The management of the shoulder skin microbiome (Cutibacterium acnes) in the context of shoulder surgery: a review of the current literature

Abstract

Background This review aims to establish current knowledge of the shoulder skin microbiome and how to manage the bacteria that reside within it. Methods A review was undertaken of the current literature through OvidSP. All abstracts were reviewed by three independent researchers. Results Thirty-five studies met the inclusion criteria. With forward referencing an additional 14 were included. None commented on organisms specific to the shoulder microbiome other than Cutibacterium acnes. Therefore, this review is focussed on the current knowledge of C. acnes. Discussion C. acnes is a skin commensal within the pilo-sebaceous glands reported to be the primary pathogen in up to 86% of shoulder joint infections. Pre-operative culture of unprepared skin can be indicative of underlying joint infection in shoulder arthroplasty revision. Intra-articular biopsies may have a high false positive due to skin contamination. Correlating the number of positive samples and certain associated signs can give a greater than 90% probability of a true infection. Standard surgical skin preparation, peri-surgical intravenous antibiotics and oral pre-operative antibiotics do not reduce bacterial load within the skin. However, topical benzoyl peroxide and clindamycin have both demonstrated significantly reduced bacteria load. Phylogenetically there are six main types. Patients may have more than one phenotype present during infection.

Techniques for Decreasing Bacterial Load for Open Shoulder Surgery

“…C. acnes forms biofilms, contributing to the pathogenesis and virulence of the bacteria 7,9,21,22 . In vitro studies suggest that C. acnes communicates through quorum sensing, which triggers the bacteria to hydrolyze the pilosebaceous gland-derived triglycerides 23 .…”

“…C. acnes is a gram-positive bacillus found in uninfected pilosebaceous glands of the dermis 7 . C. acnes has 6 main phyla (IA1, IA2, IB, IC, II, III) with unique virulence factors that trigger inflammation 7 .…”

“…C. acnes is a gram-positive bacillus found in uninfected pilosebaceous glands of the dermis 7 . C. acnes has 6 main phyla (IA1, IA2, IB, IC, II, III) with unique virulence factors that trigger inflammation 7 . PJI in shoulder arthroplasty is most often associated with C. acnes phylotype II (K1 and K2) and phylotype I (IB) 7,18,19 .…”

“…C. acnes has 6 main phyla (IA1, IA2, IB, IC, II, III) with unique virulence factors that trigger inflammation 7 . PJI in shoulder arthroplasty is most often associated with C. acnes phylotype II (K1 and K2) and phylotype I (IB) 7,18,19 . Genomic studies demonstrated that phylotype IB is most commonly implicated in orthopaedic infections 18,20 .…”

“…P eriprosthetic joint infections (PJIs) are a significant problem after joint arthroplasty that can result in significant morbidity and mortality for patients and occur in 1% to 4% of primary joint replacements [1][2][3][4] . The most frequent cause of PJI in shoulder arthroplasty is Cutibacterium acnes (39%-86%) [5][6][7][8] . C. acnes is part of the normal skin flora; is found primarily in the pilosebaceous glands on the upper chest, back, and shoulders; and is more abundant in male patients.…”