Studies of the human microbiome have revealed that even healthy individuals differ remarkably in the microbes that occupy habitats such as the gut, skin and vagina. Much of this diversity remains unexplained, although diet, environment, host genetics and early microbial exposure have all been implicated. Accordingly, to characterize the ecology of human-associated microbial communities, the Human Microbiome Project has analysed the largest cohort and set of distinct, clinically relevant body habitats so far. We found the diversity and abundance of each habitat’s signature microbes to vary widely even among healthy subjects, with strong niche specialization both within and among individuals. The project encountered an estimated 81–99% of the genera, enzyme families and community configurations occupied by the healthy Western microbiome. Metagenomic carriage of metabolic pathways was stable among individuals despite variation in community structure, and ethnic/racial background proved to be one of the strongest associations of both pathways and microbes with clinical metadata. These results thus delineate the range of structural and functional configurations normal in the microbial communities of a healthy population, enabling future characterization of the epidemiology, ecology and translational applications of the human microbiome.

Structure, function and diversity of the healthy human microbiome

https://stacks.cdc.gov/view/cdc/6674/cdc_6674_DS1.pdf

Guideline for Hand Hygiene in Health-Care Settings. Recommendations of the Healthcare Infection Control Practices Advisory Committee and the HIPAC/SHEA/APIC/IDSA Hand Hygiene Task Force.

Interest in the role of the microbiome in human health has burgeoned over the past decade with the advent of new technologies for interrogating complex microbial communities. The large-scale dynamics of the microbiome can be described by many of the tools and observations used in the study of population ecology. Deciphering the metagenome and its aggregate genetic information can also be used to understand the functional properties of the microbial community. Both the microbiome and metagenome probably have important functions in health and disease; their exploration is a frontier in human genetics.

/pdf/the-human-microbiome-at-the-interface-of-health-and-disease-8umvuebp9h.pdf

The human microbiome: at the interface of health and disease

The skin is the human body's largest organ, colonized by a diverse milieu of microorganisms, most of which are harmless or even beneficial to their host. Colonization is driven by the ecology of the skin surface, which is highly variable depending on topographical location, endogenous host factors and exogenous environmental factors. The cutaneous innate and adaptive immune responses can modulate the skin microbiota, but the microbiota also functions in educating the immune system. The development of molecular methods to identify microorganisms has led to an emerging view of the resident skin bacteria as highly diverse and variable. An enhanced understanding of the skin microbiome is necessary to gain insight into microbial involvement in human skin disorders and to enable novel promicrobial and antimicrobial therapeutic approaches for their treatment.

The skin microbiome

The Guideline for Hand Hygiene in Health-Care Settings provides health-care workers (HCWs) with a review of data regarding handwashing and hand antisepsis in health-care settings. In addition, it provides specific recommendations to promote improved hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and personnel in health-care settings. This report reviews studies published since the 1985 CDC guideline (Garner JS, Favero MS. CDC guideline for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231-43) and the 1995 APIC guideline (Larson EL, APIC Guidelines Committee. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251-69) were issued and provides an in-depth review of hand-hygiene practices of HCWs, levels of adherence of personnel to recommended handwashing practices, and factors adversely affecting adherence. New studies of the in vivo efficacy of alcohol-based hand rubs and the low incidence of dermatitis associated with their use are reviewed. Recent studies demonstrating the value of multidisciplinary hand-hygiene promotion programs and the potential role of alcohol-based hand rubs in improving hand-hygiene practices are summarized. Recommendations concerning related issues (e.g., the use of surgical hand antiseptics, hand lotions or creams, and wearing of artificial fingernails) are also included.

/pdf/guideline-for-hand-hygiene-in-health-care-settings-5dgf1j7b1v.pdf

Guideline for Hand Hygiene in Health-Care Settings: recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force.

The Microbiology of the Human Axilla and Its Relationship to Axillary Odor

Propionibacterium levels in patients with and without acne vulgaris.

The minimal inhibitory concentration (MIC) of Propionibacterium acnes in seventy-five acne patients receiving long-term antibiotic therapy demonstrated the emergence of resistant strains. The mean MIC in thirty-three patients receiving long-term tetracycline was four to five times higher than that found in control groups of acne patients not receiving antibiotic therapy and controls free of acne. The average MIC for erythromycin was more than 100 times higher in those receiving long-term antibiotic therapy. In a second group of sixty-two patients, the clinical course and number of P. acnes were correlated with the presence of "resistant strains" defined as P. acnes with a tenfold increase in MIC to tetracycline or erythromycin. Patients with resistant strains had higher counts of P. acnes and clinically were not doing as well as those with sensitive strains.

Propionibacterium acnes resistance to antibiotics in acne patients

Quantitative Microbiology of the Scalp in Non-Dandruff, Dandruff, and Seborrheic Dermatitis

Propionibacterium acnes, P. avidum, and P. granulosum were quantitatively measured in 50 young adults. The scalp, forehead, external auditory canal, alae nasi, anterior nares, groin, rectum, and antecubital and popliteal fossa were sampled. These represent various cutaneous microenvironments, differing in moisture, density of sweat, sebaceous glands, and extent of anaerobiosis. These studies show that the propionibacteria are ubiquitous on the skin, with P. acnes predominant in both prevalence and population, especially in areas rich in sebum. P. granulosum recovery paralled that of P. acnes, but the density was significantly lower. P. avidum was found mainly in moist areas and the retum, suggesting an intestinal reservoir.

https://aem.asm.org/content/aem/35/1/62.full.pdf

Kenneth J. McGinley

Papers

The Microbiology of the Human Axilla and Its Relationship to Axillary Odor

Propionibacterium levels in patients with and without acne vulgaris.

Propionibacterium acnes resistance to antibiotics in acne patients

Quantitative Microbiology of the Scalp in Non-Dandruff, Dandruff, and Seborrheic Dermatitis

Regional variations of cutaneous propionibacteria.