Ethanol production by Candida albicans in postmortem human blood samples: effects of blood glucose level and dilution

We present two cases in which the ethanol concentration in blood samples taken after death continued to increase in the absence of any remarkable increase in n-propanol concentration. Species of bacteria and yeasts, including Candida albicans were isolated from these samples. We then examined whether C. albicans, the most common yeast in the general environment, was able to produce ethanol in human blood stored at room temperature. Ethanol production increased as the glucose concentration increased, indicating that C. albicans produced ethanol from the glucose. Our results also suggested that C. albicans produced ethanol more easily in blood diluted by intravenous infusions that included glucose than in undiluted blood. These findings are useful for the evaluation of postmortem ethanol production in subjects whose blood has been diluted by infusions with glucose. Furthermore, there was no quantitative relationship between the amount of n-propanol detected and the amount of ethanol production: n-propanol appears to be an unreliable index of putrefaction and postmortem ethanol production by C. albicans. It is possible for the blood ethanol level to be high and n-propanol not to be detected, even if the subject has not been drinking alcohol. We reconfirmed the necessity of immediately adding sodium fluoride to samples for ethanol analysis to prevent postmortem ethanol production.