气体中毒患者机械通气后肺部感染病原菌监测和分子流行病学调查

Bacteriologic surveillance and molecular epidemiology for acute gas poisoning patients with mechanical ventilation

目的分析急性刺激性和窒息性气体中毒患者机械通气后肺部感染病原菌及其药物敏感性和克隆传播情况。方法动态采集15例气体中毒患者机械通气后下呼吸道、呼吸机管路、医护工作人员手拭子及纤维支气管镜样本，常规方法分离病原菌。对分离率较高的病原菌进行药物敏感性试验和脉冲场凝胶电泳（PFGE）分子分型。结果患者下呼吸道平均分离病原菌3．86种，分离率较高的为嗜麦芽窄食单胞菌、粪肠球菌、鲍曼不动杆菌、表皮葡萄球菌和白假丝酵母菌等。分离率最高的嗜麦芽窄食单胞菌对大多数常用抗菌药物的耐药率都在60％以上，且来自患者的菌株与来自工作人员手拭子和纤维支气管镜的菌株PFGE分型一致。结论急性刺激性和窒息性气体中毒机械通气患者下呼吸道存在较严重的多药耐药复合菌感染，且病原菌在不同患者间存在克隆传播。

Objective To investigate the pathogens, their drug sensitivities and molecular typing in patients suffering from acute irritant and suffocating gas poisoning under mechanical ventilation. Methods Samples from lower respiratory tracts and breathing circuits of 15 gas poisoning patients and those from hand swabs and fiberoptic bronchoscopies were collected. Pathogens were isolated and drug sensitivity tests and pulsed field gel electrophoresis （PFGE） analysis were performed for those with high isolation rates. Results There were average 3.86 kinds of isolates in the lower respiratory tracts per patient. Stenotrophomonas maltophilia ranked first, and followed by Enterococcus faecalis, Acinetobacter baumannii, Staphylococcus epidermidis and Candida albicans. Stenotrophomonas maltophilia was resistant to most antibiotics with the resistant rates above 60%. PFGE analysis showed that the isolates from patients and those from hand swabs and fiberoptic bronehoscopies were of the same type. Conclusions It suggests that multi-pathogen infections exit in the lower respiratory tracts of patients who suffered from acute irritant and suffocating gas poisoning with mechanical ventilation. The pathogens are resistant to most antibiotics and their clones may be transmitted among the patients.