Phosphorescence and Potential Antibiosis Secondary to Photorhabdus Luminescens Wound Contaminations at the Battle of Shiloh, Tennessee 1862

Abstract

During the American Civil War, contemporary accounts describe a peculiar luminescence phenomenon associated with untreated injuries sustained by fallen troops after the Battle of Shiloh (6-7 April 1862). While not experienced by all soldiers, field surgeons observed that the glow was somehow linked to reduced rates of wound infection and better outcomes. Given the wet springtime weather and unsheltered overnight conditions of the injured, it is plausible that some lacerations or punctures were incidentally infected with microscopic contaminants, including common soil nematodes. One endemic group likely present on riverbank groundcover is fam. Heterorhabditidae, a symbiotic host to Photorhabdus luminescens. Classified within the Morganellaceae, this Gram-negative pathogen is characterized by its unusual life cycle. With particular relevance to Shiloh, this sequence includes a blue-green phosphorescence phase accompanied by release of protein toxins having local antibiotic properties. Here, natural progression of this microbe from nematode symbiont to lethal secondary insect parasite lodged in an unclean wound is considered. Photorhabdus life-cycle is discussed as a component of the Martin-Curtis Hypothesis (2001), with new information on fluorophore isolation and recent genomic sequencing data. The Shiloh campaign is also placed within the context of the larger Western Theatre, noting that the engagement marked the heaviest Civil War casualty toll up to that point.