Evaluación de las características fisicoquímicas y de la actividad antimicrobiana del aceite del árbol de té contra Cutibacterium acnes (Propionibacterium acnes) ATCC 6919 / Evaluation of tea tree oil physicochemical features and its antimicrobial activity against Cutibacterium acnes (Propionibacterium acnes) ATCC 6919

Resumen: Introducción. El aceite del árbol de té es un aceite esencial reconocido por sus propiedades antimicrobianas. Objetivos. Evaluar la composición, características y efecto antimicrobiano del aceite al 2 % del árbol de té y su concentración inhibitoria mínima (CIM) contra Cutibacterium acnes (Propionibacterium acnes). Materiales y métodos. Se evaluó el quimiotipo en tres lotes diferentes de este aceite mediante cromatografía de gases, así como su actividad antimicrobiana en concentración al 2 % v/v y la CIM contra C. acnes mediante ensayo de difusión en agar (guía M11-A8 CLSI). Resultados. Los lotes evaluados presentaron los quimiotipos ajustados a la norma ISO 4730, lo que indicó la alta calidad del producto. Los lotes contenían de 30 a 40 % de terpinen-4-ol, compuesto que favorece la actividad antimicrobiana, la cual presentó en todos los lotes un efecto dependiente de la concentración contra C. acnes, con una inhibición del crecimiento microbiano en concentración al 2 % v/v en todas las pruebas. La concentración inhibitoria mínima fue de 0,25 % v/v. La actividad antimicrobiana del aceite del árbol de té contra este microorganismo ya ha sido reportada con una concentración inhibitoria mínima entre 0,05 y 1,25 % v/v, rango que cobija la obtenida en este estudio. Conclusiones. Los resultados evidenciaron la gran calidad de este producto y su capacidad como agente antibacteriano contra C. acnes. Se deben hacer estudios con otros aislamientos del microorganismo provenientes de pacientes con acné vulgar para confirmar su actividad general y la de cada uno de sus componentes.

Abstract: Introduction: Tea tree oil is an essential oil recognized for its antimicrobial properties. Objective: To evaluate the composition, features, and antimicrobial effect at 2% v/v, and its minimal inhibitory concentration (MIC) against Cutibacterium acnes (Propionibacterium acnes). Materials and methods: Three different batches of tea tree oil were evaluated. We characterized its chemotype by gas chromatography and its 2% v/v antimicrobial activity against C. acnes by agar diffusion assay (guide M11-A8 CLSI). Results: The three batches of oil had the chemotypes required by the ISO 4730 standard, which indicates that it is a high-quality product. Additionally, they had 30% to 40% of terpinen-4-ol, a compound that favors its antimicrobial activity. Antimicrobial activity against C. acnes for all batches had a concentration-dependent effect with microbial growth inhibitory activity in all assays at 2% v/v. The MIC obtained against C. acnes for all batches was 0.25% v/v. The antimicrobial activity of tea tree oil against this microorganism has been previously reported with a MIC between 0.05% and 1.25% v/v, a range that covers the one obtained in this study. Conclusion: These results show the high quality of the oil and its capacity as an antibacterial agent against C. acnes. New studies should be conducted to confirm its activity and that of its components in isolates of the microorganism from patients with acne vulgaris.

Baicalin suppresses Propionibacterium acnes-induced skin inflammation by downregulating the NF-κB/MAPK signaling pathway and inhibiting activation of NLRP3 inflammasome

Acne is a kind of common, chronic skin condition caused by the inflammation of the sebaceous glands in hair follicles. Recent studies have demonstrated that baicalin (BA) possesses potential anti-inflammatory properties. In this study, we evaluated the anti-inflammatory activity of BA in vitro and in vivo. Heat-killed Propionibacterium acnes-induced THP-1 cells and live P. acnes-injected male Sprague Dawley rats were used for establishing the acne model. The rate of ear swelling was calculated, and the severity was determined by hematoxylin and eosin staining. The production of cytokines [interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF-α)] in the cell supernatant and ear tissue homogenates was measured by ELISA. Protein levels of JNK, ERK, P38, IκBα, P65, Nod-like receptor pyrin domain-containing 3 (NLRP3), pro-caspase-1, and IL-1β in THP-1 cells and ear tissues were detected by western blotting. NLRP3 and IL-1β were detected by immunohistochemistry, and the NLRP3, IL-1β and pro-caspase-1 mRNAs were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that BA decreased the expression of pro-inflammatory cytokines in vitro and in vivo. Moreover, BA down-regulated the phosphorylation of JNK, ERK1/2, and κBα and inhibited the nuclear translocation of p65. Furthermore, BA inhibited the activation of NLRP3 inflammasome, at both the gene and protein levels. Taken together, the results demonstrated that BA might exert its anti-inflammatory activity by inhibiting NF-κB/MAPK signaling pathways and consequently suppressing the activation of the NLRP3 inflammasome both in vivo and in vitro.

