THE ROLE OF PNEUMOLYSIN IN OCULAR INFECTIONS WITH STREPTOCOCCUS-PNEUMONIAE
THE ROLE OF PNEUMOLYSIN IN OCULAR INFECTIONS WITH STREPTOCOCCUS-PNEUMONIAE
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DOI：
10.3109/02713689008997584
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发表时间：
1990-11-01
影响因子：
2
通讯作者：
CHEN, S
中科院分区：
文献类型：
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作者：
JOHNSON, MK;HOBDEN, JA;CHEN, S
肺炎链球菌溶血素是肺炎链球菌产生的一种溶细胞蛋白，具有多种特性，可能是肺炎球菌眼部感染的重要毒力因子。为了直接测试这种可能性，我们构建了肺炎链球菌溶血素阴性菌株。pneumoniae的感染，并在兔角膜内感染模型中比较它们与野生型的毒力。化学诱变产生的肺炎球菌溶血素阴性菌株（可能是一个点突变体）被认为是不低于亲本菌株的毒力。然而，在肺炎球菌溶血素基因中缺失的菌株显示出大大降低的毒力。该菌株产生较少的病理学，同时显示出显著更高的细菌计数。这些结果表明肺炎球菌溶血素分子的性质而不是其溶细胞（溶血）活性可能参与其致病作用机制。这种特性可能是激活补体的能力，已知是肺炎球菌溶血素的功能，其导致PMN的流入，减少细菌计数，但也产生组织损伤。
Pneumolysin, a cytolytic protein produced by Streptococcus pneumoniae, has many properties which suggest it may be an important virulence factor in pneumococcal ocular infections. To directly test this possibility, we have constructed pneumolysin-negative strains of S. pneumoniae and compared their virulence with that of the wild type in a rabbit model of intracorneal infection. A pneumolysin-negative strain produced by chemical mutagenesis (probably a point mutant) was found to be no less virulent than the parent strain. However, a strain bearing a deletion in the pneumolysin gene showed greatly reduced virulence. This strain produced less pathology while showing significantly higher bacterial counts. These results suggest that a property of the pneumolysin molecule other than its cytolytic (hemolytic) activity may be involved in its pathogenic mechansim of action. This property may be the ability to activate complement, known to be a function of pneumolysin, which results in influx of PMNs, reducing the bacterial counts but also producing tissue damage.