False-colour scanning electron micrograph (SEM) of Haemophilus influenzae (Pfeiffer's bacillus) showing 2 individuals of the Gram negative, non- motile, non-sporing species of bacilli (rod-shaped bacteria). H. influenzae is exclusively a para of man, living in the healthy respiratory tract of healthy individuals. Most sub-species are non- capsulate bacteria, but there are 6 types of capsulated strains (types a to f), of which type b is responsible for numerous cases of bacterial meningitis in young infants. Other type b diseases include epiglottitis (inflammation of epiglottis, causing potential obstruction in airflow to lung.) Mag: x23,400 at 6x7cm, x11,700 at 35mm size. Green bacteria on blue background.