Effect of 5-aminolevulinic Acid Photodynamics Therapy on Biofilm of / 中国医学科学院学报

To investigate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) on () biofilm. biofilms were constructed on a cell slide and treated with ALA-PDT.According to different light doses,the biofilms were divided into six groups:ALA-PDT group [ALA-PDT1 (50 J/cm),ALA-PDT2 group (100 J/cm),ALA-PDT3 group (200 J/cm)],ALA-only group (ALA group),light-only group (LED),and a negative control group (ALA-PDT-group).The biofilm structure and the ratio of the dead bacteria/live bacteria were observed using a laser confocal microscope (CLSM).Biofilm viability was measured using the XTT assay. CLSM showed that the biofilm structures of ALA group and LED group were not significantly different from that of ALA-PDT-group,whereas the biofilm structure was more seriously damaged in ALA-PDT1 group,ALA-PDT2 group,and ALA-PDT3 group than in the ALA-PDT-group.The ratios of the dead/live bacteria in ALA-PDT-group,ALA group,LED group,ALA-PDT1 group,ALA-PDT2 group,and ALA-PDT3 group were 0.350±0.033, 0.305±0.046, 0.330±0.032, 1.525±0.439, 2.293±0.148 and 3.092±0.189,respectively.ALA group(=0.003, =1.000)and LED group(=-0.025, =1.000)did not significantly differ from the ALA-PDT-group.However,the ratio of dead/live bacteria in ALA-PDT-group was significantly lower than those in ALA-PDT1 group (=-0.162, <0.001),ALA-PDT2 group (=-0.254, <0.001),and ALA-PDT3 group (=-0.352, <0.001).The values of the XTT assay were were 0.462±0.028,0.465±0.044,0.437±0.047,0.301±0.040,0.207±0.001,and 0.110±0.007,respectively,in ALA-PDT-group,ALA group,LED group,ALA-PDT1 group,ALA-PDT2 group,and ALA-PDT3 group.Although the values of XTT assay in ALA(=-0.044, =1.000)and LED groups (=-0.020, =1.000)did not significantly differ from that in ALA-PDT-group,it was significantly higher in ALA-PDT-group than in ALA-PDT1 group (=1.175, <0.001),ALA-PDT2 group (=1.942, <0.001),and ALA-PDT3 group (=-0.352, =2.742, <0.001). ALA-PDT has an inhibitory effect on biofilm.ALA-PDT destroys biofilm structure and inhibits biofilm viability.

A Therapeutic Oral Vaccine Candidate against Propionibacterium acnes: Preparation and Immunological Evaluation of Nanoparticles Encapsulated Sialidase-CAMP Fusion Protein

Abstract Acne Vulgaris is a common skin disease caused by Propionibacterium acnes, an anaerobic microbiota of human skin that plays a vital role in the pathology of acne. The aim of this study was to prepare nanoparticles containing an acne recombinant protein and determine its ability as an oral acne vaccine in mice. The recombinant Sialidase-CAMP gene was expressed and purified in a prokaryotic host. The chitosan nanoparticles containing the recombinant protein were prepared, encapsulated, and administered by both oral and subcutaneous routes to Balb/c mice. Sera IgA and IgG and stool IgA titers were measured by ELISA, and the immunized mice were challenged against P. acnes. A 65 kDa recombinant protein was confirmed by SDS-PAGE and western blot. The size and zeta potential of nanoparticles were 80 nm and +18 mV, respectively. After oral immunization, the serum IgG and IgA titers were 1:3200 and 1:16, respectively, and the stool IgA titer was 1:8. In the subcutaneous route, the serum IgG titer was 1:51200. Immunized mice showed no inflammation in the ear of challenged mice. It is the first study that examines a chitosan-nanoparticulated acne fusion protein as an applicable acne vaccine candidate with appropriate immunogenicity potential. Further studies are required to validate the clinical usefulness of this vaccine candidate.

