ABSTRACT
Neisseriae and moraxellae are a small group of medically-important bacteria. The neisseriae are Gram negative cocci, while the moraxellae comprise both Gram negative cocci and coccobacilli. The family Neisseriaceae includes several other genera that are not considered as neisseriae per se, i.e., Acinetohacter, Alysiella, Eikenella, Kingella, and Simonsiella. Whereas phylogenetic studies indicate that these latter genera are indeed more closely related to the neisseriae than the moraxellae are (l) (Figure 1), we included the discussion of the neisseriae and moraxellae together for historical reasons and given the practical similarities that exist in the laboratory. The other genera of Neisseriaceae are mentioned in Chapters 17 and 18. Our discussion therefore highlights the major human pathogens (Neisseria gonorrhoeae, Neisseria meningitidis, and Moraxella catarrhalis) and other medically relevarit species, most ofwhich belong to the commensal flora.
