金葡菌L型垂直感染影响胎儿发育的机制研究

Mechanism and effect of vertical infection by S.aureus L-forms on fetal development

目的探讨金黄色葡萄球菌(金葡菌)L型垂直感染影响胎儿发育的机制。方法采用全胚胎培养方法观察不同浓度(50、100、200和400CFU/ml)金葡菌L型感染体外培养小鼠胚胎48h后对胚胎发育的影响,及用流式细胞术法检测金葡菌L型感染脐静脉内皮细胞0、2、4、6、8与10h后各时间段的细胞凋亡率。结果金葡菌L型可影响体外小鼠胚胎的发育,50CFU/ml组胚胎生长发育指标头长和颅臀长首先受到影响,100CFU/ml及以上组胚胎生长发育各项指标均明显低于对照组。金葡菌L型可诱导脐静脉内皮细胞发生凋亡,与对照组比较差异有统计学意义(P<0.05或P<0.01)。结论金葡菌L型通过胎盘屏障后垂直感染影响胎儿发育的机制可能是通过直接作用于胚胎和/或是通过破坏脐静脉内皮细胞功能这两种方式而影响胎儿发育的。

Objective To study the mechanism and influence of vertical infection by Staphylococcus aureus （ S. aureus） L-forms on fetal development. Method A whole embryo culture（WEC） technique was used to observe the embryonic development after the 8.5-day mouse embryos were co-incubated with S. aureus L-forms （50,100,200 and 400 CFU/ml） for 48 hours. Flow cytometer was used to detect the rates of apoptosis in human umbilical vein endothelial cells （HUVECs） infected by S. aureus L-forms and then incubated for0, 2, 4, 5, 8 and 10 h, respectively. Result S. aureus L-forms influenced mouse embryos development in vitro. Head length and crown-rump length of 50 CFU/ml group were first affected. The indexes of embryonic development in the group treated with 100 CFU/ml and higher dose were significantly lower than that of control. S. aureus L-forms induced HUVEC apoptosis. The rates of apoptosis were significantly higher than that of the control （P 〈 0.05, P 〈 0.01 ）. Conclusion The mechanism of S. aureus L-forms vertical infection affecting fetal development may be that the embryos are attached directly and/or the function of umbilical vein endothelial cells are destroyed by S. aureus L-forms.