Effect of IL-1β and NLRP3 on the inflammatory response of acne vulgaris / 中南大学学报(医学版)

To investigate the pathogenesis of acne vulgaris, and to provide new ideas for non-antibiotic therapy for acne vulgaris.
 Methods: Normal human epidermal keratinocyte (NHEK) was exposed to Propionibacterium acnes (P. acnes) [multiplicity of infection (MOI)=10, 20, 30] for 12, 24, or 36 hours. The enzyme-linked immunosorbent assay (ELISA) and real-time PCR were used to detect the protein and mRNA of IL-1β in NHEK. Three groups were set up as follows: A negative control group (no NHEK pretreatment), a positive control group (P. acnes was used to stimulate NHEK), and a siRNA group (pretreated NHEK with siRNA). ELISA, real-time PCR, and Western blotting were used to detect the protein, mRNA of IL-1β and nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) in NHEK.
 Results: IL-1β of NHEK in the positive control group was significantly increased in a time and dose-dependent manner compared with the negative control group (P<0.05). After pretreating NHEK with siRNA, IL-1β level was decreased compared with the positive control group, but it was higher than that in the negative control group (P<0.05).
 Conclusion: P. ances can stimulate NHEK to secrete IL-1β, and the process is possibly involved in NLRP3. The inflammatory response induced by P. ances could be inhibited by suppressing the activity of NLRP3.

Iatrogenic pleural empyema caused by Propionibacterium acnes

Propionibacterium acnes is one of the commensals living on the human skin and glands, implicated mainly in acnes, but seldom in deep infection. Pleural empyema is rarely complicated with closed thoracostomy. We experienced 1 case of empyema caused by P. acnes after pleural biopsy and closed thoracostomy through a percutaneous pigtail catheter. A 79-year-old man was admitted for cough, purulent sputum and shortness of breath. Three weeks ago, closed thoracostomy and pleural biopsy were performed to confirm a diagnosis for his recurrent pleural effusion. He had increased amount of right pleural effusion. Through the pigtail catheter, pleural effusion was removed. Gram-positive rods were observed in Gram stain, but not cultured. By 16S rRNA analysis, P. acnes was confirmed as the pathogen. His empyema was repeatedly treated with antibiotics, fibrolysis and irrigation. Pleural decortication was recommended. We report the first case of empyema with P. acnes in Korea, possibly complicated with closed thoracostomy procedures.

Evidências do efeito da terapia fotodinâmica sobre a Propionibacterium acnes / Evidence of the effect of photodynamic therapy on Propionibacterium acnes

Introdução: A Propionibacterium acnes é uma bactéria causadora da acne. Devido aos efeitos colaterais ou à falta de resposta ao tratamento da acne, foi proposta a terapia fotodinâmica como um tratamento alternativo para a acne. Objetivo: O objetivo foi evidenciar a ação fotodinâmica do LED vermelho 660 nm e do fotossensibilizador azul de metileno sobre Propionibacterium acnes in vitro. Métodos: Os ensaios foram constituídos por quatro grupos: 1. controle (sem aplicação de luz e sem fotossensibilizador); 2. com aplicação de luz; 3. com fotossensibilizador e sem aplicação de luz; 4. com fotossensibilizador e com aplicação de luz. Os ensaios foram submetidos a aplicação de luz por 4 ciclos de 5 minutos com intervalos de 3 minutos. Resultados: Houve redução estatisticamente significante (p<0,05) nas médias dos grupos 1, 2 e 4, ainda que o grupo 3 não tenha apresentado significância estatística, mas houve redução detectada nas médias. Conclusão: A ação fotodinâmica é eficiente para a destruição do material biológico por irradiação a 660nm atribuída ao processo de fotossensibilização pela presença do fotossensibilizador.(AU)

Introduction: Propionibacterium acnes is a bacterium that causes acne. Due to the side effects or the lack of response to acne treatment, photodynamic therapy was proposed as an alternative treatment for acne. Objective: To demonstrate the photodynamic action of the 660 nm red LED and the methylene blue photosensitizer on Propionibacterium acnes in vitro. Methods: Four groups were studied: 1. control (without light application and without photosensitizer); 2. with light application; 3. with photosensitizer and without light application; 4. with photosensitizer and light application. The assays were subjected to light application for 4 cycles of 5 minutes at 3 minute intervals. Results: There was a statistically significant reduction (p <0.05) in the means of groups 1, 2 and 4, although group 3 did not present statistical significance, but there was a reduction detected in the means. Conclusion: The photodynamic action is efficient for the destruction of the biological material by irradiation at 660nm attributed to the process of photosensitization by the presence of the photosensitizer.(AU)

