INDIVIDUAL ARTCLE: Pathophysiologic Targets of Acne Treatment.

Acne vulgaris is an extremely common dermatologic condition. Individuals with acne present not only to dermatologists, but also to internists, family medicine physicians, pediatricians, estheticians, and beauty counters alike in search of a treatment. The diagnosis of acne is relatively straightforward, leading many to believe that acne is a simple condition. However, the pathophysiology of acne is anything but simple. Decades of research has ultimately revealed a complex interaction of pathogenic factors that lead to acne. This includes sebum production, C. acnes colonization, inflammation, and follicular hyperkeratinization. Understanding each of these features has been fundamental to the development of anti-acne medications. Topical agents are often used as an initial therapy given their safety and efficacy. While some topical therapies have been used for decades, new creams, gels, and lotions continue to be added to the list of approved acne treatments. Given the number of topical acne products on the market, we present an updated review of the current landscape of topical acne treatments and how each choice functions mechanistically to fight against acne. J Drugs Dermatol. 2024;23:10(Suppl 1):s4-11.

Causal effects of skin microbiota on intervertebral disk degeneration, low back pain and sciatica: a two-sample Mendelian randomization study.

OBJECTIVE: The purpose of this study is to use two-sample Mendelian randomization (MR) to investigate the causal relationship between skin microbiota, especially Propionibacterium acnes, and intervertebral disc degeneration (IVDD), low back pain (LBP) and sciatica. METHODS: We conducted a two-sample MR using the aggregated data from the whole genome-wide association studies (GWAS). 150 skin microbiota were derived from the GWAS catalog and IVDD, LBP and sciatica were obtained from the IEU Open GWAS project. Inverse-variance weighted (IVW) was the primary research method, with MR-Egger and Weighted median as supplementary methods. Perform sensitivity analysis and reverse MR analysis on all MR results and use multivariate MR to adjust for confounding factors. RESULTS: MR revealed five skin microbiota associated with IVDD, four associated with LBP, and two with sciatica. Specifically, P.acnes in sebaceous skin environments were associated with reduced risk of IVDD; IVDD was found to increase the abundance of P.acnes in moist skin. Furthermore, ASV010 [Staphylococcus (unc.)] from dry skin was a risk factor for LBP and sciatica; ASV045 [Acinetobacter (unc.)] from dry skin and Genus Rothia from dry skin exhibited potential protective effects against LBP; ASV065 [Finegoldia (unc.)] from dry skin was a protective factor for IVDD and LBP. ASV054 [Enhydrobacter (unc.)] from moist skin, Genus Bacteroides from dry skin and Genus Kocuria from dry skin were identified as being associated with an increased risk of IVDD. Genus Streptococcus from moist skin was considered to be associated with an increased risk of sciatica. CONCLUSIONS: This study identified a potential causal relationship between skin microbiota and IVDD, LBP, and sciatica. No evidence suggests skin-derived P.acnes is a risk factor for IVDD, LBP and sciatica. At the same time, IVDD can potentially cause an increase in P.acnes abundance, which supports the contamination theory.

Synovial Fluid Cutibacterium acnes Antigen Is Detected Among Shoulder Samples with High Inflammation and Early Culture Growth.

BACKGROUND: An emerging paradigm suggests that positive Cutibacterium acnes shoulder cultures can result from either true infection or contamination, with true infections demonstrating a host inflammatory response and early culture growth. This clinical retrospective study examines the relationship between C. acnes antigen, C. acnes culture results, and inflammation. METHODS: From January 2021 to July 2023, 1,365 periprosthetic synovial fluid samples from 347 institutions were tested for shoulder infection at a centralized clinical laboratory. A biomarker scoring system based on the 2018 International Consensus Meeting (ICM) definition was utilized to assign each sample an inflammation score. Associations between inflammation, culture results, and C. acnes antigen results were assessed utilizing cluster and correlation analyses. RESULTS: Of 1,365 samples, 1,150 were culture-negative and 215 were culture-positive (94 C. acnes and 121 other organisms). Among the 94 C. acnes culture-positive samples, unsupervised clustering revealed 2 distinct sample clusters (silhouette coefficient, 0.83): a high-inflammation cluster (n = 67) and a low-inflammation cluster (n = 27). C. acnes antigen levels demonstrated moderate-strong positive correlation with inflammation (Spearman ρ, 0.60), with 166-fold higher levels of C. acnes antigen in high-inflammation samples (16.6 signal/cutoff [S/CO]) compared with low-inflammation samples (0.1 S/CO) (p < 0.0001). The days to C. acnes culture positivity demonstrated weak-inverse correlation with inflammation (Spearman ρ = -0.38), with 1.5-fold earlier growth among the 67 high-inflammation samples (6.7 compared with 10.4 days; p < 0.0001). Elevated C. acnes antigen was observed in only 4 (0.38%) of 1,050 low-inflammation culture-negative samples and in only 5 (4.9%) of 103 high-inflammation non- C. acnes -positive cultures. However, 19.0% of high-inflammation, culture-negative samples demonstrated elevated C. acnes antigen. CONCLUSIONS: Synovial fluid C. acnes antigen was detected among shoulder samples with high inflammation and early culture growth, supporting the emerging paradigm that these samples represent true infection. Future research should explore antigen testing to differentiate contamination from infection and to identify culture-negative C. acnes infections. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Cryopreserved bone flaps from decompressive craniectomies: a microbiological analysis.

