Would You Like Some Drug-Resistant Bacteria With That?

By Alex Campbell on March 8, 2011 in Other

We need antibiotics. Their use in medicine saves people’s lives literally every minute of the day. Before they were discovered (by accident in 1928), catching a cold or cutting yourself might have meant the end of your young life! The advent of these ‘miracle drugs’ changed life as we knew it but in our efforts to eradicate disease have we gone a little overboard with antibiotics?

Many experts believe that antibiotics are wildly over-prescribed, particularly in Australia where up to 50% of prescriptions may be unnecessary. As well as too much medicine, antibiotics are also being overused in agriculture, doled out to chickens, pigs and cows. Farmers started to use antibiotics on livestock to treat nasty infections but quickly realised that the drugs also increased growth rates and thus, lowered food costs. These days, more than two-thirds of all the antibiotics used in our country are given to livestock, often to perfectly healthy animals.

The issue with excessive antibiotics is that bacteria can quickly become resistant to them. By having relatively short generation times and the ability to transfer genetic material between individuals, bacteria can evolve very rapidly to tolerate and thrive in previously lethal conditions. Giving animals or people substances that kill bacteria creates an environment within their tissues and organs that ‘selects’ for resistant strains. So, the unnecessary use, or failure to fully complete a prescribed course, of antibiotics increases the exposure of living bacterial cells to these substances, giving them more opportunities to adapt.

When given to livestock, drug-resistant bacteria can develop within the animals’ gastrointestinal tracts then spread into the environment through waterways, dust and even the meat on your dinner plate.  This is becoming a big problem. Back in 1999, bacteria in Australia had developed resistance to most of the antibiotics we used. Globally, antibiotic resistance has been linked to the resurgence of diseases like malaria, tuberculosis and ‘staph’ (Staphylococcus aureus) infections.

Happily, preliminary data from a new study in Japan has suggested that natural alternatives to antibiotics, like liquorice and seaweed, may help prevent microbial infections by bolstering animals’ immune systems. The researchers hope that adding these natural alternatives to animal feeds may help negate the need to use so many drugs in agriculture.

Such research into naturally occurring alternatives to antibiotics that don’t actually kill bacteria (and therefore don’t select for resistant strains) but rather inhibit their growth is encouraging. Luckily for us, natural antibiotics have been harvested from all sorts of creatures, including sea squirts, plants and algae. Hopefully some of these will prove marketable soon, because our current armoury of weapons against bacterial infections is waning. This is a frightening thought considering that in the dirty old days without antibiotics, people had only about a 20% chance of surviving a staph infection!

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