Pharmacological treatment options for acne

Acne vulgaris is a very common condition affecting up of about 80% to 90% of adolescents. The patients with acne have been shown to be adversely impacted by the effect of acne on their quality of life. Four factors are believed to play a key role in the development of acne lesions: excess sebum production, disturbed keratinization within the follicle, colonization of the pilosebaceous duct by Propionibacterium acnes, and the release of inflammatory mediators into the skin. Consequently, the target for acne therapy is these well-known pathogenic factors responsible for this disease state. Topical retinoids correct abnormal keratinization, but it should be applied cautiously because of irritation. Benzoyl peroxide is an effective bactericidal agent against P. acnes. Main topical antibiotics are erythromycin and clindamycin. Fixed combination topical products with retinoids, benzoyl peroxide and antibiotics have been introduced. Use of systemic antibiotics, including tetracyclines and macrolides rapidly improves inflammatory acne lesions. Oral isotretinoin is effective against all of the main pathogenic features of acne but is contraindicated in pregnant women and has been associated with cheilitis and dry skin. Hormonal therapy has been found to improve acne in some selective patients and should be considered for appropriate candidates. This review will present the general aspects of the pharmacological treatments for acne.

Prevalência, quantificação e viabilidade de Propionibacterium acnes nos canais radiculares de dentes com periodontite apical antes e após os procedimentos endodônticos de desinfecção: estudo molecular baseado em RNA e DNA / Prevalence, quantification and viability of Propionibacterium acnes in root canals of teeth with apical periodontitis before and after endodontic disinfection procedures: RNA- and DNA-based molecular study

O objetivo deste estudo foi avaliar a taxa de detecção, quantidade e atividade metabólica de Propionibacterium acnes, antes e após os procedimentos endodônticos de desinfecção, utilizando métodos moleculares baseados em rRNA e rDNA. Foram selecionados 22 pacientes com necrose pulpar e periodontite apical assintomática. Amostras microbiológicas foram coletadas dos canais radiculares após a cirurgia de acesso (S1), após o preparo químico-cirúrgico realizado com Sistema Reciproc e NaClO- 2,5% (S2) e após medicação intracanal com Ca(OH)2 por 14 dias (S3). As amostras dos canais radiculares foram submetidas à extração de DNA e RNA. O RNA foi submetido à reação de transcrição reversa (RT) para confecção de DNA complementar (cDNA). DNA e cDNA foram submetidos a reações de qPCR utilizando iniciadores complementares à sequência de 16S rRNA de P. acnes. O efeito dos procedimentos endodônticos na redução bacteriana foi determinado por qPCR baseada em rDNA. A atividade metabólica bacteriana foi calculada pela razão rRNA/rDNA baseados nos dados dos ensaios de qPCR. Os dados foram analisados pelo teste de Wilcoxon para análise entre as amostras e teste de McNemar para comparação da taxa de detecção dos métodos baseados em rDNA e rRNA, com nível de significância de 5%. A taxa de detecção de P. acnes nas amostras endodônticas foi maior pelo método baseado em rRNA do que pelo método baseado em rDNA (P < 0,0001). P. acnes foi detectado em 36,4% (8/22) e 90,9% (20/22) das amostras S1 utilizando qPCR baseado em rDNA e rRNA, respectivamente. Nas amostras S2, P. acnes foi detectado em 36,4% (8/22) das amostras utilizando o método baseado em rDNA e em 86,4% (19/22) pelo método baseado em rRNA. Nas amostras S3, P. acnes persistiu em níveis detectáveis em todas as amostras positivas em S2. Na análise quantitativa, o nível médio de P. acnes foi 1,28 x 103 cópias de rDNA nas amostras S1. Não houve uma alteração significante dos níveis bacterianos nas amostras S2 e S3 quando comparadas às amostras S1 (P > 0,05). O número de cópias de rRNA foi maior do que o de rDNA em todas as amostras (P < 0,0001). Em S1, o valor mediano da razão rRNA/rDNA foi 7,93 (intervalo de 2,03 a 2,04 x 102). Essa razão permaneceu positiva em S2 (mediana 16,40, intervalo de 2,21 a 4,87 x 102) e S3 (mediana 25,34, intervalo de 0,58 a 1,05 x 103), sem diferença estatística na comparação entre as amostras S1-S2 e S2-S3 (ambos P > 0,05). Baseados nesses achados, concluiu-se que o ensaio de qPCR baseado em rRNA revelou uma alta prevalência de P. acnes nas infecções endodônticas primárias e que este permaneceu metabolicamente ativo nos canais radiculares após o preparo químico-cirúrgico e medicação intracanal.

