Ahmadrajabi Roya, Dalfardi Mohammad Sadegh, Farsinejad Alireza, Saffari Fereshteh
Faculty of Medicine, Microbiology Section, Bam University of Medical Sciences, Bam, Iran.
Department of Microbiology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
APMIS. 2018 Apr;126(4):314-319. doi: 10.1111/apm.12813. Epub 2018 Jan 25.
Although Enterococcus faecalis is known as normal flora in colon, it is also amongst the most common causative agents of infective endocarditis (IE). Platelet activation resulting from adherence to platelets is an essential step in the pathogenesis of IE. One of the factors proposed in adhesion is endocarditis- and biofilm- associated pili encoded by ebp operon. The aim of this study was to investigate ebp in isolates from different origins and analyze the potential of isolates to activate human platelets of different donors. The ebp distribution was investigated in E. faecalis from different origin infections (n = 103) and fecal flora (n = 20). Then, selected isolates from blood (n = 5), urine (n = 2), and fecal flora (n = 3) were analyzed by flow cytometry assay for the ability to activate platelets of four different donors. No statistically significant difference was found for the ebp presence between infective and fecal isolates. Also, it was found that the ability for platelet activation is independent of the bacterial origin. However, significant difference was found in platelet activation between different donors. The results suggest that the presence or absence of ebp is not a critical factor for platelet activation by E. faecalis isolates. However, host factors seem to contribute in this activity.
尽管粪肠球菌在结肠中被认为是正常菌群，但它也是感染性心内膜炎（IE）最常见的病原体之一。因黏附于血小板而导致的血小板激活是IE发病机制中的关键步骤。黏附中提出的因素之一是由ebp操纵子编码的心内膜炎和生物膜相关菌毛。本研究的目的是调查不同来源分离株中的ebp，并分析分离株激活不同供体人血小板的潜力。研究了来自不同来源感染（n = 103）和粪便菌群（n = 20）的粪肠球菌中ebp的分布。然后，通过流式细胞术分析从血液（n = 5）、尿液（n = 2）和粪便菌群（n = 3）中选择的分离株激活四种不同供体血小板的能力。在感染性分离株和粪便分离株之间，ebp的存在没有统计学上的显著差异。此外，还发现血小板激活能力与细菌来源无关。然而，不同供体之间在血小板激活方面存在显著差异。结果表明，ebp的存在与否不是粪肠球菌分离株激活血小板的关键因素。然而，宿主因素似乎在这一活动中起作用。
