四带无须鲃透明品系的海分枝杆菌感染模型

【目的】了解海分枝杆菌Mycobacterium marinum对四带无须鲃Puntius tetrazona透明品系的感染特性,构建感染模型。【方法】分别采用腹腔注射、肌肉注射及与感染鱼共居的感染方式,研究海分枝杆菌对四带无须鲃透明品系的感染特性;组织切片和压片观察细菌在四带无须鲃体内不同组织的分布及其引起的特征病理变化。【结果】2种注射方式均在感染部位周围观察到病变,并导致鱼体死亡;共居感染鱼病程发展较为缓慢,并出现消瘦、体色苍白等症状。感染鱼均可分离到病原菌,主要器官观察到典型肉芽肿结构,且抗酸染色能将其中细菌特异染色;各器官有黑色素巨噬细胞中心形成,并伴有不同程度的病理变化。【结论】四带无须鲃透明品系对海分枝杆菌敏感,症状便于观测,病理变化典型,可作为感染模型系统发展。

A Mycobacterium marinum infection model for transparent tiger barb Puntius tetrazona

Objective To study the characteristics of transparent tiger barb Puntius tetrazona infected with Mycobacterium marinum and develop an infection model.Method P. tetrazona were infected with M. marinum via intraperitoneal injection, intramuscular injection and cohabitation experiment. The fish characteristics after infection were observed. Distribution of bacteria and pathological changes in the fish were evaluated by wet-mount preparations and tissue slices.Result Both injection methods resulted in pathologic damages around the infection sites, and gradually led to fish death. The disease progression was slow for the fish in the cohabitation experiment, and the fish appeared thin and pale. The pathogenic bacteria were isolated from fish with different infection treatments. Granulomas, the classic symptom for infection, were observed in major organs. M. marinum could be specifically stained by Ziehl-Neelsen stain. A number of melano-macrophage centers developed in different organs, and the organs were associated with different degrees of pathologic lesion.Conclusion The transparent line of tiger barb is a susceptible host of M. marinum, and the symptoms can be conveniently observed with typical pathological changes. P. tetrazona is an excellent model for further infection research.