I wiped a coupe of my wife's kitchen sponges on a glass microscope slide, performed a Gram stain on it, put it under my microscope, and took this picture.  Here can be seen an abundance of cocci-type bacteria. Most of these are Gram positive (stained purple), while a few are Gram negative (stained pink).

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• 2010-04-05 06:54 Bob Blaylock 3072×2304× (410614 bytes) {{Information |Description = Bacteria from a kitchen sponge |Source = I (~~~) created this work entirely by myself. |Date = ~~~~~ |Author = ~~~ |Objective = 60× |Eyepiece = 15× |NumberedTick = 20 µM |