Antibiotic Resistance: "To err is human, to forgive is medicine"
Medical science is one of the fastest growing research and application area of our times. Advancements in medicine has been so vast that today we can witness the news of a cancer patient being completely treated or a person receiving an artificial organ for an organ damaged or lost. But, since human beings have left no stone unturned in disturbing the normal processes of the environment, the medicine is also not untouched. In fact, the human interference is so severe that a time will come when people would die of very petite infections or diseases. Eyeing on the present situation, we can say that the clock has started the strike.
One of the biggest recent medical terrors has been the dreaded Antibiotic Resistance. Antibiotic Resistance, in very general terms, is the condition developed when some of the most common antibiotics, and even higher antibiotics, fail to show their action on the disease causing microorganisms. This situation is produced gradually because on continuous application of antibiotics, the microorganisms like bacteria or fungi, start fighting them and develop mechanism to evade the medicine, simply becoming resistant. The most common pathogenic microorganisms are bacteria and fungi (singular: bacterium and fungus). Among the two organisms, the bacteria develop resistance more quickly than fungi. Apart from the bacteria and fungi, World Health Organization (WHO) has identified a quick rise in the cases of HIV and Malarial resistance.
B. Basic mechanisms behind resistance
As we all know, most of the functions occurring inside the body are performed by the proteins. The microorganisms also perform all their functions with the help of proteins they synthesize. All the proteins are made by specific genes. And the law of nature says that every organism resist attack on itself. Now, for example, if a bacterium is initially killed by an antibiotic, it would gradually develop a mechanism to evade the action of the antibiotic. The most common examples of antibiotic resistance mechanisms are described below, in brief:
1) Penicillin is the most common and primitive antibiotic used against many bacteria. A large of number of bacteria has started producing an enzyme which degrades the penicillin molecule, thus, rendering the antibiotic ineffective. Similarly, almost every microorganism changes its gene structure to produce a protein (enzyme) which could deactivate the antibiotic used against it or lessen its effect.
2) Another common mechanism of antibiotic resistance is displayed when the microorganisms modify or mutate the target structure slightly so that the antibiotic can no longer be able to recognize its target molecule.
3) Certain microbes also prepare a way to remove out the drug from their cell so that it cannot act any longer. This is known as drug efflux mechanism.
Now the biggest fear arises that if the pathogenic microorganisms remain active, the severity of infection will increase and will certainly affect the quality of life. Bacteria, as stated above, are one of the quickest self-mutator. They have been shown to start developing resistance as soon as a month or two of the treatment, in certain cases. This means that most of the antibiotics currently used cannot be used longer with equal efficacy. This leads to a medical as well as economical burden on the society. The ever growing cases of resistant microorganisms is one of the biggest causes of the Hospital Acquired Infections (HAIs) medically known as Nosocomial Infections. Thus, nosocomial infections are one of the major reasons to spread the resistant microorganisms.
C. Reasons for the resistance
Scientists and medical doctors have identified certain reasons which are shown to be dependent on the geographical regions. Some of the most common reasons for the resistance are described as follows:
1) Non-judicious use of antibiotics: This is a common practice among the people, for example in India, that they start an antibiotic treatment for almost any infection as small as a common cold. On the terrifying note they do so without consulting a doctor i.e. without a latest prescription. People very often consult each other and start a therapy themselves. People, in India, very often become SELF DOCTOR.
2) Continuous use of the same antibiotic: Take this case as an example - A person "X" develop some infection or condition and visits a doctor. The doctor upon examination prescribes certain antibiotics. X starts the antibiotic course and gradually feels better and the condition is treated. Now when the next time X feels a similar condition, he/she starts the same medication without consulting a doctor this time. This kind of continuous antibiotic usage strengthens the bacteria and weakens the medicine.
Note: Common cold is a viral and not a bacterial disease, yet very often doctors prescribe an antibacterial. One reason is that the throat condition (because of cold) at that point recruits certain bacteria which get colonized there and worsen the condition.
3) Unnecessary prescription: We cannot blame the public solely for the rising antibiotic resistance. Even some of the doctors are also practicing the unnecessary prescription of the drug. This practice certainly strengthens the microorganisms to act against the medicines.
