Occurrence of Mycoplasma gallisepticum in wild birds: A systematic review and meta-analysis

Mycoplasma gallisepticum is one of the most important poultry pathogens that can also infect wild birds, but knowledge of potential non-poultry hosts that could be reservoirs of M. gallisepticum is limited. For the paper presented here, we screened three databases (PubMed, Scopus, and the Web of Knowledge) to find articles on the occurrence of M. gallisepticum in different wild bird species that were published between 1951 and 2018. Among 314 studies found, we selected and included 50 original articles that met the pre-established criteria. From those publications we extracted the following information: name of the first author, year of publication, year of sample isolation, country, region, number of birds sampled, number of birds tested by each method, number of positive samples, diagnostic criteria, and if birds were wild or captive. Because different detection techniques were used to confirm the presence of M. gallisepticum in one animal, we decided to perform the meta analyses separately for each method. The estimated prevalence of M. gallisepticum in wild birds was different by each method of detection. Our summary revealed that M. gallisepticum was present in 56 species of bird belonging to 11 different orders, of which 21 species were reported suffering both past and current infection. Our work provides information on wild bird species that could be considered potential reservoirs or carriers of M. gallisepticum and could be helpful to set the direction for future research on the spread and phylogeny of M. gallisepticum in different hosts.鸡毒支原体（Mycoplasma gallisepticum，M. gallisepticum）是一类重要的家禽病原体，同时亦可感染野生鸟类，但当前针对其潜在非家禽宿主作为该病原体储存宿主的相关认知仍较为匮乏。为撰写本研究论文，我们检索了PubMed、Scopus及Web of Knowledge三个数据库，以查找1951年至2018年间发表的、针对不同野生鸟类物种中鸡毒支原体感染情况的研究文献。在初步检索获得的314项相关研究中，我们筛选出符合预先设定纳入标准的50项原创研究纳入本分析。从上述纳入文献中，我们提取了以下信息：第一作者姓名、发表年份、样本分离年份、研究所属国家与地区、采样鸟类总数、各检测方法对应的受试样本数、阳性样本数、诊断标准，以及受试鸟类为野生个体还是圈养个体。由于不同研究采用了不同的检测技术以确认动物体内鸡毒支原体的存在，我们决定针对每种检测方法分别开展荟萃分析。不同检测方法得到的野生鸟类中鸡毒支原体的估算感染率存在差异。本研究综述结果显示，鸡毒支原体已在隶属于11个不同目、共计56种鸟类中被检出，其中21个物种被报道同时存在既往感染与当前感染情况。本研究为可被视为鸡毒支原体潜在储存宿主或携带者的野生鸟类物种提供了相关数据，可为未来针对不同宿主中鸡毒支原体的传播与系统发育研究提供方向参考。