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!
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
24.05.2017 | Physics and Astronomy
24.05.2017 | Physics and Astronomy
24.05.2017 | Event News