title: Antibiotics at subinhibitory concentrations improve the quorum sensing behavior of Chromobacterium violaceum.
abstract: Increasing evidence has shown that antibiotics function as intermicrobial signaling molecules instead of killing weapons. However, mechanisms and key factors that are involved in such functions remain poorly understood. Earlier findings have associated antibiotic signaling with quorum sensing (QS); however, results varied among experiments, antibiotics, and bacterial strains. In this study, we found that antibiotics at subinhibitory concentrations improved the violacein-producing ability of Chromobacterium violaceum ATCC 12472. Quantitative real-time polymerase chain reaction of QS-associated gene transcripts and bioassay of violacein production in a QS mutant strain demonstrated that antibiotics enhanced the production of N-acyl-L-homoserine lactones (AHLs; QS signaling molecules) and increased AHL-inducing QS-mediated virulence, including chitinase production and biofilm formation. Moreover, a positive flagellar activity and an increased bacterial clustering ability were found, which are related to the antibiotic-induced biofilm formation. Our findings suggested that antibiotic-mediated interspecific signaling also occurs in C. violaceum, thereby expanding the knowledge and language of cell-to-cell communication.
authors: Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China.
authors: Zhanjun
authors: Z
authors: Liu
authors: Weishan
authors: W
authors: Wang
authors: Ying
authors: Y
authors: Zhu
authors: Qianhong
authors: Q
authors: Gong
authors: Wengong
authors: W
authors: Yu
authors: Xinzhi
authors: X
authors: Lu
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D018441:Biofilms; D002688:Chitinases / Q000096:biosynthesis; D002861:Chromobacterium / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D005407:Flagella / Q000378:metabolism / Q000502:physiology; D007211:Indoles / Q000378:metabolism*; D007612:Kanamycin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009068:Movement / Q000187:drug effects; D053038:Quorum Sensing; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D054742:Acyl-Butyrolactones; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D007211:Indoles; D007612:Kanamycin; D002688:Chitinases; C063155:violacein