Infectious agent Staphylococcus aureus Cytomegalovirus Staphylococcus aureus Staphylococcus aureus Streptococcus faecalis Pseudomonas aeruginosa Pseudomonas aeruginosa Pseudomonas aeruginosa and Enterobacter Klebsiella pneumoniae Mycoplasma pneumoniae Herpes simplex Mycoplasma pneumoniae Enterobacte