Validity and reliability of the Rosacea Area and Severity Index: A novel scoring system for clinical assessment of rosacea severity.

BACKGROUND: Rosacea is a common chronic inflammatory facial skin disorder. Standardized evaluation of the severity and extent of rosacea is important for baseline assessment and treatment effect. The currently used Investigator's Global Assessment (IGA) is unspecific and fails to consider subtypes/phenotypes of rosacea and area involvement. The Rosacea Area and Severity Index (RASI) was developed to give a more nuanced evaluation of rosacea features in four facial skin areas adjusted to the relative importance of each area of the face to obtain an overall severity score. OBJECTIVES: To validate RASI against the IGA and to assess the inter- and intraobserver reliability for RASI. METHODS: Sixteen dermatologists evaluated photographs of 60 adult patients with rosacea (3 photographs per patient, one from the front and one from each side). IGA and RASI scores were performed for interobserver reliability assessment. To determine intraobserver reliability, 14 dermatologists evaluated 10 other patients twice with at least 1 week interval. RESULTS: The IGA and RASI correlated well (Spearman correlation coefficient (SCC) = 0.75, 95% confidence interval (CI) = 0.72-0.78). Interobserver reliability was moderate for RASI and poor to moderate for IGA. Reliability was strongest for rhinophyma, followed by papules/pustules and erythema, and rather weak for telangiectasia. For area scores, interobserver reliability was strongest for cheeks, followed by nose, chin and forehead. We found a moderate-to-strong intraobserver agreement both for IGA and RASI. CONCLUSIONS: We have designed a new practical tool to examine clinical severity of rosacea. RASI proved simple and reliable in scoring clinical severity of rosacea with an agreement comparable to the currently used IGA although RASI will provide a more nuanced view of the current rosacea extent and severity. We suggest that RASI is used in the daily clinical setting as well as in clinical studies assessing the efficacy of rosacea therapies.

Propionibacterium Acnes Phylogenetic Type III is Associated with Progressive Macular Hypomelanosis.

Progressive macular hypomelanosis (PMH) is a skin disorder that is characterized by hypopigmented macules and usually seen in young adults. The skin microbiota, in particular the bacterium Propionibacterium acnes, is suggested to play a role. Here, we compared the P. acnes population of 24 PMH lesions from eight patients with corresponding nonlesional skin of the patients and matching control samples from eight healthy individuals using an unbiased, culture-independent next-generation sequencing approach. We also compared the P. acnes population before and after treatment with a combination of lymecycline and benzoylperoxide. We found an association of one subtype of P. acnes, type III, with PMH. This type was predominant in all PMH lesions (73.9% of reads in average) but only detected as a minor proportion in matching control samples of healthy individuals (14.2% of reads in average). Strikingly, successful PMH treatment is able to alter the composition of the P. acnes population by substantially diminishing the proportion of P. acnes type III. Our study suggests that P. acnes type III may play a role in the formation of PMH. Furthermore, it sheds light on substantial differences in the P. acnes phylotype distribution between the upper and lower back and abdomen in healthy individuals.

Complete Genome Sequence of a Staphylococcus epidermidis Strain with Exceptional Antimicrobial Activity.

Staphylococcus epidermidis is a Gram-positive bacterium that is prevalent on human skin. The species is associated with skin health, as well as with opportunistic infections. Here, we report the complete genome sequence of S. epidermidis 14.1.R1, isolated from human skin. In bacterial interference assays, the strain showed exceptional antimicrobial activity.

Antagonism between Staphylococcus epidermidis and Propionibacterium acnes and its genomic basis.

