Antibiotics at subinhibitory concentrations improve the quorum sensing behavior of Chromobacterium violaceum

Authors

  • Zhanjun Liu,

    1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China
    2. Laboratory of Glycobiology, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
    Search for more papers by this author
  • Weishan Wang,

    1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China
    2. Laboratory of Glycobiology, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
    Current affiliation:
    1. State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author
  • Ying Zhu,

    1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China
    2. Laboratory of Glycobiology, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
    Search for more papers by this author
  • Qianhong Gong,

    1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China
    2. Laboratory of Glycobiology, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
    Search for more papers by this author
  • Wengong Yu,

    1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China
    2. Laboratory of Glycobiology, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
    Search for more papers by this author
  • Xinzhi Lu

    Corresponding author
    1. Laboratory of Glycobiology, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
    • Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, Qingdao, China
    Search for more papers by this author

Correspondence: Xinzhi Lu, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China. Tel.: 86-532-82032067; fax: +86 532 82033054; e-mail: lxinzhi@gmail.com

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.

Ancillary