小熊猫源大肠杆菌的药敏特性及致病性

Antibiotic Sensitivity and Pathogenicity of Escherichia coli Isolated from Red Panda(Ailurus fulgens)

为探明死亡圈养小熊猫(Ailurus fulgens)体内分离大肠杆菌(Escherichia coli,MT820501)的耐药情况及致病性,对分离菌株进行药敏特性分析,同时以小鼠感染实验检测其致病性。结果显示:该分离菌株对哌拉西林、头孢西丁、头孢曲松、头孢吡肟、美罗培南、哌拉西林-他唑巴坦、氨苄青霉素-舒巴坦、卡那霉素、丁胺卡那、新霉素、米诺环素、左氧氟沙星、呋喃唑酮、多黏菌素B敏感,对大部分β-内酰胺类药物及少部分氨基糖苷类药物耐药;小鼠感染实验结果显示,分离菌株半数致死量为8.42×10^(7) cfu/mL,死亡小鼠体内分离出与小熊猫体内一致的菌株,病理表现为各实质脏器出现不同程度水肿、充血及炎性细胞浸润,与死亡小熊猫病理损伤特点高度相似,但不完全相同,这可能与感染方式、种属差异、耐受性等相关。

In order to explore the antibiotic sensitivity and pathogenicity of Escherichia coli(MT820501)isolated from a dead captive red panda(Ailurus fulgens),the K-B disk diffusion method was used for antibiotic sensitivity tests and the mouse pathogenicity test was performed to detect its pathogenicity.The results showed the Escherichia coli was sensitive to piperacillin,cefoxitin,ceftriaxone,cefepime,meropenem,piperacillin-tazobactam,ampicillin-sulbactam,kanamycin,amikacin,neomycin,minocycline,levofloxacin,furazolidone,polymyxin B,and resistant to the majority ofβ-lactam antibiotics and a small number of aminoglycoside antibiotics.The mouse pathogenicity test showed that the median lethal dose of the E.coli was 8.42×10^(7) cfu/mL and that the strains isolated from the dead mice were the same as the E.coli from the red panda.Pathological features of the mice included the edema,hyperemia,inflammatory cell infiltration in the parenchymal organs like heart,liver,kidney and pancreas,which were highly similar to the pathological features of red panda but not completely the same.These pathological differences between red panda and mice may be related to the way of infection and perhaps species differences and tolerance.