Navigation Links
Good bacteria armed with antibiotic resistance protect gut microbiome

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.


Contact: Jim Sliwa
American Society for Microbiology

Related biology news :

1. Leading evolutionary scientist to discuss how genome of bacteria has evolved
2. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
3. Team discovers how bacteria resist a Trojan horse antibiotic
4. From scourge to saint: E. coli bacteria becomes a factory - to make cheaper, faster pharmaceuticals
5. Bacterial shock to recapture essential phosphate
6. Disarming disease-causing bacteria
7. Study shows unified process of evolution in bacteria and sexual eukaryotes
8. Invisible helpers: How probiotic bacteria protect against inflammatory bowel diseases
9. Researchers develop rapid test strips for bacterial contamination in swimming water
10. Bacteria discovery could lead to antibiotics alternatives
11. Agricultural bacteria: Blowing in the wind
Post Your Comments:
(Date:10/29/2015)... Mich. , Oct. 29, 2015  Rubicon ... Genomics for U.S. distribution of its DNA library ... kit and Rubicon,s new ThruPLEX Plasma-seq kit. ThruPLEX ... enable the preparation of NGS libraries for liquid ... for diagnostic and prognostic applications in cancer and ...
(Date:10/27/2015)... -- In the present market scenario, security is one ... verticals such as banking, healthcare, defense, electronic gadgets, and ... secure & simplified access control and growing rate of ... bank accounts, misuse of users, , and so on. ... and smartphones are expected to provide potential opportunities for ...
(Date:10/26/2015)... and LAS VEGAS , ... Nok Labs , an innovator in modern authentication and ... today announced the launch of its latest version of ... platform enabling organizations to use standards-based authentication that supports ... Nok S3 Authentication Suite is ideal for organizations deploying ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... and PETACH TIKVAH, Israel , ... BCLI ), a leading developer of adult stem ... subsidiary, Brainstorm Cell Therapeutics Ltd., has been awarded an additional ... Office of the Chief Scientist (OCS). This grant, the second ... for 2015 activities to approximately $1.8 million (approximately NIS7 million).  ...
(Date:11/27/2015)... 2015 /PRNewswire/--  Mallinckrodt plc (NYSE: MNK ), ... has closed the sale of its global contrast media ... Euronext) in a transaction valued at approximately $270 million. ... a total of approximately 1,000 employees spread across the ... Louis area. This entire workforce and the ...
(Date:11/27/2015)... , November 27, 2015 ... Growing popularity of companion diagnostics is ... cancer biomarkers market with pharmaceutical companies and ... companion diagnostic tests. . ... Complete report on global cancer biomarkers ...
(Date:11/26/2015)... England , November 26, 2015 ... innovative medical device company specializing in imaging technologies, announced today ... European Commission as part of the Horizon 2020 European Union ... carry out a large-scale clinical trial in breast cancer. ... (Logo: , --> --> ...
Breaking Biology Technology: