猪支气管败血波氏杆菌的分离鉴定及部分生物学特性的研究

Isolation,identification and biological characterization of Bordetella bronchiseptica from swine

为了解猪支气管败血波氏杆菌(Bb)在四川规模化猪场的感染情况,为猪支气管败血波氏杆菌的诊断及临床治疗提供参考,本研究从四川省5个猪场采取具有呼吸道症状的猪鼻腔棉拭子16份,采用改良Sm ith培养基分离该菌,通过对该菌的生长特性、菌落形态和革兰染色菌体形态和排列方式进行观察以及对特异性基因fla和D nt进行PCR检测,共分离鉴定出4株Bb,该菌从猪场中的分离率为80%(4/5),猪个体阳性率为25%(4/16)。小鼠皮肤坏死试验结果表明,小鼠颈部皮下注射分离菌粗提的Dnt毒素后,注射局部皮肤坏死,剖检见脾萎缩、肺充血和肝边缘坏死。药敏试验结果表明,分离菌株对头孢唑啉、四环素、环丙沙星等14种抗生素高度敏感,对氨苄西林、杆菌肽、复方新诺明等7种抗生素耐药率较高,试验结果说明,四川省猪群中存在致病性较强的猪支气管败血波氏杆菌,为选用敏感抗菌药物预防和治疗Bb病提供了依据。

The objective of this study is to investigate the infection of Bordetella bronchiseptica（Bb） in Sichuan Province,and to provide a reference for the diagnosis and clinical treatment of Bordetella bronchiseptica in pigs.Bb was isolated from 16 nasal swab samples collected from five swine farms in Sichuan with modified Smith＇s culture media.The isolated bacteria were identified by colony growth characteristics,colony morphological and gram staining characteristics,as well as PCR detections of specific fla and Dnt genes.Four Bb strains were identified from 5 farms,the isolation positive rate of the swine farms and samples were 80%（4/5） and 25%（4/16）,respectively.Skin necrosis test results showed that the primary Dnt toxin produced by the 4 isolated Bb strains caused mice skin necrosis,spleen atrophy,lung haemorrhage and necrosis of liver border.Antibiotics susceptibility test results showed that the 4 Bb were sensitive to cefazolin,tetracycline,ciprofloxacin and other 14 antibiotics,and highly tolerant to ampicillin,bacitracin,cotrimoxazole and other 7 antibiotics.The Bb is highly prevalent in Sichuan swine farms with high pathogenicity.