Microscopy:	The parvobacteria are short Gram-negative bacilli (coccobacilli). Many such as Haemophilus species are pleomorphic. Some bacilli, such as Pasteurella multocida may show bipolar staining. Occasionally, the capsules of capsulated strains of Haemophilus influenzae may be seen, e.g. Pittman type b strain, in stained smears or by immunofluorescent techniques using specific anti-capsular antibody.
Culture:	Parvobacteria are relatively fragile and specimens with these organisms need to be promptly cultured and preferably inoculated directly on to media for the best culture results. If delays are inevitable, appropriate transport media may be used for certain species such as Bordetella (seep. 196).
	Most parvobacteria species appear as small colonies on fresh blood agar after 24–48 hours’ incubation in an aerobic moist atmosphere with 5–10% added carbon dioxide. A few species will not grow on blood agar, such as Bordetella pertussis. Special enriched and selective media such as Bordet-Gengou, Lacey's medium or pertussis charcoal agar are needed for culture of Bordetella. Dorset's egg medium is required for culture of Francisella tularensis.
	Haemophilus species grow better on chocolate agar than on blood agar; moderately large colonies are apparent on chocolate agar after overnight incubation.