Thomas approached me long ago with a simple yet misguided premise; viruses are objectively better than bacteria. I’ve been playfully criticising virology for years and it sounds like I finally broke him. In any case we went back to our respective corners to put forward our respective cases. We each wrote our own arguments separately and next week you will hear our rebuttals. You got to read Thomas’ attempt at an argument last week so without any further ado…
Viruses are objectively better than bacteria. Nah, not really.
There are many ways I can attack this topic but intend to concentrate on just three. Bacteria are better at killing you than viruses, better at helping you live than any virus and are better for the environment than any virus could be. Actually, before I launch into my arguments let me paint a picture for you.
This is a photo of Thomas shooting at puppies and kittens, he does that sometimes. You shouldn’t (but totally can) let this cloud your judgment of him.
Bacteria are better killers
This one is actually pretty easy to prove actually.
Generated from 2004 data, these are the top 10 causes of death globally as reported by the World Health Organisation. I’ve added color labels to make it easier to read and to highlight some important associations: Red, association with bacteria; Green, subset of death directly caused by bacteria; Blue, directly caused by bacteria; Grey, no significant association with bacteria.
Let me explain.
Coronary heart disease kills 7.2 million people every year, it’s a big deal. Of that number 2% are DIRECTLY caused by Streptococcal infections. It is harder to calculate indirect bacterial effects on this numbers but it’s been estimated that 42% of deaths from cardiovascular diseases are related to ischemic heart disease which can also caused by bacterial infections.
Similarly, cerebrovascular diseases have a huge number of deaths both directly and indirectly caused by bacterial infections. Hence the red coloring.
In green we have lower respiratory infections. Two-thirds of those deaths are caused by S. pneumoniae which puts it on the top 10 in its own right. Nuff said.
Obstructive pulmonary diseases are caused by the physical blockage of airways in the lungs resulting in respiratory stress. As I mentioned a couple of weeks ago P. aueringinosa results in huge issues in cystic fibrosis patients. These chronically obstructed airways often lead to a decline in health but exacerbations in 25% of cases are caused by bacteria alone and another 25% of cases are caused by bacteria and viruses together. So there’s another one on the list which is caused by bacteria.
Guess what we know about diarrhoeal diseases, particularly in the third world…
“The three most deadly diarrhoeal diseases are cholera, bacillary dysentery and typhoid. Others include amoebic dysentry, giardiadis, salmonella, camplyobacteriosis and cryptosporidiosis.”
– Statement by WaterAid – an international non-governmental organisation whose mission is to improve access to safe water, hygiene and sanitation in the world’s poorest communities.
The emphasis is mine but in bold and underlined are conditions caused by bacteria. Interestingly, the others are caused by protozoa. Not one virus even mentioned.
HIV/AIDS is defiantly not caused by bacteria, let’s just make that clear before Thomo jumps down my throat. However, the way these statistics are collected often results in the chronic disease collecting the death statistic even when the actual even that caused the death was an acute infection by something else. Here’s a list of ‘other’ conditions implicated in the deaths of chronically infected HIV/AIDS patients and even the WHO acknowledge that 23% of AIDS-related deaths can be attributed to tuberculosis.
So with the exception of lung cancers, road traffic accidents and birth complications (and it’s arguable the influence that bacteria have on two of those three) bacteria have a direct effect on the rest of the ‘top 10’. Our best conservative estimate is that 10% of all deaths are directly related to bacterial infections and indirectly… I have no idea but it would be a big number looking at what I’ve introduced above.
That’s it I think, I win. Actually it kind of feels bad to win a debate on death statistics, a bit morbid. Still, I’d like to see Thomas top that.
Bacteria are better friends
Viruses form a large part of our genome. In fact 10% of our genome is incorporated and now defunct retroviruses. For the most part these DNA sequences don’t do anything anymore. For this reason I call them FAIL VIRUSES.
Bacterial integration into the genome is rarer but it does occur but that becomes irrelevant, in the scheme of things, when you consider every cell in your body is at least 2 DIFFERENT BACTERIA. Without bacteria we wouldn’t have eukaryotic cells. Essentially the prevailing theory of endosymbiosis explains why we exist at all and the role bacteria played in it. Way back in the primordial sludge one BACTERIA engulfed another BACTERIA. Rather than being destroyed the engulfed bacteria specialised in energy production. We now call them Mitochondria and they are found in all eukaryotic cells. Back to the sludge though, one of these ‘double bacteria’ engulfed another BACTERIA, this bacteria specialised in converting sunlight into carbohydrates. We now refer to these incorporated bacteria as Choloplasts and they are the location of photosynthesis in plants. Without these BACTERIA we would not be able to produce or consume energy, at all. We wouldn’t have been able to evolve past oily bubbles of muck.
Oh and at the risk of harping on about this sort of thing bacteria have co-evolved with us for long enough now to know our short-comings and help us out by performing roles we require but cannot carry out ourselves!
So all eukaryotic cells only exist because of the incorporation of bacteria. Awesome. Once again Thomas, try beat that.
Bacteria and the environment
If we zoom out and look at the role of bacteria in the environment I don’t think viruses are even on the same playing field, I mean bacteria bring the rain!
Bacteria form the lowest active trophic level which means they are the very bottom of the food chain. Without them the system falls apart. Bacteria also feed off the carcasses of higher order animals. This recycles the nutrients back into the food chain so that nothing is lost. The key products that bacteria recycle are exactly the same ones that are most prevalent in our bodies, Biologists calls them C H O N S P.
Bacteria also interact with one another in the environment as well as having to fight off bacterial viruses and protozoa. The result of this is antibiotics and disinfectants primarily but also a wide range of therapeutics from anaesthetics to blood thinners.
I believe that I have presented some pretty strong arguments for the superiority of bacteria over viruses. They are better at killing us, helping us and enriching our lives than viruses could ever be but there is one more thing I want to point out.
Why is a puppy more fun than a wall? Because you can play with a puppy and you can do that because it’s alive. Similarly bacteria will always trump viruses because viruses are technically not alive while bacteria are as alive and playful as puppies.
To qualify as a living thing you must satisfy Mrs Gren:
All complete LIVING organisms can satisfy Mrs Gren. Viruses cannot move on their own, cannot utilise energy in the environment if they are not parasitising a cell, cannot sense the environment, cannot growth un-assisted, cannot reproduce un-assisted and do not generate metabolic waste.
Or there is always the TL;DR version,
SHARE THIS !!!
Bennett Hellman, A. (2010). Gut bacteria gene complement dwarfs human genome Nature DOI: 10.1038/news.2010.104
Ricchetti M, Tekaia F, & Dujon B (2004). Continued colonization of the human genome by mitochondrial DNA. PLoS biology, 2 (9) PMID: 15361937
Morris CE, Sands DC, Vinatzer BA, Glaux C, Guilbaud C, Buffière A, Yan S, Dominguez H, & Thompson BM (2008). The life history of the plant pathogen Pseudomonas syringae is linked to the water cycle. The ISME journal, 2 (3), 321-34 PMID: 18185595
Iwase T, Uehara Y, Shinji H, Tajima A, Seo H, Takada K, Agata T, & Mizunoe Y (2010). Staphylococcus epidermidis Esp inhibits Staphylococcus aureus biofilm formation and nasal colonization. Nature, 465 (7296), 346-9 PMID: 20485435