Differential Diagnosis for Gram Negative Rod
- Single most likely diagnosis
- Escherichia coli (E. coli): This is one of the most common gram-negative rods, often found in the human gut and a frequent cause of urinary tract infections, making it a likely candidate when considering gram-negative rods.
- Other Likely diagnoses
- Klebsiella pneumoniae: Known for causing pneumonia, urinary tract infections, and sepsis, especially in healthcare settings. Its resistance to antibiotics makes it a significant concern.
- Pseudomonas aeruginosa: Commonly found in water and soil, this bacterium can cause infections, particularly in people with compromised immune systems or existing lung disease, such as cystic fibrosis.
- Proteus mirabilis: Often associated with urinary tract infections, this bacterium is known for its ability to cause stones and is commonly seen in patients with catheters or other urinary tract abnormalities.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Neisseria meningitidis: Although less common, this gram-negative rod can cause meningitis and sepsis, which are medical emergencies requiring immediate treatment.
- Haemophilus influenzae: Can cause severe infections such as meningitis, especially in unvaccinated children, and pneumonia or bronchitis in adults with chronic obstructive pulmonary disease (COPD).
- Rare diagnoses
- Francisella tularensis: The cause of tularemia, this bacterium is rare but can be deadly if not treated promptly. It's typically associated with contact with infected animals or contaminated water.
- Yersinia pestis: The bacterium responsible for plague, it's extremely rare in modern times but would be catastrophic if missed due to its high mortality rate if left untreated.
- Burkholderia pseudomallei: Causes melioidosis, a disease more common in tropical regions. It can lead to severe pneumonia or sepsis and is often associated with exposure to contaminated water or soil.