1株罗曼粉鸡源申氏不动杆菌的分离鉴定及耐药性分析

为了解贵州省某养殖场罗曼粉鸡发病病原的特征及其耐药性，本试验从病死鸡中分离出一株革兰氏阴性菌，命名为GZ2019，并对其进行纯化培养、生化试验、16S rRNA序列分析、药敏试验及动物回归试验。分离菌在普通琼脂培养基上呈圆形凸起、表面光滑、半透明的灰白色小菌落，鲜血营养琼脂培养基上菌落形态与普通琼脂培养基上的一致，但不溶血；革兰氏染色结果镜检显示，分离菌为成双排列的阴性球杆菌，偶见单个存在或链状排列；生化试验结果显示，分离菌枸橼酸盐利用、过氧化氢酶反应为阳性，硝酸还原、氧化酶、葡萄糖发酵等反应为阴性，无运动性；16S rRNA序列分析结果显示，分离株与不动杆菌的核苷酸同源性在72.6%~99.9%之间，与申氏不动杆菌LUH 4760株（GenBank登录号：AJ275041）、SNSK 752株（GenBank登录号：MG584984）、MCDA01株（GenBank登录号：KY385627）及RP1株（GenBank登录号：MG461636）的核苷酸同源性高达99.9%；药敏试验结果显示，分离菌对头孢曲松和痢特灵敏感，对头孢哌酮、头孢呋辛、头孢他啶等5种药物中度敏感，对新霉素、环丙沙星、羧苄西林等17种药物耐药；动物回归试验结果显示，试验组小鼠隔离饲养1周仅死亡1只，死亡率为20%，表明该分离菌致病性较弱。本试验成功分离出1株低致病性申氏不动杆菌GZ2019，可为鸡源申氏不动杆菌病的预防和治疗提供一定的参考依据。

Isolation,Identification and Drug Resistance Analysis of a Strain of Acinetobacter schindleri from Lohmann Pink Chickens

In order to understand the pathogenic characteristics and drug resistance of Lohmann Pink chickens in a farm in Guizhou province,a Gram-negative strain was isolated from dead chickens,named GZ2019,and the isolated bacteria were purified and cultured,biochemical test,16S rRNA sequence analysis,drug susceptibility test and animal regression test.The isolated bacteria showed round raised,smooth surface,translucent small gray colonies on the ordinary agar medium,and the colony morphology on the blood-nourishing agar medium was consistent with that on the ordinary agar medium,without hemolysis.Microscopic examination of Gram staining results showed that the isolates were diplicate negative coccidiobacteria,with occasional single presence or chain arrangement.The results of biochemical tests showed that citrate utilization and catalase reaction of isolated bacteria were positive,while nitric acid reduction,oxidase and glucose fermentation were negative,with no movement.The 16S rRNA sequence analysis results showed that the homology between the isolated strain and acinetobacter was between 72.6% and 99.9%,and the homology with Acinetobacter schindleri LUH 4760 (GenBank accession No.:AJ275041),SNSK 752 (GenBank accession No.:MG584984),MCDA01 (GenBank accession No.:KY385627) and RP1 (GenBank accession No.:MG461636) was 99.9%.The results of drug susceptibility test showed that the isolate were sensitive to ceftriaxone and furazolidone,moderately sensitive to five drugs,such as cefoperazone,cefuroxime and ceftazidine,and resistant to 17 drugs,such as neomycin,ciprofloxacin,carboxylbenzicillin.The results of the animal regression test showed that only one mouse in the experimental group died after 1 week of isolation,with a mortality rate of 20%,indicating that the pathogenicity of the isolates was weak.This study successfully isolated a strain of low pathogenicity Acinetobacter schindleri GZ2019,which could provide certain reference for the prevention and treatment of Acinetobacter schindleri in chickens.