Esteban Jaime, Gomez-Barrena Enrique, Cordero Jose, Martín-de-Hijas Nieves Zamora, Kinnari Teemu J, Fernandez-Roblas Ricardo
Department of Clinical Microbiology, Fundación Jiménez Díaz-UTE, Universidad Autónoma de Madrid, Madrid, Spain.
J Clin Microbiol. 2008 Feb;46(2):488-92. doi: 10.1128/JCM.01762-07. Epub 2007 Dec 12.
To improve the microbiological diagnosis of device-related osteoarticular infections, we have developed a protocol based on the sonication of device samples, followed by concentration and inoculation of the sonicate in a broad variety of media in a quantitative manner. Sixty-six samples from 31 patients were included in the study (17 of them with clinical diagnosis of infection). The sonication procedure had a sensitivity of 94.1%, which is better than that of conventional cultures (88.2%). One case of contamination and six cases of unexpected positive cultures were detected (specificity of 42.8%): two of these were considered to represent true infection, while the other four were considered to be nonsignificant (corrected specificity of 50%), although the clinical importance of these isolates is questionable. When we analyzed the number of CFU, no breakpoint between significant and nonsignificant isolates could be established. Based on our results, the procedure of sonication of retrieved implants is better than conventional cultures for the diagnosis of device-related infections. The significance of some isolates in patients without clinical infection remains uncertain. However, they may become pathogens and cannot be routinely considered to be contamination.
为改善与装置相关的骨关节炎感染的微生物学诊断，我们制定了一项方案，该方案基于对装置样本进行超声处理，随后将超声处理后的样本定量浓缩并接种到多种培养基中。本研究纳入了31例患者的66个样本（其中17例临床诊断为感染）。超声处理程序的敏感性为94.1%，优于传统培养法（88.2%）。检测到1例假阳性和6例意外阳性培养结果（特异性为42.8%）：其中2例被认为代表真正感染，而另外4例被认为无意义（校正特异性为50%），尽管这些分离株的临床重要性存疑。当我们分析菌落形成单位数量时，无法确定有意义和无意义分离株之间的界限。根据我们的结果，对于诊断与装置相关的感染，取出的植入物超声处理程序优于传统培养法。一些在无临床感染患者中分离出的菌株的意义仍不确定。然而，它们可能会成为病原体，不能常规地视为污染。
