Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Universitat Autònoma de Barcelona, Bellaterra, Spain.
Transbound Emerg Dis. 2018 May;65 Suppl 1:110-124. doi: 10.1111/tbed.12677. Epub 2017 Aug 23.
Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary pathogen of enzootic pneumonia, a chronic respiratory disease in pigs. Infections occur worldwide and cause major economic losses to the pig industry. The present paper reviews the current knowledge on M. hyopneumoniae infections, with emphasis on identification and analysis of knowledge gaps for optimizing control of the disease. Close contact between infected and susceptible pigs is the main route of M. hyopneumoniae transmission. Management and housing conditions predisposing for infection or disease are known, but further research is needed to better understand M. hyopneumoniae transmission patterns in modern pig production systems, and to assess the importance of the breeding population for downstream disease control. The organism is primarily found on the mucosal surface of the trachea, bronchi and bronchioles. Different adhesins and lipoproteins are involved in the adherence process. However, a clear picture of the virulence and pathogenicity of M. hyopneumoniae is still missing. The role of glycerol metabolism, myoinositol metabolism and the Mycoplasma Ig binding protein-Mycoplasma Ig protease system should be further investigated for their contribution to virulence. The destruction of the mucociliary apparatus, together with modulating the immune response, enhances the susceptibility of infected pigs to secondary pathogens. Clinical signs and severity of lesions depend on different factors, such as management, environmental conditions and likely also M. hyopneumoniae strain. The potential impact of strain variability on disease severity is not well defined. Diagnostics could be improved by developing tests that may detect virulent strains, by improving sampling in live animals and by designing ELISAs allowing discrimination between infected and vaccinated pigs. The currently available vaccines are often cost-efficient, but the ongoing research on developing new vaccines that confer protective immunity and reduce transmission should be continued, as well as optimization of protocols to eliminate M. hyopneumoniae from pig herds.
猪肺炎支原体（M. hyopneumoniae）是地方性肺炎的主要病原体，这是一种猪的慢性呼吸道疾病。该感染在全球范围内发生，给养猪业造成了重大经济损失。本文综述了目前对 M. hyopneumoniae 感染的认识，重点是确定和分析知识空白，以优化疾病控制。感染和易感猪之间的密切接触是 M. hyopneumoniae 传播的主要途径。已知导致感染或疾病的管理和饲养条件，但需要进一步研究以更好地了解现代养猪生产系统中 M. hyopneumoniae 的传播模式，并评估繁殖种群对下游疾病控制的重要性。该病原体主要存在于气管、支气管和细支气管的黏膜表面。不同的黏附素和脂蛋白参与黏附过程。然而，M. hyopneumoniae 的毒力和致病性仍然不清楚。甘油代谢、肌醇代谢和支原体 Ig 结合蛋白-支原体 Ig 蛋白酶系统的作用应该进一步研究，以了解它们对毒力的贡献。纤毛黏液装置的破坏，加上对免疫反应的调节，增强了感染猪对继发性病原体的易感性。临床症状和病变的严重程度取决于不同的因素，如管理、环境条件，可能还包括 M. hyopneumoniae 株。菌株变异对疾病严重程度的潜在影响尚未明确界定。通过开发可能检测到毒力株的检测方法、改进活体动物的采样以及设计允许区分感染和接种猪的 ELISA 来改进诊断，可以提高诊断水平。目前可用的疫苗通常具有成本效益，但应继续研究开发能够提供保护免疫并减少传播的新型疫苗，以及优化从猪群中消除 M. hyopneumoniae 的方案。
