メチシリン耐性黄色ぶどう球菌(MRSA)の病原性の解析

耐甲氧西林金黄色葡萄球菌（MRSA）的致病性分析

• 批准号: 06770425
• 负责人: 田尾 操
• 金额: $ 0.58万
• 依托单位: Nagasaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Encouragement of Young Scientists (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06770425/
• 关键词: Staphylococcus aureus; MRSA; Mouse thigh infection

メチシリン耐性黄色ぶどう球菌(MRSA)の臨床的な病原性を解析するためにまず、臨床検体(喀痰・膿・血液・尿)から分離された黄色ぶどう球菌(ぶ菌)20株について抗菌剤感受性、β-lactamase,Coagulase,Exotoxin(TSST-1,ET-A,-B,-C,-D,-E,Leucocidin)の産生能を調査した。さらに細胞壁関連蛋白、ヒト好中球に対する貪食抵抗性の解析を行なった。その結果メチシリン感受性黄色ぶどう球菌(MSSA)と比較した場合のMRSAの特異的病原性に関連する特徴ある因子はないことが判明した。そこでin vivoの系で病原性を調査するためにマウス大腿筋感染モデルを作製し、致死的効果を有するぶ菌株について生菌・ホルマリン処理死菌・加熱処理死菌および培養上清をマウス尾静脈より投与し致死的因子を検討した結果その活性は菌体自体ではなく菌体外産生物しかも易熱性のものであることが明確となった。さらに各20株についてVero細胞の変性効果を調べた結果、マウス大腿筋感染モデルにおける致死効果とぶ菌培養上清のVero細胞変性効果とが相関した。以上の結果より黄色ぶどう球菌のマウス致死活性における病原性はMRSA,MSSAの如何を問わず易熱性の細胞外毒素に起因する可能性が示唆された。さらに内因性のぶ菌性敗血症の解析のためにマウス大腿筋持続感染モデルを作製し、免疫抑制剤(Cyclophosphamide)投与にて白血球減少を招来させ、引き続く致死的敗血症モデルを作製した。

20 strains of MRSA isolated from clinical specimens (sputum, pus, blood, urine) were investigated for their susceptibility to antimicrobial agents and production of β-lactamase,Coagulase,Exotoxin(TSST-1,ET-A,-B,-C,-D,-E,Leucocidin). Cell wall-associated proteins and proteins are involved in the resolution of bulimia resistance. The results showed that MRSA was more susceptible than MRSA and its specific pathogenicity was related to MRSA. In vivo, pathogenic factors were investigated. In vitro products were detected. In vivo, pathogenic factors were detected. In vitro products were detected. In vivo, pathogenic factors were detected. In vitro, pathogenic factors were detected. In vivo, pathogenic factors were detected. In vitro, pathogenic factors were detected. In vivo, pathogenic factors were detected. In vitro, pathogenic factors were detected. In vivo, pathogenic factors were detected. 20 strains of Vero cells were isolated from the culture supernatant and the results were correlated. The above results indicate the pathogenicity of MRSA and the possibility of how MSSA can cause heat-sensitive extracellular toxins. In addition, the analysis of endogenous bacterial hemotoxicities includes the control of thigh muscle infection, the administration of immunosuppressants (Cyclophosphamide), the induction of leukopenia, and the control of fatal hemotoxicities.