奶牛乳房炎病原菌人工诱发奶山羊急性乳房炎试验

Inducing Acute Mastitis in Milk Goats by Using Three Common Pathogenic Bacteria Isolated from Dairy Mastitis

用从临床型乳房炎奶牛的乳样中分离的金黄色葡萄球菌、无乳链球菌、停乳链球菌 3种菌 ,经乳室注入不同的菌数感染泌乳奶山羊分别诱导急性乳房炎试验。结果表明 ,3种菌经奶山羊乳头注入均可引起程度不等的乳房炎症状 ,出现乳腺肿胀湿热、触之硬实或有痛感 ,乳汁颜色发生变化 ,奶中氯化物及细胞数均升高 ,产奶量下降 ,并伴有体温升高 ,心率增加等全身症状。这些病理变化的严重程度与攻菌菌株的毒力及攻菌量有一定的关系 ,其中以金黄色葡萄球菌攻菌后引起的乳房炎病理变化最为明显 ,无乳链球菌次之 ,停乳链球菌较轻。通过本试验初步测得了 3种菌人工感染奶山羊引起急性乳房炎的最小攻菌量 ,金黄色葡萄球菌为1 .52× 1 0 6个菌 ,无乳链球菌为 7.7× 1 0 6个菌 ,停乳链球菌为 3 .0× 1 0 5个菌 ,同时初步建立了人工感染泌乳奶山羊的乳房炎实验动物病理模型 ,为进一步研究乳房炎菌苗、病理学。

To induce acute mastitis in milk goats,the experiment was conducted by using three strains of bacteria (Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae) which were isolated from milk of dairy clinic mastitis.The results showed that injection of the three bacteria resulted in mastitis syndromes in different extent,such as mammary swelling, and hardening, solid and moist heat with painful feeling, changes of milk color, reduction of milk production, increased chloride and somatic cells, high body temperature, increased pulse and heart rate etc. The infection severity of mastitis in goats was closely related to virulence of bacteria and their dosages. Of three bacteria in milk goats, S. aureus can cause severe mastitis, next S. agalactiae. S. dysgalactiae cause only slight mastitis in milk goats. Generally, the syndromes of the disease appeared at 2 to 3 days post-infection and gradually declined and even disappeared completely. The minimum challenge dose of the three bacteria which cause acute mastitis in milk goats was: S. aureus, 1.52×10~6;S.agalactiae, 7.7×10~6 and S. dysgalactiae, 3.0×10~5. In order to study physiology and pathology of mastitis, antibacterial medicine, medicine dynamics and metabolism, we established the disease model in experimental animals that created better conditions for further study this disease.