Virulence of Escherichia coli Isolates Obtained from Layer Chickens with Colibacillosis Associated with Pericarditis, Perihepatitis, and Salpingitis in Experimentally Infected Chicks and Embryonated Eggs
Virulence of Escherichia coli Isolates Obtained from Layer Chickens with Colibacillosis Associated with Pericarditis, Perihepatitis, and Salpingitis in Experimentally Infected Chicks and Embryonated Eggs
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DOI：
10.1637/11685-060717-resnote.1
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发表时间：
2018-06-01
期刊：
影响因子：
1.4
通讯作者：
Murase, T.
中科院分区：
文献类型：
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作者：
Ozaki, H.;Yonehara, K.;Murase, T.
为评价鸡致病性大肠埃希菌(APEC)分离株的毒力，采用鸡胚胎致死率试验和雏鸡实验性感染模型，对分离自鸡心包炎、肝炎和输卵管炎的大肠埃希菌进行了毒力测定。根据以胚胎致死试验中的死亡率为基础的评估大肠杆菌分离株毒力的既定标准，26株与心包炎和周围肝炎有关的APEC菌株中有23株被发现具有毒力，20株与输卵管炎有关的菌株中有8株被发现具有毒力。分别用从心包炎和肝炎病例中获得的D137菌株和D445菌株进行实验感染，D137菌株的胚胎死亡率为92%，D445菌株从心包炎和肝炎病例中获得的胚胎死亡率为17%。通过气囊接种D137菌株的5只11日龄雏鸡中，有4只在接种后1天死亡，从气囊、心包囊或肝脏中恢复了挑战株；然而，5只鸡中只有1只在死后发现了大肠杆菌病。接种D445菌株的5只雏鸡在接种后7d全部存活，并在接种后7d出现气囊炎或心包炎病变，攻击株在死后未从病变中恢复。本研究的结果表明，不同的APEC分离株通过不同的致病机制引起鸡的疾病。
To evaluate the virulence of avian pathogenic Escherichia coli ( APEC) isolates obtained from colibacillosis cases associated with pericarditis, perihepatitis, and salpingitis, the embryo lethality assay and experimental infection model in chicks were used in this study. According to the established criteria based on mortality in the embryo lethality assay for evaluating the virulence of E. coli isolates, 23 of the 26 APEC isolates associated with pericarditis and perihepatitis and 8 of the 20 isolates associated with salpingitis were found to be virulent. Isolate D137, which had been obtained from a case with pericarditis and perihepatitis and had an embryo mortality of 92%, and isolate D445, which had been obtained from a case with pericarditis and perihepatitis and had an embryo mortality of 17%, were used for the experimental infection. Four of the five 11-day-old chickens inoculated through the air sac with isolate D137 died 1 day postinoculation, and the challenge strain was recovered from the air sac, pericardial sac, or liver; however, colibacillosis lesions were found in only one of the five birds postmortem. All five chicks inoculated with isolate D445 survived for 7 days postinoculation and exhibited airsacculitis or pericarditis lesions at 7 days postinoculation; the challenge strain was not recovered from the lesions postmortem. The results obtained in this study suggest that the different APEC isolates tested cause illness in chickens through distinct pathogenesis.