Haemophilus influenzae. Coloured Scanning Electron Micrograph (SEM) of a cluster of Haemophilus influenzae bacteria, cause of bronchitis and pneumonia in children. These non-motile, Gram- negative bacilli are covered with a lumpy coat which helps the bacteria to stick together & form clumps. H. influenzae harmlessly colonize the upper respiratory tract in most humans within the first few months of life. They may spread to cause diseases such as bronchitis and pneumonia. Certain capsulated strains are the most common cause of bacterial meningitis and epiglottitis in children. Treatment includes antibiotic drugs. Magnification: x6,200 at 6x7cm size. Magnification: x20,000 at 8x10 inch size.