BACKGROUND: Propionibacterium acnes and Staphylococcus epidermidis live in close proximity on human skin, and both bacterial species can be isolated from normal and acne vulgaris-affected skin sites. The antagonistic interactions between the two species are poorly understood, as well as the potential significance of bacterial interferences for the skin microbiota. Here, we performed simultaneous antagonism assays to detect inhibitory activities between multiple isolates of the two species. Selected strains were sequenced to identify the genomic basis of their antimicrobial phenotypes. RESULTS: First, we screened 77 P. acnes strains isolated from healthy and acne-affected skin, and representing all known phylogenetic clades (I, II, and III), for their antimicrobial activities against 12 S. epidermidis isolates. One particular phylogroup (I-2) exhibited a higher antimicrobial activity than other P. acnes phylogroups. All genomes of type I-2 strains carry an island encoding the biosynthesis of a thiopeptide with possible antimicrobial activity against S. epidermidis. Second, 20 S. epidermidis isolates were examined for inhibitory activity against 25 P. acnes strains. The majority of S. epidermidis strains were able to inhibit P. acnes. Genomes of S. epidermidis strains with strong, medium and no inhibitory activities against P. acnes were sequenced. Genome comparison underlined the diversity of S. epidermidis and detected multiple clade- or strain-specific mobile genetic elements encoding a variety of functions important in antibiotic and stress resistance, biofilm formation and interbacterial competition, including bacteriocins such as epidermin. One isolate with an extraordinary antimicrobial activity against P. acnes harbors a functional ESAT-6 secretion system that might be involved in the antimicrobial activity against P. acnes via the secretion of polymorphic toxins. CONCLUSIONS: Taken together, our study suggests that interspecies interactions could potentially jeopardize balances in the skin microbiota. In particular, S. epidermidis strains possess an arsenal of different mechanisms to inhibit P. acnes. However, if such interactions are relevant in skin disorders such as acne vulgaris remains questionable, since no difference in the antimicrobial activity against, or the sensitivity towards S. epidermidis could be detected between health- and acne-associated strains of P. acnes.

Genome stability of Propionibacterium acnes: a comprehensive study of indels and homopolymeric tracts.

We present a species-wide comparative analysis of 90 genomes of Propionibacterium acnes that represent the known diversity of the species. Our results are augmented by six high-quality genomes and a manual investigation of all gene-sized indels found in the strains. Overall, the order of genes is conserved throughout the species. A public sybil database for easy comparative analysis of the 90 genomes was established. The analysis of indels revealed a total of 66 loci of non-core genes that correlate with phylogenetic clades. No gene was strain-specific in agreement with our conclusion that the P. acnes pan-genome is closed. An exhaustive search for homopolymeric tracts (HPTs) identified a total of 54 variable-length HPTs almost exclusively of guanine/cytosines located between genes or affecting the reading frame of genes. The repeat variation was consistent with phylogenetic clades suggesting slow accumulation over time rather than active modification. By transcriptome analysis we demonstrate how an HPT variation can affect the gene expression levels. Selected cases of both indels and HPTs are described. The catalogued data and the public P. acnes Sybil database provide a solid foundation for generating hypotheses and facilitate comparative genetic analyses in future P. acnes research.

Draft Genome Sequences of Two Propionibacterium acnes Strains Isolated from Progressive Macular Hypomelanosis Lesions of Human Skin.

Propionibacterium acnes is a Gram-positive bacterium that is prevalent on human skin. It has been associated with skin disorders such as acne vulgaris and progressive macular hypomelanosis (PMH). Here, we report draft genome sequences of two type III P. acnes strains, PMH5 and PMH7, isolated from PMH skin lesions.

Proteome analysis of human sebaceous follicle infundibula extracted from healthy and acne-affected skin.

