Uzel A, Cogulu D, Oncag O
Basic and Industrial Microbiology Section, Department of Biology, School of Science, Ege University, Bornova-Izmir, Turkey.
Int J Dent Hyg. 2008 Feb;6(1):43-7. doi: 10.1111/j.1601-5037.2007.00269.x.
The microbial quality of water in a dental unit water systems (DUWS) is of considerable importance because patients and dental staff are regularly exposed to water and aerosol generated from the dental units. The objective of this study was to evaluate the 20 DUWS in general dental practices and to determine the antibiotic susceptibility of the colonizing bacteria.
Three water and one biofilm samples from each DUWS were investigated for total viable count (TVC), oral streptococci, Pseudomonas spp., Enterobacteria, Candida albicans and Legionella pneumophila.
A total of 44 morphologically different colonies were obtained from water samples and 20 types of colonies (45.5%) could be identified using API test strips. The mean TVC values were 4.36 log CFU ml(-1) for source waters, 4.95 log CFU ml(-1) for 3-in-1 syringe samples, 4.91 log CFU ml(-1) for air rotor samples and 3.66 log CFU cm(-2) for biofilm samples. Susceptibilities of the isolates were tested against piperacillin, ampicillin, ceftazidime, meropenem, gentamicin, tetracycline, ofloxacin and chloramphenicol by using microdilution method according to NCCLS. The meropenem and ofloxacin have shown the broadest spectrum against to the tested isolates.
The study emphasizes the need for effective mechanisms to reduce the microbial contamination in DUWS, and highlights the risk for cross-infection in general dental practice.
牙科单位水系统（DUWS）中的水微生物质量至关重要，因为患者和牙科工作人员经常接触牙科单位产生的水和气溶胶。本研究的目的是评估普通牙科诊所中的20个DUWS，并确定定殖细菌的抗生素敏感性。
对每个DUWS的三个水样和一个生物膜样本进行总活菌计数（TVC）、口腔链球菌、假单胞菌属、肠杆菌、白色念珠菌和嗜肺军团菌的调查。
从水样中总共获得了44个形态不同的菌落，使用API试纸条可鉴定出20种菌落（45.5%）。源水的平均TVC值为4.36 log CFU ml(-1)，三合一注射器样本为4.95 log CFU ml(-1)，气涡轮样本为4.91 log CFU ml(-1)，生物膜样本为3.66 log CFU cm(-2)。根据美国国家临床实验室标准委员会（NCCLS）的方法，采用微量稀释法测试分离株对哌拉西林、氨苄西林、头孢他啶、美罗培南、庆大霉素、四环素、氧氟沙星和氯霉素的敏感性。美罗培南和氧氟沙星对测试分离株显示出最广的抗菌谱。
该研究强调需要有效的机制来减少DUWS中的微生物污染，并突出了普通牙科诊所中交叉感染的风险。
