Dolka Beata, Chrobak-Chmiel Dorota, Czopowicz Michał, Szeleszczuk Piotr
Department of Pathology and Veterinary Diagnostics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Warsaw, Poland.
Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Warsaw, Poland.
PLoS One. 2017 Sep 21;12(9):e0185199. doi: 10.1371/journal.pone.0185199. eCollection 2017.
Enterococcus cecorum (EC) is known as a commensal in the intestines of mammals and birds. However, it has been described as an emerging pathogen in poultry industry worldwide. The aim of this study was to analyze and compare EC isolated from clinical material collected from poultry groups with different production purposes. The genetic diversity among pathogenic EC in relation to each specific poultry type was examined. In total, 148 isolates from independent infection outbreaks (2011-2016) were used: 76 broiler chickens (CB), 37 broiler breeders (BB), 23 layers (CL), 7 waterfowl (W) and 5 turkey (T) flocks (1 isolate/1 flock). We provided age ranges at diagnosis of EC-infection for 5 poultry groups. Isolates obtained from CB were significantly more frequently retrieved from bone marrow, joints, spine, and contrary to BB, CL less frequently retrieved from respiratory system. The study showed differences between EC of various poultry types in relation to 10/32 (31.3%) biochemical parameters. EC isolates from CB were significantly more often positive for βGAL, βNAG, MLZ, and less often positive for PAL and βMAN than isolates from other poultry types. However, BB and W isolates showed higher ability to metabolise mannitol than CB, CL, and T. CB isolates showed lower ability to survive at 60°C. Only chicken EC-isolates harbored virulence genes: CB (8.1%) > BB (3.4%) > CL (2%). No specific pulsotype of EC was associated with a specific poultry. One or several various (up to 6) genetic types of EC may be involved in outbreaks in CB flocks within one year in one region. Outbreaks reported in following years in the same region were usually caused by a distinct set of EC-genetic types. PFGE results indicated at the genetic heterogeneity among pathogenic isolates involved in outbreaks in relation to each poultry type. To our best knowledge, this is the first study which provides a comparison between clinical EC from 5 poultry groups. The study provides a new insight into EC as pathogen of different bird species. The obtained data may be useful in further studies on EC-infections more focused on a specific type of poultry.
盲肠肠球菌（EC）被认为是哺乳动物和鸟类肠道中的共生菌。然而，它已被描述为全球家禽业中一种新出现的病原体。本研究的目的是分析和比较从不同生产目的家禽群体收集的临床材料中分离出的EC。研究了致病EC与每种特定家禽类型相关的遗传多样性。总共使用了来自独立感染暴发（2011 - 2016年）的148株分离株：76只肉鸡（CB）、37只肉种鸡（BB）、23只蛋鸡（CL）、7只水禽（W）和5只火鸡（T）群（每群1株分离株）。我们提供了5个家禽群体确诊EC感染时的年龄范围。从CB分离得到的菌株从骨髓、关节、脊柱中检出的频率显著更高，与BB相反，从CL中从呼吸系统检出的频率较低。该研究显示不同家禽类型的EC在10/32（31.3%）生化参数方面存在差异。与其他家禽类型的分离株相比，来自CB的EC分离株βGAL、βNAG、MLZ呈阳性的频率显著更高，而PAL和βMAN呈阳性的频率更低。然而，BB和W分离株代谢甘露醇的能力高于CB、CL和T。CB分离株在60°C下的存活能力较低。只有鸡的EC分离株携带毒力基因：CB（8.1%）> BB（3.4%）> CL（2%）。没有特定的EC脉冲型与特定家禽相关。在一个地区的一年内，CB鸡群的暴发可能涉及一种或几种不同（多达6种）遗传类型的EC。在同一地区随后几年报告的暴发通常由一组不同的EC遗传类型引起。PFGE结果表明参与暴发的致病分离株在与每种家禽类型相关的遗传异质性。据我们所知，这是第一项对5个家禽群体的临床EC进行比较的研究。该研究为EC作为不同鸟类物种的病原体提供了新的见解。所获得的数据可能有助于更专注于特定家禽类型的EC感染的进一步研究。
