Like staphylococcus aureus, or escherichia coli… or candida albicans. On second thoughts, probably not candida.
But given that you are half-bacteria by cell count (yes, really), I think we owe the little guys some credit. You’ll have to forgive the apparent compassion I now have for microbiota, but anthropomorphising them is quite probably the only way to survive the current stage of this degree. So belt up, you’re in for a geeky blog post.
For the last two weeks, it’s been a non-stop tour of the microscopic world. Bacteriology and immunology are turning out to be a pretty conflicting mixture of terrifying, fascinating and really, really tedious. It’s likely to become a bugbear (haha) for me, but at the same time, the more I learn about these tiny little organisms, and the elaborate defences animals put up against them, the more my respect for them grows.
Despite being only one cell big and containing a genome around 1/6 the size of yours, they’re pretty damn smart – and the most successful organisms on Earth.
I won’t bore you with details which frankly blow my geeky mind, but long story short, they outwit and outcompete humans at every turn. In just the last fortnight, my lecturers have shown me how they have evolved to scoot around, tolerate extremes of temperature and acidity, metabolise everything from starch to sulphur, commandeer the host’s cellular functions to their benefit, swap and change DNA and even coordinate with other bacteria. They are the ultimate little survival machines, and have been for quite literally billions of years.
In contrast, ‘modern’ humans have been around about 100’000 years. And at every step along our evolutionary paths, there’s been an arms race between our species. Bacteria, viruses, protozoa and fungi have all made a living out of hitching a ride on bigger organisms, causing no harm the vast majority of the time. Some of these can be opportunistically pathogenic, which means they’ll stay sweet while you’re healthy, but give them the chance and they’ll eat you alive! A small minority are true pathogens, and they don’t ask questions first.
As a result, we’ve been coevolving since the beginning of life on Earth. For every mutation or fancy genomic re-shuffling that’s given pathogens the edge, the animal body has found a way to parry the attack. It’s been a life and death ping-pong ever since. Ironically enough, antibiotics seemed at the time to be the final victorious move for the humans. But while we were busy basking in the success, bacteria were actually using this new threat as a strategy to accelerate their own genetic fortifications. Enter stage MRSA.
Not deliberately, of course, pathogens are mindless to the point of being regarded as non-living, in the case of viruses (a very interesting debate in itself!). But watching their intricate and almost strategic forms of camouflage, genetic manipulation and host invasion, it’s really hard not to attribute their success to some kind of military-minded intelligence.
Just as strategic are the immune defences that animals put in place to deal with this ever-changing plethora of sneaky invaders.
Bacteria have the edge on DNA manipulation, simply because they replicate so blinking quickly. Not only that, but they can share useful snippets for stuff like antibiotic resistance between themselves, which means news travels fast. You don’t have to wait to stumble upon the right genetic sequences yourself, just cut to the chase and get the recipe from your neighbour!
But large, multicellular organisms have something that bacteria (almost) never have: altruism. The immune defence cells have been a pretty endless source of both awe and academic despair for me in recent days, such is their complexity. But at the end of the day, there are quite literally billions of immune cells, in each and every one of us, willing to die for the greater good. It only takes one to raise the alarm, and they all come flooding in like the Light Brigade, ready to meet a similar end too, if it means that their host will survive.
The great array of different cells are like military units, each with special areas of expertise. The granulocytes are the bombardiers against parasites and bacteria, B lymphocytes the munitions factory for antibodies, T lymphocytes are snipers against virus-infected body cells, while Natural Killer Cells weed out cancerous traitors from within and phagocytes sweep up the enemy and present their parts to higher ranks, which initiates secondary and tertiary waves of chemically-coordinated attack.
All happening right now… while you sit reading the Dogsbody.
You’re under constant assault, but it’s okay, they’ve got this. Just chill.
More recently, my lectures have been addressing how we can prime our cellular regiments for attack by giving them a practice drill, via… vaccine! Not only this, but how mothers do this for their young from the moment of birth, providing them with the ammunition they need to fight off infection whilst they assemble their own forces to take on the microscopic world.
All that ^^. It was painfully, sickeningly geeky… I know this. But hell, if this is what I have to study until the end of the semester, don’t judge me for trying to enjoy it.
But speaking of mothers and offspring, lambing is just around the corner! For two weeks of my Easter “holiday”, I’ll be living in with a sheep farmer to help her lamb the flock. I love lambing, and I cannot wait.
But lambing as a vet student is somewhat different to lambing as a schoolkid. This time we’re responsible for what happens, and eventually we’ll be left to carry out and coordinate pretty critical medical and husbandry tasks by ourselves. But we’re not going going in completely blind… just very visually impaired… thanks to our lambing practical this last week.
In Basic Obstetrics, we gloved up to the shoulders to practice lambing on simulators. When I say ‘simulator’, I don’t mean something you might find NASA using to train astronauts. I mean there was a tub of lukewarm water on legs, with a ‘vagina’ hole cut into one end and a plastic bag running inwards from it, through a sheep’s pelvis. The setup was meant to replicate, as best as possible, the plumbing of a pregnant ewe.
And inside the tubs were newborn lambs. Unfortunate losses from last year, that had been frozen so that they could teach us lot how not to lose a lamb. And so they were set up in the simulator in all the wacky positions you might find them in inside an actual ewe. All in all, I must have proudly delivered the same lamb at least eight times.
Following this, we met the Easter Bush shepherd, who took us to the ewes that had already lambed on the unit, and spent the session teaching us how to nanny them after birth. Navel dipping, bottle feeding, stomach tubing, ewe leading, the works. Don’t get me wrong, the session was very intellectually stimulating, but the opportunity to cuddle lambs was by far the best bit.
To round off, we were taught resuscitation, castration and docking on stuffed toy lambs. Unsurprisingly, children’s toys are not usually supplied with the correct… anatomy.. for practicing castration, and so our teacher had kindly taken the time to sew a pair of danglies onto each one. Bravo.
Suffice to say I am very excited at the prospect of getting back into the lambing action on a completely new level, and no doubt I’ll have myriad stories to come back to you with. But for now, my next week is set to be another full-time microbiology course. But so far the practicals in this field have been far funnier that I had anticipated, particularly due to my ace lab partners, Rowena and Claire. But I’ll save those particular shenanigans for later.
Meanwhile, have a great week – and appreciate the (very) little things!