Symptoms and Signs of NDM-1 (New Delhi metallo-beta-lactamase)
and Antibiotic Resistance by Bacteria

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 3/11/2019

Doctor's Notes on NDM-1 (New Delhi metallo-beta-lactamase)
and Antibiotic Resistance by Bacteria

NDM-1 is stands for New Delhi metallo-beta-lactamase, an enzyme discovered in 2009, which can be produced by some types of infectious bacteria that cause the bacteria to become resistant to many commonly used antibiotics. The beta-lactamase enzymes effect older antibiotics such as penicillins and cephalosporins and newer carbapenem antibiotics, such as imipenem, that contain a beta-lactam ring.

The main symptom of NDM-1 bacterial infection is failure of antibiotic treatments (oral or IV) to improve a patient's condition, especially if the patient is infected with a gram-negative bacterial type and is being treated with an antibiotic that contains a beta-lactam ring structure. NDM-1 can be carried by several types of gram-negative bacteria, so symptoms of a diseases are usually of little in determining whether the patient has an organism expressing the enzyme until antibiotic treatments fail. Gram-negative bacteria are known to cause many diseases (including gastrointestinal problems, urinary tract infections (UTIs), pneumonia, and some wound infections), so patients with these conditions that require antibiotics and do not recover appropriately with treatment need the gram-negative bacteria isolated and tested for antibiotic resistance.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.