摘要
【目的】研究枯草芽孢杆菌素(Bacillus subtilis bacteriocin)Subticin112在体内外对金黄色葡萄球菌(Staphylococcus aureus)CVCC 1885的抑菌活性(bacteriostatic activity),为Subticin112的临床应用提供理论依据。【方法】体外抑菌:取相同有效质量的Subticin112、土霉素、青霉素、万古霉素、新霉素、链霉素和庆大霉素等分别溶于等体积的无菌生理盐水中,然后采用琼脂扩散法比较相同浓度的上述药物对金黄色葡萄球菌的抑菌活性。体内抑菌:将体重为18-22 g的SPF级KM雄鼠120只分成6组,分别为空白对照组、阴性对照组、土霉素治疗组、低浓度Subticin112治疗组、中浓度Subticin112治疗组和高浓度Subticin112治疗组。试验开始后,各组小鼠每隔8 h分别灌胃0.4 mL不同浓度的上述药物或无菌生理盐水,3次灌胃结束后,各组小鼠分别腹腔注射0.5 mL绝对致死剂量(absolute lethal dose,LD100)的金黄色葡萄球菌或无菌生理盐水。试验结束后测定死亡率、促炎性细胞因子水平、腹腔液金黄色葡萄球菌浓度并制作病理组织切片进行观察。【结果】体外抑菌:与抗生素相比,相同浓度的Subticin112对金黄色葡萄球菌具有很好的抑菌活性,其中与万古霉素和新霉素相比,Subticin112对该致病菌的抑制活性更好,且差异极显著(P<0.01),而与其它抗生素相比抑菌活性相当,差异不显著(P>0.05)。体内抑菌:试验结束后,阴性对照组小鼠死亡率为100%,低浓度Subticin112治疗组为30%,其它组小鼠均无死亡;与阴性对照组相比,药物治疗组小鼠的促炎性细胞因子(IL-1β,IL-6和TNF-α)水平均有下降,差异显著(P<0.05),药物治疗组小鼠腹腔液中的金黄色葡萄球菌浓度也均有下降,差异极显著(P<0.01),且呈明显的量效关系;病理切片显示阴性对照组肝脏和脾脏具有明显的病变,而药物治疗组病变轻微或无病变。【结论】可以得出细菌素Subticin112在动物体内外对金黄色葡萄球菌CVCC 1885均具有较好的抑菌活性,具备开发为新型抗菌药物的潜力。
[ Objective ] In order to provide the theoretical basis for clinical application of the bacteriocin Subticin I 12 secreted by Bacillus subtilis, a research was conducted on bacteriostatic activity of bacteriocin Subticin112 against Staphylococcus aureus CVCC 1885 in vitro and in vivo. [ Method ] Bacteriostasis in vitro： Subticin 112, oxytetracycline, penicillin, vancomycin, neomycin, strepomycin and gentamicin in the same effective weight were dissolved into equal volume of sterile saline, respectively. Then the agar diffusion method was used to compare the bacteriostatic activity of the medicines against S. aureus. Bacteriostasis in vivo： 120 SPF-class KM male mice （weighted from 18 g to 22 g） were divided into six groups, they were blank control group, negative control group, oxytetracycline treating group and three Subticin112 treating groups. After the beginning of the experiment, every mouse in each group was orallly administrated 0.4 mL different concentrations of medicine or sterile saline every other 8 hours, after 3 times of oral administration, the mice in each group were intraperitoneal injected at the absolute lethal dose of S. aureus or sterile saline. At the end of the experiment, the mortality was calculated, the proinflammatory cytokines and the cfu values of S. aureus in the peritoneum of the mice were determined, and then the histopathological changes of the tissues were observed. [Result] Bacteriostasis in vitro： Subticin112 expressed a fine bacteriostatic activity compared to the same concentration of other medicines. The bacteriostatic activity of Subticin112 was highly significantly better than that of vancomycin and neomycin （P〈0.01）, but differed insignificantly from other antibiotics （P〉0.05）. Bacteriostasis in vivo： after the experiment, the mortality in negative control group was 100%, while which was 30% in low-dose Subticinll2 treating group, and other groups did not have dead mice. The medicine treating groups showed a low concentration of the proinflammatory cytokines （P〈0.05）, also had a low cfu values compared to the negative control group （P〈0.01） and the dose-respones relationship was clear. The histopathological observations showed that the liver and spleen of the mice in the negative control group had obvious pathological lesions, whereas the pathological changes in the medicine treating groups was slight or not distinct. [ Conclusion] These studies provided evidences that Subticin112 have a fine bacteriostatic activity against S. aureus CVCC 1885 in vitro and vivo, and can be developed as a new type of antibacterial agent.
出处
《中国农业科学》
CAS
CSCD
北大核心
2011年第13期2830-2837,共8页
Scientia Agricultura Sinica
基金
国家高技术研究发展计划(863)重大项目(2006AA10A208)
国家自然科学基金(30972124)
关键词
枯草芽孢杆菌素
金黄色葡萄球菌
抑菌活性
绝对致死剂量
Bacillus subtilis bacteriocin
Staphylococcus aureus
bacteriostatic activity
absolute lethal dose