Acne vulgaris is a very common disease of the pilosebaceous unit of the human skin. The pathological processes of acne are not fully understood. To gain further insight sebaceous follicular casts were extracted from 18 healthy and 20 acne-affected individuals by cyanoacrylate-gel biopsies and further processed for mass spectrometry analysis, aiming at a proteomic analysis of the sebaceous follicular casts. Human as well as bacterial proteins were identified. Human proteins enriched in acne and normal samples were detected, respectively. Normal follicular casts are enriched in proteins such as prohibitins and peroxiredoxins which are involved in the protection from various stresses, including reactive oxygen species. By contrast, follicular casts extracted from acne-affected skin contained proteins involved in inflammation, wound healing and tissue remodeling. Among the most distinguishing proteins were myeloperoxidase, lactotransferrin, neutrophil elastase inhibitor and surprisingly, vimentin. The most significant biological process among all acne-enriched proteins was 'response to a bacterium'. Identified bacterial proteins were exclusively from Propionibacterium acnes. The most abundant P. acnes proteins were surface-exposed dermatan sulphate adhesins, CAMP factors, and a so far uncharacterized lipase in follicular casts extracted from normal as well as acne-affected skin. This is a first proteomic study that identified human proteins together with proteins of the skin microbiota in sebaceous follicular casts.

A novel high-resolution single locus sequence typing scheme for mixed populations of Propionibacterium acnes in vivo.

The Gram-positive anaerobic bacterium Propionibacterium acnes is a prevalent member of the normal skin microbiota of human adults. In addition to its suspected role in acne vulgaris it is involved in a variety of opportunistic infections. Multi-locus sequence-typing (MLST) schemes identified distinct phylotypes associated with health and disease. Being based on 8 to 9 house-keeping genes these MLST schemes have a high discriminatory power, but their application is time- and cost-intensive. Here we describe a single-locus sequence typing (SLST) scheme for P. acnes. The target locus was identified with a genome mining approach that took advantage of the availability of representative genome sequences of all known phylotypes of P. acnes. We applied this SLST on a collection of 188 P. acnes strains and demonstrated a resolution comparable to that of existing MLST schemes. Phylogenetic analysis applied to the SLST locus resulted in clustering patterns identical to a reference tree based on core genome sequences. We further demonstrate that SLST can be applied to detect multiple phylotypes in complex microbial communities by a metagenomic pyrosequencing approach. The described SLST strategy may be applied to any bacterial species with a basically clonal population structure to achieve easy typing and mapping of multiple phylotypes in complex microbiotas. The P. acnes SLST database can be found at http://medbac.dk/slst/pacnes.

Clonality and anatomic distribution on the skin of antibiotic resistant and sensitive Propionibacterium acnes.

Increasing antibiotic resistance in the population of Propionibacterium acnes is a major concern. Our aims were to examine the clonal relationships and anatomical distribution of resistant and sensitive P. acnes. A collection of 350 P. acnes isolates was therefore used to determine the minimum inhibitory concentration of tetracycline, erythro-mycin and clindamycin, multilocus sequence type, and the identity of genetic resistance markers. Two hitherto unknown resistance mutations were detected. Resistant P. acnes mainly belonged to clonal clusters in division I-1a frequently isolated from skin and associated with moderate to severe acne. All high-level tetracycline resistant strains were members of a single clone. Multiple isolates from distinct anatomic areas of surface skin and follicles of 2 acne patients revealed substantial clonal diversity between areas and co-existence of resistant and sensitive clones. Fifty-two percent of Danish acne patients and 43% of controls carried at least one resistant P. acnes strain, resistance to clindamycin being most frequent followed by tetracycline and erythromycin. Resistance to tetracycline was detected exclusively among isolates from acne patients. In conclusion, antibiotic resistance is associated with particular evolutionary clades of P. acnes and a substantial part is due to a single geographically widespread clone (ST3). Individuals carry a strikingly complex population of P. acnes with distinct virulence potential and antibiotic resistance.

The flexible gene pool of Propionibacterium acnes.

