Causes formerly whooping cough (pertussis) in children & latter causes a mild pertussis-like illness.They multiply by binary fission.o Small Gram-negative cocobacilli with bipolar metachromatic granules.o Strict human pathogen, not normal human flora.o Non motile, Capsulated, Non sporulated.Dr RaghThought to be viruses but they shared bacteria in: 1.They have Gram-negative cell wall (no peptidoglycan, difficult/poor Gram Stain).They contain prokaryotic ribosomes.They contain both DNA & RNA.2.3.4.5.Dr Raghdaa