不同血清型鸭疫里氏杆菌对雏鸭的致病性研究

Pathogenicity of Riemerella anatipestifer of different serotypes in duckling

摘要

旨在研究鸭疫里氏杆菌（RA）不同血清型以及同一血清型不同菌株对雏鸭的致病性。将403只20日龄樱桃谷鸭随机均分为13组，每组31只，包括1组对照组（生理盐水），12组试验组分别用血清1型、2型、6型、7型各3株RA菌液颈部皮下注射进行攻毒，剂量为1.0×10 ⁹ CFU/只。攻毒后每天观察各组临床症状，且于攻毒后24、48、72、96、120、144、168 h，采集各组眼棉拭子进行PCR检测，分析排毒情况；每组随机抽取3只鸭，剖检观察各组织脏器病理变化。结果：不同血清型的RA菌株感染雏鸭后临床症状和剖检症状基本相同，血清2型、6型和7型RA感染鸭比1型RA发病早、死亡快、死亡率高。血清2型、6型和7型RA感染鸭在攻毒后24～48 h出现站立不稳，比血清1型RA早48～72 h；心包炎和肝周炎、气囊炎、输卵管堵塞多在攻毒后48 h前、72 h前、72～120 h出现，均比血清1型RA早24～72 h；死亡最早出现在攻毒后24 h内，48～72 h为死亡高峰，致死率为50%～100%，血清1型RA感染死亡主要出现在攻毒后48～120 h，死亡率为10%～20%。同一血清型不同RA菌株感染鸭脏器病变出现的时间和死亡率存在差异。综上，血清2型、6型、7型RA对樱桃谷鸭的致病性强于血清1型，同一血清型的不同RA菌株致病性也有差异。

Abstract

The study aimed to investigate the differences in pathogenicity of different serotypes and different strains within the same serotype of Riemerella anatipestifer (RA) in ducklings. A total of 403 twenty-day-old Cherry Valley ducks were randomly divided into 13 equal groups (31 ducks per group), with one group serving as the control. The experimental groups were inoculated with 3 strains of type 1, type 2, type 6 and type 7 bacterial suspensions of RA in the neck subcutaneously, respectively, at a dose of 1.0×10 ⁹ CFU per duck. After the challenge, the ducklings in each group (including the control group) were observed daily for clinical symptoms. At 24 h, 48 h, 72 h, 96 h, 120 h, 144 h, and 168 h post-challenge, three ducklings were randomly selected from each group. Eye swab samples were collected from the ducklings for PCR detection of viral shedding, and they were necropsied to observe pathological changes in various tissues and organs. The result showed that the clinical and postmortem findings in the ducklings infected with different serotypes of RA strains were largely similar. However, the ducklings infected with serotype 2, 6, and 7 RA strains exhibited earlier onset, faster progression, and higher mortality, compared with those infected with serotype 1. The ducklings infected with serotype 2, 6, and 7 RA strains developed unsteady stance within 24-48 hours post-challenge, 48-72 hours earlier than those infected with serotype 1. Pericarditis, perihepatitis, airsacculitis, and oviduct obstruction predominantly manifested before 48 hours, before 72 hours, and at 72-120 hours post-challenge, respectively, all occurring 24-72 hours earlier than in serotype 1 infection. Mortality initiated within 24 hours post-challenge, peaked at 48-72 hours, and reached a case fatality rate of 50%-100%. In contrast, serotype 1 infections primarily caused deaths at 48-120 hours post-challenge, with a mortality rate of 10%-20%. Variations existed in the timing of visceral lesions and mortality rates among different RA strains within the same serotype. The above results indicated that the pathogenicity of serotypes 2, 6 and 7 RA in Cherry Valley ducks was stronger than that of serotype 1, and there were also differences in pathogenicity among different RA strains of the same serotype.

关键词

雏鸭 / 鸭疫里氏杆菌 / 血清型 / 致病性

Key words

duckling / Riemerella anatipestifer / serotype / pathogenicity

参考文献

[1] ZHANG Y, WANG Y, ZHANG Y, et al. Genome-wide analysis reveals that PhoP regulates pathogenicity in Riemerella anatipestifer [J]. Microbiol Spectr, 2022, 10(5): e01883-22.

[2] VO T T, DANG V T, LE D H, et al. Identification, serotyping, and antimicrobial susceptibility of Riemerella anatipestifer isolated from ducks in Vietnam [J]. Open Vet J, 2022, 12(3): 391-398.

[3] LYU Z, HAN S, LI J, et al. Epidemiological investigation and drug resistance characteristics of Riemerella anatipestifer strains from large-scale duck farms in Shandong Province, China from March 2020 to March 2022 [J]. Poult Sci, 2023, 102(7): 102759.

[4] ZHU M, CHEN Z, SHEN R, et al. Riemerella anatipestifer AS87_RS02955 acts as a virulence factor and displays endonuclease activity [J]. Appl Environ Microbiol, 2022, 88(19): e01276-22.

