Abstract:
Riemerella anatipestifer (R. anatipestifer) can cause serositis in multiple poultry species, resulting in significant losses. Although R. anatipestifer-caused infections in ducks have been well established, the literature about this disease in geese is rare. Here, we isolated and identified 56 strains of R. anatipestifer from the eastern regions of Hebei Province, China, and further determined their serotypes, antibiotic resistance, and pathogenicity. A total of 75 strains of causative bacteria were isolated from 70 sick geese with serositis. After Gram staining microscopy, PCR, and 16S rDNA sequence analysis, 56 isolates were identified as members of R. anatipestifer and 19 as Escherichia coli (E. coli). The results of serotyping showed that there were 4 serotypes prevalent in the isolate, including serotype 1 (37/56), serotype 2 (9/56), serotype 11 (8/56), and serotype 13 (2/56). The results of antibiotic susceptibility testing revealed that all 56 R. anatipestifer isolates showed varying degrees of multidrug resistance (MDR). A total of 10 antibiotic resistance genes (ARG) were determined in these isolates. Four isolates of different serotypes were selected for pathogenicity examination, and all were able to reproduce serositis-like symptoms in 15-day-old goslings, with neurological symptoms and a 100% mortality rate. Hemorrhagic congestion of the brain tissue, steatosis of the hepatocytes, and disorganization of some cardiac myofibers were observed in R. anatipestifer-infected geese. All these findings will contribute to our insights into the prevalence characteristics, antibiotic resistance profile, and pathogenicity of R. anatipestifer infection in geese in eastern Hebei Province and provide scientific guidance for the treatment and control of this disease.
摘要:
鼠疫Riemerellaanatipestifer(R.anatipestifer)可引起多种家禽的浆膜炎,造成重大损失。尽管鸭中由鼠疫菌引起的感染已经得到了很好的证实,关于鹅这种疾病的文献很少见。这里,我们从河北省东部地区分离鉴定了56株。中国,并进一步确定了它们的血清型,抗生素耐药性,和致病性。从70只患有浆膜炎的病鹅中分离出75株致病菌。革兰氏染色显微镜检查后,PCR,和16SrDNA序列分析,56个分离株被鉴定为R.anatipestifer的成员,19个被鉴定为大肠杆菌(E.大肠杆菌)。血清分型结果表明,该分离株中流行的血清型有4种,包括血清型1(37/56),血清型2(9/56),血清型11(8/56),和血清型13(2/56)。抗生素药敏试验结果表明,所有56株鼠疫菌分离株均表现出不同程度的多药耐药性(MDR)。在这些分离物中总共确定了10个抗生素抗性基因(ARG)。选择4个不同血清型的分离株进行致病性检测,并且都能够在15天大的鹅身上重现浆膜炎样症状,神经症状和100%的死亡率。脑组织出血性充血,肝细胞的脂肪变性,在感染鼠疫菌的鹅中观察到一些心脏肌纤维的紊乱。所有这些发现将有助于我们对患病率特征的了解,抗生素耐药性概况,并对河北省东部地区鹅的鼠疫菌感染进行了致病性研究,为该病的治疗和控制提供了科学指导。