Medieval “Eyesalve” kills MRSA

So the microbiologists have been working alongside medieval historians at Nottingham University on what they are calling “The AncientBiotics Project”. They are looking at medieval remedies and seeing if they can treat modern superbugs because many bacteria are becoming resistant to antibiotics. This is a growing problem in hospitals and healthcare environments as it increases the spread of infections and makes it more difficult to treat. This investigation/experiment/headline caught my eye in particular because we are studying antibiotic resistance in biology, and we are doing MRSA as one of our case studies.

So, firstly, I’m just going to say a bit about Antibiotics and MRSA…

Antibiotics are “substances produced by living organisms that can destroy or inhibit the growth of microorganisms.” Most are produced by bacteria and a few (e.g. penicillin) are produced by fungi. The term “antibiotics” can also describe synthetic and semi-synthetic drugs which destroy microorganisms.

Antibiotics work by inhibiting the synthesis and assembly of peptide cross-linkages in bacterial cell walls, weakening the cell wall and so too much water is allowed to cell, causing it to burst (osmotic lysis). Unfortunately this means that antibiotics only work whilst the bacteria is growing and it can’t kill viruses, as they have a different covering form bacteria.

There are two situations in which bacteria become resistant to antibiotics: when people unnecessarily take antibiotics or when the patient doesn’t finish her/his course of antibiotics.

In the first situation, people take antibiotics for what they think is a bacterial infection or as they, but in truth, it isn’t (so, maybe a viral infection). Antibiotics don’t work for these types of infection, but due to the overuse of the antibiotic, other bacteria in the body have a greater chance of the bacterial plasmid DNA randomly mutating to become resistant, and then pass on this beneficial mutation.

In the second case, the patient stops taking their course of antibiotics too early (as the patient starts to feel better), but not all the bacteria have been killed. The remaining bacteria are those which are most resistant to the antibiotics. These strains survive, pass their resistance on, multiply and spread to others.

These random beneficial mutations can be passed on vertically (from one generation to the next, when the bacteria asexually reproduces) or horizontally (by conjugation). Conjugation is the transfer of the allele in the bacterial DNA (plasmid) for the resistance, from one species of bacteria to another. The donor cell produces a small projection between it and another cell, forming a pilus (conjugation tube) between the two cells. The donor cell then replicates the plasmid containing the mutated allele. This plasmid is broken and made linear before passing through the pilus into the recipient cell. Only a small portion of the plasmid is transferred as there is only brief contact. The recipient cell gains the characteristics from the allele, in this case for antibiotic resistance.

MRSA (methicillin-resistant staphylococcus aureus) is the name given to any strain of Staphylococcus aureus (which is a common type of bacteria, carried in the throat and nostrils and on the skin, which only causes mild infections to healthy people), which is resistant to one or more antibiotics. If the Staphylococcus aureus bacteria breaks the skin, it could cause blood poisoning or endocarditis (infection of the inner lining of the heart), which are potentially fatal.

MRSA is a massive problem in hospitals, as it is easily transmittable; patients live in close conditions, are examined by doctors and other health workers who have examined other patients and the patients are also already more vulnerable to infection. Also, due to the vast amount of antibiotics used in hospitals, more strains of the virus are likely to mutate and form multiple resistances to the antibiotics.

Well, anyway, “The AncientBiotics Project” have found a medieval recipe for an eyesalve, which they followed as faithfully as they could to try and recreate it (they even sourced out wine from a vineyard which was around in the 9th century! (And yes, it was for the recipe 😉 )). They then tested the recipe by growing established biofilms (any group of microorganisms in which cells stick to each other on a surface), in this case they used staphylococcus aureus, added the recipe, left them for 24 hours and then counted how many bacteria were still alive. They found that the population reduced from a few billion cells (all stuck together in a highly protective biofilm coat) to a few thousand cells. This wasn’t a one hit wonder either- it is reliable! They’ve made four different batches with fresh ingredients and it’s worked for each. They’ve also tested the batches which have been left and stored for a while and they’ve worked too.

They don’t know exactly how it works, but they think it could be that there are a number of different active compounds within the eyesalve which attacks the staphylococcus aureus on different fronts, making it very difficult to resist. They also think, due to leaving this alcohol containing mixture for nine days, it could be because a reaction happens which forms a new molecule which has this effect on the staphylococcus aureus.

If this turns out to work as an antibiotics in a human situation (unfortunately, just because it works in the lab, doesn’t mean it will work with us…), then it would hopefully put an end to the massive problem of the spread of staphylococcus aureus in the hospital environment, and make it treatable (as long as people finish their course of the “eyesalve” so it doesn’t mutate and become resistant…).

Well, anyway, hopefully we will be hearing more about this research from our medlink home of Nottingham University J  and hopefully they will continue to progress with their brilliant work and research.

Goodbye future doctors! See you soon! …And Happy Easter!

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