Pasteuria ramosa

Pasteuria ramosa is a gram-positive, endospore-forming bacterium in the Bacillus/Clostridia clade within Firmicutes. It is an obligate pathogen with cladoceran crustaceans from the Daphnia genus serving as its hosts. An established and widely used coevolutionary model of host-pathogen interactions exists with P. ramosa and D. magna.