kingella kingella kingella is a genus of bacteria of the family neisseriaceae. it belongs to the hacek group of fastidious gram-negative bacteria that tend to cause endocarditis. kingella kingae is its type species. kingella kingella kingae in sheep blood agar scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: neisseriales family: neisseriaceae genus: kingellahenriksen and bøvre 1976 species as of 2021, five species belong to the genus: kingella denitrificans snell & lapage 1976 kingella kingae (henriksen & bøvre 1968) henriksen & bøvre 1976 kingella negevensis el houmami et al. 2017 kingella oralis corrig. dewhirst et al. 1993 kingella potus lawson et al. 2005