中华鳖弗氏柠檬酸杆菌的鉴定及病理组织观察  

Identification and pathological observation of Citrobacter freundii from Pelodiscus sinensis

作　　者：黄莉萍 安莉丽 李芳[1] 杨成年 李虹 吕光俊[1] 向枭[1] 孙翰昌 翟旭亮 朱成科[1] HUANG Liping;AN Lili;LI Fang;YANG Chengnian;LI Hong;LYU Guangjun;XIANG Xiao;SUN Hanchang;ZHAI Xuliang;ZHU Chengke(College of Animal Science,Southwest University,Chongqing 402460,China;Chongqing Fishery Technology Extension Station,Chongqing 400020,China;College of Forestry and Life Sciences,Chongqing University of Arts and Sciences,Chongqing 402160,China)

机构地区：[1]西南大学动物科学学院,重庆402460 [2]重庆市水产技术推广总站,重庆400020 [3]重庆文理学院林学与生命科学学院,重庆402160

出　　处：《浙江农业学报》2020年第7期1176-1186,共11页Acta Agriculturae Zhejiangensis

基　　金：重庆市生态渔产业技术体系建设专项(4321600126);技术创新与应用发展专项重点项目(cstc2019jscx-gksbX0147)。

摘　　要：为了确定重庆地区仿生态养殖中华鳖(Pelodiscus sinensis)患病死亡的原因,从患病鳖的肠道分离得到一株优势菌PS01,对该菌进行了形态学观察、人工感染、生理生化特性测定、16S rRNA和gyrB基因序列分析、病理切片观察以及药敏试验。结果表明:人工感染中华鳖患病症状同自然发病症状;16S rRNA和gyrB序列构建的进化树表明,该菌与弗氏柠檬酸杆菌(Citrobacter freundii)同为一枝,相似性分别为99.7%、98.7%;病理组织观察发现,患病中华鳖的肝、脾、肾、胰和肠均有不同程度病变,其中以肠、肝脏、脾脏3个组织病变最为严重,肠绒毛大部分坏死脱落、肝细胞肿胀、胞核空泡化、脾脏红白髓混合分布、胰脏和肾脏轻度病变、胰腺细胞与肾小管上皮细胞肿大,其余组织未观察到明显变化。药敏试验表明,菌株PS01对多西环素等18种抗菌药物高度敏感,对氟苯尼考等3种抗菌药物中度敏感,对复方新诺明等18种抗菌药物表现为耐药。研究结果表明,弗氏柠檬酸杆菌为中华鳖的致病菌,其对30 g左右的中华鳖半致死浓度为9.3×104 CPU·g-1,有较强的致病性,可造成中华鳖多个组织病变。In order to determine the cause of death about the simulated ecological Pelodiscus sinensis in Chongqing,the pathogenic bacteria named strain PS01 was isolated from the intestinal and pharynx of deseased P.sinensis.The pathogen isolation,artificial infection,physical and chemical characteristics of isolated bacteria,sequence analysis of 16S rRNA and gyrB,drug sensitivity test and pathological section were carried out and investigated.The results showed that artificial infection symptoms with P.sinensis were similar to the natural symptoms.The phylogenetic tree constructed by 16S rRNA and gyrB sequences was the same as C.freundii,with a similarity of 99.7%and 98.7%.Pathological observation showed,there were various degrees of damage such as cytopathic and necrotic and so on.The pathological observation showed that the liver,spleen,kidney,ancreas,and intestinal had different degrees of lesions of the diseased C.freundii,among them,the three tissues of intestine,liver and spleen were the most serious.Most of intestinal villi were necrotic and shed,hepatocytes swell,nucleus vacuoles,mixed distribution of red and white marrow of spleen,mild pancreatic and renal lesions,pancreatic cells and renal tubular epithelial cells swell,no significant change was observed in other tissues.The drug susceptibility test showed that the strain PS01 was highly sensitive to 18 antibacterial drugs,such as doxycycline;and middle sensitive to 3 antibacterial drugs,such as florfeniol;resistant to 18 antibacterial drugs,such as sulfamethoxazole compound.This study proved that the disease of P.sinensis caused by C.freundii in Chongqing,whose half-lethal concentration for Chinese sturgeon of about 30 g was 9.3×104 CPU·g-1,which had strong pathogenicity and could cause multiple tissue lesions of P.sinensis.

关 键 词：中华鳖 弗氏柠檬酸杆菌 药敏试验 病理切片 

分 类 号：S941.1[农业科学—水产养殖]