PURPOSE: Surgical site infection (SSI) is a serious complication after cranioplasty. Due to the relatively frequent occurrence of post-cranioplasty SSI, the utility of autologous bone flap swab cultures surrounding cryopreservation as a reliable predictor has been the subject of an ongoing debate. This bicentric study aims to contribute to this topic by conducting an in-depth analysis of bone flaps obtained via decompressive craniectomies. This study had three major aims: assessments of 1) bacterial contamination of bone flaps after decompressive craniotomy, 2) impact of cryoconservation on contamination rates and 3) potential effectiveness of anti-infective treatment to reduce the germ load prior to cranioplasty. METHODS: Cryopreserved bone flaps from two centers were used. Microbiological cultivations of swabs prior to and after cryopreservation were taken and assessed for aerobic and anaerobic growth over a 14-day incubation period. Additionally, in a subset of bone flaps, swab testing was repeated after thorough rinsing with an anti-infectant (octenidine-phenoxyethanol) followed by saline. RESULTS: All 63 bone flaps (patients median age at surgery: 59 years) were obtained via decompressive craniectomies. Swabs done prior to cryopreservation revealed a 54% infection rate with Propionibacterium acnes being the most common microorganism in 65% of those cases. After thorough disinfection of the preserved bone flaps, all but one case showed no bacterial growth in swab testing. Furthermore, no relevant risk factors for bacterial contamination could be identified. CONCLUSION: This retrospective study showed the common presence of bacterial growth in cryopreserved bone flaps before and after freezing. Rinsing with octenidine-phenoxyethanol and saline effectively prevented bacterial growth in a notable percentage of cases, suggesting a potential strategy to reduce contamination. However, persistent bacterial growth in some cases underscores the need for further research to optimize antiseptic measures during autologous cranioplasty.

Cutibacterium acnes in spine surgery: pathophysiology, diagnosis, and treatment.

Cutibacterium acnes (C. acnes) previously named Propionibacterium acnes (P. acnes) has been increasingly recognized by spine surgeons as a cause of indolent postsurgical spinal infection. Patients infected with C. acnes may present with pseudarthrosis or nonspecific back pain. Currently, microbiological tissue cultures remain the gold standard in diagnosing C. acnes infection. Ongoing research into using genetic sequencing as a diagnostic method shows promising results and may be another future way of diagnosis. Optimized prophylaxis involves the use of targeted antibiotics, longer duration of antibiotic prophylaxis, antibacterial-coated spinal implants, and evidence-based sterile surgical techniques all of which decrease contamination. Antibiotics and implant replacement remain the mainstay of treatment, with longer durations of antibiotics proving to be more efficacious. Local guidelines must consider the surge of antimicrobial resistance worldwide when treating C. acnes.

Intradermal injection of Cutibacterium acnes and staphylococcus: A pustular acne-like murine model.

