Walsh & Hoyt: Bordetella

The genus Bordetella consists of four species: B. pertussis, B. parapertussis, B. bronchiseptica, and B. avium. Two of these species, B. pertussis and B. parapertussis, commonly cause infection in humans, although B. bronchiseptica occasionally causes disease in debilitated or compromised hosts. For example, a case of post-traumatic meningitis caused by B. bronchiseptica was reported in a 9-year-old boy who was kicked by a horse and sustained multiple fractures of the orbit. The Bordetellae are minute, gram-negative, aerobic, coccobacillary bacteria that occur singly or in pairs. B. pertussis and B. parapertussis are nonmotile, whereas the other two species have peritrichous flagellae that provide motility. There are no animal reservoirs for the human pathogens, and transmission of these organisms thus occurs from infected individual to susceptible host.