2例犬死亡原因的实验室诊断

对昆明某犬场2例死亡犬的死亡原因进行实验室鉴定。采集犬肠内容物分别做细菌和病毒检测。细菌检测包括:犬肠内容物划线培养,纯化,分离,革兰氏染色,镜检,生化试验,血清试验,药敏试验。病毒检测包括:提取病料的总DNA,用犬细小病毒的特异引物进行PCR扩增,扩增产物经胶回收后克隆到pMD18-T载体,转化受体菌DH5α,挑取阳性克隆质粒进行序列测定,并与已知参考毒株序列进行比对,分析核苷酸的同源性。分离到一株有部分耐药性的侵袭性大肠埃希菌;检测到一株犬细小病毒,由引物P1/P2扩增的基因与参考毒株CPV-b同源性为98.58%,由引物P3/P4扩增的基因与参考毒株CPV-b同源性为92.1%。结果表明,2例死亡犬的死亡原因分别为侵袭性大肠埃希菌感染和犬细小病毒感染。

Laboratory Diagnosis of Dead Causes of Two Dogs

The objective of this pepar was to identify the dead cause of two Kunming dogs. Canine intestinal contents were collected for bacteriological identification and virus identification. Bacteriological identification included crossed culture purification, gram staining, microscopy, biochemical tests, serum test and sensitivity test. Virus identification was done by PCR.PCR products were cloned into pMD18-T vector and then transformed into receptors bacteria DH5α. Positive clones were picked by identification and sequencing of plasmid. At last, the homology with reference strains known sequence was compared and analyzed. A resistant strain of Escherichia coli was isolated and a canine parvovirus was detected.Homology analysis showed that viral partial sequence amplified by the primers P1/P2 was 98.58%, compared with Cpv-b. The other viral partial sequence amplified by the primers P3/P4 was 92.1%. The dead causes of two dogs were the infection of Escherichia coli and canine parvovirus, respectively.