摘要
目的为研制供福氏志贺氏菌增菌用的培养基。方法按蛋白胨2．0％，复合氨基酸0．2％，牛肉膏0．5％配成供志贺氏菌培养用的基础液，加入三号胆盐（B）、柠檬酸钠（C）和硫代硫酸钠（T）等量组合的抑菌剂，各按三种浓度配制增菌培养基（简称BCT肉汤）。干扰菌为从健康儿童粪便分离的10株大肠埃希氏菌，试验菌为地方分离的福氏志贺氏菌2a4205687，分别测定生长率和模拟标本的阳性检出率，以GN肉汤作对比观察。结果抑菌剂浓度为0．43％，培养8h，对福氏志贺氏菌的增菌效果最好。福氏志贺氏菌与大肠埃希氏菌菌量之比从1：1到10－2：1时培养阳性检出率为93．3％，从10－3：1到10－6：1时培养阳性检出率为35％，增菌效果明显优于GN肉汤。结论含0.43％抑菌剂的BCT肉汤是培养福氏志贺氏菌一种良好的增菌培养基，对于福氏志贺氏菌含量少的标本，使用本培养基可显著提高阳性检出率。
Objective To develop an enrichment medium for culture of Shigella flexeneri. Methods Basal medium contains: peptone 2. 0%, amino acids complex 0. 2%, and beef extract 0. 5%. Inhibitor consists equal amont of bile salt No. 3(B), sodium citrate(C) and sodium thiosulfate(T), enrichment media(BCT broth) contain inhibitor of three different concentrations 0. 85%, 0. 43% and 0. 35% respectively. Interfering organisms were ten strains of Escherichia coli isolated from feces of healthy children. Test organism was locally isolated Shigella flexneri 2a 4205687. Growth rate and positive detectable rate of simulated specimens were determined respectively. GN broth was used for control. Results The best enrichment efficiency was obtained from the medium containing 0. 43 % of inhibitor, cultured for 8 hours. When the ratio of amount in mixed specimen was 1.1 to 10-2: 1 between Shigella flexneri and Escherichia coli the positive detectable rate was 93. 3%; and when tLhe ratio was 10- 3: 1 to 10- 6: 1, it was 35%,with much better effect than those cultured in GN broth. Conclusion BCT broth containing 0.43% inhibitor is an excellent enrichment medium for culture of S.flexneri. The positive detectable rate can be raised when only few Shigella organisms are cultured in this mediun.
出处
《江西医学检验》
1999年第4期206-208,共3页
Jiangxi Journal of Medical Laboratory Sciences
