Cutibacterium Acnes is Isolated from Air Swabs: Time to Doubt the Value of Traditional Cultures in Shoulder Surgery?

Document Type : RESEARCH PAPER


Rothman Institute, Thomas Jefferson University, Department of Orthopaedic Surgery, Philadelphia, PA, USA


Background: Given high rates of positive Cutibacterium acnes (C. acnes) cultures in cases of both primary and revision
shoulder surgery, the ramifications of positive C. acnes cultures remain uncertain. Next generation sequencing (NGS)
is a molecular tool that sequences the whole bacterial genome and is capable of identifying pathogens and the relative
percent abundance in which they appear within a sample. The purpose of this study was to report the false positive
culture rate in negative control specimens and to determine whether NGS has potential value in reducing the rate of
false positive results.
Methods: Between April 2017 and May 2017 swabs were taken during primary shoulder arthroplasty. After surgical
time out, using sterile gloves, a sterile swab was opened and exposed to the air for 5 seconds, returned to its contained,
and sealed. One swab was sent to our institution’s microbiology laboratory for aerobic and anaerobic culture and held
for 13 days. The other sample was sent for NGS (MicroGen Dx, Lubbock, TX), where samples were amplified for
pyrosequencing using a forward and reverse fusion primer and matched against a DNA library for species identification.
Results: For 40 consecutive cases, swabs were sent for culture and NGS. C. acnes was identified by culture in 6/40
(15%) swabs and coagulase negative staphylococcus (CNS) was identified in 3/40 (7.5%). Both cases with positive
NGS sequencing reported polymicrobial results with one sample (2.5%), including a relative abundance of 3% C.
acnes. At 90 days after surgery, there were no cases of clinical infection in any of the 40 cases.
Conclusion: We demonstrate that the two most commonly cultured organisms (C. acnes and CNS) during revision
shoulder arthroplasty are also the two most commonly cultured organisms from negative control specimens.
Contamination can come from air in the operating room or laboratory contamination.
Level of evidence: III


