Rosa davurica Pall. Improves Propionibacterium acnes-Induced Inflammatory Responses in Mouse Ear Edema Model and Suppresses Pro-Inflammatory Chemokine Production via MAPK and NF-κB Pathways in HaCaT Cells.

Acne, also known as acne vulgaris, is a common disorder of human skin involving the sebaceous gland and Propionibacterium acnes (P. acnes). Although there are a number of treatments suggested for acne, many of them have limitations in their safety and have efficacy issues. Therefore, there is a high demand to develop safe and effective novel acne treatments. In the present study, we demonstrate the protective effects of Rosa davurica Pall. leaves (RDL) extract against P. acnes-induced inflammatory responses in vitro and in vivo. The results showed that RDL dose-dependently inhibited the growth of skin bacteria, including P. acnes (KCTC3314) and aerobic Staphylococcus aureus (KCTC1621) or Staphylococcus epidermidis (KCTC1917). The downregulation of proinflammatory cytokines by RDL appears to be mediated by blocking the phosphorylations of mitogen-activated protein kinase (MAPK) and subsequent nuclear factor-kappa B (NF-κB) pathways in P. acnes-stimulated HaCaT cells. In a mouse model of acne vulgaris, histopathological changes were examined in the P. acnes-induced mouse ear edema. The concomitant intradermal injection of RDL resulted in the reduction of ear swelling in mice along with microabscess but exerted no cytotoxic effects for skin cells. Instrumental analysis demonstrated there were seven major components in the RDL extract, and they seemed to have important roles in the anti-inflammatory and antimicrobial effects of RDL. Conclusively, our present work showed for the first time that RDL has anti-inflammatory and antimicrobial effects against P. acnes, suggesting RDL as a promising novel strategy for the treatment of acne, including natural additives in anti-acne cosmetics or pharmaceutical products.

Anti-Inflammatory and Antibacterial Activity Constituents from the Stem of Cinnamomum validinerve.

One new dibenzocycloheptene, validinol (1), and one butanolide firstly isolated from the natural source, validinolide (2), together with 17 known compounds were isolated from the stem of Cinnamomum validinerve. Among the isolates, lincomolide A (3), secosubamolide (7), and cinnamtannin B1 (19) exhibited potent inhibition on both superoxide anion generation (IC50 values of 2.98 ± 0.3 µM, 4.37 ± 0.38 µM, and 2.20 ± 0.3 µM, respectively) and elastase release (IC50 values of 3.96 ± 0.31 µM, 3.04 ± 0.23 µM, and 4.64 ± 0.71 µM, respectively) by human neutrophils. In addition, isophilippinolide A (6), secosubamolide (7), and cinnamtannin B1 (19) showed bacteriostatic effects against Propionibacterium acnes in in vitro study, with minimal inhibitory concentration (MIC) values at 16 µg/mL, 16 µg/mL, and 500 µg/mL, respectively. Further investigations using the in vivo ear P. acnes infection model showed that the intraperitoneal administration of the major component cinnamtannin B1 (19) reduced immune cell infiltration and pro-inflammatory cytokines TNF-α and IL-6 at the infection sites. The results demonstrated the potential of cinnamtannin B1 (19) for acne therapy. In summary, these results demonstrated the anti-inflammatory potentials of Formosan C. validinerve during bacterial infections.

The role of the skin microbiota in acne pathophysiology.

BACKGROUND: The role of skin microbiota in acne remains to be fully elucidated. Initial culture-based investigations were hampered by growth rate and selective media bias. Even with less biased genomic methods, sampling, lysis and methodology, the task of describing acne pathophysiology remains challenging. Acne occurs in sites dominated by Cutibacterium acnes (formerly Propionibacterium acnes) and Malassezia species, both of which can function either as commensal or pathogen. OBJECTIVES: This article aims to review the current state of the art of the microbiome and acne. METHODS: The literature regarding the microbiome and acne was reviewed. RESULTS: It remains unclear whether there is a quantitative difference in microbial community distribution, making it challenging to understand any community shift from commensal to pathogenic nature. It is plausible that acne involves (i) change in the distribution of species/strains, (ii) stable distribution with pathogenic alteration in response to internal (intermicrobe) or external stimuli (host physiology or environmental) or (iii) a combination of these factors. CONCLUSIONS: Understanding physiological changes in bacterial species and strains will be required to define their specific roles, and identify any potential intervention points, in acne pathogenesis and treatment. It will also be necessary to determine whether any fungal species are involved, and establish whether they play a significant role. Further investigation using robust, modern analytic tools in longitudinal studies with a large number of participants, may make it possible to determine whether the microbiota plays a causal role, is primarily involved in exacerbation, or is merely a bystander. It is likely that the final outcome will show that acne is the result of complex microbe-microbe and community-host interplay.

