Influenzae, Haemophilus, Type B (H. influenzae, Hib) (AP)

Haemophilus influenzae is a small (1x3um), pleomorphic, gram-negative coccobacillus. It is a nonmotile, non-spore-forming, fastidious, facultative anaerobe. Some strains of H. influenzae possess a polysaccharide capsule. All strains are serotyped into 6 different types (a-f) based on their biochemically different capsules. The most virulent strain is H. influenzae type b (Hib), with its polyribosyl ribitol phosphate (PRP) capsule. It accounts for more than 95% of H. influenzae invasive diseases, including bacteremia, meningitis, cellulitis, epiglottitis, septic arthritis, pneumonia, and empyema....