MicrobiologyOpen, October 2017, Vol.6(5), pp.n/a-n/a
Two‐component systems in are associated with its virulence, drug resistance, motility, biofilm formation, and other characteristics. In this study, we used Rec, a genetic engineering method, to investigate the function of A1S_2811 in strain 17978. A1S_2811, a hypothetical hybrid sensor histidine kinase/response regulator, has four histidine‐containing phosphotransfer domains, a CheA‐like regulatory domain, and a CheY‐like receiver domain at its C terminus. Compared with the 17978 strain, both surface motility and biofilm formation at the gas–liquid interface decreased significantly in the A1S_2811 knock‐out strain. The number of pilus‐like structures and the amount of extrapolymeric substances on the cell surface also decreased in the A1S_2811 null strain. Transcription of , which encodes an ‐acylhomoserine lactone synthase in , decreased significantly in the A1S_2811 null strain, and supplementation with synthetic ‐(3‐oxodecanoyl) homoserine‐‐lactone rescued the surface motility and biofilm formation phenotype in the null mutant. We speculate that A1S_2811 regulates surface motility and biofilm formation, not by regulating type pili‐associated genes expression, but by regulating the chaperone/usher pili‐associated operon and the AbaI‐dependent quorum‐sensing pathway‐associated A1S_0112‐0119 operon instead. A1S_2811 regulates surface motility and biofilm formation not by regulating the expression of genes associated with type IV pili, but regulating the csuA/BABCDE operon associated with CU pili and A1S_0112‐0119 operon associated with AbaI‐dependent quorum‐sensing pathway instead.
Acinetobacter baumannii ; Biofilm Formation ; Motility ; Pili ; Quorum Sensing ; Two‐Component Systems