Safety and Efficacy of Topically Applied Selected Cutibacterium acnes Strains over Five Weeks in Patients with Acne Vulgaris: An Open-label, Pilot Study.

Imbalance in skin microflora, particularly related to certain Cutibacterium acnes strains, may trigger acne. Application of non-acne-causing strains to the skin may modulate the skin microbiome and thereby lead to a reduction in acne. This pilot study evaluates the safety and efficacy of microbiome modulation on acne-prone skin. The study had 2 phases: active induction (5% benzoyl peroxide gel, 7 days) and interventional C. acnes strains treatment (5 weeks). Patients were randomized to either topical skin formulations PT1 (2 strains of C. acnes Single Locus Sequence Typing [SLST] type C3 and K8, 50% each) or PT2 (4 strains of C. acnes SLST type C3 [55%], K8 [5%], A5 [30%] and F4 [10%]). Safety and efficacy was evaluated in 14 patients (PT1=8/14, PT2=6/14). Skin microbiome composition shifted towards study formulations. No untoward adverse events, visible irritation, or significant flare-up were observed. Non-inflamed lesions and skin pH were reduced. Comedone counts improved clinically with no deterioration in inflammatory lesions.

Sarcoidosis of the fallopian tube: A rare case study with confirmed Propionibacterium acnes infection.

Sarcoidosis is a systemic granulomatous disease that is most commonly manifested in the pulmonary system. Though the entire etiology of sarcoidosis remains unknown, it has been reported that Propionibacterium acnes (P. acnes) has been isolated from sarcoid lesions. Herein, we report a case of salpingitis arising from sarcoidosis. A female patient aged 37 years, gravida 2 para 0, who had been diagnosed with sarcoidosis at the age of 36 years, underwent laparoscopic right salpingectomy due to obvious right hydrosalpinx with recurrent refractory right lower abdominal pain. The pathological diagnosis was granulomatous salpingitis of the right fallopian tube suspecting sarcoidosis. Immunocytochemistry using a specific monoclonal antibody against P. acnes lipoteichoic acid (PAB antibody) revealed PAB-positive reaction in sarcoid granuloma. This is the first case of sarcoidosis that the presence of P. acnes was shown in sarcoid lesions in the fallopian tube.

The therapeutic effect of tanshinone IIA on Propionibacterium acnes-induced inflammation in vitro.

Acne vulgaris, a chronic inflammatory skin disease, affects many adolescents. New therapeutic agents for acne allow for a higher therapeutic activity, but fewer side effects. Tanshinone IIA, a natural product, has been proved to exhibit antibacterial and anti-inflammatory abilities in many diseases. However, its antibacterial and anti-inflammatory activities against Propionibacterium acnes have not been described. In the present study, the broth microdilution method was used to evaluate the antibacterial activity of tanshinone IIA and it had an inhibitory effect on the growth of P. acnes. Enzyme-linked immunosorbent assay and quantitative real-time PCR were used to investigate the effect of tanshinone IIA on IL-1ß, IL-8, and TNF-α expression, and western blot was used to examine TLR2, NF-κB, and intercellular cell adhesion molecule-1 (ICAM-1) protein level induced by P. acnes in THP-1 cells. Results showed that the expression of inflammatory cytokines and TLR2, NF-κB, ICAM-1 protein levels were inhibited by Tanshinone IIA, suggesting that tanshinone IIA appeared to suppress P. acnes-induced inflammation by blockade of TLR2/NF-κB signaling pathway. In conclusion, the present study revealed the inhibitory effect of tanshinone IIA on P. acnes-induced inflammation, providing an evidence to support the mechanism of anti-acne properties of tanshinone IIA.

Low virulence bacterial infections in cervical intervertebral discs: a prospective case series.

