Aggregatibacter , Capnocytophaga , Eikenella , Kingella , Pasteurella , and Other Fastidious or Rarely Encountered Gram‐Negative Rods

Abstract

This chapter covers the bacterial genera that are taxonomically diverse and belong to the families Cardiobacteriaceae , Flavobacteriaceae , Leptotrichiaceae , Neisseriaceae , Pasteurellaceae , and Porphyromonadaceae ; common traits justify their discussion as a group. The taxonomy of the family Pasteurellaceae has undergone important changes; the family consists of over 100 named species distributed in over 25 genera, of which 4 include human pathogens: Actinobacillus , Aggregatibacter , Haemophilus , and Pasteurella . The chapter focuses on species commonly isolated from humans. Direct microscopy of specimens or of positive blood cultures supported by clinical information may help identify the corresponding bacteria, e.g., the typical morphology of spindle‐shaped cells in the Gram stain in the context of a dog bite allows the presumptive identification of C. canimorsus . Phenotypic identification of fastidious Gram‐negative rods presents several challenges.