Fishpool Samuel Jc, Osborne Jonathan E, Looker Nicholas
Department of Otolaryngology, Glan Clwyd Hospital, Rhyl, UK.
Cochlear Implants Int. 2012 Aug;13(3):181-3. doi: 10.1179/146701011X12950038111693. Epub 2011 Jul 5.
Biofilm forming microorganisms are responsible for the infection of a number of different indwelling medical devices including cochlear implants. The current definitive technique for proving biofilm infection is the use of scanning electron microscopy that is expensive and of limited availability.
A persistently infected cochlear implant was explanted. At operation it was surrounded by a fibrous capsule containing a glue-like substance, characteristic of biofilm formation that yielded Staphylococcus aureus after ultrasonication of the device.
The explanted cochlear implant was placed in a nutrient broth in an ultrasonic water bath. The implant was ultrasonicated for 5 minutes and the broth cultured on blood agar, incubated aerobically and anaerobically for 48 hours, and then incubated in air on Maconkey agar for 24 hours. This produced a heavy, confluent growth of S. aureus, in contrast to previous aspirates from a blister that lay over the infected implant that grew a coliform organism and Pseudomonas sp.
Ultrasonication is a widely available and relatively inexpensive technique that can be used to improve the recovery of biofilm-associated organisms from explanted cochlear implants.
形成生物膜的微生物会导致包括人工耳蜗在内的多种不同植入式医疗器械发生感染。目前用于证明生物膜感染的权威技术是使用扫描电子显微镜，该技术成本高昂且可用性有限。
取出一枚持续感染的人工耳蜗。手术时，它被一个纤维囊包裹，囊内含有一种类似胶水的物质，这是生物膜形成的特征，对该器械进行超声处理后产生了金黄色葡萄球菌。
将取出的人工耳蜗置于超声水浴中的营养肉汤中。对植入物进行5分钟的超声处理，然后将肉汤接种在血琼脂上，分别在需氧和厌氧条件下培养48小时，接着在空气中于麦康凯琼脂上培养24小时。结果产生了大量金黄色葡萄球菌的融合生长，这与之前从覆盖在感染植入物上的水疱中抽取的样本不同，后者培养出了一种大肠菌和假单胞菌属细菌。
超声处理是一种广泛可用且相对廉价的技术，可用于提高从取出的人工耳蜗中回收生物膜相关微生物的效率。
