| Organism | Type and /or Site of Infection |
|---|
| Gram-Positive Bacteria |
| Clostridium difficile | Pseudomembranous colitis |
| Staphylococcus aureus | Pneumonia, cellulitis, boils, impetigo, toxic shock, postoperative bone/joints, eyes, peritonitis |
| Staphylococcus epidermidis | Postoperative bone/joints, IV line–related phlebitis |
| Streptococcus pneumoniae (pneumococcus) | Pneumonia, meningitis, otitis media, sinusitis, septicemia |
| Streptococcus pyogenes | Scarlet fever, pharyngitis, impetigo, rheumatic fever, erysipelas |
| Viridans group Streptococci | Endocarditis |
| |
| Gram-Negative Bacteria |
| Campylobacter jejuni | Diarrhea (most common worldwide cause) |
| Escherichia coli | Urinary tract, pyelonephritis, septicemia, gastroenteritis, peritonitis |
| Haemophilus influenzae | Pneumonia, meningitis, otitis media, epiglottitis |
| Klebsiella pneumoniae | Pneumonia, wounds |
| Legionella pneumophilia | Pneumonia |
| Neisseria gonorrhoeae | Gonorrhea |
| Neisseria meningitidis (meningococcus) | Meningitis |
| Pseudomonas aeruginosa | Wounds, urinary tract, pneumonia, IV lines |
| Salmonella enteritidis | Gastroenteritis, food poisoning |
| Salmonella typhi | Typhoid fever |
| Shigella dysenteriae | Dysentery |
| Vibrio cholerae | Cholera |