09:32pm Sunday 19 November 2017

Antibiotic resistance is a gut reaction for some bacteria

The bacteria produce compounds, called cephalosporinases, which inactivate and destroy certain antibiotics such as penicillin derivatives and cephalosporins, protecting themselves and other beneficial bacteria that live in close proximity. However, they may also give protection from these antibiotics to harmful bacteria, such as Salmonella.

The gut is home to hundreds of trillions of bacteria, which have important roles in maintaining our health. But a side effect of taking antibiotics is that these may also kill off some of our beneficial gut bacteria, allowing harmful bacteria to gain a foothold and cause an infection. Susceptibility to antibiotics isn’t uniform in the hundreds of species that colonise our guts, and some of the most common bacteria, the Bacteroides, are among the most resistant.

By scanning the genome of strains of Bacteroides bacteria that live in the gut, the researchers found genes that produce an enzyme called cephalospoprinase, which specifically destroys certain antibiotics. They also showed that the cephalosporinases are exported out of the bacterial cells, attached to the surface of special packages called outer membrane vesicles (OMVs).

Bacteria use OMVs to distribute compounds made inside the bacterial cells to the outside world. Among these packaged compounds are cephalosporinases that can help protect any other bacteria that are in the same environment against antibiotics such as ampicillin. This was shown by adding the cephalosporinase-containing OMVs to cultures containing the ampicillin-susceptible gut bacteria, Bifidobacteria breve, which effectively protected them against high concentrations of antibiotics. A similar test showed that Salmonella bacteria were also protected.

The researchers at IFR, which is strategically funded by the Biotechnology and Biological Sciences Research Council, now want to see whether the protection against antibiotics from gut bacteria OMVs occurs in the gut itself. If so, this would have implications for how we use antibiotics. It will also improve our understanding of the growing problem of antibiotic resistant bacteria.

ENDS

 

Notes to editors

 

Reference: Cephalosporinases associated with outer membrane vesicles released by Bacteroides spp. protect gut pathogens and commensals against {beta}-lactam antibiotics, Regis Stentz et al, Journal of Antimicrobial Chemotherapy doi: 10.1093/jac/dku466

 

About the Institute of Food Research

 

The mission of the Institute of Food Research, www.ifr.ac.uk, is to be an international leader in research that addresses the fundamental relationships between food and health, food and the gut and the sustainability of the food chain in order to further the production of safe, healthy foods. It is a company limited by guarantee, with charitable status.

 

IFR is one of eight institutes that receive strategic funding from the Biotechnology and Biological Sciences Research Council. IFR received a total of £17.9M investment from BBSRC in 2013-14.

 

The institutes deliver innovative, world class bioscience research and training, leading to wealth and job creation, generating high returns for the UK economy. They have strong links with business, industry and the wider community, and support policy development.

 

The institutes’ research underpins key sectors of the UK economy such as agriculture, bioenergy, biotechnology, food and drink and pharmaceuticals. In addition, the institutes maintain unique research facilities of national importance.

 

External contact

Andrew Chapple, IFR Press Office


Tel: +44 1603 251490

Laura Knight, IFR Press Office


Tel: +44 1603 255310

 

Contact

BBSRC Media Office


Tel: +44 1793 414694


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