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A microorganism that forms pus. The principal ones are Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, , Clostridium perfringens, Pseudomonas aeruginosa, Neisseria gonorrhoeae, and Neisseria meningitidis. These pathogens stimulate a huge influx of neutrophils to the site. The pus is formed from dead organisms, white blood cells, and other cells destroyed during the immune response.
See also: microorganism