Expert Health Articles

What Are Multidrug-Resistant Organisms (MDROs)?

Gina Bailey, BSN, RN

Infection Preventionist
Quality/Infection Control
Blanchard Valley Health System

A multidrug-resistant organism (MDRO) is a living organism, bacteria, or fungi that has evolved and mutated to protect itself from medications that were once used to treat the infection they cause. MDROs can affect any person but are especially concerning for individuals in hospitals, long-term care facilities, group living facilities, those who are immunosuppressed, or those who have chronic conditions.

A Look at a Few Numbers

Healthcare providers and the Centers for Disease Control and Prevention (CDC) are concerned about the spread of drug-resistant organisms. They estimate more than 2.8 million resistant infections occur in the U.S. According to a collaborative study with the CDC, the estimated cost to treat infections caused by only six MDROs is more than $4.6 billion annually.​ 

Examples of MDROs

The list of MRDOs is growing, but some examples include methicillin-resistant staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum beta-lactamases (ESBL), and Candida auris (C. auris). These can cause infections in any part of the body, including skin, lungs, urinary tract, bloodstream, and open wounds. These organisms can be hard to treat as they may not respond to common antibiotics. These organisms can be caused by the overuse of antibiotics, not taking an antibiotic for the full-time prescribed, and can occur when fed in animals raised for food. The more often antibiotics are used, the more likely it is that resistant bacteria will develop.

How MDROs Are Spread

Drug-resistant organisms can be contagious. People who are infected or colonized with any germ, including an MDRO, can carry these organisms on their skin and in the body. Understanding that colonized individuals are not sick and do not need treatment is important. However, an individual carrying an MDRO, such as MRSA in the nose, can spread it to others. In healthcare and group living facilities, MDROs are often spread by contact or touch. Outside of these settings, MDRO infections often spread through skin-to-skin contact, shared towels, sports equipment, or close contact.


Drug-resistant infections can be difficult to treat; therefore, it is important to take steps to prevent them. The best way to prevent the spread of all germs, including MDROs, is hand hygiene. Clean your hands often, either with soap and water or hand sanitizer. Other ways to prevent MDROs include taking antibiotics as prescribed, only if needed, and for the full duration.

If you have or are taking care of someone with an MDRO infection, wash bed linens, towels, and clothing in hot water with detergent and bleach. Additionally, clean with a disinfectant containing bleach. Do not share personal care items such as deodorant, bar soap, or toothpaste.

Take Action

Lastly, if you have been diagnosed or have a history of a drug-resistant infection, it is important to let your healthcare providers know. Taking these precautions can help prevent the spread of infection.