B. pertussis Overview and Culture Conditions

Overview of B. pertussis

• Minute gram-negative coccobacilli resembling H. influenzae.
• Possesses fine filamentous appendages on the cell surface.
• Exhibits a unique lipopolysaccharide with a different phosphate composition than typical lipid A found in other Gram-negative bacteria.
• Lipopolysaccharide functions as an endotoxin.
• Can be stained with toluene blue to reveal bipolar metachromatic granules.
• Presence of a capsule enhances virulence.

Culture Conditions

• Requires enriched media for primary isolation.
• Bordet-Gengou medium (blood-glycerol agar) supplemented with penicillin G (0.5 g/mL) is a suitable culture medium.
• Preferably cultured on charcoal-containing media for optimal growth.
• Incubation should be conducted at 35-37°C for a duration of 3-7 days.
• A moist environment, such as sealed plastic bags, is essential for preventing desiccation.
• Identification of small, faintly staining gram-negative rods is achieved through immunofluorescence staining.