Propionibacterium acnes biofilm is present in intervertebral discs of patients undergoing microdiscectomy

Background In previous studies, Propionibacterium acnes was cultured from intervertebral disc tissue of similar to 25% of patients undergoing microdiscectomy, suggesting a possible link between chronic bacterial infection and disc degeneration. However, given the prominence of P. acnes as a skin commensal, such analyses often struggled to exclude the alternate possibility that these organisms represent perioperative microbiologic contamination. This investigation seeks to validate P. acnes prevalence in resected disc cultures, while providing microscopic evidence of P. acnes biofilm in the intervertebral discs. Methods Specimens from 368 patients undergoing microdiscectomy for disc herniation were divided into several fragments, one being homogenized, subjected to quantitative anaerobic culture, and assessed for bacterial growth, and a second fragment frozen for additional analyses. Colonies were identified by MALDI-TOF mass spectrometry and P. acnes phylotyping was conducted by multiplex PCR. For a sub-set of specimens, bacteria localization within the disc was assessed by microscopy using confocal laser scanning and FISH. Results Bacteria were cultured from 162 discs (44%), including 119 cases (32.3%) with P. acnes. In 89 cases, P. acnes was cultured exclusively;in 30 cases, it was isolated in combination with other bacteria (primarily coagulase-negative Staphylococcus spp.) Among positive specimens, the median P. acnes bacterial burden was 350 CFU/g (12 - similar to 20,000 CFU/g). Thirtyeight P. acnes isolates were subjected to molecular sub-typing, identifying 4 of 6 defined phylogroups: IA1, IB, IC, and II. Eight culture-positive specimens were evaluated by fluorescence microscopy and revealed P. acnes in situ. Notably, these bacteria demonstrated a biofilm distribution within the disc matrix. P. acnes bacteria were more prevalent in males than females (39% vs. 23%, p = 0.0013). Conclusions This study confirms that P. acnes is prevalent in herniated disc tissue. Moreover, it provides the first visual evidence of P. acnes biofilms within such specimens, consistent with infection rather than microbiologic contamination

The Open Brain Consent: Informing research participants and obtaining consent to share brain imaging data

Having the means to share research data openly is essential to modern science. For human research, a key aspect in this endeavor is obtaining consent from participants, not just to take part in a study, which is a basic ethical principle, but also to share their data with the scientific community. To ensure that the participants' privacy is respected, national and/or supranational regulations and laws are in place. It is, however, not always clear to researchers what the implications of those are, nor how to comply with them. The Open Brain Consent (https://open-brain-consent.readthedocs.io) is an international initiative that aims to provide researchers in the brain imaging community with information about data sharing options and tools. We present here a short history of this project and its latest developments, and share pointers to consent forms, including a template consent form that is compliant with the EU general data protection regulation. We also share pointers to an associated data user agreement that is not only useful in the EU context, but also for any researchers dealing with personal (clinical) data elsewhere

Distribution of <i>P</i>. <i>acnes</i> colony counts in culture-positive disc tissue specimens.

<p>Distribution of <i>P</i>. <i>acnes</i> colony counts in culture-positive disc tissue specimens.</p

Summary of the microorganisms isolated in 162 cases from 368 patient intervertebral disc specimens by anaerobic culture.

<p>Summary of the microorganisms isolated in 162 cases from 368 patient intervertebral disc specimens by anaerobic culture.</p

<i>Propionibacterium acnes</i> biofilm is present in intervertebral discs of patients undergoing microdiscectomy

<div><p>Background</p><p>In previous studies, <i>Propionibacterium acnes</i> was cultured from intervertebral disc tissue of ~25% of patients undergoing microdiscectomy, suggesting a possible link between chronic bacterial infection and disc degeneration. However, given the prominence of <i>P</i>. <i>acnes</i> as a skin commensal, such analyses often struggled to exclude the alternate possibility that these organisms represent perioperative microbiologic contamination. This investigation seeks to validate <i>P</i>. <i>acnes</i> prevalence in resected disc cultures, while providing microscopic evidence of <i>P</i>. <i>acnes</i> biofilm in the intervertebral discs.</p><p>Methods</p><p>Specimens from 368 patients undergoing microdiscectomy for disc herniation were divided into several fragments, one being homogenized, subjected to quantitative anaerobic culture, and assessed for bacterial growth, and a second fragment frozen for additional analyses. Colonies were identified by MALDI-TOF mass spectrometry and <i>P</i>. <i>acnes</i> phylotyping was conducted by multiplex PCR. For a sub-set of specimens, bacteria localization within the disc was assessed by microscopy using confocal laser scanning and FISH.</p><p>Results</p><p>Bacteria were cultured from 162 discs (44%), including 119 cases (32.3%) with <i>P</i>. <i>acnes</i>. In 89 cases, <i>P</i>. <i>acnes</i> was cultured exclusively; in 30 cases, it was isolated in combination with other bacteria (primarily coagulase-negative <i>Staphylococcus spp</i>.) Among positive specimens, the median <i>P</i>. <i>acnes</i> bacterial burden was 350 CFU/g (12 - ~20,000 CFU/g). Thirty-eight <i>P</i>. <i>acnes</i> isolates were subjected to molecular sub-typing, identifying 4 of 6 defined phylogroups: IA₁, IB, IC, and II. Eight culture-positive specimens were evaluated by fluorescence microscopy and revealed <i>P</i>. <i>acnes in situ</i>. Notably, these bacteria demonstrated a biofilm distribution within the disc matrix. <i>P</i>. <i>acnes</i> bacteria were more prevalent in males than females (39% vs. 23%, p = 0.0013).</p><p>Conclusions</p><p>This study confirms that <i>P</i>. <i>acnes</i> is prevalent in herniated disc tissue. Moreover, it provides the first visual evidence of <i>P</i>. <i>acnes</i> biofilms within such specimens, consistent with infection rather than microbiologic contamination.</p></div

Visualization of bacterial biofilm in the disc tissue by CSLM and confirmation of <i>P</i>. <i>acnes</i> by FISH.

<p>A. Three dimensional reconstructed CSLM image of biofilm bacteria stained with a DNA stain (SYTO9, green) in a disc tissue sample (#4, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174518#pone.0174518.t002" target="_blank">Table 2</a>). B-C. The presence of <i>P. acnes</i> biofilms in this sample verified using FISH. Epifluorescence micrographs of a biofilm cluster showing red fluorescence from the CY5-labeled EUB338 general eubacterial probe (B) and green fluorescence from the CY3-labled <i>P. acnes</i>-specific probe (C). Co-localization of the red and green fluorescence indicates that all of the bacteria in this biofilm were <i>P. acnes</i>.</p