STUDY DESIGN: A prospective cross-sectional case series study. OBJECTIVE: To investigate the prevalence of low virulence disc infection and its associations with characteristics of patients or discs in the cervical spine. BACKGROUND: Low virulence bacterial infections could be a possible cause of intervertebral disc degeneration and/or back pain. Controversies are continuing over whether these bacteria, predominantly Propionibacterium acnes (P. acnes), represent infection or contamination. However, the current studies mainly focus on the lumbar spine, with very limited data on the cervical spine. METHODS: Thirty-two patients (20 men and 12 women) who underwent anterior cervical fusion for degenerative cervical spondylosis or traumatic cervical cord injury were enrolled. Radiological assessments included X-ray, CT, and MRI of the cervical spine. Endplate Modic changes, intervertebral range of motion, and disc herniation type were evaluated. Disc and muscle tissues were collected under strict sterile conditions. Samples were enriched in tryptone soy broth and subcultured under anaerobic conditions, followed by identification of the resulting colonies by the PCR method. RESULTS: Sixty-six intervertebral discs were excised from thirty-two patients. Positive disc cultures were noted in eight patients (25%) and in nine discs (13.6%). The muscle biopsy (control) cultures were negative in 28 patients and positive in 4 patients (12.5%); three of whom had a negative disc culture. Seven discs (10.6%) were positive for coagulase-negative Staphylococci (CNS) and two discs were positive for P. acnes (3.0%). A younger patient age and the extrusion or sequestration type of disc herniation, which represented a complete annulus fibrous failure, were associated with positive disc culture. CONCLUSIONS: Our data show that CNS is more prevalent than P. acnes in degenerative cervical discs. The infection route in cervical discs may be predominantly through an annulus fissure. Correlation between these infections and clinical symptoms is uncertain; therefore, their clinical significance needs to be investigated in the future. These slides can be retrieved under Electronic Supplementary Material.

Latent infection of low-virulence anaerobic bacteria in degenerated lumbar intervertebral discs.

BACKGROUND: The existence of latent low-virulence anaerobic bacteria in degenerated intervertebral discs (IVDs) remains controversial. In this study, the prevalence of low-virulence anaerobic bacteria in degenerated IVDs was examined, and the correlation between bacterial infection and clinical symptoms was analysed. METHODS: Eighty patients with disc herniation who underwent discectomy were included in this study. Under a stringent protocol to ensure sterile conditions, 80 disc samples were intraoperatively retrieved and subjected to microbiological culture. Meanwhile, tissue samples from the surrounding muscle and ligaments were harvested and cultured as contamination markers. The severity of IVD degeneration and the prevalence of Modic changes (MCs) were assessed according to preoperative MRI analysis. RESULTS: Of the 80 cultured discs, 54 were sterile, and 26 showed the presence of bacteria: Propionibacterium acnes (21 cases) and coagulase-negative staphylococci (5 cases). MRI revealed that the presence of bacteria was significantly associated with MCs (P<0.001). However, there was no significant association between bacterial infection and the severity of IVD degeneration (P = 0.162). CONCLUSIONS: Our findings further validated the presence of low-virulence anaerobic bacteria in degenerated IVDs, and P. acnes was the most frequent bacterium. In addition, the latent infection of bacteria in IVDs was associated with Modic changes. Therefore, low-virulence anaerobic bacteria may play a crucial role in the pathophysiology of MCs and lumbar disc herniation.

Hemolytic strains of Propionibacterium acnes do not demonstrate greater pathogenicity in periprosthetic shoulder infections.

BACKGROUND: Hemolysis has been suggested as a feature conferring increased pathogenicity to certain Propionibacterium acnes strains in the setting of shoulder infection. The purpose of this study was to compare the virulence of hemolytic and nonhemolytic P acnes strains in patients undergoing revision shoulder arthroplasty. METHODS: Thirty-nine patients with at least 1 positive culture growth for P acnes at the time of revision surgery were identified with P acnes isolates available for hemolysis testing. Patients were grouped into those with P acnes isolates positive (n = 20) and negative (n = 19) for hemolysis. The groups were retrospectively compared based on objective perioperative findings around the time of revision surgery and the postoperative clinical course, including the need for revision surgery. All cases were classified into categories of infection (definite infection, probable infection, and probable contaminant) based on objective perioperative criteria. RESULTS: The presence of hemolysis was not significantly associated with an increased likelihood of infection (P = .968). Hemolysis demonstrated a 75% sensitivity and 26% specificity for determining infection (definite infection and probable infection categories). The hemolytic and nonhemolytic groups showed no difference regarding preoperative serum erythrocyte sedimentation rate and/or C-reactive protein level (P = .70), number of positive cultures (P = .395), time to positive culture (P = .302), and presence of positive frozen section findings (P = .501). Postoperatively, clindamycin resistance, shoulder function, and the rate of reoperation were not significantly different between the hemolytic and nonhemolytic groups. CONCLUSION: The presence of hemolysis was not associated with increased pathogenicity in patients with P acnes-positive cultures following revision shoulder arthroplasty, when assessed by objective perioperative criteria and the postoperative clinical course.

