【摘要】 目的研究牛奶中不同浓度抗生素残留对婴儿双歧杆菌、嗜酸乳杆菌标准菌株生长的影响。方法牛奶中残留的抗生素在经过离体肠道模拟系统作用后,与婴儿双歧杆菌、嗜酸乳杆菌标准菌株共同厌氧培养一定时间,观察低浓度氨苄青霉素、磺胺间甲氧嘧啶、硫酸链霉素对婴儿双歧杆菌、嗜酸乳杆菌生长的影响。结果牛奶中氨苄青霉素浓度在2、100μg/L时,嗜酸乳杆菌、婴儿双歧杆菌菌株的菌落生长数分别是494、285菌落形成单位(cfu)/皿,低于对照组的577、451 cfu/皿,差异均有统计学意义(u=2.52、9.15,P<0.05),表明从这2个剂量开始对这2种细菌生长有抑制作用并存在剂量效应关系;牛奶中硫酸链霉素在20 mg/L时嗜酸乳杆菌、婴儿双歧杆菌的菌落生长数分别是429、127 cfu/皿,低于对照组的598、174 cfu/皿,差异均有统计学意义(u=5.26、2.68,P<0.05),表明此浓度对这2种细菌生长有抑制作用;牛奶中磺胺间甲氧嘧啶浓度在800μg/L时,嗜酸乳杆菌、婴儿双歧杆菌的菌落生长数分别是56、79 cfu/皿,低于对照组的80、111 cfu/皿,差异均有统计学意义(u=2.02、2.29,P<0.05),表明此浓度对这2种细菌生长有抑制作用。结论嗜酸乳杆菌对氨苄青霉素敏感,浓度低于中国农业部颁布的牛奶中氨苄青霉素最大允许残留限量(MRL)10μg/kg水平时生长即受到抑制。更多还原

【Abstract】 Objective To study the effect of antimicrobial residues in milk on the growth of Bifidobacterium and Lactobacillus. Methods An in vitro gut simulation model was used to mimic the situation of antimicrobial residues passing through human gastrointestinal tract,then the standard Bifidobacterium infantis(B.infantis) or Lactobacillus acidophilus(L.acidophilus) was added to the culture in anaerobic incubation. The number of bacteria was counted to explore the effect of antimicrobial residues on B. infantis and L.acidophilus. Results The effective inhibitory concentration of ampicillin residues in milk on L.acidophilus was 2 μg/L(P < 0. 05) and that on B. Infantis was 100 μg/L(< 0. 05). There was an obvious dose-response relationship w hen the concentration of ampicillin residues in milk was 2-8 μg/L. The effective inhibitory concentration of streptomycin sulfate on B. infantis and L.acidophilus was 20 mg/L(P < 0. 05). The effective inhibitory concentration of sulfamonomethoxin on B. infantis and L.acidophilus. was 800 μg/L(P < 0. 05). Conclusion L.acidophilus was sensitive to ampicillin. The growth of L acidophilus was inhibited when the concentration of ampicillin in the milk was 2μg/L,which was low er than the current Chinese maximum residue level(MRL)(10 μg/kg) in milk.更多还原