Photodynamic action of the red laser on Propionibacterium acnes

Abstract: Background: Photodynamic therapy is a therapeutic modality that has consolidated its activity in the photooxidation of organic matter, which arises from the activity of reactive oxygen species. Objective: To evaluate the effect of red laser 660nm with the photosensitizer methylene blue on Propionibacterium acnes in vitro. Method: The experimental design was distributed into four groups (1 - control group without the application of light and without photosensitizer, 2 - application of light, 3 - methylene blue without light, and 4 - methylene blue with light). Tests were subjected to red laser irradiation 660nm by four cycles of 5 minutes at 3-minute intervals. Results: It was evidenced the prominence of the fourth cycle (20 minutes) groups 2, 3 and 4. Study limitations: Despite the favorable results, the laser irradiation time photosensitizer associated with methylene blue were not sufficient to to completely inhibit the proliferation of bacteria. Conclusion: Further studies in vitro are recommended to enable the clinical application of this photosensitizer in photodynamic therapy.

G2A Attenuates Propionibacterium acnes Induction of Inflammatory Cytokines in Human Monocytes

BACKGROUND: Acne vulgaris is a disease of the pilosebaceous unit characterized by increased sebum production, hyperkeratinization, and immune responses to Propionibacterium acnes (PA). Here, we explore a possible mechanism by which a lipid receptor, G2A, regulates immune responses to a commensal bacterium. OBJECTIVE: To elucidate the inflammatory properties of G2A in monocytes in response to PA stimulation. Furthermore, our study sought to investigate pathways by which lipids modulate immune responses in response to PA. METHODS: Our studies focused on monocytes collected from human peripheral blood mononuclear cells, the monocytic cell line THP-1, and a lab strain of PA. Our studies involved the use of enzyme-linked immunosorbent, Western blot, reverse transcription polymerase chain reaction, small interfering RNA (siRNA), and microarray analysis of human acne lesions in the measurements of inflammatory markers. RESULTS: G2A gene expression is higher in acne lesions compared to normal skin and is inducible by the acne therapeutic, 13-cis-retinoic acid. In vitro, PA induces both the Toll-like receptor 2-dependent expression of G2A as well as the production of the G2A ligand, 9-hydroxyoctadecadienoic acid, from human monocytes. G2A gene knockdown through siRNA enhances PA stimulation of interleukin (IL)-6, IL-8, and IL-1β possibly through increased activation of the ERK1/2 MAP kinase and nuclear factor kappa B p65 pathways. CONCLUSION: G2A may play a role in quelling inflammatory cytokine response to PA, revealing G2A as a potential attenuator of inflammatory response in a disease associated with a commensal bacterium.

Acne fulminans

Abstract: Acne fulminans is a rare and severe variant of acne. In Brazilian medical journals, cases are infrequently reported, confirming its rarity. We followed five young male patients with this severe variant of cutaneous lesions, accompanied by also severe systemic symptoms: fever, anorexia, weight loss, and arthralgia. All had a good response to corticosteroids (prednisone), but had significant scarring.

Effects of Magnesium Ascorbyl Phosphate on the Expression of Inflammatory Biomarkers after Treatment of Cultured Sebocytes with Propionibacterium acnes or Ultraviolet B Radiation

No abstract available.

