【作者】 万荣峰；

【导师】 江善祥；

【作者基本信息】 南京农业大学 ， 基础兽医学， 2005， 硕士

【摘要】 对乳酸乳杆菌、嗜酸乳杆菌、乳酸链球菌三株乳酸菌的抑菌特性和耐药性进行了研究,依据微生态学原理,研制了三株菌和低聚异麦芽糖复合的益生菌制剂,并测定了该制剂的临床药效,以期为临床提供优良的产品。 乳酸菌体外对大肠埃希菌的拮抗作用。将乳酸菌与大肠埃希菌体外共培养,观察拮抗情况及乳酸菌滤液对大肠杆菌的抑制情况。结果显示,等量同时间接种,96h内乳酸菌就将大肠埃希菌全部抑杀;乳酸菌早24h接种,72h内将大肠埃希菌全部抑杀;大肠埃希茵早24h接种,在120h内也可全部被抑杀。三株菌按一定比例复合,会使拮抗的效果增强。乳酸菌的培养滤液对大肠埃希菌抑制实验显示,对大肠埃希菌的抑菌圈直径均在13-15mm之间,乳酸菌培养滤液与同等PH乳酸相比,直径略大,但差异不显著。 乳酸菌制剂中三株乳酸菌菌种的药敏性及耐药传递的体外试验。结果显示,本制剂中的三株乳酸菌对多种抗菌药物有耐药性,仅对氨苄西林和氯霉素有着不同程度的敏感性;耐药性传递的体外试验结果提示,无论是24h还是18次传代试验,链霉素的抗性未转移给链霉素敏感株大肠埃希菌。 低聚异麦芽糖和低聚果糖体外对乳酸菌的增殖和对大肠埃希菌的拮抗作用;两种低聚糖对雏鸡大肠埃希菌病的拮抗作用和对雏鸡盲肠乳酸菌、大肠埃希菌的影响;低聚异麦芽糖与乳酸菌的正交复合对禽大肠埃希菌病的预防作用。结果显示:添加低聚糖组对乳酸菌有一定的生长促进作用,pH值明显下降,但与对照组相比,差异不显著;低聚糖+复合益生菌组对大肠埃希菌的拮抗作用显著,对雏鸡盲肠乳酸菌的定植和大肠埃希菌的拮抗作用,在5d后呈现显著性;低聚糖+益生菌两个剂量组对禽大肠埃希菌病的治愈率为75%-90%,而对照组为10%。两种低聚糖之间比较差异均不显著。低聚异麦芽糖与复合益生菌正交复合预防禽大肠埃希菌病的试验显示,4g低聚异麦芽糖+10~2个益生菌效果较好。 复合乳酸菌对9日龄雏鸡人工诱发禽大肠埃希菌病的临床疗效及对雏鸡的生产性能和盲肠乳杆菌、大肠埃希菌的影响。结果显示,对人工诱发禽大肠埃希菌病预防试验,中高剂量治愈率达80%,药物组70%-75%,对照组存活率仅为40%,差异极显著(P<0.01);对禽大肠埃希菌病的治愈率为70%左右,与药物组效果相当,对照组存活率仅为50%,但与药物组相比,复合乳酸菌治疗的存活率不及药物;对雏鸡21d的增重实验,平均增重较对照组提高7.5%,料肉比下降6.7%,t检验差异显著更多还原

【Abstract】 In this paper, the antagonistic property and drug resistance of three Lactobacillus were studied. Based on the microecological principle, a multi-modulater of probiotics which including Lactobacillus acidophilus, Lactobacillus lacti , Streptococcus lactic and Isomalto- oligosaccharides were researched. In order to offer a choiceness production for clinic, we investigated clinical efficacy of the multi-modulater of probiotics.To investigate whether there is antagonism of Lactobacillus toward Escherichia coli in vitro, Lactobacillus and Escherichia coli were cultured together, then observed the survive of Escherichia coli and the inhibition of the Lactobacillus’ filtrate on Escherichia coli. The results showed that Inoculated Lactobacillus and Escherichia coli at the same time and volumes, Escherichia coli were killed in 96 h. Escherichia coli were killed in 72 h and 120 h, respectively , when inoculated Lactobacillus 24 h earlier and later than Escherichia coli. The antagonism effect of Lactobacillus toward Escherichia coli will be improved, if the three strains were compounded in given proportion. The experiment of the filtrate of Lactobacillus inhibiting Escherichia coli showed that antimicrobial zone diameters of the filtrate and lactic acid on Escherichia coli were 13- 15mm, and there were no significant differences between the filtrate and lactic acid, but the antimicrobial zone diameters of filtrate showed bigger.Antibiotic susceptibility and conjugal transfer of streptomycin resistance in vitro from Lactobacillus to Escherichia coli were studied. The result showed that three Lactobacillus strains were resisted to many antibiotics, only sensitive to ampicillin and chloramphenicol. Three Lactobacillus strains didn’t transfer their resistance of streptomycin to Escherichia coli which is susceptive to streptomycin whereas in 24h or in long time test.The effect of multiplication of oligosaccharides to Lactobacillus and antagonism of oligosaccharides to Escherichia coli in vitro, the effect of preventing from avian colibacillosis, adhesion of Lactobacillus and inhibition of Escherichia coli in chicken’s jejunum, and different dosages of Isomalto-oligosaccharides compounded with different dosage of Lactobacillus to prevent from avian colibacillosis were studied. The result showed that LABs were growing more and PH were lower in oligosaccharides group thanthat in controlled group, no distinct difference were found between the two groups. There were distinct antagonism effect of oligosaccharides plus LABs to Escherichia coli. There were distinct difference between compound group and controlled group on their promoting plantation of Lactobacillus and antagonism of Escherichia coli in chicken’s cecum in five days. The cure rates of multi-modulater group to prevent from avian colibacillosis were 75%-90%, and that of controlled group was 10%. There were no distinct difference between two oligosaccharide groups. The trial of different dosages of Isomalto-oligosaccharides compounded with probiotics indicated that effect of four gramme Isomalto-oligosaccharides plus the 10 probiotics were better than that of other dosages.The effect of multi-modulater of Lactobacillus on artificial induced avian colibacillosis, growth performance of chicken and chicken flora was studied. In preventive experiment, the cure rates of middle and high dosage groups were 80%, and that of drug groups were 70%-75%, while the survival rates of controlled groups were 40%. In treatment test, the cure rates of multi-modulater groups were about 70%, the same as drug groups, while the survival rates of controlled groups were 50%. The survival rates of multi-modulater groups were inferior to drug groups. In growth experiment, the multi-modulater group increased the average weight gain ,which was 7.5% higher than the control group, the feed-weight ratio was 6.7% lower than the control group. There were significant differences between two groups (P<0.05), and no significant differences between multi-modulater of Lactobacillus and Lactobacillus groups (P>0.05). I更多还原