产物，往往是所需的IV型菌毛的回缩。运动性还依赖于群体感应，因为鲍鱼自诱导合成酶中的无效等位基因会降低运动性，而添加外源N-（3-羟基）-十二烷酰基高丝氨酸内酯（3-OH C-12-HSL）可以恢复鲍鱼突变体的运动性。转座子诱变被用来确定运动所需的其他基因，并揭示了基因座编码的各种功能：非核糖体合成的推定脂肽，传感器激酶（BfmS），溶解转糖基酶，O-抗原生物合成（RmIB），外膜孔蛋白（OmpA）和从头嘌呤生物合成（PurK）。运动所需的上述基因中的两个被群体感应高度激活，并可以部分解释运动中对群体感应的需求。
The Gram-negative pathogen Acinetobacter baumannii strain M2 was found to exhibit a robust surface motility on low-percentage (0.2-0.4%) agar plates. These patterns of motility were dramatically different depending on whether Difco or Eiken agar was used. Motility was observed in many, but not all, clinical and environmental isolates. The use of drop collapse assays to demonstrate surfactant production was unsuccessful, and the role of surfactants in A. baumannii M2 motility remains unclear. Surface motility was impaired by an insertion in pilT, encoding a gene product that is often required for retraction of the type IV pilus. Motility was also dependent on quorum sensing, as a null allele in the abal autoinducer synthase decreased motility, and the addition of exogenous N-(3-hydroxy)-dodecanoylhomoserine lactone (3-OH C-12-HSL) restored motility to the abal mutant. Transposon mutagenesis was used to identify additional genes required for motility and revealed loci encoding various functions: non-ribosomal synthesis of a putative lipopeptide, a sensor kinase (BfmS), a lytic transglycosylase, O-antigen biosynthesis (RmIB), an outer membrane porin (OmpA) and de novo purine biosynthesis (PurK). Two of the above genes required for motility were highly activated by quorum sensing, and may explain, in part, the requirement for quorum sensing in motility.