Antimicrobial Susceptibility and Characterization of Propionibacterium acnes by Multilocus Sequence Typing and Repetitive-Sequence-Based PCR

Propionibacterium acnes, a gram-positive, anaerobic, and aerotolerant bacterium that is found frequently in the skin as part of the human microbiome causes inflammatory acne, shoulder infection, and the contamination of medical devices. The study goals were the antibiotic resistant and molecular epidemiological characterization of the P. acnes isolates in Korea. A total of 22 P. acnes isolates originated from diverse patients were obtained from three National Culture Collections for Pathogens in South Korea. The hemolytic properties and minimum inhibitory concentrations (MIC) of five antibiotics (tetracycline, doxycycline, clindamycin, erythromycin, and minocycline) were determined. Only one isolate showed high MIC values and resistance to all five antibiotics. Genotypic characterization was achieved by multilocus sequence typing (MLST) for eight loci (aroE, guaA, tly, camp2, atpD, gmk, lepA, and sodA) and repetitive-sequence-based PCR (rep-PCR) analysis using the DiversiLab kit. MLST revealed four phylogroups that were type IA₁ (27.3%), type IA₂ (18.2%), type IB (13.6%), and type II (40.9%). Rep-PCR results demonstrated three clusters that were cluster I (39.1%), cluster II (45.5%), and cluster III (13.6%). The isolates of cluster I were part of phylogroup type IA (both IA₁ and IA₂), and the isolates of cluster II belonged to phylogroup type II. All isolates of phylogroup type IB were hemolytic and belonged to cluster III. The results of rep-PCR clustering analysis showed a good correlation with those of MLST phylogroups, suggesting that rep-PCR could be an alternative method to track P. acnes subtype lineages.

Efficacy of Red or Infrared Light-Emitting Diodes in a Mouse Model of Propionibacterium acnes-Induced Inflammation

BACKGROUND: Laser/light-based devices may provide an alternative to conventional acne therapeutics in some patients with nonresponsive acne. OBJECTIVE: We investigated the efficacy of red or infrared light-emitting diode (LED) devices in a mouse model of Propionibacterium acnes-induced inflammation through clinical examination and histopathological and immunohistochemical studies. METHODS: A human-derived Propionibacterium acnes suspension (10(9) colony-forming units /µl) was injected into the back of an HR-1 mouse. Then, a 28.9 J/cm2 650-nm red LED or 9.3 J/cm2 830-nm infrared LED was applied to the mouse with P. acnes-induced inflammation once daily for 2 weeks. Two weeks after treatment, histological findings with hematoxylin and eosin staining and expression levels of inflammatory biomarkers (integrin α6, neutrophils, interleukin [IL]-1β, and matrix metalloproteinase [MMP]-2/9) were evaluated in tissue specimens using immunohistochemical staining. RESULTS: Mice treated with red and infrared LED showed clinical improvement in inflammatory nodules compared to mice in the control group. Red LED was much more effective than infrared LED. Epidermal hyperplasia, comedone-like cysts, and integrin α6 expression improved to a similar extent in the red and infrared LED treatment groups and control group. Neutrophil, IL-1β, MMP-2, and MMP-9 expression after treatment with red and infrared LED decreased considerably compared to expression in the control group. CONCLUSION: In a mouse model of P. acnes-induced inflammatory nodules, red and infrared LED devices may be an alternative to conventional acne therapies. In addition, a mouse model of P. acnes-induced inflammatory nodules is helpful for laboratory research of acne.

Effect of Vitamin D on the Expression of Inflammatory Biomarkers in Cultured Sebocytes Treated with Propionibacterium acnes or Ultraviolet B Irradiation

No abstract available.

Effect of Vitamin D on the Expression of Inflammatory Biomarkers in Cultured Sebocytes Treated with Propionibacterium acnes or Ultraviolet B Irradiation

No abstract available.

Identification of Non-Aggregatibacter actinomycetemcomitans Bacteria Grown on the Tryptic soy-Serum-Bacitracin-Vancomycin Medium

The aim of this study was to identify the non-Aggregatibacter actinomycetemcomitans bacteria grown on the tryptic soy-serum-bacitracin-vancomycin (TSBV) medium, an A. actinomycetemcomitans selective medium. A total of 82 unidentified bacterial isolates from the oral cavities of a Korean population were kindly provide by the Korean Collection for Oral Microbiology. All the clinical isolates were grown on TSBV medium and bacterial DNA purified from each isolate was subjected to PCR with universal primers specific for bacterial 16S rRNA genes (16S rDNAs) sequence. The each bacterial 16S rDNA was amplified by PCR and the nucleotide sequences of it was determined by the dideoxynucleotide chain termination method. They were identified by 16S rDNA sequence comparison method at the specie-level. The data showed that Neisseria spp. (42 strains), Fusobacterium spp. (10 strains), Capnocytophaga spp. (8 strains), Propionibacterium acnes (5 strains), Aggregatibacter aprophilus (4 strains), Campylobacter spp. (5 strains), Veillonella dispar (3 strains), Streptococcus sp. (1 strain), Haemophilus parainfluenzae (1 strain), Leptotrichia wadei (1 strain), Morococcus sp./Neisseria sp. (1 strain), and Staphylococcus sp. (1 strain) were identified. These results could be used to develop a new A. actinomycetemcomitans-selective medium which is more effective than the TSBV medium in future studies.

