Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Good bacteria armed with antibiotic resistance protect gut microbiome

13.06.2014

Researchers from Case Western Reserve University in Cleveland have discovered that populating the gastrointestinal (GI) tracts of mice with Bacteroides species producing a specific enzyme helps protect the good commensal bacteria from the harmful effects of antibiotics. Their research is published ahead of print in Antimicrobial Agents and Chemotherapy.

Antibiotics are powerful weapons against pathogens, but most are relatively indiscriminate, killing the good bacteria, along with the bad. Thus, they may render patients vulnerable to invasion, particularly by virulent, antibiotic-resistant pathogens that frequently populate hospitals.

The novel aspect of the research is that the enzyme produced by these bacteria, beta-lactamase, is a major cause of antibiotic resistance, says first author, Usha Stiefel. Interestingly, the enzyme is not only protecting the bacteria that produce it but also the rest of the bacteria making up the intestinal microbiome.

In the study, the investigators established populations of beta-lactamase producing Bacteroides in some mice, but not others. They then gave all the mice ceftriaxone, a beta-lactam antibiotic, for three days and then oral doses of vancomycin-resistant enterococcus, or Clostridium difficile, both of which are virulent GI pathogens.

The mice that had been populated with Bacteroides maintained their diverse species of commensal gut bacteria, free of pathogens, while the control mice saw their commensals decimated by antibiotics, enabling establishment of the pathogens.

"When patients in the hospital or nursing home setting receive antibiotics, it is doubly dangerous when they lose their native colonic bacteria, because healthcare settings are full of resistant or particularly virulent bacteria, and so patients are especially vulnerable to acquiring these bacteria within their intestinal tracts," says Stiefel.

Since the Bacteroides, which comprise roughly one quarter of the intestinal microbiome, are absent elsewhere in the body, the investigators believe that the beta-lactamase will not interfere with treatment of infections in other organ systems, such as in the respiratory tract, or the blood, explains Stiefel.

"The results of our study are exciting because they show how it might be possible to take antibiotics without suffering from the loss of your colonic microbiome and then becoming colonized by virulent pathogens," says Stiefel. For example, beta-lactamase enzymes could be given orally as drugs, to protect the gut bacteria from systemic antibiotics. Alternatively, as with the mice, patients' GI tracts might be populated with antibiotic-degrading bacteria.

One weakness of the strategy is that while it could protect against acquiring a GI infection, C. difficile, for example, it could not be used to combat such an infection.

"The recognition of the importance of an intact and diverse microbiome has probably best been demonstrated by the successful treatment of Clostridium difficile colitis by fecal microbiota transplantation, or 'stool transplant,'" says Stiefel. "If you have an intact intestinal microbiome, you simply are going to be resistant to acquiring many types of infection."

"If we can find ways to preserve the microbiome in hospitalized patients who are receiving antibiotics, we are on our way to preventing a large proportion of hospital-acquired infections," says Stiefel.

###

The manuscript can be found online at http://bit.ly/asmtip0614d. The final version of the article is scheduled for the August 2014 issue of Antimicrobial Agents and Chemotherapy.

Antimicrobial Agents and Chemotherapy is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Jim Sliwa | Eurek Alert!
Further information:
http://www.asmusa.org

Further reports about: ASM Clostridium antibiotic enzyme pathogens resistance transplant

More articles from Health and Medicine:

nachricht Researchers find promise in new treatments for GBM
02.10.2014 | Boston University Medical Center

nachricht EHFG 2014 on the Ebola crisis: Strong health care systems are the best defence against epidemics
02.10.2014 | European Health Forum Gastein

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

BrainScaleS Conference: From Neurobiology to New Computer Architectures

25.09.2014 | Event News

17th European Health Forum Gastein: “Electing Health – The Europe We Want”

23.09.2014 | Event News

Future questions regarding data processing

22.09.2014 | Event News

 
Latest News

Stressed Out: Research Sheds New Light on Why Rechargeable Batteries Fail

02.10.2014 | Power and Electrical Engineering

Nanoparticles Accumulate Quickly in Wetland Sediment

02.10.2014 | Ecology, The Environment and Conservation

'Smart' bandage emits phosphorescent glow for healing below

02.10.2014 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>