Impact of single and mixed infections with Escherichia coli and Mycoplasma gallisepticum on Newcastle disease virus vaccine performance in broiler chickens: an in vivo perspective
Impact of single and mixed infections with Escherichia coli and Mycoplasma gallisepticum on Newcastle disease virus vaccine performance in broiler chickens: an in vivo perspective
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DOI：
10.1111/jam.14303
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发表时间：
2019-08-01
影响因子：
4
通讯作者：
Mahmoud, H. I.
中科院分区：
文献类型：
--
作者：
Awad, N. F. S.;Abd El-Hamid, M. I.;Mahmoud, H. I.
目的研究鸡毒支原体（Mycoplasma gallisepticum，MG）和大肠杆菌（Escherichia coli，E.coli）单独和联合感染对鸡新城疫（纽卡斯尔disease virus，NDV）疫苗免疫应答的影响。方法与结果采用血凝抑制试验和酶联免疫吸附试验分别检测新城疫病毒抗体和抗新城疫病毒IgG抗体滴度。此外，使用定量逆转录PCR分析促炎细胞因子基因（白细胞介素（IL）6、IL 4和干扰素（IFN）γ）的表达水平。与暴露于细菌感染的鸡组相比，在接种的未感染鸡组中检测到所有免疫学参数的显著结果（P < 0，中心点0.05）。细菌感染沿着疫苗接种阻碍了NDV抗体的产生并减少了疫苗上调的细胞因子基因。与单一感染组相比，接种疫苗的混合感染组报告了较低的抗体滴度和细胞因子表达水平。所有先前增强的免疫学参数反映了在接种疫苗的未感染鸡组中用趋化性强的内脏NDV攻击后的最大保护。结论这些结果为MG和E.鸡新城疫疫苗接种后感染大肠杆菌的情况。本研究的意义和影响本研究希望能对病原菌对鸡的免疫抑制作用提供更好的认识。这将有助于改善未来NDV疫苗接种期间的生物安全策略。
Aims This study was designed to investigate, in an in vivo setting, the effects of single and combined infections with either Mycoplasma gallisepticum (MG) and/or Escherichia coli on the chicken immune response induced by Newcastle disease virus (NDV) vaccine. Methods and Results Humoral immunity was measured through detection of NDV antibody and anti-NDV IgG titres using haemagglutination-inhibition test and enzyme-linked immunosorbent assay, respectively. In addition, the expression levels of pro-inflammatory cytokines' genes (interleukin (IL) 6, IL4 and interferon (IFN) gamma) were analysed using quantitative reverse transcription PCR. Significant (P < 0 center dot 05) results in all immunological parameters were detected in the vaccinated noninfected chicken group in comparison with those in groups exposed to bacterial infections. Bacterial infection along with vaccination hampered the NDV antibodies production and reduced the vaccine upregulated cytokine genes. The vaccinated mixed infection group reported lower antibody titres and cytokines expression levels compared to those in the single infection groups. All the previously enhanced immunological parameters reflected the maximum protection post challenge with velogenic viscerotropic NDV in the vaccinated noninfected chicken group. Conclusions These findings provide novel insights into the immunosuppression activities of MG and E. coli infection in chickens vaccinated against NDV. Significance and Impact of the Study This study hopes to provide a better insight to the immunosuppressive action of bacterial pathogens in chickens. This will help to improve biosecurity strategies during NDV vaccination in the future.