【摘要】 大肠杆菌病是严重危害养鸭业的一类细菌性疾病,临床上多使用抗生素治疗,但耐药菌株的增多使抗生素的治疗效果大大下降,同时带来食品安全隐患。因此,筛选安全、天然抑菌药物成为研究热点。本试验从疑患大肠杆菌病死鸭无菌采集病料,分离出1株细菌,并对分离的细菌进行形态特征、生化试验、药敏试验、16S rDNA遗传分析,最终判定该分离菌为大肠杆菌。随后,选用本实验室提取的辣木叶水提物（MLHE）进行体外试验验证抑菌活性,利用微量肉汤稀释法检测MLHE最小抑菌浓度（MIC）、分光光度计测定OD₆₃₀细菌生长曲线以及半固体培养基测定MLHE对分离大肠杆菌丛动能力的影响。结果表明,0.25g/mL的MLHE可显著抑制大肠杆菌的增殖及丛动能力。该研究结果为指导鸭大肠杆菌临床用药及防控提供了理论依据。更多还原

【Abstract】 Colibacillosis is a type of bacterial disease that seriously harms the duck industry.Clinically, antibiotics are often used to treat such diseases. However, the increase of drugresistant strains has greatly reduces the therapeutic effect of antibiotics and brings food safety hazards. Therefore, screening of safe and natural antibacterial drugs has become a research hotspot. In this experiment, we aseptically collected disease feed from dead ducks suspected of E. coli disease, and one strain of bacteria was isolated. After identifying with morphological characteristics observation, biochemical tests, drug sensitivity tests, and 16S rDNA genetic analysis, the isolates was E. coli. Subsequently, the water extract of Moringa oleifera leaves(MLHE) extracted by our laboratory was used to verify the antibacterial activity in vitro, the minimum inhibitory concentration(MIC) of MLHE was detected by the micro broth dilution method, the bacterial growth curve was determined by a spectrophotometer. Semi-solid medium was used to determine the effect of MLHE on the clump motility of isolated E. coli. The results show that 0.25 g/mL MLHE can significantly inhibit the proliferation and clumping ability of E.coli. This study provides a theoretical basis for guiding the clinical medication and prevention and control of duck E. coli.更多还原