Isolation and identification of a self-growth-inhibiting substance produced by Legionella sp. and its application as an anti-Legionella drug

军团菌产生的自我生长抑制物质的分离和鉴定。

• 批准号: 12556016
• 负责人: SAKUDA Shohei
• 金额: $ 4.29万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12556016/
• 关键词: Legionella species; self-growth-inhibiting substance; sulfur; Legionnaires' disease; Legionella pneumophila

Legionella species, ubiquitous Gram-negative bacteria, are found in natural or man-made water systems. Their natural hosts are probably various amoebae species. If humans inhale aerosolized water from sources contaminated with them, such as cooling towers or whirlpool spas, the bacteria can invade and replicate within alveolar macrophages, causing a severe form of pneumonia called Legionnaires' disease. If the pneumonia is not treated promptly with antibiotics effective against the bacterium, the mortality rate can approach 15-20%. Therefore, control and management of Legionella contamination in some water systems are very important. Activated charcoal is usually added to a medium for the culture of Legionella species to enhance the growth of the bacteria. We found that activated charcoal can be replaced by Diaion HP-20 resin and that methanol extracts of the resins recovered from the culture broth of Legionella pneumophila showed strong growth-inhibitory activity toward the bacterium itself. The growth inhibitor was isolated from the methanol extracts and identified as sulfur. Sulfur was not obtained from the resins in a medium without cultivation of the bacterium, indicating that it was produced endogenously by the bacterium. Sulfur shows strong growth-inhibitory activity toward all Legionella species tested. Our results obtained in this study showed that sulfur may be a good candidate as a drug for preventing Legionella contamination in water systems effectively and cheaply.

在天然或人造的水系统中发现了军团菌种，无处不在的革兰氏阴性细菌。他们的天然宿主可能是各种变形虫物种。如果人类吸入被它们污染的源的气动燃料，例如冷却塔或漩涡式水疗中心，则细菌可以在肺泡巨噬细胞中侵入和复制，从而导致严重的肺炎形式称为军团疾病。如果未用抗生素对细菌有效治疗肺炎，死亡率可能接近15-20％。因此，在某些水系统中控制和管理军团菌污染非常重要。活性炭通常被添加到培养基中，以增强细菌的生长。我们发现，活化的木炭可以被诊断HP-20树脂取代，并且从肺炎军团菌的培养汤中回收的树脂的甲醇提取物显示出对细菌本身的强烈抑制活性。从甲醇提取物中分离出生长抑制剂，并鉴定为硫。在没有细菌的情况下，在培养基中未从树脂中获得硫，表明它是由细菌内源产生的。硫显示出对所有测试的军团菌种类的强烈抑制活性。我们在这项研究中获得的结果表明，硫可能是有效，廉价地防止水军团污染的良好候选者。