BACKGROUND: Skin 16S microbiome diversity analysis indicates that the Staphylococcus genus, especially Staphylococcus aureus (S. aureus), plays a crucial role in the inflammatory lesions of acne. However, current animal models for acne do not fully replicate human diseases, especially pustular acne, which limits the development of anti-acne medications. AIMS: The aim is to develop a mouse model for acne, establishing an animal model that more closely mimics the clinical presentation of pustular acne. This will provide a new research platform for screening anti-acne drugs and evaluating the efficacy of clinical anti-acne experimental treatments. METHODS: Building upon the existing combination of acne-associated Cutibacterium acnes (C. acnes) with artificial sebum, we will inject a mixture of S. aureus and C. acnes locally into the dermis in a 3:7 ratio. RESULTS: We found that the acne animal model with mixed bacterial infection better replicates the dynamic evolution process of human pustular acne. Compared to the infection with C. acnes alone, mixed bacterial infection resulted in pustules with a distinct yellowish appearance, resembling pustular acne morphology. The lesions exhibited redness, vascular dilation, and noticeable congestion, along with evident infiltration of inflammatory cells. This induced higher levels of inflammation, as indicated by a significant increase in the secretion of inflammatory factors such as IL-1ß and TNF-α. CONCLUSION: This model can reflect the clinical symptoms and development of human pustular acne, overcoming the limitations of animal models commonly used in basic research to study this situation. It provides support for foundational research and the development of new acne medications.

Risk factors associated with low-grade virulent infection in intervertebral disc degeneration: a systematic review and meta-analysis.

BACKGROUND: An increasing number of research indicates an association between low-grade bacterial infections, particularly those caused by Propionibacterium acnes (P. acnes), and the development of intervertebral disc degeneration (IDD). However, no previous meta-analysis has systematically assessed the risk factors for low-grade bacterial infections that cause IDD. PURPOSE: This study reviewed the literature to evaluate the risk factors associated with low-grade bacterial infection in patients with IDD. STUDY DESIGN: Systematic review and meta-analysis. METHODS: The systematic literature review was conducted using the PubMed, Web of Science, Embase, and Cochrane Library databases. Eligible articles explicitly identified the risk factors for low-grade bacterial infections in IDD patients. Patient demographics and total bacterial infection rates were extracted from each study. Meta-analysis was performed using random- or fixed-effects models, with statistical analyses conducted using Review Manager (RevMan) 5.4 software.aut. RESULTS: Thirty-three studies involving 4,109 patients were included in the meta-analysis. The overall pooled low-grade bacterial infection rate was 30% (range, 24%-37%), with P. acnes accounting for 25% (range, 19%-31%). P. acnes constituted 66.7% of bacteria-positive discs. Fourteen risk factors were identified, of which 8 were quantitatively explored. Strong evidence supported male sex (odds ratio [OR] = 2.15; 95% confidence interval [CI]=1.65-2.79; p<.00001) and Modic changes (MCs) (OR=3.59; 95% CI=1.68-7.76; p=.0009); moderate evidence of sciatica (OR=2.31; 95% CI=1.33-4.00; p=.003) and younger age (OR=-3.47; 95% CI=-6.42 to -0.53; p=.02). No evidence supported previous disc surgery, MC type, Pfirrmann grade, smoking, or diabetes being risk factors for low-grade bacterial infections in patients with IDD. CONCLUSIONS: Current evidence highlights a significant association between IDD and low-grade bacterial infections, predominantly P. acnes being the most common causative agent. Risk factors associated with low-grade bacterial infections in IDD include male sex, MCs, sciatica, and younger age.

Are Cutibacterium acnes present at the end of primary shoulder prosthetic surgeries responsible for infection? Prospective study.

The purpose of this study was to investigate if the C. acnes present at the end of a primary shoulder arthroplasty could be responsible for shoulder arthroplasty infection. Prospective study includes patients undergoing primary shoulder arthroplasty from January 2015 until December 2018. From all the patients included, 5 to 12 tissue samples were obtained and were specifically cultured to detect the presence of C. acnes. DNA was extracted from the C acnes isolated colonies and Whole Genome Sequencing (WGS) analysis was done. A cohort of 156 patients was finally included. In twenty-seven patients, the C. acnes was present at the end of the primary surgery. Two of these patients developed a C. acnes periprosthetic shoulder infection at 6 and 4 months after the primary surgery. WGS of C. acnes isolated colonies showed that all the revision-surgery isolates clustered near to the corresponding primary-surgery isolates compared to the other independent bacterial colonies. (99.89% of similarity). C. acnes present at the end of the primary surgery can be the cause of early or delayed periprosthetic joint infections in shoulder arthroplasty.

