为了寻找具有优势性能的乳酸菌,减少或替代抗生素在肉鸽养殖中的使用,试验采集2只健康肉鸽肠道内容物,用微量生化法结合分子生物学法进行细菌分离鉴定,用比对法进行生长特性试验,用琼脂扩散法进行体外抑菌试验,分离的乳酸菌腹腔接种小鼠进行菌株安全性试验.结果表明从2只健康肉鸽肠道内容物中分离得到4株生长迅速、产酸能力强的分离菌(分别标记为G2、G3、G4和G5),其生化特性与乳酸菌基本一致;分离菌16S rRNA核苷酸序列与唾液乳杆菌相似性最高,均大于99％;分离菌对氨苄西林等耐药,对罗红霉素高度敏感,对巴氏杆菌等指示菌均有较强的抑制作用;pH值越小分离菌G2发酵液抑菌活性越强,高温会略微降低抑菌活性但变化较小,酶可增加抑菌活性;腹腔接种分离菌发酵液的小鼠生长良好,未见异常.说明分离菌均为唾液乳杆菌,产酸能力强,耐胃蛋白酶和胆盐,对部分病原菌有较强抑制作用,安全无毒,具备成为益生菌的优势.

为鉴定外伤感染死亡兔的病原菌,采集病死兔肝、肺、肾等器官进行细菌分离鉴定及体外抑菌试验.结果表明:分离菌靛基质、枸橼酸盐等试验为阴性,凝固酶和过氧化氢酶试验为阳性,分解葡萄糖、麦芽糖等,不能分解淀粉;病菌对青霉素、卡那霉素等高度敏感,对氨卡西林,阿莫西林等耐药;枯草芽孢杆菌和鸡唾液乳酸杆菌对其均有较强的抑制作用.因此,分离菌为兔金黄色葡萄球菌,该病是由金黄色葡萄球菌引起的兔葡萄球菌病,防治首选药物为青霉素,枯草芽孢杆菌和鸡唾液乳酸杆菌可减少或部分取代抗生素对该病的防治.

为了确诊临床疑似猪丹毒病例,采集病死猪的内脏,用常规生化法和PCR法进行细菌分离鉴定,用牛津杯法做体外抑菌试验.结果:分离菌H2S、靛基质、枸橼酸盐等试验为阴性;分解葡萄糖、麦芽糖等,不能分解蔗糖;对青霉素、头孢唑啉等高度敏感,对氯霉素、链霉素等中度敏感;枯草芽孢杆菌、鸡唾液乳酸杆菌和猪小肠乳酸杆菌对其均有较强的抑制作用.结论:分离菌为猪丹毒杆菌,该病是由猪丹毒杆菌引起的急性热性传染病,防治首选药物为青霉素,枯草芽孢杆菌、鸡唾液乳酸杆菌和猪小肠乳酸杆菌可减少或部分取代抗生素对该病的防治.

In order to get biological drugs with no resistance or toxic side effects and to reduce the use of antibiotics, a strain of Bacillus subtilis was isolated from animal intestine, and the isolate was identified by molecular biological method; in vitro antibacterial test of the isolate was performed using agar diffusion method; the optimal fermentation condition of the isolate was screened by conventional culture method;the antibacterial crude protein of the isolate was extracted by saturated ammonium sulfate method; the physicochemical properties of antibacterial crude protein was detected by comparison method; The results showed that the isolate was B. subtilis ,which had antibacterial effects on Staphylococcus aureus, streptococcus and swine erysipelas. The fermentation effect of the isolate was the best under the condition of temperature 30 ℃, pH 7, liquid volume 75 ml/250 ml, inoculation volume 20％ and culture time 48 h. The antibacterial effect of the isolate was the best when extracted by 80％ saturated ammonium sulfate. The antibacterial crude protein had strong resistance to heat and acid. Organic solvent and UV irradiation had some influences on antibacterial crude protein. Proteases had hydrolytic effects on antibacterial crude protein. The isolated B. subtilis can be used to prevent and control the diseases caused by S. aureus, streptococcus and swine erysipelas, and can regulate intestinal microecology by adding into expanded feeds.