Freshwater bacterioplankton cultured from liver, kidney and lungs of a decomposed cadaver retrieved from a sandy seashore: Possibility of drowning in a river and then floating out to sea

A decomposed female body with an open abdomen and pleural cavity washed up on a beach after a powerful typhoon. Autopsy findings could not determine the cause of death because of leaching and putrefaction. Numbers and types of diatoms in organs overall, suggested the aspiration of fresh or brackish water with low salinity. However, this could not be confirmed because of contamination via the open cavities. We simultaneously investigated the presence of bacterioplankton in liver, kidney and lung homogenates using a modification of our reported bacteriological method. The freshwater bacterioplankton Plesiomonas shigelloides was identified in each of these organs, but marine bacterioplankton were undetectable despite the circumstances under which the body was discovered. The presence of freshwater bacterioplankton reinforced the results of the diatom test, and we concluded that this victim had died of drowning in fresh or brackish water with low salinity.