Propionibacterium acnes is a Gram-positive bacterium that is intimately associated with humans. The nature and consequences of this symbiosis are poorly understood; it might comprise both mutualistic and parasitic properties. Recent advances in distinguishing phylotypes of P. acnes have revealed that certain type I lineages are predominantly associated with acne vulgaris. Genome analyses revealed a highly conserved core genome and the existence of island-like genomic regions and possible mobile genetic elements as part of the flexible gene pool. The analysis of clustered regularly interspaced short palindromic repeats (CRISPR), found exclusively in type II P. acnes, recently revealed the presence of CRISPR spacers that derived from mobile genetic elements. These elements are present in a subset of P. acnes type I lineages. Their significance for type-specific host-interacting properties and their contribution to pathogenicity is currently under investigation.

CRISPR/cas loci of type II Propionibacterium acnes confer immunity against acquisition of mobile elements present in type I P. acnes.

Propionibacterium acnes is a skin commensal that occasionally acts as an opportunistic pathogen. The population structure of this species shows three main lineages (I-III). While type I strains are mainly associated with sebaceous follicles of human skin and inflammatory acne, types II and III strains are more often associated with deep tissue infections. We investigated the occurrence and distribution of the clustered regularly interspaced short palindromic repeats (CRISPR) in P. acnes, assessed their immunological memory, and addressed the question if such a system could account for type-specific properties of the species. A collection of 108 clinical isolates covering all known phylotypes of P. acnes was screened for the existence of CRISPR/cas loci. We found that CRISPR loci are restricted to type II P. acnes strains. Sequence analyses of the CRISPR spacers revealed that the system confers immunity to P. acnes-specific phages and to two mobile genetic elements. These elements are found almost exclusively in type I P. acnes strains. Genome sequencing of a type I P. acnes isolate revealed that one element, 54 kb in size, encodes a putative secretion/tight adherence (TAD) system. Thus, CRISPR/cas loci in P. acnes recorded the exposure of type II strains to mobile genetic elements of type I strains. The CRISPR/cas locus is deleted in type I strains, which conceivably accounts for their ability to horizontally acquire fitness or virulence traits and might indicate that type I strains constitute a younger subpopulation of P. acnes.

Multilocus sequence typing and phylogenetic analysis of Propionibacterium acnes.

Propionibacterium acnes is a commensal of human skin but is also implicated in the pathogenesis of acne vulgaris, in biofilm-associated infections of medical devices and endophthalmitis, and in infections of bone and dental root canals. Recent studies associate P. acnes with prostate cancer. As the species includes evolutionary lineages with distinct association with health and disease, there is a need for a high-resolution typing scheme. Recently, two multilocus sequence typing (MLST) schemes were reported, one based on nine and one based on seven housekeeping genes. In the present study, the two schemes were compared with reference to a phylogenetic tree based on 78 P. acnes genomes and their gene contents. Further support for a basically clonal population structure of P. acnes and a scenario of the global spread of epidemic clones of P. acnes was obtained. Compared to the Belfast scheme, the Aarhus MLST scheme (http://pacnes.mlst.net/), which is based on nine genes, offers significantly enhanced resolution and phylogenetic inferences more concordant with analyses based on a comprehensive sampling of the entire genomes, their gene contents, and their putative pathogenic potential.

Comparative genomics and transcriptomics of Propionibacterium acnes.

The anaerobic gram-positive bacterium Propionibacterium acnes is a human skin commensal that is occasionally associated with inflammatory diseases. Recent work has indicated that evolutionary distinct lineages of P. acnes play etiologic roles in disease while others are associated with maintenance of skin homeostasis. To shed light on the molecular basis for differential strain properties, we carried out genomic and transcriptomic analysis of distinct P. acnes strains. We sequenced the genome of the P. acnes strain 266, a type I-1a strain. Comparative genome analysis of strain 266 and four other P. acnes strains revealed that overall genome plasticity is relatively low; however, a number of island-like genomic regions, encoding a variety of putative virulence-associated and fitness traits differ between phylotypes, as judged from PCR analysis of a collection of P. acnes strains. Comparative transcriptome analysis of strains KPA171202 (type I-2) and 266 during exponential growth revealed inter-strain differences in gene expression of transport systems and metabolic pathways. In addition, transcript levels of genes encoding possible virulence factors such as dermatan-sulphate adhesin, polyunsaturated fatty acid isomerase, iron acquisition protein HtaA and lipase GehA were upregulated in strain 266. We investigated differential gene expression during exponential and stationary growth phases. Genes encoding components of the energy-conserving respiratory chain as well as secreted and virulence-associated factors were transcribed during the exponential phase, while the stationary growth phase was characterized by upregulation of genes involved in stress responses and amino acid metabolism. Our data highlight the genomic basis for strain diversity and identify, for the first time, the actively transcribed part of the genome, underlining the important role growth status plays in the inflammation-inducing activity of P. acnes. We argue that the disease-causing potential of different P. acnes strains is not only determined by the phylotype-specific genome content but also by variable gene expression.

