Pseudomonas aeruginosa or pyocyanic bacillus, pathogenic bacterium. It is very resistant and often at the root of nosocomial infections. It is one of the hardest bacteria to eradicate clinically. Pathologies are various : eye infections, infection of burns and operating wounds, urine, lung or gastro-intestinal infections, meningitis from inoculation, septicemia. Optical microscope X 1000.