Multidrug-Resistant Organisms (MDROs) represent a growing challenge in global health. These microorganisms, primarily bacteria, have developed the ability to resist multiple antimicrobial drugs, making the infections they cause difficult to treat. This resistance complicates infection management. The World Health Organization recognizes MDROs as a significant and increasing worldwide threat, posing a considerable public health risk.
How Multidrug Resistance Develops
Microorganisms develop resistance to antibiotics through several mechanisms, often driven by the misuse and overuse of these medications. When antibiotics are used, they kill susceptible bacteria, but a few naturally resistant ones may survive. These surviving resistant bacteria then multiply, passing on their resistance traits to new generations. This process exemplifies natural selection, where the strongest organisms survive and reproduce.
Bacteria can also acquire resistance genes from other microorganisms through genetic transfer. This means a gene for antibiotic resistance can spread from one bacterium to another, potentially moving from a harmless microbe to one that causes disease. Overprescribing antibiotics, using them for viral infections, or not completing a full course of treatment contribute significantly to the development and spread of multidrug resistance.
Major MDROs Linked to High Mortality
Several multidrug-resistant organisms are frequently associated with elevated death rates due to their resistance profiles and the severe infections they cause.
- Methicillin-resistant Staphylococcus aureus (MRSA) is a well-known example, commonly found in healthcare settings and sometimes in the community. MRSA can lead to serious infections such as bloodstream infections, pneumonia, and surgical site infections, which can be challenging to treat.
- Vancomycin-resistant Enterococci (VRE) are another group of MDROs often encountered in hospitals and can cause bloodstream infections, urinary tract infections, and wound infections.
- Carbapenem-resistant Enterobacteriaceae (CRE), including resistant strains of Klebsiella pneumoniae and Escherichia coli, are a concern as carbapenems are often a last resort for treating severe bacterial infections. CRE can cause life-threatening pneumonia, bloodstream infections, and urinary tract infections, especially in hospitalized patients.
- Acinetobacter baumannii is a bacterium that can resist nearly all available antibiotics, making its infections extremely difficult to manage. It commonly causes pneumonia and bloodstream infections, particularly in intensive care units.
- Pseudomonas aeruginosa is another opportunistic pathogen, often resistant to multiple drugs, that can cause severe infections like pneumonia, urinary tract infections, and wound infections, especially in patients with weakened immune systems.
Why MDRO Infections Are So Deadly
Infections caused by multidrug-resistant organisms frequently lead to high death rates due to factors beyond the organism’s resistance. A primary reason is the severely limited number of effective treatment options available. The lack of new antibiotics means few drugs remain to combat these infections.
These infections often affect vulnerable populations, such as hospitalized patients, the elderly, and individuals with compromised immune systems or underlying health conditions. These patients are already in a weakened state, making them less able to fight off severe infections.
MDROs have the capacity to cause highly invasive infections, including sepsis, which is the body’s overwhelming and life-threatening response to an infection. Such severe infections can rapidly lead to organ failure and death. Challenges in rapidly diagnosing MDRO infections and initiating appropriate, timely therapy further contribute to poorer patient outcomes.
Protecting Against MDRO Infections
Protecting against multidrug-resistant organism infections involves a combination of individual actions and broader public health efforts. Practicing good hand hygiene is a simple yet effective measure; frequent hand washing with soap and water or using an alcohol-based hand sanitizer helps prevent the spread of germs. This is particularly important after using the restroom, before eating, and after contact with healthcare environments.
Using antibiotics responsibly is another important step. Antibiotics should only be taken when prescribed by a healthcare professional for bacterial infections, and the full course of medication should always be completed, even if symptoms improve. Sharing antibiotics with others or saving them for future use is not advisable.
Staying current on recommended vaccinations also helps, as vaccines prevent infections that might otherwise require antibiotic treatment, thereby reducing overall antibiotic use. Infection control measures within healthcare settings, such as proper sterilization and isolation protocols, also play a significant role in limiting MDRO transmission.