General Information: This strain is a spontaneous nalidixic acid-resistant derivative of virulent strain 197. This group of organisms is capable of invading the respiratory tract of animals and causing severe diseases. They express a number of virulence factors in order to do this including filamentous hemagglutins for attachment, cytotoxins, and proteins that form a type III secretion system for transport of effector molecules into host cells. This organism infects the respiratory tract of birds, and causes bordetellosis in commercially important animals such as turkeys, resulting in devastating losses every year due to secondary infections.