Avian pathogenic Escherichia coli (APEC).
Avian pathogenic Escherichia coli (APEC).
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DOI：
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发表时间：
1999-03
影响因子：
4.4
通讯作者：
M. Dho-Moulin;J. Fairbrother
中科院分区：
文献类型：
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作者：
M. Dho-Moulin;J. Fairbrother
禽致病性大肠杆菌（APEC）可引起鸡、火鸡等禽类的气溶胶囊炎、多浆膜炎、败血症等主要肠道外疾病。APEC存在于健康鸟类的肠道菌群中，大多数与之相关的疾病都是继发于环境和宿主易感因素。亚太经合组织分离株通常属于某些血清群，O1，O2和O78，和有限数量的克隆。目前已建立了几种实验模型，为评价大肠杆菌的致病性提供了可靠的方法。鸡和火鸡的大肠杆菌。因此，在APEC上鉴定的毒力因子是粘附素，如F1和P菌毛，和curli，需氧肌动蛋白铁螯合系统，K1荚膜，温度敏感性血凝素（TSH），对血清杀菌作用和细胞毒性作用的抗性。实验感染研究表明，肺部和气囊的换气区域是大肠杆菌进入的重要部位。在感染初期，禽流感病毒可透过大肠杆菌进入禽鸟的血液，而对吞噬作用的抵抗力可能是疾病发展的重要机制。他们还证明F1菌毛在呼吸道中表达，而P菌毛在感染鸡的内脏中表达。然而，这些菌毛粘附素在疾病发展中的作用尚未完全了解。最近使用的遗传方法来识别新的毒力因子将大大提高我们的知识APEC致病机制。APEC感染的诊断是基于临床表现、病变和E.杆菌这可以通过血清分型和使用免疫学或分子方法如DNA探针和PCR鉴定毒力因子来加强。预防和控制APEC感染的方法包括控制环境污染和环境参数，如湿度和通风。抗生素治疗被广泛使用，尽管APEC经常对各种抗生素产生耐药性。含有灭活或减毒的毒力细菌的疫苗可防止同源菌株的感染，但对异源菌株的效率较低。因此，大肠杆菌病的疫苗接种并没有广泛实施，因为在现场暴发中涉及的血清群种类繁多。
Avian pathogenic Escherichia coli (APEC) cause aerosacculitis, polyserositis, septicemia and other mainly extraintestinal diseases in chickens, turkeys and other avian species. APEC are found in the intestinal microflora of healthy birds and most of the diseases associated with them are secondary to environmental and host predisposing factors. APEC isolates commonly belong to certain serogroups, O1, O2 and O78, and to a restricted number of clones. Several experimental models have been developed, permitting a more reliable evaluation of the pathogenicity of E. coli for chickens and turkeys. Hence, virulence factors identified on APEC are adhesins such as the F1 and P fimbriae, and curli, the aerobactin iron sequestering system, K1 capsule, temperature-sensitive hemagglutinin (Tsh), resistance to the bactericidal effects of serum and cytotoxic effects. Experimental infection studies have shown that the air-exchange regions of the lung and the airsacs are important sites of entry of E. coli into the bloodstream of birds during the initial stages of infection and that resistance to phagocytosis may be an important mechanism in the development of the disease. They have also demonstrated that F1 fimbriae are expressed in the respiratory tract, whereas P fimbriae are expressed in the internal organs of infected chickens. The role of these fimbrial adhesins in the development of disease is not yet, however, fully understood. The more recent use of genetic approaches for the identification of new virulence factors will greatly enhance our knowledge of APEC pathogenic mechanisms. Diagnosis of APEC infections is based on the clinical picture, lesions and isolation of E. coli. This may be strengthened by serotyping and identification of virulence factors using immunological or molecular methods such as DNA probes and PCR. Approaches for the prevention and control of APEC infections include the control of environmental contamination and environmental parameters such as humidity and ventilation. Antibiotherapy is widely used, although APEC are frequently resistant to a wide range of antibiotics. Vaccines containing killed or attenuated virulent bacteria protect against infection with the homologous strain but are less efficient against heterologous strains. Hence, vaccination for colibacillosis is not widely practised because of the large variety of serogroups involved in field outbreaks.