Assessment of Chitosan-Based Hydrogel and Photodynamic Inactivation against Propionibacterium acnes.

Chitosan (CH) is a biopolymer that exhibits a number of interesting properties such as anti-inflammatory and antibacterial activity and is also a promising platform for the incorporation of photosensitizing agents. This study aimed to evaluate the efficacy of antimicrobial activity of chitosan hydrogel formulation alone and in combination with the methylene blue (MB) associated with antimicrobial photodynamic therapy (aPDT) against planktonic and biofilm phase of Propionibacterium acnes. Suspensions were sensitized with 12.5, 25.0, 37.5, 50.0 µg/mL of MB for 10 min and biofilms to 75, 100 and 150 µg/mL for 30 min then exposed to red light (660 nm) at 90 J/cm² and 150 J/cm² respectively. After treatments, survival fractions were calculated by counting the number of colony-forming units. The lethal effect of aPDT associated with CH hydrogel in planktonic phase was achieved with 12.5 µg/mL MB and 1.9 log10 biofilm reduction using 75 µg/mL MB. Rheological studies showed that formulations exhibited pseudoplastic non-Newtonian behavior without thixotropy. Bioadhesion test evidenced that the formulations are highly adhesive to skin and the incorporation of MB did not influence the bioadhesive force of the formulations.

[Subdural Empyema Caused by Propionibacterium Acnes after Burr-Hole Surgery of Chronic Subdural Hematoma:A Case Report].

A 63-year old man with fever, headache, aphasia, and right hemiparesis was admitted to our hospital one month after the initial burr-hole surgery for left chronic subdural hematoma. Computed tomography(CT)revealed no regrowth of residual subdural hematoma. However, on the basis of the findings from magnetic resonance imaging(MRI)with diffusion-weighted images(DWI), an infection due to residual subdural hematoma was suspected. A small craniotomy was performed, and a little fluid with pus was aspirated from the subdural space. Postoperative antibiotic therapy for subdural empyema was performed, and subsequent culture of pus revealed Propionibacterium acnes(P. acnes). The patient's symptoms resolved, and he returned to work two months later. Subdural empyema caused by P. acnes after burr-hole surgery for chronic subdural hematoma is rare. We should consider infection due to residual hematoma in patients with recurrent symptoms and signs of inflammation, even in the absence of apparent regrowth of residual hematoma after burr-hole surgery.

Activity of Electrical Current in Experimental Propionibacterium acnes Foreign-Body Osteomyelitis.

Foreign-body-associated infections are often difficult to treat, given that the associated microorganisms are in a biofilm state. Previously, we showed that a low-amperage direct electrical current (DC) reduces Propionibacterium acnes biofilms formed on implant-associated materials in vitro In this study, low-amperage DC was compared to ceftriaxone treatment or no treatment in a novel rat femur model of foreign-body osteomyelitis. A platinum implant seeded with a P. acnes biofilm (107 CFU/cm2) and 109 CFU of planktonic P. acnes was placed in the femoral medullary cavity. One week later, rats were assigned to one of three treatment groups: no treatment, ceftriaxone treatment, or 200-µA-DC treatment. After 2 weeks of treatment, there were fewer bacteria in the bones of the ceftriaxone group (3.06 log10 CFU/g of bone [P = 0.0209]) and the 200-µA-DC group (0.5 log10 CFU/g [P = 0.0015]) than in those of the control group (6.58 log10 CFU/g). The DC-exposed animals exhibited fewer bacteria than the ceftriaxone-treated animals (P = 0.0330). There were fewer bacteria on the implanted wires in the groups treated with ceftriaxone (0.1 log10 CFU/cm2) or a 200-µA DC (0.1 log10 CFU/cm2) than in the control group (2.53 log10 CFU/cm2 [P, 0.0003 for both comparisons]). Low-amperage DC may be useful for treating, or aiding in the treatment of, foreign-body infections caused by P. acnes.

Factors shaping the composition of the cutaneous microbiota.

