Colored transmission electron micrograph (TEM) of Pseudomonas aeruginosa bacteria. Pseudomonas are a genus of small, motile gram-negative bacilli with polar flagella. Most are saprophytic, live in soil and decompose organic matter. P. aeruginosa is sometimes pathogenic in man. May cause urinary tract infections or otitis externa. Most of the cells seen here are motile by monotrichous flagella. Mag: 8250x @77mm.