The ability to generate an oxygen-free atmosphere for the growth of anaerobic bacteria is an essential aspect of work currently being undertaken at University College London's Eastman Dental Institute, where researchers are investigating genetic mechanisms involved in the transfer of antimicrobial resistance between species. Oxoid's Atmosphere Generation System, AnaeroGen, is regularly used to assist in the culture of resistant anaerobes which have been isolated from the mouth, and whose resistance genes have been shown to be capable of transfer to other oral micro-organisms.

AnaeroGen is a quick and convenient system which generates an anaerobic atmosphere without the need for evacuation/replacement or the production of hydrogen, and is activated on contact with air. The AnaeroGen product is simply removed from its protective foil packet and placed into an anaerobic jar immediately prior to sealing, producing a final atmosphere of less than 1% oxygen, supplemented with carbon dioxide. No catalyst is needed and no water is required.

"This simple system works extremely well when we need to grow obligate anaerobes", says Adam Roberts, Research Fellow at the Eastman Dental Institute. "We work with specially created biofilms which are grown in a constant depth film fermentor to simulate the microbial environment of the mouth. After growing the biofilms, we take them out of the fermentor, disrupt them and then plate out dilutions of the cells on to agar plates (usually Brain Heart Infusion Agar from Oxoid) before incubating them both aerobically and anaerobically. We can then identify any resistant bacteria and see if they can transfer their resistance to other sensitive bacteria. We have found that transfer readily occurs in biofilms and well as in filter-mating experiments on agar plates."

Oxoid AnaeroGen sachets and anaerobic jars are available in 2.5 L and 3.5 L formats, forming part of an expanding range of products that make up Oxoid Atmosphere Generation Systems (AGS). AnaeroGen is also available in a 'Compact' format which enables small culture batches to be prepared easily in transparent pouches.