He killed one million Germans after the war was over.
In open air prison camps where they were exposed to weather and denied shelter and food. They were also forced to use slit trenches as sanitary facilities. This, of course, caused spread of disease. ;)
The main pathogens that are commonly looked for in feces include:
Bacteroides species
Salmonella and Shigella
Yersinia tends to be incubated at 30 °C (86 °F), which is cooler than usual
Campylobacter incubated at 42 °C (108 °F), in a special environment Aeromonas
Candida if the person is immunosuppressed (e.g., undergoing cancer treatment)