RESUMO
BACKGROUND: The pathogenesis of acne vulgaris is multifactorial with increased sebum production, alteration in the quality of sebum lipids, dysregulation of the hormone microenvironment, follicular hyperkeratinization and Propionibacterium acnes-driven inflammation as major contributory factors. Hyperproliferation of keratinocytes is believed to contribute to hypercornification and eventually leads to comedone development. While the distribution of P. acnes is relatively well documented in acneic and healthy skin, little is known about P. granulosum and P. avidum. OBJECTIVES: To visualize directly the three major Propionibacterium in 117 control and 26 acneic skin samples. In addition, keratinocyte proliferation was evaluated. METHODS: Propionibacteria were visualized by immunofluorescence microscopy, and keratinocyte proliferation was assessed by Ki67, keratin (K) 16 and p63 immunochemistry. RESULTS: P. acnes was identified in 68 samples (48%), while P. granulosum was identified in 12 (8%) samples; P. avidum was not detected at all. Unexpectedly, acne samples did not show higher keratinocyte proliferation than controls, nor was there any association between bacterial colonization and expression of Ki67/K16/p63. CONCLUSIONS: Our findings do not support earlier notions of follicular keratinocyte hyperproliferation as a cause of ductal hypercornification in acneic facial skin. Further studies on the mechanisms underlying hypercornification in acne pathogenesis are needed.
Assuntos
Acne Vulgar/microbiologia , Queratinócitos/microbiologia , Propionibacterium/isolamento & purificação , Sebo/microbiologia , Acne Vulgar/patologia , Adolescente , Adulto , Anticorpos Antibacterianos/metabolismo , Estudos de Casos e Controles , Proliferação de Células/fisiologia , Criança , Feminino , Humanos , Queratinócitos/citologia , Masculino , Propionibacterium/imunologia , Pele/microbiologia , Adulto JovemRESUMO
BACKGROUND: Acne vulgaris is a disorder of the sebaceous follicles. Propionibacterium acnes can be involved in inflammatory acne. OBJECTIVES: This case-control study aimed at investigating the occurrence and localization of P. acnes in facial biopsies in acne and to characterize the P. acnes phylotype in skin compartments. METHODS: Specific monoclonal and polyclonal antibodies were applied to skin biopsies of 38 patients with acne and matching controls to localize and characterize P. acnes and to determine expression of co-haemolysin CAMP factor, a putative virulence determinant. RESULTS: Follicular P. acnes was demonstrated in 18 (47%) samples from patients with acne and eight (21%) control samples [odds ratio (OR) 3·37, 95% confidence interval (CI) 1·23-9·23; P = 0·017]. In 14 (37%) samples from patients with acne, P. acnes was visualized in large macrocolonies/biofilms in sebaceous follicles compared with only five (13%) control samples (OR 3·85, 95% CI 1·22-12·14; P = 0·021). Macrocolonies/biofilms consisting of mixed P. acnes phylotypes expressing CAMP1 were detected in both case and control samples. Only four samples tested positive for the presence of Staphylococcus spp. and fungi were not observed. CONCLUSIONS: We have for the first time visualized different P. acnes phylotypes in macrocolonies/biofilms in sebaceous follicles of skin biopsies. Our results support the hypothesis that P. acnes can play a role in the pathogenesis of acne as acne samples showed a higher prevalence of follicular P. acnes colonization, both in terms of follicles containing P. acnes and the greater numbers of bacteria in macrocolonies/biofilms than in control samples.
Assuntos
Acne Vulgar/microbiologia , Biofilmes/crescimento & desenvolvimento , Propionibacterium acnes/fisiologia , Pele/microbiologia , Adolescente , Adulto , Biópsia/métodos , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Fenótipo , Adulto JovemRESUMO
A connection between acne vulgaris and Propionibacterium acnes has long been suggested. Over the years, several human skin microbiota sampling methods have been evolved and applied, e.g. swab, scrape, extraction techniques including cyanoacrylate gel sampling as well as punch biopsy. Collected samples have been processed following various methodologies ranging from culture studies to probe labelling and molecular analysis. Direct visualization techniques have recently shown the existence of anatomically distinct skin P. acnes populations: epidermal and follicular. P. acnes biofilms appear to be a common phenomenon. Current sampling approaches target different skin populations of P. acnes and the presence of microbial biofilms can influence the retrieval of P. acnes. The anatomical considerations must be taken into account while interpreting microbiological data.