目的　研究细菌L型在体外培养的单层细胞中的致病作用。方法　用金黄色葡萄球菌 (金葡菌 )、金葡菌稳定L型及经 0 45 μm滤过的L型原生小体感染猴肾细胞。结果　发现金葡菌L型及滤过的原生小体对细胞致病性降低 ,细胞不出现明显病变 ,部分细胞出现空泡样变 ,免疫组化及金葡菌PCR显示感染细胞内出现金葡菌抗原及DNA。结论　细菌L型在感染细胞中可出现类似病毒的致病特点 ,L型可在细胞内长期存在而不出现明显的细胞病变 ,其DNA可否与细胞DNA整合值得进一步研究。 Objective To study the pathogenic role of bacterial L type in monolayer cells cultured in vitro. Methods Monkey kidney cells were infected with Staphylococcus aureus (Staphylococcus aureus), Staphylococcus aureus Stabilized L-form and L-type protoplasts filtered through 0 45 μm. The results showed that Staphylococcus aureus L-type and filtered protoplasts decreased the pathogenicity of the cells, the cells did not appear obvious lesions, some cells vacuole-like changes, immunohistochemistry and S. aureus PCR showed that infected cells appear in the Portuguese Bacterial antigens and DNA. Conclusions Bacterial L-forms may show virulence characteristics in infected cells. L-forms may exist in cells for a long time without obvious cytopathic effect. Whether DNA can integrate with DNA can be further studied.