Quorum sensing signal molecules (acylated homoserine lactones) in Gram-negative fish pathogenic bacteria*

Diseases of Aquatic Organisms

Inger Dalsgaard Kristian F. Nielsen Christiane Buchholtz Jens L. Larsen Lone Gram¹  Jesper B. Bruhn¹ 

关键词: Quorum sensing;    Signal molecules;    Acylated homoserine lactones;    AHL;    Fish pathogenic bacteria;   

DOI  :  10.3354/dao065043

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The aim of the present study was to investigate the production of quorum sensing signals (specifically acylated homoserine lactones, AHLs) among a selection of strains of Gram-negative fish bacterial pathogens. These signals are involved in theregulation of virulence factors in some human and plant-pathogenic bacteria. A total of 59 strains, representing 9 different fish pathogenic species, were tested against 2 AHL monitor bacteria (Agrobacterium tumefaciens NT1 [pZLR4] andChromobacterium violaceum CV026) in a well diffusion assay and by thin-layer chromatography (TLC). Representative samples were further characterized by high performance liquid chromatography-high resolution mass spectrometry (HPLC-HR-MS). AHLs wereproduced by all strains of Aeromonas salmonicida, Aeromonas hydrophila, Yersinia ruckeri, Vibrio salmonicida, and Vibrio vulnificus. Some strains of atypical Aeromonas salmonicida and Vibrio splendidus were also positive.Aeromonas species produced N-butanoyl homoserine lactone (BHL) and N-hexanoyl homoserine lactone (HHL) and 1 additional product, whereas N-3-oxo-hexanoyl homoserine lactone (OHHL) and HHL were detected in Vibriosalmonicida. N-3-oxo-octanoyl homoserine lactone (OOHL) and N-3-octanoyl homoserine lactone (OHL) were detected in Y. ruckeri. AHLs were not detected from strains of Photobacterium damselae, Flavobacterium psychrophilum orMoritella viscosa. AHLs were extracted from fish infected with Y. ruckeri but not from fish infected with A. salmonicida. In conclusion, the production of quorum sensing signals, AHLs, is common among the strains that we examined. Ifthe AHL molecules regulate the expression of the virulence phenotype in these bacteria, as shown to occur in some bacterial pathogens, novel disease control measures may be developed by blocking AHL-mediated communication and suppressing virulence.

【 授权许可】

Unknown