Cutibacterium acnes clonal complexes display various growth rates in blood culture vials used for diagnosing orthopedic device-related infections.

OBJECTIVES: Blood culture bottles (BCBs) are commonly used for the diagnosis of infections associated with orthopedic devices. Although Cutibacterium acnes is an important pathogen in orthopedics, relatively little is known about its growth characteristics in BCBs. This prompted us to analyze the influence of bacterial genotype and clinical significance on time-to-detection (TTD) in BCBs. METHODS: We reviewed 59 cases of orthopedic device-related infections in which at least one intraoperative specimen yielded a pure C. acnes culture from anaerobic BCBs (BD Bactec Lytic/10 Anaerobic/F; Lytic-Ana) and/or solid media. A strain was considered infectant if the same genotype was present in two or more intraoperative samples. From these cases, we isolated a total of 72 unique C. acnes strains belonging to four multilocus sequence type clonal complexes (CCs): CC18, CC28, CC36 and CC53. Growth rate and TTD in Lytic-Ana BCB were studied under experimental conditions (inoculation of standard inoculum) and in clinical samples (inoculation of periprosthetic tissue samples). RESULTS: Median TTD values were shorter for CC53 compared to other CCs under experimental conditions (69 vs. 103 h; p < 0.001) and from clinical specimens (70 vs. 200 h; p = 0.02). Infectant strains had a shorter median TTD compared to contaminant strains in a clinical situation, while the difference was not observed under experimental conditions. CONCLUSIONS: The detection dynamics of C. acnes in Lytic-Ana BCBs were associated with genotype. Thus, TTD not only reflects the bacterial load in clinical samples, but may also reflect the intrinsic properties of the clonal complex of C. acnes.

Incidence of Cutibacterium acnes in open shoulder surgery.

In recent years, Cutibacterium acnes (C. acnes) has been reported to affect postoperative outcomes. The purpose of this study was to examine the detection rate and clinical features of C. acnes infection after open shoulder surgery. Fifty-nine patients (33 males and 26 females; mean age, 69.1 years) were included. Samples were collected from a skin swab at the incision site prior to skin preparation. Further samples were collected from synovial swabs at the glenohumeral joint immediately after incision and before incision closure. Samples with C. acnes-positive skin swab cultures were defined as Group A, and those with negative cultures were defined as Group N. Age, sex, presence of diabetes mellitus, operation time, presence of deep infection after surgery, and rate of positive synovial swab cultures were compared between groups. There were 27 patients in Group A (mean age 69.1±13.3 [SD], 21 males and 6 females) and 32 patients in Group N (mean age 69.1±11.0 [SD], 12 males and 20 females). No significant difference in the presence of diabetes mellitus and operation time were found between groups. From the glenohumeral joint immediately after incision, C. acnes was detected in 22.2% and 0% of patients in Group A and Group N, respectively. For the glenohumeral joint before incision closure, C. acnes was detected in 22.2% and 0% of patients in Group A and Group N, respectively, demonstrating a significantly higher rate in Group A. Our findings suggest that the route of infection following open shoulder surgery is via contamination.

Recognizing Cutibacterium acnes as a cause of infectious pericarditis: A case report and review of literature.

Cutibacterium acnes is an anaerobic bacterium commonly thought of as a culture contaminant rather than a pathogen. We present a case of Cutibacterium acnes pericarditis in a 22-year-old immunocompetent woman managed with surgical pericardial window and a 4-week course of penicillin G and review related literature on Cutibacterium acnes pericarditis.

A Retrospective Chart Review of Inflamed Epidermal Inclusion Cysts.

