Shimwellia blattae

Shimwellia blattae (formerly Escherichia blattae) is a species of Gram-negativebacterium, one of two in the genusShimwellia. It is an aerobicenteric bacterium first isolated from the hindgut of cockroaches. Although it is related to human pathogens, including Escherichia coli, S. blattae is not pathogenic to humans. It is notable for its ability to synthesize vitamin B12de novo.