Campler Magnus R, Hashish Amro, Ghanem Mostafa, El-Gazzar Mohamed M, Arruda Andréia G
Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
Pathogens. 2023 Jul 31;12(8):1004. doi: 10.3390/pathogens12081004.
Respiratory infections caused by (ORT) and (PM) bacteria are significant threats to the poultry industry by causing economic losses and welfare issues. Due to characterization difficulties and underutilization of epidemiological tools, description of the spatio-temporal spread of these diseases in the field is limited. The objectives of this retrospective observational cross-sectional study were to (a) investigate the existence of space-time clusters (hotspots); and (b) investigate the association between genetic similarity and spatial proximity for both pathogens using molecular typing and a recently developed Core-Genome Multilocus Sequencing Typing (cgMLST) scheme. ORT ( = 103) and PM ( = 69) isolates from confirmed disease outbreaks from one commercial company between 2013 and 2021 were obtained from a veterinary diagnostic laboratory, characterized using a cgMLST scheme and visualized using a minimum spanning tree. Spatio-temporal cluster analysis using SaTScan and a Spearman's rank correlation were performed to investigate clustering and any association between allelic diversity and geospatial distance. The cgMLST sequencing revealed three allelic clusters for ORT and thirteen clusters for PM. The spatio-temporal analysis revealed two significant clusters for PM, one with a 259.3 km cluster containing six cases between May and July 2018 and a 9 km cluster containing five cases between February 2019 and February 2021. No spatio-temporal clusters were found for ORT. A weak negative correlation between allelic diversity and geospatial distance was observed for ORT (r = -0.04, < 0.01) and a weak positive correlation was observed for PM (r = 0.11, < 0.01). This study revealed regional spatio-temporal clusters for PM in commercial turkey sites between 2018 and 2021 and provided additional insight into bacterial strain subgroups and the geographical spread of ORT and PM over time.
由禽致病性大肠杆菌（ORT）和多杀性巴氏杆菌（PM）引起的呼吸道感染对家禽业构成重大威胁，会造成经济损失和福利问题。由于存在鉴定困难以及流行病学工具利用不足的情况，这些疾病在实际中的时空传播描述有限。这项回顾性观察性横断面研究的目的是：（a）调查时空聚集（热点）的存在情况；（b）使用分子分型和最近开发的核心基因组多位点测序分型（cgMLST）方案，研究两种病原体的遗传相似性与空间邻近性之间的关联。从一家商业公司2013年至2021年确诊疾病暴发中获取的ORT（n = 103）和PM（n = 69）分离株来自一家兽医诊断实验室，使用cgMLST方案进行鉴定，并使用最小生成树进行可视化展示。使用SaTScan进行时空聚集分析，并进行斯皮尔曼等级相关性分析，以研究聚集情况以及等位基因多样性与地理空间距离之间的任何关联。cgMLST测序显示ORT有三个等位基因簇，PM有十三个等位基因簇。时空分析显示PM有两个显著聚集区，一个是2018年5月至7月间一个259.3公里的聚集区，包含6例病例，另一个是2019年2月至2021年2月间一个9公里的聚集区，包含5例病例。未发现ORT的时空聚集区。观察到ORT的等位基因多样性与地理空间距离之间存在弱负相关（r = -0.04，P < 0.01），PM存在弱正相关（r = 0.11, P < 0.01）。本研究揭示了2018年至2021年间商业火鸡养殖场中PM的区域时空聚集情况，并为ORT和PM的细菌菌株亚群以及随时间的地理传播提供了更多见解。
