Response to Long Et Al Regarding: "cutibacterium Acnes and the Shoulder Microbiome".

We thank Long et al for their letter highlighting the limitations of using V4 16S ribosomal RNA (rRNA) gene primers for detecting Cutibacterium (formerly Propionibacterium) acnes in microbiome analyses. All of the analyses reported in our study were performed in the first quarter of 2016, 3 Qiu B. Al K. Pena-Diaz A.M. Athwal G.S. Drosdowech D. Faber K.J. et al. Cutibacterium acnes and the shoulder microbiome. J Shoulder Elbow Surg. 2018; 27: 1734-1739https://doi.org/10.1016/j.jse.2018.04.019 Google Scholar prior to the publication by Meisel et al 2 Meisel J.S. Hannigan G.D. Tyldsley A.S. SanMiguel A.J. Hodkinson B.P. Zheng Q. et al. Skin microbiome surveys are strongly influenced by experimental design. J Invest Dermatol. 2016; 136: 947-956https://doi.org/10.1016/j.jid.2016.01.016 Google Scholar detailing the limitations of this primer set for detecting Cutibacterium. We were previously unaware of this problem with the V4 primer set, and as we were successful in detecting C acnes in skin samples using these primers, we had no reason to suspect that our approach was biased against polymerase chain reaction (PCR) amplification of Cutibacterium 16S rRNA gene sequences. Having assessed the references Long et al have provided, we agree that the use of V4 primers in our study may have resulted in an underestimation of the true frequency of C acnes in the tissue samples we assessed in our study. 3 Qiu B. Al K. Pena-Diaz A.M. Athwal G.S. Drosdowech D. Faber K.J. et al. Cutibacterium acnes and the shoulder microbiome. J Shoulder Elbow Surg. 2018; 27: 1734-1739https://doi.org/10.1016/j.jse.2018.04.019 Google Scholar Letter to the Editor regarding Qui et al: “Cutibacterium acnes and the shoulder microbiome”Journal of Shoulder and Elbow SurgeryVol. 28Issue 8PreviewWe share the interest of Qui et al10 in understanding the potential existence of endogenous Cutibacterium (formerly Propionibacterium) acnes within the glenohumeral joint and agree that advances in our understanding of the surgical-site microbiome may yield new avenues for prevention of surgical infections. In their recent article characterizing the shoulder microbiome, Qui et al used 16S bacterial ribosomal RNA (rRNA) amplicon sequencing to quantify bacterial species present in skin, subcutaneous fat, and rotator cuff tissues. The reported absence of C acnes in the skin and subcutaneous fat samples is an unexpected finding and contrasts with several prior studies in which C acnes has consistently been cultured from shoulder samples following standard skin antisepsis measures. Full-Text PDF