BACKGROUND: Epidermal inclusion cysts (EIC) are one of the most common forms of cysts found on and/or underneath the skin. Inflamed EICs typically show signs and symptoms such as pain and erythema, mimicking cutaneous abscess. However, prior studies have demonstrated at least 20% of lesions are culture negative. OBJECTIVE: To determine the rate of culture positivity in mild inflamed epidermal inclusion cysts, in particular to identify whether empiric antibiotics are warranted. METHODS: In a retrospective chart review 76 cases of inflamed EIC that were mild (lacking systemic symptoms) were analyzed who presented to the department of dermatology at Mount Sinai between 2016–2019. RESULTS: Of cultures taken from inflamed cysts, 47% resulted in no bacterial growth or growth of normal flora, 38.4% resulted in growth of aerobic bacteria with methicillin-resistant Staphylococcus aureus (8%), Staphylococcus lugdunensis (5%), and methicillin-sensitive Staphylococcus aureus (13%) predominating, and 9.3% resulting in growth of anaerobic bacteria with Finegoldia magna, Peptostreptococcus, and Cutibacterium acnes presenting. Review of prescribed treatment regimens often involved antibiotic medication, despite a high prevalence of negative culture. CONCLUSIONS: Almost half of cases of mild inflamed EIC (lacking systemic symptoms) cultured will not grow pathogenic bacteria, therefore incision and drainage with culture and appropriate therapy is a viable therapeutic option in uncomplicated inflamed EIC lesions. In this way, over prescription of antibiotics can be minimized. J Drugs Dermatol. 2021;20(2):199-202. doi:10.36849/JDD.5014.

A novel mutation in early-onset sarcoidosis/Blau syndrome: an association with Propionibacterium acnes.

BACKGROUND: Early-onset sarcoidosis (EOS) and Blau syndrome (BS) are systemic inflammatory granulomatous diseases without visible pulmonary involvement, and are distinguishable from their sporadic and familial forms. The diseases are characterized by a triad of skin rashes, symmetrical polyarthritis, and recurrent uveitis. The most common morbidity is ocular involvement, which is usually refractory to conventional treatment. A gain-of-function mutation in the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene has been demonstrated in this disease; however, little is known about the relationship between the activation of NOD2 and the pathophysiology of EOS/BS. Here we describe EOS/BS with a novel mutation in the NOD2 gene, as well as detection of Propionibacterium acnes (P. acnes) in the granulomatous inflammation. CASE PRESENTATION: An 8-year-old Japanese girl presented with refractory bilateral granulomatous panuveitis. Although no joint involvement was evident, she exhibited skin lesions on her legs; a skin biopsy revealed granulomatous dermatitis, and P. acnes was detected within the sarcoid granulomas by immunohistochemistry with P. acnes-specific monoclonal (PAB) antibody. Genetic analyses revealed that the patient had a NOD2 heterozygous D512V mutation that was novel and not present in either of her parents. The mutant NOD2 showed a similar activation pattern to EOS/BS, thus confirming her diagnosis. After starting oral prednisolone treatment, she experienced an anterior vitreous opacity relapse despite gradual prednisolone tapering; oral methotrexate was subsequently administered, and the patient responded positively. CONCLUSIONS: We presented a case of EOS/BS with a novel D512V mutation in the NOD2 gene. In refractory granulomatous panuveitis cases without any joint involvement, EOS/BS should be considered as a differential diagnosis; genetic analyses would lead to a definite diagnosis. Moreover, this is the first report of P. acnes demonstrated in granulomas of EOS/BS. Since intracellular P. acnes activates nuclear factor-kappa B in a NOD2-dependent manner, we hypothesized that the mechanism of granuloma formation in EOS/BS may be the result of NOD2 activity in the presence of the ligand muramyl dipeptide, which is a component of P. acnes. These results indicate that recognition of P. acnes through mutant NOD2 is the etiology in this patient with EOS/BS.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes?

BACKGROUND: Cutibacterium acnes is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination. METHODS: The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary care hospital with the senior author during the study period. Culture swab samples, testing for presence of C acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as "positive" or "negative" after 21 days. Institutional review board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades "culture positive" for C acnes. RESULTS: 17 patients were identified and fit inclusion criteria. There were 12 men (mean age 64.3 years, range 48-79 years) and 5 women (mean age 69.8 years, range 59-79 years). Two patients (11.8%) were found to have C acnes growth on the skin knife. Both patients were male and older than 70 years undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections. CONCLUSION: The presence of C acnes on the skin blade in 2 patients validates concerns that there is C acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.

Acne vulgaris: new evidence in pathogenesis and future modalities of treatment.

Acne vulgaris, a common and chronic disorder of the pilosebaceous unit, affects up to 85% of adolescent and young adults. While a lot is already known about acne and its treatment, still the gaps in our understanding of acne remains. This article will review the emerging evidence in the complex pathogenesis of acne and provide an overview of the potential future therapy in management of acne vulgaris.Key pointsWhat is known? Propionibacterium acnes targeted therapy has been the mainstay in the management of acne till now.What is new? Sebocyte activity is controlled via a range of cellular pathways and hormones in addition to androgens. This has opened an array of therapeutic options to be available for treating acne in the near future.