HR-1 Mice: A New Inflammatory Acne Mouse Model

BACKGROUND: There is no appropriate in vivo animal model that reflects the inflammatory response of human acne. OBJECTIVE: This study investigated the effect of Propionibacterium acnes on the development of inflammatory acne-like lesions in four mouse strains with different degrees of immune response for the development of an optimal mouse model of inflammatory acne. METHODS: Human P. acnes suspensions (10(8) and 10(9) colony forming unit [CFU]/microl) were injected into the backs of HR-1, BALB/c, vitamin D receptor-knockout (VDR k/o), and severe combined immunodeficiency disease mice. Inflammation levels were evaluated two weeks after injection of P. acnes suspensions. In addition, histopathological examination and immunohistochemical staining of the expressions of inflammatory biomarkers (i.e., CD4+/CD8+ T lymphocytes, neutrophils, myeloperoxidase, interleukin-1beta, matrix metalloprotease (MMP)-2, MMP-3, MMP-9, toll-like receptor (TLR)-2, LL-37, and integrin alpha6) were performed on tissue specimens. RESULTS: The HR-1 mouse strain exhibited the most remarkable inflammatory reaction with epithelial proliferation and microcomedone-like cyst formation. HR-1 mice also demonstrated aberrant integrin expression in the epidermis around both inflamed lesions and newly formed microcomedones. These findings were more prominent in the group receiving 10(9) CFU/microl P. acnes than 10(8) CFU/microl. MMP-9 expression in HR-1 mice was also upregulated around the microcomedone-like cysts. Finally, expression levels of TLR-2 and LL-37 were higher in HR-1 and BALB/c mice than the VDR k/o and SCID mice strains. CONCLUSION: P. acnes induces acneiform inflammation with small microcomedones in HR-1 mice. Therefore, the HR-1 mouse strain represents a good candidate for the development of a new inflammatory acne mouse model.

Clinicopathologic Features of Progressive Macular Hypomelanosis in Korea / 대한피부과학회지

BACKGROUND: Progressive macular hypomelanosis, a disease of uncertain etiology, was first described by Guillet et al. in 1988. It is characterized by asymptomatic hypopigmented macules and patches that appear on the trunk and upper extremities. It is a relatively recently described disorder and more case reports are needed. OBJECTIVE: The purpose of the study was to document the clinicopathologic and ultrastructural features of progressive macular hypomelanosis in Korean patients. METHODS: Patients who presented to our hospital and were diagnosed with progressive macular hypomelanosis from July 2009 to June 2014 were enrolled in this study. Skin scrapings were taken for fungal tests, and skin biopsy specimens from lesional and normal skin were obtained. Sections of the skin biopsies were stained with hematoxylin and eosin, Brown and Brenn Gram stain, and Fontana-Masson stain, and they were incubated with a panel of immunohistochemical reagents used to identify melanocytes, namely, gp-100, melan-A, and microphthalmia-associated transcription factor. The tissues from two patients were also examined using electron microscopy. RESULTS: Over the course of 5 years, 16 patients presented with ill-defined hypopigmented macules on their trunks and upper extremities. The mean age of the patients was 28.4+/-9.0 years and the male to female ratio was about 1 : 4. Histopathologically, lesional skin showed a reduced level of pigmentation, while the number of melanocytes was preserved. None of the patients showed bacterial colonization of the pilosebaceous units. Electron microscopy demonstrated smaller and less melanized melanosomes in the lesional keratinocytes. CONCLUSION: Progressive macular hypomelanosis is a hypopigmentary disorder that is characterized by a loss of melanosomes without damage to the melanocytes. Although there are several reports that describe a possible relationship between Propionibacterium acnes and progressive macular hypomelanosis, it remains unclear.