Kimura Soichiro, Tateda Kazuhiro, Ishii Yoshikazu, Horikawa Manabu, Miyairi Shinichi, Gotoh Naomasa, Ishiguro Masaji, Yamaguchi Keizo
Department of Microbiology and Infectious Diseases, Toho University Faculty of Medicine, Ota-ku, Tokyo 143-8540, Japan.
Suntory Institute for Bioorganic Research, Mishima-gun, Osaka 618-8503, Japan.
Microbiology (Reading). 2009 Jun;155(Pt 6):1934-1939. doi: 10.1099/mic.0.026641-0. Epub 2009 Apr 21.
Bacteria commonly communicate with each other by a cell-to-cell signalling mechanism known as quorum sensing (QS). Recent studies have shown that the Las QS autoinducer N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C(12)-HSL) of Pseudomonas aeruginosa performs a variety of functions not only in intraspecies communication, but also in interspecies and interkingdom interactions. In this study, we report the effects of Pseudomonas 3-oxo-C(12)-HSL on the growth and suppression of virulence factors in other bacterial species that frequently co-exist with Ps. aeruginosa in nature. It was found that 3-oxo-C(12)-HSL, but not its analogues, suppressed the growth of Legionella pneumophila in a dose-dependent manner. However, 3-oxo-C(12)-HSL did not exhibit a growth-suppressive effect on Serratia marcescens, Proteus mirabilis, Escherichia coli, Alcaligenes faecalis and Stenotrophomonas maltophilia. A concentration of 50 microM 3-oxo-C(12)-HSL completely inhibited the growth of L. pneumophila. Additionally, a significant suppression of biofilm formation was demonstrated in L. pneumophila exposed to 3-oxo-C(12)-HSL. Our results suggest that the Pseudomonas QS autoinducer 3-oxo-C(12)-HSL exerts both bacteriostatic and virulence factor-suppressive activities on L. pneumophila alone.
细菌通常通过一种称为群体感应（QS）的细胞间信号传导机制相互交流。最近的研究表明，铜绿假单胞菌的Las QS自诱导物N-（3-氧代十二烷酰基）-L-高丝氨酸内酯（3-氧代-C（12）-HSL）不仅在种内交流中发挥多种功能，而且在种间和跨界相互作用中也发挥作用。在本研究中，我们报告了铜绿假单胞菌的3-氧代-C（12）-HSL对其他经常与铜绿假单胞菌在自然环境中共存的细菌物种的生长和毒力因子抑制的影响。发现3-氧代-C（12）-HSL而非其类似物以剂量依赖的方式抑制嗜肺军团菌的生长。然而，3-氧代-C（12）-HSL对粘质沙雷氏菌、奇异变形杆菌、大肠杆菌、粪产碱菌和嗜麦芽窄食单胞菌没有生长抑制作用。50微摩尔浓度的3-氧代-C（12）-HSL完全抑制了嗜肺军团菌的生长。此外，在暴露于3-氧代-C（12）-HSL的嗜肺军团菌中，生物膜形成受到显著抑制。我们的结果表明，铜绿假单胞菌QS自诱导物3-氧代-C（12）-HSL对嗜肺军团菌单独发挥抑菌和毒力因子抑制活性。
