Nakagami Gojiro, Sanada Hiromi, Sugama Junko, Morohoshi Tomohiro, Ikeda Tsukasa, Ohta Yasunori
Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Wound Repair Regen. 2008 Jan-Feb;16(1):30-6. doi: 10.1111/j.1524-475X.2007.00329.x.
Quorum sensing is a cell-to-cell communication that occurs via autoinducers, regulating a number of bacterial virulence factors including the opportunistic wound pathogen Pseudomonas aeruginosa, which uses the N-(3-oxododecanoyl)-homoserine lactone as one of the two main autoinducers; however, little is known about its role in chronic wound infection. This study was designed to quantify this autoinducer from P. aeruginosa-infected wounds with the aim of examining the possible use of autoinducers as an indicator of chronic wound infection. Pressure-induced ischemic wounds were infected with P. aeruginosa (N=12) or uninfected as a control (N=12). The autoinducer was quantified by bioassay method employing Escherichia coli DH5 alpha (pJN105L, pSC11) or Agrobacterium tumefaciens NTL4 (pZLR4) reporter, which expresses beta-galactosidase when exposed to P. aeruginosa quorum sensing signals. The average concentration of autoinducer was 0.33 pmol/g at day 3 and 0.49 pmol/g at day 7 in the infected wounds, as detected from tissue samples. A linear correlation between autoinducer concentration and bacterial counts was observed. No autoinducer was detected in tissue samples from the uninfected control group. Our findings indicate that the quantification of autoinducers is possible and quorum sensing system could play a role in in vivo wound infection models, and also suggest possible clinical implications of autoinducer signal quantification in diagnosis of chronic wound infection.
群体感应是一种通过自诱导物进行的细胞间通讯，它调控许多细菌毒力因子，包括机会性伤口病原体铜绿假单胞菌，该菌使用N-(3-氧代十二烷酰)-高丝氨酸内酯作为两种主要自诱导物之一；然而，其在慢性伤口感染中的作用鲜为人知。本研究旨在对铜绿假单胞菌感染伤口中的这种自诱导物进行定量，目的是检验自诱导物作为慢性伤口感染指标的可能用途。对压力诱导的缺血性伤口接种铜绿假单胞菌（N = 12）或不接种作为对照（N = 12）。采用大肠杆菌DH5α（pJN105L，pSC11）或根癌农杆菌NTL4（pZLR4）报告基因通过生物测定法对自诱导物进行定量，当暴露于铜绿假单胞菌群体感应信号时，该报告基因表达β-半乳糖苷酶。从组织样本检测到，感染伤口中自诱导物的平均浓度在第3天为0.33 pmol/g，在第7天为0.49 pmol/g。观察到自诱导物浓度与细菌计数之间存在线性相关性。在未感染对照组的组织样本中未检测到自诱导物。我们的研究结果表明，自诱导物的定量是可行的，群体感应系统可能在体内伤口感染模型中发挥作用，并且还提示了自诱导物信号定量在慢性伤口感染诊断中的可能临床意义。
