家兔支气管败血波氏杆菌的分离鉴定及耐药基因检测

Isolation and Identification of Bordetella Bronchiseptica from Rabbit and Detection of Resistance Gene

为深入了解兔支气管败血波氏杆菌(Bordetella bronchiseptica,Bb),试验将病兔体内分离得到的菌株进行菌株鉴定、生长曲线测定、致病性研究、药敏试验及耐药基因检测,期望了解该菌的生长规律,为临床用药及防控奠定基础。通过Gram染色镜检、分离培养、16S rDNA序列分析对分离菌株进行鉴定,测定了该分离株的生长曲线、半数致死量、耐药性并对分离菌株进行β-内酰胺酶耐药基因的检测。结果表明:分离得到1株革兰氏阴性杆菌,命名为P201215,该分离株的16S rDNA基因序列与GenBank中支气管败血波氏杆菌(登录号为NR113628.1)的同源性为99%。分离株的对数生长期为2~9 h,9 h后进入平台期;对KM小鼠的半数致死量为1.19×107 CFU。药敏试验结果显示,分离株对部分头孢菌素类药物耐药,对大部分β-内酰胺类、喹诺酮类、四环素类及氨基糖苷类药物敏感,PCR检测未检出超广谱β-内酰胺酶耐药基因。

In order to have a deep understanding of rabbit Bordetella bronchiseptica(Bb),the strain identi-fication,growth curve determination,pathogenicity study,drug susceptibility test,drug resistance test and gene detection were expected to understand the growth pattern of the bacteria and lay a foundation for clinical drug use and prevention and control.The isolates were identified by Gram staining,microscopy,isolation and culture,16S rDNA sequencing analysis;the growth curve,LD50,drug resistance of the iso-lates were studied and the isolates were tested forβ-lactamase resistance gene.A strain of Gram-negative Bacillus,named P201215,was isolated,and the 16S rDNA gene sequence of the isolate had 99%homology with that of Bordetella bronchiseptica(accession number:NR113628.1)in GenBank.The results showed that the logarithmic growth period of the isolate was 2-9 h,and it entered the plateau pe-riod after 9 h.The LD50 of the isolate was 1.19×107 CFU in KM mice,and the results of the drug sensitivity test showed that the isolate was resis-tant to some cephalosporins and sensitive to mostβ-lactams,quinolones,tetracyclines and aminogly-cosides,and no extended-spectrumβ-lactamase resistance gene was detected by PCR.