[5] 冯雅婷, 朱敏, 刘丹, 等. 鸭疫里默氏杆菌流行菌株的分离鉴定及生物学特性 [J]. 微生物学通报, 2022, 49(11): 4778-4785.

[6] 周星禅, 邹导夫, 黎智, 等. 鸭疫里默氏杆菌病的流行病学、致病机制及防控策略 [J]. 今日畜牧兽医, 2025, 41(5): 35-37.

[7] 田大川. 兖州及周边地区肉鸭常见疫病流行病学调查 [D]. 泰安: 山东农业大学, 2021.

[8] 南文金, 吴静波, 黄健强, 等. 粤北地区鸭大肠杆菌和鸭疫里默氏杆菌及沙门菌流行病学调查与菌株耐药性研究 [J]. 韶关学院学报, 2024, 45(12): 49-55.

[9] 吕泽昊. 山东省部分地区鸭疫里默氏杆菌的流行病学调查及分离菌株耐药性研究 [D]. 泰安: 山东农业大学, 2023.

[10] 侯水生, 刘灵芝. 2019年水禽产业现状、未来发展趋势与建议 [J]. 中国畜牧杂志, 2020, 56(3): 130-135.

[11] 彭凌, 杨旭夫, 朱必凤, 等. 粤西地区两株鹅源鸭疫里氏杆菌的分离鉴定 [J]. 中国兽医科学, 2015, 45(5): 463-468.

[12] 郑志强, 张永红, 郑世学. 鸭疫里默氏杆菌病的研究进展 [J]. 养禽与禽病防治, 2018(1): 2-6.

[13] 程安春, 汪铭书, 刘维平, 等. 鸭不同途径人工感染鸭疫里默氏杆菌病理学发展规律及其致病机理的初步研究 [C]// 中国畜牧兽医学会动物微生态学分会第三届第七次学术研讨会. 无锡, 2004.

[14] LI J, ZHANG Y, WANG Y, et al. Immunogenicity of live phoP gene deletion strain of Riemerella anatipestifer serotype 1 [J]. Poult Sci, 2023, 102(1): 102294.

[15] WU X, GE J, SONG G, et al. The GE296_RS03820 and GE296_RS03830 genes are involved in capsular polysaccharide biosynthesis in Riemerella anatipestifer [J]. FASEB J, 2024, 38(13): e23763.

[16] WU M, GUO R, CHEN M, et al. Development of a multiplex PCR assay for detection of Riemerella anatipestifer serotype 1 and serotype 2 strains [J]. Vet Microbiol, 2025, 303: 110435.

[17] LIANG Z, LI H, YANG D, et al. A novel bivalent inactivated vaccine for ducks against Riemerella anatipestifer based on serotype distribution in Southern China [J]. Poult Sci, 2024, 103(3): 103427.

[18] MAGYAR T, GYURIS É, UJVÁRI B, et al. Genotyping of Riemerella anatipestifer by ERIC-PCR and correlation with serotypes [J]. Avian Pathol, 2019, 48(1): 12-16.

[19] 杨智灿, 张美琳, 李仕楷, 等. 18型鸭疫里默氏杆菌的分离鉴定及致病性研究 [J]. 中国预防兽医学报, 2024, 46(9): 909-914.

[20] 程冰花, 郝东敏, 钟洪义, 等. 安徽地区鸭疫里默氏杆菌的分离鉴定及药物筛选 [J]. 当代畜牧, 2019(9): 12-15.

[21] 张连秀, 李富金, 季善军, 等. 2019-2022年我国鸭传染性浆膜炎的流行病学分析 [J]. 中国兽医杂志, 2024, 60(12): 41-45.

[22] 张燕. 鸭疫里默氏杆菌安徽分离株耐药性分析与致病性研究 [D]. 扬州: 扬州大学, 2022.

[23] 顾玉美, 侯军, 钟万金, 等. 鸭疫里默氏杆菌流行菌株的血清型分析与最小感染量测试 [J]. 中国禽业导刊, 2023, 40(3): 60-63.

[24] 陈亦杏, 张美琳, 李仕楷, 等. 广东部分地区鸭疫里默氏杆菌的分离鉴定和耐药性分析 [J]. 中国畜牧兽医, 2024, 51(7): 3185-3194.

[25] 罗玲, 罗青平, 王红琳, 等. 鸭疫里默氏杆菌病病原分离鉴定与血清抗体检测 [J]. 中国家禽, 2019, 41(6): 59-61.

[26] 欧芳杏, 张霞, 陈佳琪, 等. 2021-2023年贵州省鸭疫里默氏杆菌病流行病学调查 [J]. 中国畜禽种业, 2024, 20(6): 110-119.

基金资助

河南省重点研发计划项目(221111111300)

现代农业产业体系建设专项(CARS-42)