Jarzembowski Tomasz, Daca Agnieszka, Witkowski Jacek M, Bryl Ewa, Rutkowski Bolesław
Department of Microbiology, Medical University of Gdańsk, Do Studzienki 38 Street, 80-227 Gdańsk, Poland.
Department of Pathology and Experimental Rheumatology, Medical University of Gdańsk, Dębinki 7 Street, 80-211 Gdańsk, Poland.
Biomed Res Int. 2015;2015:432579. doi: 10.1155/2015/432579. Epub 2015 Mar 10.
Infections caused by opportunistic pathogens such as enterococci remain difficult to manage, especially in immunocompromised patients. Because of infections' limited symptoms in such patients the additional problems are to find proper diagnostic criteria and the management of infection. Here we aimed to compare the resistance of commensal enterococcal strains and RTx patients' isolates, to PMNs phagocytosis. Thirty-six enterococcal urine and faecal isolates from RTx patients and 17 faecal isolates from healthy volunteers were cultured in planktonic and biofilm forms in 37°C or 42°C. Another tested variable was the addition of immunosuppressant to the culture media. Bacterial cells were stained with fluorescent reporter (CFDA, PI) and incubated with PMNs. Results of phagocytosis were estimated as a mean fluorescence intensity (MFI) of PMNs using flow cytometry. Commensal enterococci cultured in all abovementioned (37°C and 42°C/the addition of immunosuppressant) conditions were less resistant to phagocytosis compared to RTx isolates. Observed significant difference in phagocytosis resistance suggests that patients in immunosuppression are colonized with high risk strains which may lead to the development of infection.
由肠球菌等机会性病原体引起的感染仍然难以控制,尤其是在免疫功能低下的患者中。由于此类患者感染症状有限,额外的问题是找到合适的诊断标准和感染管理方法。在这里,我们旨在比较共生肠球菌菌株和肾移植(RTx)患者分离株对中性粒细胞吞噬作用的抵抗力。将来自RTx患者的36株肠球菌尿液和粪便分离株以及来自健康志愿者的17株粪便分离株分别以浮游和生物膜形式在37°C或42°C下培养。另一个测试变量是在培养基中添加免疫抑制剂。用荧光报告染料(羧基荧光素二乙酸酯,碘化丙啶)对细菌细胞进行染色,并与中性粒细胞一起孵育。使用流式细胞术将吞噬作用的结果估计为中性粒细胞的平均荧光强度(MFI)。与RTx分离株相比,在上述所有条件(37°C和42°C/添加免疫抑制剂)下培养的共生肠球菌对吞噬作用的抵抗力较低。观察到的吞噬作用抵抗力的显著差异表明,免疫抑制患者被高风险菌株定植,这可能导致感染的发生。