Mycoplasma gallisepticum (MG) is an economically significant pathogen of poultry which results in severe disease especially when complicated by other respiratory pathogens. The objectives of this study, were to establish preliminary baseline data on the respiratory pathogens in MG positive commercial turkey flocks in California and to identify key predictor variables of MG serologic status. The retrospective study analyzed a total of 54 flocks in which MG was confirmed in central California from 2008 to 2019 by California Animal Health and Food Safety laboratories (CAHFS). Of the 54 flocks that were confirmed positive by quantitative polymerase chain reaction (qPCR), 34 (63%) had positive MG ELISA titers and 20 (37%) were negative. Escherichia coli was the most common pathogen isolated in 13 (24.1%) flocks followed by Bordetella avium, Mycoplasma synoviae, and Ornithobacterium rhinotracheale in 10 (18.5%), 8 (14.8%), and 7 (13%), respectively. The mean age at which flocks were submitted for necropsy to the CAHFS laboratories and confirmed as MG qPCR positive was approximately 15 wk. To assess the main effects on MG serologic status, a stepwise logistic regression model was developed. Of the 6 independent variables examined (age of flock, season, farm size, company, number of concurrent pathogens and year), only age of flock (odds ratio = 1.7, P= 0.002) was determined to be a significant factor in the final model. This study provides preliminary baseline data on the concurrent infectious pathogens in qPCR MG positive commercial turkeys. It also identified potentially critical information as well as the age of detection, which may aid in the implementation of targeted control and prevention strategies.

鸡毒支原体( MG ) 是一种具有重要经济意义的家禽病原体，可导致严重的疾病，尤其是当与其他呼吸道病原体并发时。本研究的目的是在加利福尼亚州 MG 阳性商业火鸡群中建立呼吸道病原体的初步基线数据，并确定 MG 血清学状态的关键预测变量。回顾性研究分析了 2008 年至 2019 年加利福尼亚州中部动物健康和食品安全实验室 ( CAHFS )共确认 54 只鸡群的 MG 。在通过定量聚合酶链反应 ( qPCR )确认为阳性的 54 只鸡群中，34 只 (63%) 的 MG ELISA 滴度为阳性，​​20 只 (37%) 为阴性. 大肠杆菌是在 13 个 (24.1%) 鸡群中分离出的最常见病原体，其次是鸟博德特氏菌、滑膜支原体和鼻气管鸟杆菌分别为 10 个 (18.5%)、8 个 (14.8%) 和 7 个 (13%)。鸡群提交给 CAHFS 实验室进行尸检并确认为 MG qPCR 阳性的平均年龄约为 15 周。为了评估对 MG 血清学状态的主要影响，开发了逐步逻辑回归模型。在检查的 6 个自变量（鸡群年龄、季节、农场规模、公司、并发病原体数量和年份）中，只有鸡群年龄（优势比 = 1.7，P= 0.002) 被确定为最终模型中的一个重要因素。本研究提供了 qPCR MG 阳性商业火鸡中并发感染性病原体的初步基线数据。它还确定了潜在的关键信息以及检测年龄，这可能有助于实施有针对性的控制和预防策略。