共培养对猪源粪肠球菌N41株部分生物学特性的影响

Influence of co-cultivation on some biological characteristics of Enterococcus faecalis isolate N41

为探讨粪肠球菌在体外共培养条件下其生物膜形成、黏附能力和抗吞噬作用等生物学特性的变化,本研究以猪源粪肠球菌N41菌株为受试菌株,将其分别与大肠杆菌O157∶H7、沙门氏菌肠炎亚种ATCC 14028以及金黄色葡萄球菌ATCC 25923等参考菌株共培养,通过结晶紫染色法测定其生物被膜生成量,通过菌落计数对猪肠上皮细胞黏附情况和小鼠腹腔巨噬细胞的抗吞噬能力进行定量。结果显示,大肠杆菌O157∶H7对粪肠球菌N41菌株生物膜生成量、黏附作用和抗吞噬作用的变化均不明显(p>0.05);沙门氏菌ATCC 14028对粪肠球菌N41菌株的黏附作用明显增强(0.01<p<0.05),而对其生物膜量和抗吞噬作用变化不明显(p>0.05);而金黄色葡萄球菌ATCC 25923则对粪肠球菌N41菌株的生物膜量增加和黏附作用明显增强(p<0.01),抗吞噬作用也所有增强(0.01<p<0.05)。上述研究结果表明,不同细菌与粪肠球菌共培养后对粪肠球菌影响不同,大肠杆菌和沙门氏菌对粪肠球菌毒力影响较小,金黄色葡萄球菌则明显促进粪肠球菌的致病特性。本研究阐明了粪肠球菌在与其它致病菌共培养时,其毒力表现有增强的风险。

This research was performed to explore the biological changes of Enterococcus faecalis strain N41 in biofilm formation, adhesion and anti-phagocytosis characteristics when the N41 strain was co-cultivated with other bacteria such as E.coli O157∶H7, Salmonella enteritidis subspecies ATCC14028, and staphylococcus aureus ATCC25923. The biofilm production was detected by 1% crystal violet dyeing method, the potentials of adhesion to porcine intestinal epithelial cells（IPEC） and anti-phagocytosis to mouse peritoneal macrophages of the N41 strain were enumerated by plate counts. The results showed that neither of the biofilm production, cell adhesion and anti-phagocytosis traits of the N41 isolate was significantly influenced by E.coli （p〉0.05）. While co-cultivated with Salmonella, the adhesion ratio of the N41 strain increased dramatically （0.01〈p〈0.05）, but the biofilm amount and anti-phagocytosis ability were not much affected （p〉0.05）. In contrast, Staphylococcus aureus co-culture with N41 strain remarkably enhanced the adhesion ability and anti-phagocytosis of the N41 strain （0.01〈p〈0.05）, and significantly increased biofilm amount （p〈0.01）. These results indicated that the effect of diffenent bacteria on Enterococcus feacalis co-cultivated with them was different. Pathogenic E.coli and Salmonella showed limited influence on Enterococcus faecalis, whilst taphylococcus aureusprobably could promot the pathogenicity of Enterococcus faecalis. This study showed that the virulence of Enterococcus faecalis might be enhanced when it was co-cultured with other pathogens.