Navigation Links
Gut microbes in healthy kids carry antibiotic resistance genes

Friendly microbes in the intestinal tracts (guts) of healthy American children have numerous antibiotic resistance genes, according to results of a pilot study by scientists at Washington University School of Medicine in St. Louis. The genes are cause for concern because they can be shared with harmful microbes, interfering with the effectiveness of antibiotics in ways that can contribute to serious illness and, in some cases, death.

"From birth to age 5, children receive more antibiotics than during any other five-year time span in their lives," said senior author Gautam Dantas, PhD, assistant professor of pathology and immunology. "Frequent exposure to antibiotics accelerates the spread of antibiotic resistance. Our research highlights how important it is to only use these drugs when they are truly needed."

The results appear Nov. 13 in PLOS ONE.

With funding from the Children's Discovery Institute, the International Center for Advanced Renewable Energy and Sustainability, the National Academies Keck Futures Initiative and the National Institutes of Health (NIH), the researchers analyzed fecal samples from 22 infants and children ranging in age from six months to 19 years. The samples were provided by Phillip Tarr, MD, the Melvin E. Carnahan Professor of Pediatrics at Washington University School of Medicine.

Despite the small sample size, the analysis identified 2,500 new antibiotic resistance genes, expanding the list of known antibiotic resistance genes by more than 30 percent.

"Microbes have been battling each other for millennia, regularly inventing new antibiotic synthesis genes to kill off rivals and new antibiotic resistance genes to defend themselves," Dantas said. "That microbial arms race is where this vast array of genetic resources comes from."

The scientists identified the new resistance genes by testing intestinal microbial DNA from the children against 18 antibiotics. The genes they identified impaired the effectiveness of all but four of the drugs. Many of the resistance genes were found clustered on sections of DNA that can easily jump from one microbe to another.

Babies lack microbes in their intestinal tracts at birth. Scientists have shown that infants establish their communities of gut microbes through ingestion of microorganisms from their environment from crawling on the floor, for example, to putting toys and other objects into their mouths, to nursing and other contacts with their primary caregivers.

Dantas and his colleagues have been leaders in the development of functional metagenomics, in which scientists identify and analyze all the DNA from a microbial community. Instead of focusing either only on individual cultured organisms or computationally predicting functions from DNA sequences, researchers experimentally screen the DNA for specific functions, such as antibiotic resistance.

Dantas' primary research interest is the ecology and evolution of antibiotic resistance. According to a recent report by the Centers for Disease Control and Prevention, antibiotic-resistant infections cause at least 2 million illnesses and 23,000 deaths annually, adding $20 billion in health-care costs. Dantas noted that methicillin-resistant Staphylococcus aureus, one of the most dangerous antibiotic-resistant bacteria, now causes more deaths in the United States than HIV. Scientists use the term resistome to refer to the collective antibiotic resistance genes of a microbial community.

"There were quite a few resistance genes in microbes from every child we looked at," Dantas said. "This was true even in children who were only six months old. When we compared their resistomes to those of older children, there didn't seem to be much difference."

Dantas' results, which must be confirmed through additional testing, suggest the resistome in the gut may become fixed more quickly than the distribution of species in the microbial community. The latter typically stabilizes three years after birth, but the study suggests the resistome may be set as early as six months after birth.

"This study gives us a snapshot of antibiotic resistance genes at single points in different children's lives," he said. "We're now analyzing the resistome's development via samples taken from the same children at multiple points in their lives."


Contact: Michael C. Purdy
Washington University School of Medicine

Related biology news :

1. Killer silk: Making silk fibers that kill anthrax and other microbes in minutes
2. Breast-fed babies gut microbes contribute to healthy immune systems
3. Honoring the fundamental role of microbes in the natural history of our planet
4. CU-Boulder-led team finds microbes in extreme environment on South American volcanoes
5. AGU: Unique microbes found in extreme environment
6. Waves of Berkeley Lab responders deploy omics to track Deepwater Horizon cleanup microbes
7. Gut microbes battle a common set of viruses shared by global populations
8. MBL scientists to explore hidden realm of microbes, viruses beneath the ocean floor
9. Stanford-Penn State scientists use microbes to make clean methane
10. Microbes make clean methane
11. Roots and microbes: Bringing a complex underground ecology into the lab
Post Your Comments:
(Date:11/12/2015)... 12, 2015  Arxspan has entered into an ... Harvard for use of its ArxLab cloud-based suite ... The partnership will support the institute,s efforts to ... research information internally and with external collaborators. The ... managing the Institute,s electronic laboratory notebook, compound and ...
(Date:11/9/2015)... DUBLIN , Nov. 09, 2015 /PRNewswire/ ... announced the addition of the "Global ... to their offering. --> ... "Global Law Enforcement Biometrics Market 2015-2019" ... Research and Markets ( ) ...
(Date:10/29/2015)... LA JOLLA, Calif. , Oct. 29, 2015 /PRNewswire-USNewswire/ ... released a new report titled, "DNA Synthesis and Biosecurity: ... how well the Department of Health and Human Services ... was issued in 2010. --> ... advances, but it also has the potential to pose ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... , November 25, 2015 2 nouvelles ... fois les différences entre les souches bactériennes retrouvées ... des êtres humains . Ces recherches  ouvrent ... envisager la prise en charge efficace de l,un ... chez les chats .    --> 2 ...
(Date:11/25/2015)... 2015  Neurocrine Biosciences, Inc. (Nasdaq: NBIX ) ... CEO of Neurocrine Biosciences, will be presenting at the ... New York . .   ... 5 minutes prior to the presentation to download or ... will be available on the website approximately one hour ...
(Date:11/25/2015)... Nov. 25, 2015 Orexigen® Therapeutics, Inc. (Nasdaq: ... in a fireside chat discussion at the Piper Jaffray ... . The discussion is scheduled for Wednesday, December ... .  A replay will be available for 14 ... , Julie NormartVP, Corporate Communications and Business Development ...
(Date:11/24/2015)... 24, 2015  Asia-Pacific (APAC) holds the third-largest ... market. The trend of outsourcing to low-cost locations ... higher volume share for the region in the ... margins in the CRO industry will improve. ... ( ), finds that the market earned ...
Breaking Biology Technology: