The Microbial Ecology of Pilosebaceous Units Isolated from Human Skin

Leeming, J.P.; Holland, K. T.; Cunliffe, W.J.

doi:10.1099/00221287-130-4-803

Cited by 71 publications

(81 citation statements)

References 14 publications

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“…Folliculitis appears to be more common in tropical countries (1,199), probably due to the heat and humidity. Although Malassezia has frequently been isolated from folliculitis lesions (137,149,212,318), this may not be significant, since it can also be isolated from normal pilosebaceous follicles (243) and noninflamed open comedones in acne vulgaris (193). Other organisms commonly found in normal follicles include propionibacteria and staphylococci (243).…”

Section: Malassezia Folliculitismentioning

confidence: 99%

“…Although Malassezia has frequently been isolated from folliculitis lesions (137,149,212,318), this may not be significant, since it can also be isolated from normal pilosebaceous follicles (243) and noninflamed open comedones in acne vulgaris (193). Other organisms commonly found in normal follicles include propionibacteria and staphylococci (243). Few studies of Malassezia folliculitis have attempted to culture the follicular contents, but one that did also found propionibacteria and staphylococci present within affected follicles (212).…”

Section: Malassezia Folliculitismentioning

confidence: 99%

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Immunology of Diseases Associated withMalasseziaSpecies

2002

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SUMMARY Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed individuals. Studies examining cellular and humoral immune responses specific to Malassezia species in patients with Malassezia-associated diseases and healthy controls have generally been unable to define significant differences in their immune response. The use of varied antigenic preparations and strains from different Malassezia classifications may partly be responsible for this, although these problems can now be overcome by using techniques based on recent work defining some important antigens and also a new taxonomy for the genus. The finding that the genus Malassezia is immunomodulatory is important in understanding its ability to cause disease. Stimulation of the reticuloendothelial system and activation of the complement cascade contrasts with its ability to suppress cytokine release and downregulate phagocytic uptake and killing. The lipid-rich layer around the yeast appears to be pivotal in this alteration of phenotype. Defining the nonspecific immune response to Malassezia species and the way in which the organisms modulate it may well be the key to understanding how Malassezia species can exist as both commensals and pathogens.

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Section: Malassezia Folliculitismentioning

confidence: 99%

Section: Malassezia Folliculitismentioning

confidence: 99%

Immunology of Diseases Associated withMalasseziaSpecies

2002

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“…P. acnes colonizes the skin and follicles of both acne-affected and healthy individuals, and no correlation has been observed between the absolute number of bacteria and the severity of disease (8,9,23,25). It has even been reported that not all comedones or early inflamed lesions harbor microorganisms (23,24). In addition, beta-lactam antibiotics are ineffective against acne, although P. acnes is fully sensitive to these drugs (36).…”

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confidence: 99%

Acne is Not Associated with Yet-Uncultured Bacteria

2008

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Current clinical and microbiological information on acne fails to demonstrate a clear association between particular species, including Propionibacterium acnes, and disease, and the disease continues to be a considerable problem. To test if acne is associated with hitherto uncultured bacteria residing in diseased skin follicles, sequencing and phylogenetic analysis of approximately 5,700 amplified and cloned 16S rRNA genes were used to determine the microbial diversity in follicles from acne patients and healthy individuals and from the superficial skin of acne patients. Follicles from healthy skin were exclusively colonized by P. acnes, whereas the follicular microbiota of acne patients included, in addition, Staphylococcus epidermidis and minor proportions of other species. In comparison, samples from superficial skin showed a complex microbiota represented by 12 to 16 bacterial species. The findings of the study exclude the possibility that acne is associated with yet-uncultured bacteria and shows that healthy skin follicles constitute a remarkably exclusive habitat allowing colonization only by P. acnes.

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“…Microorganisms colonizing the skin not only reside on the skin surface but are also found to inhabit hair follicles and lower skin depths (8). Many antimicrobial agents exhibit restricted permeation of the skin (8) and fail to reach the deeper layers, including the hair follicles, which harbor coagulasenegative staphylococci (2,7,8,13,15) and propionibacteria (13). Commensal microorganisms may therefore persist at the site of incision following skin antisepsis (4, 22), and such resident organisms may cause infection when the protective skin barrier is breached during surgical procedures (12,20,26).…”

mentioning

confidence: 99%

Penetration of Chlorhexidine into Human Skin

Kärpänen

Worthington

Conway

et al. 2008

Antimicrob Agents Chemother

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This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 m following serial sectioning of the skin using a microtome and analysis by high-performance liquid chromatography. Poor penetration of chlorhexidine into skin following 2-min and 30-min exposures to chlorhexidine was observed (0.157 ؎ 0.047 and 0.077 ؎ 0.015 g/mg tissue within the top 100 m), and levels of chlorhexidine were minimal at deeper skin depths (less than 0.002 g/mg tissue below 300 m). After 24 h of exposure, there was more chlorhexidine within the upper 100-m sections (7.88 ؎ 1.37 g/mg tissue); however, the levels remained low (less than 1 g/mg tissue) at depths below 300 m. There was no detectable penetration through the full-thickness skin. The model presented in this study can be used to assess the permeation of antiseptic agents through various layers of skin in vitro. Aqueous chlorhexidine demonstrated poor permeation into the deeper layers of the skin, which may restrict the efficacy of skin antisepsis with this agent. This study lays the foundation for further research in adopting alternative strategies for enhanced skin antisepsis in clinical practice.Effective skin antisepsis is essential in preventing infections associated with invasive procedures, such as intravascular catheter insertion or surgery. A range of skin antiseptic agents are available in the clinical setting, such as povidone-iodine and chlorhexidine compounds at various concentrations with alcoholic or aqueous solutions. However, a 2% (wt/vol) chlorhexidine solution is the recommended agent to be used prior to invasive procedures according to the EPIC (evidence-based practice in infection control) and CDC guidelines (18,19). Two percent chlorhexidine digluconate (CHG) has been shown to significantly reduce intravascular catheter-related infections (14), yet 2% (wt/vol) CHG in 70% (vol/vol) isopropyl alcohol demonstrates activity superior to that of aqueous CHG solution in a preoperative skin preparation (9) and in vitro carrier tests (1). However, little is known about the kinetics of chlorhexidine skin permeation from either of these solutions (11,25). Microorganisms colonizing the skin not only reside on the skin surface but are also found to inhabit hair follicles and lower skin depths (8). Many antimicrobial agents exhibit restricted permeation of the skin (8) and fail to reach the deeper layers, including the hair follicles, which harbor coagulasenegative staphylococci (2,7,8,13,15) and propionibacteria (13). Commensal microorganisms may therefore persist at the site of incision following skin antisepsis (4, 22), and such resident organisms may cause infec...

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The Microbial Ecology of Pilosebaceous Units Isolated from Human Skin

Cited by 71 publications

References 14 publications

Immunology of Diseases Associated withMalasseziaSpecies

Immunology of Diseases Associated withMalasseziaSpecies

Acne is Not Associated with Yet-Uncultured Bacteria

Penetration of Chlorhexidine into Human Skin

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