MDRO

MDRO stands for multidrug-resistant organism. It is a microorganism that is resistant to multiple antimicrobial drugs, which limits treatment options and can lead to higher morbidity and mortality. The term is used in clinical and public health contexts to describe infections that are difficult to treat because the organism no longer responds to standard antibiotics. Definitions vary, but many guidelines describe MDRO as organisms resistant to three or more antimicrobial classes.

Common MDROs include methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E), carbapenem-resistant Enterobacteriaceae (CRE), multidrug-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, and drug-resistant Mycobacterium tuberculosis. These organisms can cause a range of infections, including skin and soft tissue infections, pneumonia, bloodstream infections, and urinary tract infections.

Transmission is typically through person-to-person contact, especially via the hands of healthcare workers, contaminated surfaces, and invasive devices. Risk factors include recent antibiotic use, hospitalization, invasive procedures or devices, immunosuppression, advanced age, and exposure in long-term care facilities. Diagnosis relies on culture with antimicrobial susceptibility testing, and rapid molecular methods may be used in some settings.

Prevention and control emphasize antimicrobial stewardship to minimize unnecessary antibiotic use, strict infection prevention practices (hand hygiene, contact precautions, environmental cleaning), surveillance, and isolation of colonized or infected patients when appropriate. Treatment decisions depend on the specific MDRO and may require use of agents with retained activity, combination therapy, and supportive care. Global efforts seek to slow spread and improve patient outcomes.