MDR Full Form

Multiple Drug-Resistant is defined as the lack of susceptibility of some micro-organisms like bacteria, viruses, fungi, among others that do not respond to treatment by anti-microbial drugs. These anti-microbial drugs are referred to as anti-microbial agents. When the organisms are resistant to drugs from three or more categories, they are said to be multiple drug-resistant. Antimicrobial categories are said to be a class of drugs that act in a similar way or on a similar set of organisms. Multiple Drug-resistant types are a serious public health hazard.

Two other terms are commonly used in this context. They are Extensive Drug-resistant (XDR) and pan drug-resistant (PDR). Extensive Drug-resistant is the lack of susceptibility of the microorganisms to all drug categories except one or two categories. Pan drug resistance is the non-susceptibility of the microorganisms to all drug categories and drugs therein.

One of the most common diseases in the MDR category is multi-drug resistant Tuberculosis.

It is interesting to note that along with the evolution of human beings, the microorganisms have also evolved and have grown resistant to various anti-microbial drugs and agents. This happens in these microorganisms due to DNA transfer or mutation. When this transformation happens in the organisms they can oppose the action of certain antibiotics, thereby they become resistant to those antibiotics.

Multiple drug resistance in organisms happens due to any of the following actions

• They do not any longer depend on the glycoprotein cell wall
• Deactivation of antibiotics
• Cell walls become less permeable to antibiotics (the cell walls do not allow antibiotics to enter the cells of the microorganisms thus not allowing the antibiotics to kill the organism)
• These organisms learn to send out the infused antibiotics
• Severe mutations

Several bacteria have been discovered to be exhibiting multiple drug resistance now. One of the serious concerns with this is that these bacteria are now able to transfer the resistance to other bacteria that are related to them. This happens through a process called cell-cell conjugation.

There are also yeasts (a kind of fungus) called Candida that have become resistant to a certain category of drugs. This creates a need for treating candida infections with some other drugs. 

Viruses resistant to drugs

Some viruses have become resistant to drugs. A good example is that of HIV (human immunodeficiency virus.) It has grown to have developed multidrug resistance to several categories of antiviral drugs. It is known to mutate and change rapidly. The Influenza virus (commonly known as the flu virus) also has become resistant to several categories of drugs and antivirals. 

At one point Chloroquine was a standard treatment for Malaria. Malaria is caused by a microorganism called plasmodium. Today plasmodium is well known to be resistant to chloroquine. It is also reported that malaria-causing microorganism has mutated in certain parts of the world.

Prevention multiple drug resistance

Several methods are used by doctors who specialize in treating infections (they are called infectious disease specialists). Some of the methods that the doctors adopt are:

• Not using antibiotics for viral infections. Using only specific drugs for specific antimicrobials
• Trying to identify specific disease-causing microbes (there are specific tests that can do this)
• Not relying on broad-spectrum anti-microbials, and relying on specific categories of drugs to target the identified microbes
• Completing the full cycle of anti-microbial drugs (neither it should be too short, nor should it be too long)
• Using correct dosage
• Asking doctors not to prescribe antibiotics too often and use them only when necessary

One of the important efforts that need to be undertaken in managing multiple drug resistance diseases is to educate the prescribers. Also, the public should be educated about the dangers of it simultaneously. 

Conclusion

MDR or multiple drug resistance is seen in disease-causing microorganisms when they become resistant to three or more categories of drugs. MDR is caused due to several reasons. Several strategies can be adopted to prevent the occurrence of MDR.