Happy Microbe Monday my darling creatures!

So there's this fun little story that is probably anachronistic but still accurate to how these creatures actually work. When this microbe comes up this story comes up. People really like to tell it. So much that I'll tell it too. But I want to emphasize there's a real dearth of actual firsthand accounts here. And it's really the sort of thing you'd expect people to write about a lot. Feel free to correct me if I'm wrong and if anyone has decent primary sources on this.

During the American Civil War, on some particularly muddy battlefields, such as those of the Battle of Shiloh, injured soldiers began to develop glowing wounds. This is broadly considered Concerning by interested parties. Wounds are not generally speaking wont to glow.

The thing about these eerie wounds was that they were not a portent of death or divine retribution. Those soldiers who developed wounds were more likely to live. Even at the time this was noticed. It was celebrated as the "Angel's Glow," some strange divine protection.

This glow, of course, was caused by the soil bacterium Photorhabdus luminescens. This little guy is fairly widespread. It lives within the gut of entomopathogenic nematodes. When these nematodes infect insects, P. luminescens is released and does the actual killing with the various toxins it can produce. At least one of these toxins is made through the expression of the mcf gene. The "mcf" in this gene stands for "makes caterpillars floppy."

When the insect is dead, it uses enzymes to turn it into nutrient goop for it and the nematode to eat. They produce tapinarof/3,5-Dihydroxy-4-isopropyl-trans-stilbene which has an antibiotic mechanism, helping prevent other microbes from colonizing their beloved nematodes or eating their insect-meals.

Also it glows. It's bioluminescent. You may expect an explanation but honestly not many people have studied it and it's all a bit inconclusive. It does glow though. A few years back I worked with a researcher studying this bioluminescence, actually! I got a chance to interview them which was really neat. They had insect traps set out in the forest to capture wild specimens.

So, back to our wounds. All this information we've discussed about P. luminescens combines to make this story. Nematodes get in the infected wound. The bacteria within produce antibiotics, preventing pathogenic bacteria from colonizing. The bacteria glow, which adds an eerie, otherworldly vibe to the whole thing.

Is it feasible? Well, kind of. Neither creature has much incentive to stick to wounds, but on a muddy battlefield you're gonna get all sorts of microbial colonization so anything could end up there. They also don't produce the most efficacious antibiotic out there, but ANY antibiotic is pretty good during the American "Yeah I gave this gauze a good wash between uses don't worry pal" Civil War. There's actually a ton of microbes that release antibiotics to deter competition though, so it's not like this is a unique factor. But still. Broadly speaking, pretty feasible.

Use this in your wargames and tabletop RPGs to your liking.

And once again have a happy microbe monday. Remember that aeroplankton are real and ubiquitous. They ride the wind and the water; we are never without them.