鸭源多重耐药鼠鼻罗氏菌的分离鉴定、耐药性及耐药基因检测

Isolation and Identification of Duck Multidrug-resistant Rothia nasimurium and Detection of Its Drug Resistance and Relevant Genes

鼠鼻罗氏菌是一种常见的条件性致病菌。2020年我国东北地区某农场的鸭出现流黏性鼻液、咳嗽、呼吸急促等散发性呼吸系统症状以及进食量减少、精神低沉等症状。为了确定发病原因,提出针对性的预防和治疗方案,无菌采集发病鸭鼻拭子进行细菌分离培养。分离菌株经培养特性鉴定、染色镜检、生化试验、16S rDNA序列分析,确定为鼠鼻罗氏菌。动物致病性试验结果显示,分离菌株对鸭具有一定的致病性。分离菌株药物敏感性测定结果显示,其对卡那霉素、庆大霉素、链霉素、红霉素、氟苯尼考、头孢氨苄、恩诺沙星耐药,对多西环素敏感。β-内酰胺类耐药基因(TEM、OXA-23)检测结果均为阴性。结果表明,引发疫情的病原为鸭源鼠鼻罗氏菌,其对多种药物耐药。本研究首次在东北地区禽体内分离出致病性鼠鼻罗氏菌,对多重耐药鼠鼻罗氏菌病的预防和控制具有一定指导意义。

Rothia nasimurium is a common opportunistic pathogen.In 2020,sporadic respiratory symptoms including mucinous nasal fluid,cough and shortness of breath,as well as reduced food intake and depression were observed in ducks in a farm in Northeast China.In order to confirm the causes and to put forward targeted prevention and treatment measures,nose swabs were collected from the infected ducks in a sterilized way for bacterial isolation and culture.The isolated strain was identified as Rothia nasimurium through identification of culture characteristics,staining microscopy,biochemical test and 16 s rDNA sequence analysis.It was shown that,by animal pathogenicity test,the isolate could bring certain pathogenicity to healthy ducks,and by drug sensitivity test,the isolate was resistant to kanamycin,gentamicin,streptomycin,erythromycin,florfenicol,cephalexin and enrofloxacin,and only sensitive to doxycycline.The detection results ofβ-lactam resistance genes(TEM and OXA-23)were negative.In conclusion,the outbreak was caused by Rothia nasimurium that was resistant to several drugs.It was the first time to isolate pathogenic Rothia nasimurium from poultry in Northeast China,which provided certain guidance for future prevention and control of the disease.