Isolated Microbial Systems

The fun thing about revising for final year exams in Biological Sciences (Microbiology), is that the top marks for exams will go to those who have incorporated wider reading into their answers. This can give you the excuse of reading, listening or watching a science piece, and making you think ‘this counts as revision’. It most definitely does!!

Recently, I was cruising through the BBC website when I found a BBC Radio 4 programme talking about a comparative study on an isolated indigenous people, specifically focusing on their microbiome.

Scientists had been aware for the past decade that the microbial community in your gut played a great role in health that we had never noticed before. Obvious things like inflammatory bowel disease were known, but the impact these organisms have on your ability to gain weight and contribution to antibiotic resistance of collective pathogens were only recently realised. Researchers wanted to understand whether differences in microbiota have occurred in humans due to changing lifestyles.

The Yanomami Amerindians have lived in the remote mountains of Southern Venezuela, untouched by the rest of civilisation for about 11,000 years. Along with a rich diversity of microbes found cultured in their mouths, skin and guts, researchers also found genes responsible for antibiotic resistance. These were shown to have the same effects as in organisms such as MRSA; when these bacterial communities were given synthetic antibiotics and found to deactivate them!

Before antibiotics, bacteria and fungi (where the noted penicillin was isolated from) would produce antimicrobial agents to drive off competition from others for nutrients. This is where antibiotic production started from. However, even in the environment, other bacteria were already evolving resistance genes, most probably by gene transfer within bacterial communities. While these genes can defend microbes against natural antibiotics, the structural similarities of these to recent antibiotics like synthetic, 3rd generation cephalosporins, means that even communities never treated with antibiotics are likely to resist mainstream antiinfectious drugs also.

This is an interesting find and also has greater implications as our knowledge on the microbiome and human health has also increased. In industrialised times, our diets and modern antibiotics have all contributed to a decreased microbial diversity in the human microbiome. There has also been a rise in immunological and metabolic diseases such as asthma, obesity and diabetes. The researchers believe these factors could be interrelated and highlights the need for further research into the microbiome in determining definite causal relationships and cures for these disorders.

Revision is pretty interesting right now, and like to do my part in educating the masses too xo