Fe3+及血红蛋白铁对眼源性蜡样芽胞杆菌生长能力的影响

目的 探讨Fe³⁺及血红蛋白铁对眼源性蜡样芽胞杆菌生长能力的影响。方法 实验研究。收集2011年6月至2017年2月温州医科大学附属眼视光医院外伤性蜡样芽胞杆菌性眼内炎患者26例并分离出蜡样芽胞杆菌26株。根据患者治疗后有无光感将菌株分为有光感（LP）组和无光感（NLP）组,以蜡样芽胞杆菌模式菌株ATCC14579作为对照组,检测不同菌株在缺铁环境、不同Fe³⁺浓度环境、富含Hb环境中生长的光密度（OD）值。采用独立样本t检验对数据进行统计分析。结果 26株眼部来源的蜡样芽胞杆菌在缺铁环境中生长的OD值小于模式菌株ATCC14579（t=54.098,P<0.001）。在一定范围内（0~500 μmol/L）增加Fe³⁺浓度,菌株生长的OD值随之逐渐增加,当Fe³⁺浓度高于1 000 μmol/L时,细菌生长的OD值开始下降。在Fe³⁺或血红蛋白铁为主要铁资源的环境中,NLP组菌株生长的OD值均高于LP组（t=2.618,P=0.015;t=2.202,P=0.037）。结论 眼源性蜡样芽胞杆菌的生长对Fe³⁺具有较强的依赖性;在Fe³⁺或血红蛋白铁为主的铁资源环境中生长较快的菌株感染患者,其临床预后较差。

Effects of Fe3+ and Hemoglobin Iron on the Growth Ability of Bacillus Cereus Isolated from the Eye

Objective: To study the effects of Fe³⁺ and hemoglobin (Hb) iron on the ability of Bacillus cereus to grow when isolated from the eye. Methods: In this experimental study, 26 patients with post-traumatic Bacillus cereus endophthalmitis were recruited from Eye Hospital, Wenzhou Medical University and 26 strains of Bacillus cereus isolated from the eyes were obtained. The strains were divided into a light-perception (LP) group and no-light-perception (NLP) group, based on whether the patient's light perception was preserved after treatment, and the Bacillus cereus strain ATCC14579 was used as a control group. Optical density (OD) values of different strains of growth in an iron-deficient environment, different Fe³⁺ concentration environments, and Hb environments were measured. Data analysis was performed by independent samples t-tests. Results: The OD values of 26 strains of Bacillus cereus isolated from the eye and grown in an iron-deficient environment were weaker than the Bacillus cereus standard strain ATCC14579 (t=54.098, P<0.001). By increasing the Fe³⁺concentrations within a certain range (0-500 μmol/L), the OD values of the strains were gradually enhanced, and when the Fe³⁺ concentration was higher than 1 000 μmol/L, the OD values of the bacteria decreased. Moreover, in the environment where Fe³⁺ or Hb was the main iron resource, the OD values of the strains of the growth in the NLP group were stronger than that of the LP group (t=2.618, P=0.015; t=2.202, P=0.037). Conclusions: The growth of Bacillus cereus isolated from the eyes are more dependent on Fe³⁺, and the clinical prognosis is worse after infection with bacteria that grows faster in Fe³⁺ or Hb iron environments.