Pseudomonas fluorescens bacterium, coloured transmission electron micrograph (TEM). P. fluorescens is a common gram-negative rod-shaped non-invasive and opportunistic pathogen that rarely infects healthy individuals. It has multiple flagella (hair-like) that it uses for locomotion. It is found in soil and water and is an obligate aerobe. Several strains have developed antibiotic resistance. Magnification: x15,300 when printed at 10 centimetres tall.