Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

NIH Researchers Conduct First Genomic Survey of Human Skin Fungal Diversity

Published: Thursday, May 23, 2013
Last Updated: Thursday, May 23, 2013
Bookmark and Share
Location on the body surface determines fungal composition with the greatest diversity on feet.

While humans have harnessed the power of yeast to ferment bread and beer, the function of yeast or other types of fungi that live in and on the human body is not well understood. In the first study of human fungal skin diversity, National Institutes of Health researchers sequenced the DNA of fungi at skin sites of healthy adults to define the normal populations across the skin and to provide a framework for investigating fungal skin conditions.

Human skin surfaces are complex ecosystems for microorganisms, including fungi, bacteria and viruses, which are known collectively as the skin microbiome. Although fungal infections of the skin affect about 29 million people in the United States, fungi can be slow and hard to grow in laboratories, complicating diagnosis and treatment of even the most common fungal skin conditions, such as toenail infections.

The research team from the National Human Genome Research Institute (NHGRI) and the National Cancer Institute (NCI), both parts of NIH, extended their recent genome sequencing study of skin bacteria, using DNA sequencing techniques optimized for identifying fungi. The study appears in the May 22, 2013 early online issue of Nature.

The researchers found that a single type of fungus, belonging to the genus Malassezia, is predominant on the head and trunk. Hands, which harbor a great diversity of bacteria, are home for relatively few types of fungi. In contrast, feet, including toenails, heels and toe webs contain tremendous diversity.

“Applying DNA sequencing to a study of the skin’s fungi is the natural progression in understanding microbial life that co-exists on our bodies,” said NHGRI Scientific Director Daniel Kastner, M.D., Ph.D. “Along with recent genome sequencing to define bacterial diversity, this analysis of fungal diversity provides a more complete human microbiome picture.”

“Fungal communities occupy complex niches, even on the human body,” said Heidi Kong, M.D., co-senior author and an investigator in the dermatology branch of NCI’s Center for Cancer Research. “By gaining a more complete awareness of the fungal and bacterial ecosystems, we can better address associated skin diseases, including skin conditions which can be related to cancer treatments.”

The researchers collected samples at 14 body sites from 10 healthy adults. DNA sequencing of the fungi in the samples identified fragments of DNA, called phylogenetic markers, which can be counted and used to distinguish one type of fungus from another. The sequencing efforts generated more than 5 million markers, from the samples, representing more than 80 fungal types, or genera. In contrast, traditional culturing methods produced 130 colonies of fungi that represented only 18 fungal genera.

In 20 percent of the study participants, the researchers observed problems such as heel and toe web scaling or toenail changes consistent with possible fungal infections. From genome sequencing analysis, the researchers found that different individuals with heel site infections have common fungal communities at that site, while those with toenail infections display tremendously different fungal communities.

“DNA sequencing reveals the great diversity of fungi, even those that are hard to grow in culture,” said Julie Segre, Ph.D., co-senior author and senior investigator, NHGRI Genetics and Molecular Biology Branch. Her expertise is the development of microbial DNA sequencing technology. “DNA sequencing enabled us to learn immeasurably more about where fungi predominate as a part of the human skin microbiome.”

The researchers identified fungi from two phyla, Ascomycetes and Basidiomycetes, as part of the normal fungal census at the 14 skin sites. The most common genus Malassezia was present in 11 of 14 sites sampled on the body. The researchers found Malassezia fungus on every skin surface of healthy volunteers, whether on the back of the head, behind the ears, in nostrils and on the heels. Heels were also home to many additional fungi, including the genera Aspergillus, Cryptococcus, Rhodotorula, and Epicoccum.

“DNA sequence-based methods of identification enabled us to differentiate among species of fungi and to conclude that the diversity of fungi is highly dependent on the body site rather than the person who is sampled,” said Dr. Kong. A dermatologist, Dr. Kong explained why these sites were selected for exploration: “Our study focused on areas of the skin where we commonly find skin diseases that have been associated with fungi.”

The most complex site, the heel, is home to about 80 genus-level types of fungi. The researchers found about 60 types in toenail swab samples and 40 types in samples from the webs of the toes. Sites with moderate fungal diversity are inside the bend of the arm, inside of the forearm and palm, with each location supporting 18 to 32 genera of fungi. Surprisingly, head and trunk body sites — including the back, back of the neck, inside the ears, behind the ears, and between the eyebrows — have far fewer fungi types, with just two to 10 genera each.

The research team compared fungal diversity data with the skin bacteria on the same healthy adults. They found that while arms have high measures of bacterial diversity, they have lower fungal diversity. They found the reverse to be true for sites on the feet. Core body sites had neither a high bacterial diversity nor a high fungal diversity. The researchers had previously shown that bacterial diversity can be predicted by whether skin is moist, dry or oily. Fungal diversity, instead, seems to depend upon where a particular skin site is on the body.

The researchers observed, in addition, that there is greater similarity in the fungal community structure on the left and right sides of the same person’s body compared to the same body parts on any two individuals. Fungal communities also appear to be quite stable over time, with little change when tested on two separate occasions, up to three months apart.

