Color enhanced TEM (transmission electron micrograph) of negatively stained Serratia marcescens with 0.5% of aqueous solution of ammonium molybdate showing long flagella and numerous but less prominent pili compared with that of E. coli. Serratia marcescens is a rod-shaped, gram-negative bacterium associated with nosocomial or hospital related infections. Serratia marcescens colonize in the respiratory and urinary tracts of adults causing nosocomial bactermia, cather-associated bacteremia, urinary tract infections and wound infections. The bacteria can also be found in the damp environment of bathrooms as a pink, slimy film that can be killed with bleach. Magnification: 30,000x.