Toyoda K, Kusano N, Saito A
First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus.
Kansenshogaku Zasshi. 1995 Mar;69(3):308-15. doi: 10.11150/kansenshogakuzasshi1970.69.308.
The pathogenicity of Streptococcus constellatus in pulmonary infections was investigated in mice in correlation with the phagocytic killing of the microorganisms by human polymorphonuclear neutrophils (PMNs). The histological inflammation score of the lungs in mice inoculated intratracheally with 10(8) cfu/mouse of the virulent strain S. constellatus RZYK001 obtained from bronchoalveolar fluid of a patient with pneumonia, was significantly higher than in mice inoculated with the avirulent strains S. constellatus RT4303 and RT6002 obtained from saliva of healthy adults (p < 0.001). The bactericidal activity of human PMNs against Staphylococcus aureus ATCC 25923 was not inhibited at all by the culture filtrate of the virulent strain, but the killing index against RZYK001 was 36.4% after 90-min incubation whereas that against RT4303 and RT6002 was 94.7% and 99.4%, respectively (p < 0.001). Therefore, these results suggest a possible pathogenic mechanism of S. constellatus apparently mediated by a structural component of the organisms so that a virulent strain is less likely to be killed than an avirulent one, predisposing it to survive in the infection sites.
研究了星座链球菌在肺部感染中的致病性，并将其与人类多形核中性粒细胞（PMN）对微生物的吞噬杀伤作用进行关联分析。将从一名肺炎患者支气管肺泡灌洗液中分离得到的10⁸cfu/只强毒株星座链球菌RZYK001经气管内接种小鼠，其肺部组织学炎症评分显著高于接种从健康成年人唾液中分离得到的无毒株星座链球菌RT4303和RT6002的小鼠（p<0.001）。强毒株的培养滤液对人类PMN针对金黄色葡萄球菌ATCC 25923的杀菌活性完全没有抑制作用，但孵育90分钟后，对RZYK001的杀伤指数为36.4%，而对RT4303和RT6002的杀伤指数分别为94.7%和99.4%（p<0.001）。因此，这些结果提示星座链球菌可能存在一种由菌体结构成分介导的致病机制，使得强毒株比无毒株更不易被杀伤，从而使其更易在感染部位存活。