From birth, we are constantly exposed to bacteria, fungi and viruses, some of which are capable of transiently or permanently inhabiting our different body parts as our microbiota. The majority of our microbial interactions occur during and after birth, and several different factors, including age, sex, genetic constitution, environmental conditions and lifestyle, have been suggested to shape the composition of this microbial community. Propionibacterium acnes is one of the most dominant lipophilic microbes of the postadolescent, sebum-rich human skin regions. Currently, the role of this bacterium in the pathogenesis of the most common inflammatory skin disease, acne vulgaris, is a topic of intense scientific debate. Recent results suggest that Westernization strongly increases the dominance of the Propionibacterium genus in human skin compared with natural populations living more traditional lifestyles. According to the disappearing microbiota hypothesis proposed by Martin Blaser, such alterations in the composition of our microbiota are the possible consequences of socioeconomic and lifestyle changes occurring after the industrial revolution. Evanescence of species that are important elements of the human ecosystem might lead to the overgrowth and subsequent dominance of others because of the lack of ecological competition. Such changes can disturb the fine-tuned balance of the human body and, accordingly, our microbes developed through a long co-evolutionary process. These processes might lead to the transformation of a seemingly harmless species into an opportunistic pathogen through bacterial dysbiosis. This might have happened in the case of P. acnes in acne pathogenesis.

Proteomic and transcriptomic investigation of acne vulgaris microcystic and papular lesions: Insights in the understanding of its pathophysiology.

BACKGROUND: The pathogenesis of acne vulgaris involves several phases including androgen-dependent hyper-seborrhea, colonization by Propionibacterium acnes, and inflammation. Recent investigations have shown that in fact P. acnes provokes the activation of the inflammasome present in macrophages and dendritic cells. This signaling pathway leads to excessive production of interleukin IL-1ß, a proinflammatory cytokine. Nevertheless, these well-studied phenomena in acne fail to elucidate the mechanisms responsible for the appearance of different lesions. METHODS: We investigate response pathways for specific acne lesions such as microcysts and papules using shot-gun proteomic followed by systemic biology and transcriptomic approaches. RESULTS: Results show that most of the proteins identified as differentially expressed between the normal and acne tissue biopsies associated with the immune system response were identified as highly or exclusively expressed in the papule biopsies. They were also expressed in microcysts, but in lower amounts compared to those in papules. These results are supported by the identification of CAMP factor protein produced by P. acnes in microcysts, indicating its enhanced proliferation in this type of lesion CONCLUSIONS: As CAMP factor protein was not detected in papule biopsies, we can see a clear delineation in the stages of progression of acne pathogenesis, which begins with a hyphenated inflammatory response in the papule stage, followed by imbalance of lipid production, which in turn triggers the enhanced proliferation of P. acnes. GENERAL SIGNIFICANCE: We demonstrate that expression inflammation varies across the two types of lesions, suggesting different pathways enhanced as a function of the progression of P. acnes.

Risk factors for Propionibacterium acnes infection after neurosurgery: A case-control study.

Propionibacterium acnes is increasingly known as a causative organism for post-neurosurgical infection; however, no clinical studies have examined the risk factors associated with P. acnes infections. Clinical data obtained from 14 cases of P. acnes infection and 28 controls infected with other pathogens were analyzed. Craniotomy, malignancy, and prolonged duration of operation were significantly associated with the onset of P. acnes infection. No fatal cases were reported.

What is new in the pathophysiology of acne, an overview.

Acne is a chronic inflammatory disease of the pilosebaceous unit. Its pathophysiology includes hyperseborrhoea, abnormal follicular keratinization and Propionibacterium acnes proliferation in the pilosebaceous unit. Recent research has shed some new light on the involvement of the sebaceous gland, as well as on the pro-inflammatory activity of the cutaneous microbiome. During puberty, alteration of the sebaceous lipid profile, called dysseborrhoea, stress, irritation, cosmetics and potential dietary factors lead to inflammation and formation of different types of acne lesions. Dysbiosis, the process leading to a disturbed skin barrier and disequilibrium of the cutaneous microbiome, resulting in the proliferation of P. acnes strains, is another important process that triggers acne. P. acnes activates the innate immunity via the expression of protease activated receptors (PARs), tumour necrosis factor (TNF) α and toll-like receptors (TLRs), and the production of interferon (INF) γ, interleukins (IL-8, IL12, IL-1), TNF, and matrix metalloproteinases (MMPs) by keratinocytes, resulting in the hyperkeratinization of the pilosebaceous unit. Rebalancing the natural microbiome of the skin by restoring the natural skin barrier, limiting the proliferation of P. acnes on the skin by using topical antibacterials which do not cause resistance and regulating quantity and quality of sebum will be the main acne treatment challenges in the future. The aim of this article to provide an update on the involvement of the sebaceous gland, the innate immunity and the cutaneous microbiome, how all of these factors promote acne and to illustrate their links with current and future treatments.

