鱼源乳酸菌的分离及药敏试验

Isolation and Antibiotic Sensitivity Tests of Lactic Acid Bacteria from Different Fishes

从4种海鱼和5种淡水鱼肠道内容物中,以溴甲酚紫MRS培养基为鉴别培养基,分离出11株乳酸菌,通过生理生化试验进行菌种鉴定。利用药敏纸片琼脂扩散法检测其对20种常用抗生素的药敏性,结果表明:11株乳酸菌对新霉素、丁胺卡那霉素、苯唑西林、卡那霉素、庆大霉素的耐药率较高,分别为100%,91%,91%,82%,55%;对除复达欣和羧苄西林以外的其他抗生素敏感率均达70%以上。淡水鱼来源的乳酸菌对丁胺卡那霉素、羧苄青霉素、红霉素、卡那霉素和庆大霉素比海鱼来源的乳酸菌耐药率高,海鱼来源的乳酸菌对苯唑西林比淡水鱼来源的乳酸菌耐药率高。所有菌株均表现出不同程度的多重耐药性。

A total of 11 strains of lactic acid bacteria were isolated from the intestinal tracts of 4 kinds of marine fishes and 5 kind of freshwater fishes by using bromcresol purple MRS culture medium as differential medium. They were identified by physiological and biochemical experiments as well. The agar disc diffusion method was used to detect their sensitivities to 20 kinds of commonly used antibiotics. Results show that 11 stains of lactic acid bacteria were more resistant to neomycin, amikacin, oxacillin, kanamycin, and gentamicin and the antibiotic resistant rates are 100%, 91%,91%, 82%, 55% respectively. These 11 stains were 70% or more sensitive to other antibiotics except ceftazidime and carbenicillin. The strains isolated from the intestinal tracts of freshwater fishes showed higher 1evel resistance to amikacin, carbenicillin, erythromycin, kanamycin and gentamicin, while the strains isolated f-rom the intestinal tracts of marine fishes showed higher 1evel resistance to oxacillin. All isolated lactic acid bacteria stains showed different levels of multi-drug resistance.