绍兴市售酸奶中乳酸菌的分离鉴定及耐药性分析简

目的]从绍兴市售酸奶中分离并鉴定乳酸菌，研究乳酸菌分离株对6种抗生素的耐药性。方法]利用MRS培养基迎过稀释法分离酸奶样品中的乳酸菌并进行菌落计数，对分离菌株进行革兰染色和生化反应鉴定，同时采用纸片扩散法进行耐药性分析。结果]从15种绍兴市售酸奶样品中共分离出31株菌，生化反应鉴定为嗜酸乳杆菌（6株）、保加利亚乳杆菌（7株）、嗜热链球菌（11株）和双歧杆菌（7株）；活菌计数结果显示，4份样品（26．7％）中乳酸菌计数低于国家标准，11份样品（73．3％）中活菌计数符合国家标准规定；耐药性试验结果显示，31株乳酸菌对4种抗生素均有一定程度的耐受性，且90．3％的菌株具有多重耐药性，能耐受2～3种抗生素。结论]绍兴市售酸奶中乳酸菌已具有一定程度的耐药性，对酸奶产品进行耐药性监测和安全评价已势在必行。

Isolation of the Lactic Acid Bacteria and Analysis of the Antibiotic Resistance from the Yogurt Sold in Shaoxing City

Objective ] To analyze the antimicrobial susceptibility of lactic acid bacteria isolated from yogurt sold in Shaoxing to erythromycin, compound sulfamethoxazole, cefotaxime sodium, vancomycin, gentamicin and clindamycin. Method ] Lactic acid bacteria were recovered and counted from yoghourt by plate count method. The recovered isolates were characterized by Gram＇s strain, biochemical test, antimicrobial susceptibility test. Result] 31 probiotic isolates were recovered from 15 yoghourt products, which was identified as Lactobacillus acidophilus （ 6 strains ）, Lactobacillus bulgaricus （ 7 strains ）, Streptococcus thermophilus （ 11 strains）, Bifidobacterium （ 7 strains ） ; 4 （ 26.7 % ） products showed a lower probiotic quantity than 1 ~ 106 CFU/ml of the national standard, and 11 （73.3%） products measured up the national stand- ard; drug resistance test results showed that the 31 isolates were resistant to 4 types of antibiotics, and 28 isolates （90.3%） were of multiple resistance, and resistant to 2 - 3 types of antibiotics. Conclusion ] The antimicrobial resistances of lactic acid bacteria had been developed, and monitoring their antimicrobial resistance and evaluatinz their safety should be imperative.