Fluorescence in situ hybridization and microbial community profiling analysis of explanted cochlear implants

Abstract

Background

Cochlear implant (CI) infections affect a small, but significant number of patients. Unremitting infections can lead to explantation. Fluorescence in situ hybridization (FISH) and microbial community profiling (MCP) are methods of studying microbial environments of explanted devices that can provide information to reduce morbidity and costs of infected CIs.

Aims/objectives

To describe the results and clinical significance of bacterial analyses conducted on explanted CIs.

Material and methods

Between 2013 and 2017, 12 explanted devices underwent microbiological analysis in addition to the manufacturer’s device failure analysis. Patients’ clinical history, infection status and outcome were reviewed and correlated with microbial analysis results.

Results

From 2013 to 2017, 12 Cochlear™ devices from 11 patients underwent additional MCP or FISH analysis. Five devices were explanted due to suspected implant associated infection, and seven were explanted for other reasons. FISH analysis revealed biofilm presence on all infected devices, only partial correlation of cultures with biofilm composition and confirmation that biofilm formation occurs preferentially at particular device interfaces and geometries. MCP analysis presented challenges in data analysis inherent to its technique but correlated with cultures of infected devices and suggested a diverse microbial composition of explanted devices.

Conclusions and significance

Microbial analysis of explanted devices can aid in further elucidating treatment approaches to infected CIs.

Chinese Abstract

背景：人工耳蜗 (CI) 感染会影响数量虽小但足够说明问题的患者。持续感染可导致外植。荧光原位杂交 (FISH) 和微生物群落分析 (MCP) 是研究外移设备微生物环境的方法, 可以提供信息以降低感染 CI 的发病率和成本。

目的：描述对外移 CI进行的细菌分析的结果和临床意义。

材料与方法：2013 年至 2017 年间, 除了对12 台外移装置进行了制造商的设备故障分析, 还对此进行了微生物分析。回顾了患者的临床病史、感染状态和结果, 并将其与微生物分析结果相联系。

结果：从 2013 年到 2017 年, 对来自 11 名患者的 12 个CochlearTM 装置进行了额外的 微生物群落分析或荧光原位杂交分析。 5 个装置因疑似植入物相关感染而被移出, 7 个因其它原因被移出。 荧光原位杂交分析显示所有受感染装置上都存在生物膜, 培养物与生物膜组成仅部分相关, 并确认生物膜形成常发生于某个装置接口和某种几何形状。 微生物群落分析对技术固有的数据分析提出了质疑, 但与受感染装置的培养物相关, 并建议外植装置应具多种微生物成分。

结论和意义：外移装置的微生物分析有助于进一步阐明受感染 CI 的治疗方法。

Keywords:

• Cochlear implant infection
• biofilm
• fluorescence in situ hybridization
• microbial analysis
• microbial community profiling

Acknowledgments

Thank you to Cochlear Ltd. for providing the results of the FISH and MCP analysis.

Disclosure statement

Dr Roland is on the Cochlear Americas Surgical Advisory Board.