犊牛腹泻症的病原学检测及鉴定

Etiological detection and identification of calf diarrhea

  • 摘要: 【目的】 研究新疆某规模化牛场犊牛腹泻症的主要病原。 【方法】 采用RT-PCR方法,检测14份腹泻犊牛粪便中的病毒,对4头死亡犊牛肝组织进行细菌分离培养及鉴定、小鼠致病性和药物敏感性试验。将分离的致病菌扩增16S rDNA基因片段并测序,并将其结果在NCBI中用BLAST搜索同源序列,分析遗传进化特性。 【结果】 该牛场犊牛腹泻的病原为牛冠状病毒(Bovine coronavirus, BCoV)、牛轮状病毒(Bovine rotavirus, BRV)、大肠埃希氏杆菌(Escherichia coli, E.coli)和肺炎克雷伯氏菌(Klebsiella pneumoniae, K.pneumoniae)。14份粪便中,BCoV检出率为64.29%,BRV检出率为50.00%;4份肝组织中, E.coli检出率为100.00%,K.pneumoniae检出率为50.00%。分离的2种致病菌E.coliK.pneumoniae对阿米卡星敏感,对其它16种抗生素均耐药。 【结论】 该牛场引起犊牛腹泻的主要病原为BCoV、BRV、E.coliK.pneumoniae,存在病毒与细菌的混合感染。选择阿米卡星药物防治E.coliK.pneumoniae

     

    Abstract: 【Objective】 This article aims to identify the main pathogens of calf diarrhea in a large-scale cattle farm in Xinjiang. 【Methods】 Virus detection was performed on 14 diarrhea calf feces using RT-PCR. Besides, bacteria were isolated from the liver tissues of four dead calves, cultured and identified, and mouse pathogenicity and drug sensitivity tests were conducted on these bacteria. Afterwards, the 16 S rDNA gene fragment of the isolated pathogenic bacteria was amplified and sequenced, and the sequencing results were searched for homologous sequences using BLAST in NCBI for genetic evolution analysis. 【Results】 The pathogens of diarrhea in the cattle farm were Bovine coronavirus (BCoV), Bovine rotavirus (BRV), Escherichia coli (E.coli), and Klebsiella pneumoniae (K.pneumoniae). Among the 14 feces, the detection rate of BCoV was 64.29%, and the detection rate of BRV was 50.00%; Among the four liver tissues, the detection rate of E. coli was 100.00%, and the detection rate of K.pneumoniae was 50.00%. The two isolated pathogenic bacteria E.coli and K. pneumoniae were sensitive to amikacin and resistant to all 16 other antibiotics. 【Conclusion】 The main pathogens causing calf diarrhea in this cattle farm are BCoV, BRV, E.coli, and K.pneumoniae, with mixed infection of viruses and bacteria. Amikacin can be used as the preferred drug for the prevention and treatment of E. coli and K. pneumoniae.

     

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