病死大鲵嗜水气单胞菌分离鉴定和感染美蛙组织病理观察及药敏分析

Isolation and Identification of Aeromonas hydrophila from Dead Giant Salamander and Histopathological Observation of Infected Frog and Drug Sensitivity Analysis

摘要: 为了解重庆大鲵嗜水气单胞菌对几种动物的致病性和对美蛙组织脏器的损害以及对常用药物的敏感性，从患病死亡大鲵体分离鉴定两株菌TG-2，TG-5，用16srRNA测序，并使用BIOFOSUN-GN-48鉴定板条测定生化特性；接种鲫鱼、小鼠和美蛙及药敏试验，结果显示2株菌均为嗜水气单胞菌。TG-5能使鲫鱼死亡70%，蛙死亡40%，小白鼠死亡100%。TG-2能使鲫鱼死亡80%，蛙死亡70%，小白鼠死亡100%；组织病理观察显示，蛙肝组织坏死严重，肝细胞质溶解，出现空泡变性，细胞核碎裂，肝索分布紊乱，肝血窦扩张，肾间质血管充血、出血，肾小囊腔扩张，上皮细胞肿大，空泡变性，肾小管腔内有蛋白物渗出；21种药物药敏试验结果表明，TG-2对头孢哌酮、头孢曲松、头孢他啶、米诺环素、头孢他啶、多粘菌素B高度敏感，TG-5对多粘菌素B、头孢他啶、敏感。其他且呈现出较强耐药性。

Abstract: In order to understand the pathogenicity of Aeromonas hydrophila from giant salamander in Chongqing to several animals and damage to organs of the American frog tissue and sensitivity to commonly used drugs, two strains of TG-2, TG-5 were isolated and identified from dead giant salamander. Biochemical characteristics were determined by 16srRNA sequencing and BIOFOSUN-GN-48. Squid, mouse and frog were inoculated, and drug susceptibility test was made. The results showed that all of the 2 strains were Aeromonas hydrophila. TG-5 killed 70% of cru-cian carp, 40% of frogs and 100% of white mice. TG-2 killed 80% of crucian carp, 70% of frogs and 100% of white mice. Histopathological observation showed that the frog’s liver tissue was severely necrotic; hepatocytoplasmic lysis and vacuolar degeneration occurred; cell nucleus fragmented; distribution of hepatic cord was disordered; hepatic sinus dilated; hyperemia was found in the kidney mesenchyme; renal capsule dilated; epithelial cells were enlarged; vacuolar degeneration was observed; and there was a protein exudation in the renal tubules. The results of 21 drug sensitivity tests showed that TG-2 was highly sensitive to cefoperazone, ceftriaxone, ceftazidime, minocycline, ceftazidime, and polymyxin B. TG-5 was sensitive to polymyxin B, ceftazidime, and ceftazidime. Others showed strong resistance.