1. Patel A, Calfee RP, Plante M, Fischer SA, Green A.
Propionibacterium acnes colonization of the human
shoulder. Journal of shoulder and elbow surgery. 2009
Nov-Dec;18(6):897-902. PubMed PMID: 19362854.
2. Dodson CC, Craig EV, Cordasco FA, Dines DM, Dines
JS, Dicarlo E, et al. Propionibacterium acnes infection
after shoulder arthroplasty: a diagnostic challenge.
Journal of shoulder and elbow surgery. 2010
Mar;19(2):303-7. PubMed PMID: 19884021.
3. Bossard DA, Ledergerber B, Zingg PO, Gerber C,
Zinkernagel AS, Zbinden R, et al. Optimal Length of
Cultivation Time for Isolation of Propionibacterium
acnes in Suspected Bone and Joint Infections Is
More than 7 Days. Journal of clinical microbiology.
2016 Dec;54(12):3043-9. PubMed PMID: 27733637.
Pubmed Central PMCID: 5121398.
4. Sethi PM, Sabetta JR, Stuek SJ, Horine SV, Vadasdi KB,
Greene RT, et al. Presence of Propionibacterium acnes
in primary shoulder arthroscopy: results of aspiration
and tissue cultures. Journal of shoulder and elbow
surgery. 2014 Dec 4. PubMed PMID: 25483906.
5. Ahsan ZS, Somerson JS, Matsen FA, 3rd. Characterizing
the Propionibacterium Load in Revision Shoulder
Arthroplasty: A Study of 137 Culture-Positive Cases.
The Journal of bone and joint surgery American
volume. 2017 Jan 18;99(2):150-4. PubMed PMID:
6. Mook WR, Klement MR, Green CL, Hazen KC, Garrigues
GE. The Incidence of Propionibacterium acnes in 
Open Shoulder Surgery: A Controlled Diagnostic
Study. The Journal of bone and joint surgery American
volume. 2015 Jun 17;97(12):957-63. PubMed PMID:
7. Namdari S, Nicholson T, Parvizi J, Ramsey M.
Preoperative doxycycline does not decolonize
Propionibacterium acnes from the skin of the
shoulder: a randomized controlled trial. Journal of
shoulder and elbow surgery. 2017 Jul 19. PubMed
PMID: 28734717.
8. Ramanathan B, Jindal HM, Le CF, Gudimella R,
Anwar A, Razali R, et al. Next generation sequencing
reveals the antibiotic resistant variants in the
genome of Pseudomonas aeruginosa. PloS one.
2017;12(8):e0182524. PubMed PMID: 28797043.
9. Salzberg SL, Breitwieser FP, Kumar A, Hao H, Burger
P, Rodriguez FJ, et al. Next-generation sequencing
in neuropathologic diagnosis of infections of the
nervous system. Neurology(R) neuroimmunology &
neuroinflammation. 2016 Aug;3(4):e251. PubMed
PMID: 27340685. Pubmed Central PMCID: 4907805.
10. Wilson MR, Naccache SN, Samayoa E, Biagtan
M, Bashir H, Yu G, et al. Actionable diagnosis of
neuroleptospirosis by next-generation sequencing.
The New England journal of medicine. 2014 Jun
19;370(25):2408-17. PubMed PMID: 24896819.
Pubmed Central PMCID: 4134948.
11. Hashimoto S, Shime N. Evaluation of semi-quantitative
scoring of Gram staining or semi-quantitative culture 
for the diagnosis of ventilator-associated pneumonia:
a retrospective comparison with quantitative culture.
Journal of intensive care. 2013;1(1):2. PubMed PMID:
25705397. Pubmed Central PMCID: 4336129.
12. Clarridge JE, 3rd. Impact of 16S rRNA gene sequence
analysis for identification of bacteria on clinical
microbiology and infectious diseases. Clinical
microbiology reviews. 2004 Oct;17(4):840-62, table
of contents. PubMed PMID: 15489351. Pubmed
Central PMCID: 523561.
13. Khot PD, Ko DL, Fredricks DN. Sequencing and analysis
of fungal rRNA operons for development of broadrange
fungal PCR assays. Applied and environmental
microbiology. 2009 Mar;75(6):1559-65. PubMed
PMID: 19139223. Pubmed Central PMCID: 2655463.
14. Haas BJ, Gevers D, Earl AM, Feldgarden M, Ward
DV, Giannoukos G, et al. Chimeric 16S rRNA
sequence formation and detection in Sanger and
454-pyrosequenced PCR amplicons. Genome research.
2011 Mar;21(3):494-504. PubMed PMID: 21212162.
Pubmed Central PMCID: 3044863.
15. Edgar RC. Search and clustering orders of magnitude
faster than BLAST. Bioinformatics. 2010 Oct
01;26(19):2460-1. PubMed PMID: 20709691.
16. Achermann Y, Sahin F, Schwyzer HK, Kolling C,
Wust J, Vogt M. Characteristics and outcome of 16
periprosthetic shoulder joint infections. Infection.
2013 Jun;41(3):613-20. PubMed PMID: 23124880.
17. Frangiamore SJ, Saleh A, Grosso MJ, Alolabi B, Bauer
TW, Iannotti JP, et al. Early Versus Late Culture Growth
of Propionibacterium acnes in Revision Shoulder
Arthroplasty. The Journal of bone and joint surgery
American volume. 2015 Jul 15;97(14):1149-58.
PubMed PMID: 26178890.
18. Horneff JG, Hsu JE, Huffman GR. Propionibacterium
acnes infections in shoulder surgery. The Orthopedic
clinics of North America. 2014 Oct;45(4):515-21.
PubMed PMID: 25199422.
19. Levy PY, Fenollar F, Stein A, Borrione F, Cohen E,
Lebail B, et al. Propionibacterium acnes postoperative
shoulder arthritis: an emerging clinical entity. Clinical
infectious diseases : an official publication of the
Infectious Diseases Society of America. 2008 Jun
15;46(12):1884-6. PubMed PMID: 18462110.
20. Shields MV, Abdullah L, Namdari S. The challenge
of Propionibacterium acnes and revision shoulder 
arthroplasty: a review of current diagnostic options.
Journal of shoulder and elbow surgery. 2016
Jun;25(6):1034-40. PubMed PMID: 27038565.
21. Falconer TM, Baba M, Kruse LM, Dorrestijn O,
Donaldson MJ, Smith MM, et al. Contamination of
the Surgical Field with Propionibacterium acnes
in Primary Shoulder Arthroplasty. The Journal of
bone and joint surgery American volume. 2016 Oct
19;98(20):1722-8. PubMed PMID: 27869623.
22. Koh CK, Marsh JP, Drinkovic D, Walker CG, Poon
PC. Propionibacterium acnes in primary shoulder
arthroplasty: rates of colonization, patient risk factors,
and efficacy of perioperative prophylaxis. Journal of
shoulder and elbow surgery. 2016 May;25(5):846-52.
PubMed PMID: 26704361.
23. Maccioni CB, Woodbridge AB, Balestro JC, Figtree MC,
Hudson BJ, Cass B, et al. Low rate of Propionibacterium
acnes in arthritic shoulders undergoing primary total
shoulder replacement surgery using a strict specimen
collection technique. Journal of shoulder and elbow
surgery. 2015 Aug;24(8):1206-11. PubMed PMID:
24. Smith EB, Raphael IJ, Maltenfort MG, Honsawek S,
Dolan K, Younkins EA. The effect of laminar air flow
and door openings on operating room contamination.
The Journal of arthroplasty. 2013 Oct;28(9):1482-5.
PubMed PMID: 23890828.
25. Burman WJ, Reves RR. Review of false-positive
cultures for Mycobacterium tuberculosis and
recommendations for avoiding unnecessary
treatment. Clinical infectious diseases : an official
publication of the Infectious Diseases Society of
America. 2000 Dec;31(6):1390-5. PubMed PMID:
26. Dowen D, Jeavons RP, Michla Y, Berrington A, Green
S. Laboratory contamination affecting orthopedic
surgical management. The Journal of arthroplasty.
2011 Dec;26(8):1570 e5-7. PubMed PMID: 21397450.
27. Pottinger P, Butler-Wu S, Neradilek MB, Merritt A,
Bertelsen A, Jette JL, et al. Prognostic factors for
bacterial cultures positive for Propionibacterium
acnes and other organisms in a large series of revision
shoulder arthroplasties performed for stiffness, pain,
or loosening. The Journal of bone and joint surgery
American volume. 2012 Nov 21;94(22):2075-83.
PubMed PMID: 23172325.