The Battle of Shiloh, which lasted two days from April 6 to April 7, 1862, marked a defining moment in the American Civil War.
The clash, also known as the Battle of Pittsburg Landing, pitted Union forces under Major General Ulysses S. Grant against Confederate forces under General Albert Sidney Johnston. The battle took place in southwestern Tennessee and was one of the first large-scale engagements of the war in the Western Theater.
The bloodiest battle to date in the war claimed 23,000 victims on both sides. The battlefield itself was a swampy, mud-soaked hellhole. Medical services on both the Confederate and Union sides were woefully unprepared for the scale of the carnage, and many wounded were left to fend for themselves in the watery swamp.
When help finally managed to reach these poor souls, their rescuers noticed something strange. Their wounds gave off a faint glow in the night.
Furthermore, the wounded whose wounds glowed had a better survival rate than their peers whose wounds did not. Unable to explain what was happening, the bewildered soldiers named the strange phenomenon “Angel’s Glow,” because it truly seemed like the work of angels.
For a long time the story was considered little more than folklore. That is, until seventeen-year-old Bill Martin heard the story and asked his mother, Phyllis Martin, who is a microbiologist, if the bioluminescent soil bacterium she was studying, photorhabdus luminecens, could be responsible for the strange story.
She encouraged her son and his friend, John Curtis, to continue research and experiment to discover the answer (because that’s what happens when mom is a scientist). What they discovered was a remarkable explanation behind a story long considered little more than legend.
The strange lifestyle of Photohabdus luminescens
P. luminescens is an unlikely savior. The bacterium hangs out in the intestines of several species of nematode worms and lives in a strange symbiosis. The nematodes are soil predators and prey on insect larvae which they devour with the help of P. luminescens.
The nematodes burrow into the bloodstream of the unfortunate larva, where they vomit their bacterial load. P. luminescens releases toxins that kill the insect in a short time, giving the nematode quick access to an insect buffet. These toxins also inhibit the growth of bacteria that would break down the insect corpse, giving the germ and worm plenty of time to feast and multiply in the carcass of their prey.
It is this poison that was likely responsible for helping the soldiers survive their horrific wounds. The hypothesis developed by Martin and Curtis claimed that the glowing bacteria entered soldiers’ wounds when nematodes attacked the insect larvae, which are naturally attracted to such wounds. The resulting contamination would wipe out any normal, disease-causing bacteria in wounds.
The only problem with the hypothesis was that P. luminescens cannot survive at human body temperatures. The teenage scientists came up with a new way to approach this problem.
For once, hypothermia was a good thing
Their answer lay in the muddy battlefield itself. The battle took place in early April, when temperatures were relatively low. Adding to the misery, it rained occasionally during the battle. In some cases, wounded men were exposed to the elements for two days.
By then there would be hypothermia. That would have given P. luminescens time to develop and kill harmful bacteria. When the soldiers were then taken in and rewarmed, their bodies are said to have killed the bug naturally. For once, hypothermia was a good thing.
In doing so, the teens managed to provide a plausible explanation for the Angel Glow, a phenomenon long thought to be nothing more than the fanciful thinking of desperate men.
The exact nature of the poison the bacteria uses to perform its medical wonders has yet to be identified, but the duo are working to isolate it. Perhaps the bacteria that saved lives 150 years ago can save even more today.