Population genetic analysis of Propionibacterium acnes identifies a subpopulation and epidemic clones associated with acne.

The involvement of Propionibacterium acnes in the pathogenesis of acne is controversial, mainly owing to its dominance as an inhabitant of healthy skin. This study tested the hypothesis that specific evolutionary lineages of the species are associated with acne while others are compatible with health. Phylogenetic reconstruction based on nine housekeeping genes was performed on 210 isolates of P. acnes from well-characterized patients with acne, various opportunistic infections, and from healthy carriers. Although evidence of recombination was observed, the results showed a basically clonal population structure correlated with allelic variation in the virulence genes tly and camp5, with pulsed field gel electrophoresis (PFGE)- and biotype, and with expressed putative virulence factors. An unexpected geographically and temporal widespread dissemination of some clones was demonstrated. The population comprised three major divisions, one of which, including an epidemic clone, was strongly associated with moderate to severe acne while others were associated with health and opportunistic infections. This dichotomy correlated with previously observed differences in in vitro inflammation-inducing properties. Comparison of five genomes representing acne- and health-associated clones revealed multiple both cluster- and strain-specific genes that suggest major differences in ecological preferences and redefines the spectrum of disease-associated virulence factors. The results of the study indicate that particular clones of P. acnes play an etiologic role in acne while others are associated with health.

Paring and intense pulsed light versus paring alone for recalcitrant hand and foot warts: a randomized clinical trial with blinded outcome evaluation.

BACKGROUND AND OBJECTIVES: Treatment of recalcitrant viral warts remains a therapeutic challenge. Intense pulsed light (IPL) has been suggested effective to clear wart tissue. The objective was in a randomized controlled trial to assess the efficacy of paring followed by IPL versus paring alone for recalcitrant hand and foot warts. MATERIALS AND METHODS: Eighty-nine patients with recalcitrant hand and foot warts were included and randomized (1:1) to three treatments at 3-week intervals with either paring of warts followed by IPL or paring of warts alone. IPL was given with the Ellipse Flex IPL system (Danish Dermatologic Development A/S, Hørsholm, Denmark, 400-950 nm, 5.5 millisecond pulse duration in double pulses with a 2 millisecond interval, 26.0-32.5 J/cm(2) repetitive passes). The primary outcome was complete and partial clearance of warts evaluated by blinded photo assessment at 6 weeks after final treatment. Secondary outcomes were treatment related pain and adverse reactions. RESULTS: We found no significant difference in clearance of warts between the two intervention groups (OR 1.64, 95% confidence interval 0.62-4.38). Paring followed by IPL resulted in complete or partial clearance of wart tissue in nine (22%) and five patients (12.2%) versus five (13.5%) and four patients (10.8%) from paring alone. Mostly plantar warts were treated (92.1%). The pain intensity after paring and IPL was moderate and significantly higher than the pain intensity after paring alone (P<0.0005). No adverse reactions were observed from the two interventions. CONCLUSION: Paring followed by IPL did not differ significantly from paring alone in clearance of recalcitrant hand and foot warts but caused significantly more pain.