Bacteria Identification

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Pseudomonas aeruginosa is a gram negative, rod shaped, non spore forming, aerobic bacteria which belongs to the family pseudomonadaceae, genus Pseudomonas and species aeruginosa. It has polar flagella used in locomotion.   The major distinguishing characteristic is the ability to produce fluorescent pigments known as pyoverdine (blue green) and pyocyanin (yellow green). The ability to produce these pigments plays a great role in identification, understanding metabolic activities, genetic characteristics and growth requirements.   Pseudomonas aeruginosa inhabits soil, water plants and animals (including humans) (Balcht et al 83-84).   This bacterium only causes diseases in immunocomprised individuals and rarely in healthy persons hence referred to as an opportunistic pathogen. In most cases patients who have been admitted for more than week develops infections related to Pseudomonas aeruginosa. Such Infections which arise from a hospital set up are referred to as nosocomial infections (Cowan and Steele 16).
The mixture of the unknown specimen was plated on the TSA media and incubated at 37oc for 24 hours. This produced distinct colonies. Gram staining was done to know the unknown was gram positive or gram negative. A portion of the colony was picked and smeared on a slide. The slide was stained with crystal violet as the primary stain and then washed in distilled water slowly. The smear was then treated with a few drops of iodine solution which acts as a mordant. Once more the slide was with distilled water and then decolorized with acetone (alcohol) (Leboffe and Pierce 11). The smear was then stained with a counter stain and in this case it was safranin. Finally it was washed with distilled water, blot dried and mounted on a microscope for observation.
The results were a mixture of purple cocci and purple rod shaped bacteria. This means both the gram negative and gram positive bacteria were present. Smears were then made on...