Oral Antibiotics for Acne.

Oral antibiotics are integral for treating inflammatory acne based on what is understood about the pathogenesis as well as the role of Cutibacterium acnes. However, rising concerns of antibiotic resistance and the perception of "antibiotic phobia" create potential limitations on their integration in an acne treatment regimen. When prescribing oral antibiotics, dermatologists need to consider dosage, duration, and frequency, and to avoid their use as monotherapy. These considerations are important, along with the use of newer strategies and compounds, to reduce adverse-event profiles, antibiotic resistance, and to optimize outcomes. Aside from concomitant medications, allergies, and disease severity, costs and patient demographics can influence variability in prescribing plans. There are multiple published guidelines and consensus statements for the USA and Europe to promote safe antibiotic use by dermatologists. However, there is a lack of head-to-head studies and evidence for comparative superiority of any individual antibiotic, as well as any evidence to support the use of agents other than tetracyclines. Although oral antibiotics are one of the main options for moderate to severe acne, non-antibiotic therapy such as isotretinoin and hormonal therapies should be considered. As newer therapies and more outcomes data emerge, so will improved management of antibiotic therapy to foster patient safety.

Antibiotic resistant Cutibacterium acnes among acne patients in Jordan: a cross sectional study.

BACKGROUND: Antibiotics have been used for decades against Cutibacterium acnes (previously known as Propionibacterium acnes; C. acnes). Alarmingly, antibiotic resistance to this bacterium has become a worldwide problem in recent years. No studies are available on the antibiotic susceptibility patterns of C. acnes among Jordanian acne patients and how that is influenced by antibiotic use. This study aims to assess antibiotic resistance patterns of C. acnes clinical isolates and neighboring Gram-positive normal flora of the skin obtained from acne patients attending dermatology clinics in Amman -Jordan appraising the role of antibiotic consumption. METHODS: This is a cross-sectional study of acne patients presenting to selected dermatology outpatient clinics over a 6-month study period. Swabs obtained from inflamed lesions were cultured aerobically and anaerobically. Isolates were identified and screened for antibiotic susceptibility. In addition, all patients were asked to fill in a questionnaire that included questions about the history of antibiotic treatment. RESULTS: C. acnes was isolated from lesions of 100 patients out of 115 participants included in this study. 73% of the isolates were resistant to erythromycin and 59% to clindamycin 37% to doxycycline, 36% to tetracycline, 31% to trimethoprim / sulfamethoxazole, 15% to levofloxacin, and 3% to minocycline. Multi drug resistance (MDR) in C. acnes isolates as well as Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) with a similar pattern of resistance were detected from the same patient in most cases. A pattern of higher resistance towards variable antibiotic was observed in patients previously treated with antibiotics for acne management. CONCLUSIONS: The findings of this study demonstrate the distribution of antibiotic resistance of C. acnes towards used antibiotics and emphasizes the influence of antibiotic consumption on development of antibiotic resistance. The similar pattern of resistance between skin bacteria tested in this study highlights the genetic transfer of resistance between skin commensals including S. aureus and S. epidermidis hence promoting its circulation in the community.

Propionibacterium acnes-associated sarcoidosis complicated by acute bird-related hypersensitivity pneumonitis.

BACKGROUND: The number of reports on sarcoidosis complicated by hypersensitivity pneumonitis (HP) is limited, and most describe cases complicated by chronic bird-related HP. Here, we present for the first time a case with Propionibacterium acnes-associated sarcoidosis complicated by acute bird-related HP. CASE PRESENTATION: A 62-year-old man with a past medical history of sarcoidosis was admitted to our department, and chest computed tomography showed diffuse ground-glass opacities, which appeared as he rapidly increased the number of pigeons he kept for a competition. Random transbronchial lung biopsy revealed well-formed non-caseating epithelioid granulomas, which contained positively stained substances on immunohistochemistry using the PAB antibody, a specific monoclonal antibody against P. acnes lipoteichoic acid. Poorly formed non-caseating granulomas without positively stained substances were also detected. CONCLUSION: We describe the successful identification of this exceptionally rare case of sarcoidosis complicated by acute bird-related HP in which two morphologically and immunohistologically different types of granulomas were present in the same lung.