牙科综合治疗台水路系统污染微生物调查及其消毒方法

Microbial contamination in dental unit waterlines and its disinfection method

摘要:

目的 分离鉴定牙科综合治疗台水路系统（DUWLs）中污染微生物，通过优势菌对不同消毒剂的抗性评价现行消毒与感染控制措施。 方法 选取某三甲专科口腔医院DUWLs作为研究对象，采用菌落计数法对使用中的DUWLs进行微生物培养计数，采用质谱分析仪分离鉴定优势菌，通过最低抑菌浓度试验（MIC）和最小杀菌浓度试验（MBC）评价优势菌对不同消毒剂的抗性，通过悬液定量杀菌法比较产黏液分枝杆菌与标准菌株（龟分枝杆菌脓肿亚种）的抗力。 结果 24台DUWLs的48个水标本菌落检出率100.00%，平均菌落数为（2.25±1.43）×10⁵ CFU/mL，并分离出9种污染微生物，优势菌为产黏液分枝杆菌（35.72%），其次为真菌（21.43%）。分离的产黏液分枝杆菌对醋酸氯己定、次氯酸钠、过氧乙酸、过氧化氢4种常用消毒剂的MIC分别为1.5、500、5、100 mg/L，MBC分别为3、500、10、200 mg/L，对次氯酸钠的抗力接近标准菌株；0.5%醋酸氯己定在30 min内无法有效杀灭分离的产黏液分枝杆菌和标准菌株龟分枝杆菌脓肿亚种，0.1%次氯酸钠、3%过氧化氢及0.1%过氧乙酸在30 min内均可有效杀灭分离的产黏液分枝杆菌和标准菌株龟分枝杆菌脓肿亚种。 结论 对含氯消毒剂抗力更强的非结核分枝杆菌已取代铜绿假单胞菌与军团菌成为本研究所选医院DUWLs中优势菌群，DUWLs的消毒应选择合适的消毒剂种类、浓度，以及有效的作用时间和使用频率。

Abstract:

Objective To isolate and identify microorganism contaminated in dental unit waterlines (DUWLs), evaluate current disinfection and infection control measures through the resistance of dominant pathogens to different disinfectants. Methods DUWLs in a tertiary first-class dental hospital were selected as the research object, microorganisms in DUWLs were cultured and conducted colony counting, dominant bacteria were isolated and identified by mass spectrometry, resistance of dominant bacteria to different disinfectants was evaluated by minimum inhibitory concentration (MIC) test and minimum bactericidal concentration (MBC) test, resistance of Mycobacterium mucogenicum was compared with that of standard strain (Mycobacterium chelonei subsp.abscessus) by suspension quantitative germicidal method. Results Detection rate of colonies in 48 water specimens from 24 DUWLs was 100.00%, the average number of colony was (2.25±1.43)×10⁵ CFU/mL, 9 kinds of contaminated microorganisms were isolated, the dominant pathogen was Mycobacterium mucogenicum (35.72%), followed by fungi (21.43%). MICs of the isolated Mycobacterium mucogenicum to chlorhexidine acetate, sodium hypochlorite, peracetic acid, and hydrogen peroxide were 1.5, 500, 5 and 100 mg/L respectively, and MBC were 3, 500, 10 and 200 mg/L respectively, resistance to sodium hypochlorite was close to the standard strain; 0.5% chlorhexidine acetate could not effectively kill the isolated Mycobacterium mucogenicum and standard strain Mycobacterium chelonei subsp.abscessus within 30 minutes, 0.1% sodium hypochlorite, 3% hydrogen peroxide and 0.1% peracetic acid could effectively kill the isolated Mycobacterium mucogenicum and standard strain Mycobacterium chelonei subsp.abscessus within 30 minutes. Conclusion Non-tuberculous mycobacterium, which has strong resistance to chlorine-containing disinfectant, has replaced Pseudomonas aeruginosa and Legionella as the dominant flora in DUWLs of the hospital selected in this study, appropriate disinfectant types, concentration, effective action time and use frequency should be selected for the disinfection of DUWLs.