Tropism and virulence of Cutibacterium (formerly Propionibacterium) acnes involved in implant-associated infection.

The recognition of the pathogenicity of Cutibacterium acnes in implant-associated infection is not always obvious. In this paper, we aimed to distinguish pathogenic and non-pathogenic C. acnes isolates. To reach this goal, we investigated the clonal complex (CC) of a large collection of C. acnes clinical isolates through Multi-Locus Sequence Typing (MLST), we established a Caenorhabditis elegans model to assess C. acnes virulence and we investigated the presence of virulence factors in our collection. Ours results showed that CC36 and CC53 C. acnes isolates were more frequently observed in prosthetic joint infections (PJI) than CC18 and CC28 C. acnes isolates (p = 0.021). The C. elegans model developed here showed two distinct virulence groups of C. acnes (p < 0.05). These groups were not correlated to CC or clinical origin. Whole genome sequencing allowed us to identify a putative gene linked to low virulent strains. In conclusion, MLST remains a good method to screen pathogenic C. acnes isolates according to their clinical context but mechanisms of C. acnes virulence need to be assess thought transcriptomic analysis to investigate regulatory process.

Consensus-Based Acne Classification System and Treatment Algorithm for Spain. / Consenso español para establecer una clasificación y un algoritmo de tratamiento del acné.

Acne is a chronic inflammatory disease whose psychosocial effects can greatly impair quality of life. Various scales are used to classify the severity of acne, and several treatment algorithms are currently applied: no consensus on a common scale or treatment guidelines has been reached. A group of Spanish experts therefore met to identify a scale the majority could accept as the most appropriate for classifying severity and treating accordingly. The group chose the following classifications: comedonal acne, mild or moderate papulopustular acne, severe papulopustular acne, moderate nodular acne, and nodular-cystic acne (or acne tending to leave scars). Consensus was reached on first- and second-choice treatments for each type and on maintenance treatment. The experts also issued specific recommendations on antibiotic use (starting with mild or moderate papulopustular acne), always in combination with retinoids and/or benzoyl peroxide. The use of isotretinoin (starting at severe papulopustular or moderate nodular acne) was also covered.

Propionibacterium acnes inhibits FOXM1 and induces cell cycle alterations in human primary prostate cells.

Propionibacterium acnes has been detected in diseased human prostate tissue, and cell culture experiments suggest that the bacterium can establish a low-grade inflammation. Here, we investigated its impact on human primary prostate epithelial cells. Microarray analysis confirmed the inflammation-inducing capability of P. acnes but also showed deregulation of genes involved in the cell cycle. qPCR experiments showed that viable P. acnes downregulates a master regulator of cell cycle progression, FOXM1. Flow cytometry experiments revealed that P. acnes increases the number of cells in S-phase. We tested the hypothesis that a P. acnes-produced berninamycin-like thiopeptide is responsible for this effect, since it is related to the FOXM1 inhibitor siomycin. The thiopeptide biosynthesis gene cluster was strongly expressed; it is present in subtype IB of P. acnes, but absent from type IA, which is most abundant on human skin. A knock-out mutant lacking the gene encoding the berninamycin-like peptide precursor was unable to downregulate FOXM1 and to halt the cell cycle. Our study reveals a novel host cell-interacting activity of P. acnes.

The use of oral antibiotics in treating acne vulgaris: a new approach.

Although acne is not an infectious disease, oral antibiotics have remained a mainstay of treatment over the last 40 years. The anti-inflammatory properties of oral antibiotics, particularly the tetracyclines, are efficacious in treating inflammatory acne lesions. Common prescribing practices in Dermatology exert significant selection pressure on bacteria, contributing to the development of antibiotic resistance. Antibiotic use for acne not only promotes resistance in Propionibacterium acnes, but also affects other host bacteria with pathogenic potential. This review will summarize the commonly used treatments for acne vulgaris, and how they should be combined as rational treatment. The indications for using oral antibiotics in acne will be highlighted. Strategies described in the literature to conserve the utility of oral antibiotics will be summarized. These include limiting the duration of antibiotic therapy, concomitant use of a topical non-antibiotic agent, use of subantimicrobial dose doxycycline, and the introduction of topical dapsone.