“The data from our study gives us a baseline about normal individuals that we never had before,” Dr. Segre said. “The bottom line is your feet are teeming with fungal diversity, so wear your flip flops in locker rooms if you don’t want to mix your foot fungi with someone else’s fungi.”


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More Than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

NIH Study Shows No Benefit of Omega-3 Supplements for Cognitive Decline
Research was published in the Journal of the American Medical Association.
Thursday, August 27, 2015
NIH Launches Human RSV Study
Study aims to understand infection in healthy adults to aid development of RSV medicines, vaccines.
Thursday, August 27, 2015
In Uveitis, Bacteria in Gut May Instruct Immune Cells to Attack the Eye
NIH scientists propose novel mechanism to explain autoimmune uveitis.
Wednesday, August 19, 2015
Novel Mechanism to Explain Autoimmune Uveitis Proposed
A new study on mice suggests that bacteria in the gut may provide a kind of training ground for immune cells to attack the eye.
Wednesday, August 19, 2015
Large Percentage of Youth with HIV May Lack Immunity to Measles, Mumps, Rubella
NIH study finds those vaccinated before starting modern HIV therapy may be at risk.
Tuesday, August 18, 2015
Cellular Factors that Shape the 3D Landscape of the Genome Identified
Researchers have identified 50 cellular factors required for the proper 3D positioning of genes by using novel large-scale imaging technology.
Tuesday, August 18, 2015
Nuclear Process in the Brain That May Affect Disease Uncovered
Scientists have shown that the passage of molecules through the nucleus of a star-shaped brain cell, called an astrocyte, may play a critical role in health and disease.
Tuesday, August 18, 2015
Scientists Uncover Nuclear Process in the Brain that May Affect Disease
NIH-funded study highlights the possible role of glial brain cells in neurological disorders.
Tuesday, August 18, 2015
Newly Discovered Cells Restore Liver Damage in Mice Without Cancer Risk
The liver is unique among organs in its ability to regenerate after being damaged. Exactly how it repairs itself remained a mystery until recently, when researchers supported by the NIH discovered a type of cell in mice essential to the process
Monday, August 17, 2015
Study Finds Cutting Dietary Fat Reduces Body Fat More than Cutting Carbs
In a recent study, restricting dietary fat led to body fat loss at a rate 68 percent higher than cutting the same number of carbohydrate calories when adults with obesity ate strictly controlled diets.
Friday, August 14, 2015
Inappropriate Medical Food Use in Managing Patients with a Type of Metabolic Disorder
Researchers have proposed that there is a need for more rigorous clinical study of dietary management practices for patients with IEMs, including any associated long-term side effects, which may in turn result in the need to reformulate some medical foods.
Friday, August 14, 2015
PINK1 Protein Crucial for Removing Broken-Down Energy Reactors
NIH study suggests potential new pathway to target for treating ALS and other diseases.
Thursday, August 13, 2015
Tell-tale Biomarker Detects Early Breast Cancer in NIH-funded Study
The study published online in the issue of Nature Communications.
Thursday, August 13, 2015
Neurons’ Broken Machinery Piles Up in ALS
NIH scientists identify a transport defect in a model of familial ALS.
Thursday, August 13, 2015
Dr. Peter Kilmarx Appointed Deputy Director of Fogarty International Center
An expert in infectious disease research and HIV/AIDS prevention.
Wednesday, August 12, 2015
Scientific News
The Changing Tides of the In Vitro Diagnostics Market
With the increasing focus in personalized medicine, diagnostics plays a crucial role in patient monitoring.
LaVision BioTec Reports on the Neuro Research on the Human Brain After Trauma
Company reports on the work of Dr Ali Ertürk from the Institute for Stroke and Dementia Research at LMU Munich.
NIH Study Shows No Benefit of Omega-3 Supplements for Cognitive Decline
Research was published in the Journal of the American Medical Association.
Less May Be More in Slowing Cholera Epidemics
Mathematical model shows more cases may be prevented and more lives saved when using one dose of cholera vaccine instead of recommended two doses.
Investigating the Vape
Expert independent review concludes that e-cigarettes have potential to help smokers quit.
NIH Launches Human RSV Study
Study aims to understand infection in healthy adults to aid development of RSV medicines, vaccines.
Researchers Discover Synthesis of a New Nanomaterial
Interdisciplinary team creates biocomposite for first time using physiological conditions.
Poor Survival Rates in Leukemia Linked to Persistent Genetic Mutations
For patients with an often-deadly form of leukemia, new research suggests that lingering cancer-related mutations – detected after initial treatment with chemotherapy – are associated with an increased risk of relapse and poor survival.
Flu Remedies Help Combat E. coli Bacteria
Physiologists from the University of Zurich have now discovered why the intestinal bacterium Escherichia coli (E. coli) multiplies heavily and has an inflammatory effect.
Marijuana Genome Unraveled
A study by Canadian researchers is providing a clearer picture of the evolutionary history and genetic organization of cannabis, a step that could have agricultural, medical and legal implications for this valuable crop.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!