4) Consulting the quacks: Quacks are one of the biggest medical menaces of the present society. They are the unregistered and bogus people who claim to be doctors and easily catch the people from the lower strata of the society. These quaks often make the condition so worse that it becomes difficult to treat medically.
5) Transfer of resistant microorganisms among the animals: In this case, the microorganisms, which have developed resistance against certain antibiotics, are easily suspended in the environment through fecal matters and other animal wastes. These wastes are then carried away through local water bodies or by certain insects like houseflies. Consumption of edible items contaminated with these microbes becomes one of the major threats. Thus, our body already has the mutated microbe and a normal treatment regimen for an eventual infection would not act effectively. Many a time, we consume poultry or meat contaminated with these mutated microbes, making this one of the causes of antibiotic resistance.
D. Common resistant microorganisms
Antibiotic resistance has prompted two basic causes of worry - firstly that very common and easily treatable infections are now becoming difficult to treat; secondly some dreaded infections of the past, which were treatable for past few years, are now again emerging to be monster. Some common organisms which have developed resistance are Mycobacterium tuberculosis (bacteria which cause TB), Staphylococcus aureus (resistant form known as Methicillin Resistant Staphylococcus Aureus or MRSA), Plasmodium falciparum (protozoa which causes the lethal form of malaria), Escherichia coli, Human Immuno-deficiency Virus (HIV which causes AIDS) and many others.
E. The case of Tuberculosis
Tuberculosis (known as TB) was once considered a lethal disease and people used to hate and disregard the patients. But the development of specific anti-bacterial agents for TB changed the face of treatment and soon the disease lost its deadly face. The antibiotics, namely Isoniazid, Rifampicin, Ethambutol and Pyrazinamide were the mainstay of the treatment and were given together in a procedure known as DOTS (Direct Observation Treatment Short-course). This was a WHO run program and the patients were given the medicine at a government health centre (or public health centre) or government hospitals for free. Patients were required to consume the medicine in presence of a medical or health staff so that the patient does not miss even a single dose. But gradually, two things happened - firstly the bacteria responsible started developing resistance, secondly the patients started missing the complete treatment regimen because they felt better in between the treatment schedule. Now these bacteria which developed initial resistance came to be known as Multi-Drug Resistant (MDR) variants. Now these were also easily communicable from one patient to another healthy individual. To overcome the increasing effects of MDR bacteria, one or two more different antibiotics were added to the original DOTS structure. The cycle repeated itself again after some time and the newer resistant bacteria were known as Extreme Drug Resistant (XDR) variants. Presently, we have almost no newer antibiotics for these XDR variants and already available antibacterial medicines are being tried in different combinations. To surprise all with the most disturbing situation, a few years back a reputed hospital in India reported 12 cases of Total Drug Resistant (TDR) which was termed by WHO as Extra Extreme Drug Resistant (XXDR-TB) variant of the bacteria. This means no available anti-TB antibiotic will act on the bacteria and the situation can get worse to any extent. But fortunately, to some extent, doctors have been lucky to show some improvements in these patients.
F. Suggestion and Request
I personally feel this section to be as important as the above sections because the points suggested here would be very helpful in decreasing the antibiotic resistance what is termed as the greatest menace of medical science. Kindly remember:
1) DO NOT consume medicine without an advice from a doctor without a prescription.
2) YOU MUST NOT become self doctor. It is very dangerous.
3) If you get symptoms similar to a previous infection in past, DO consult a doctor again for a fresh advice and new prescribed medicine. DO NOT repeat the previous medicines on the last prescription.
4) DO NOT advice other people for any medicine unless you are a registered medical practitioner.
5) BEWARE of the quacks. They are a major social problem.
1. Davies J, Davies D. (2010) Origins and Evolution of Antibiotic Resistance. Microbiol Mol Biol Rev; 74(3): 417-33.
2. Worldwide country situation analysis: response to antimicrobial resistance; WHO: April 2015.
3. About antimicrobial resistance; CDC: [ http://www.cdc.gov/drugresistance/about.html ].
5. Udwadia Z et al. Totally Drug-Resistant Tuberculosis in India. Clin Infect Dis. 2012; 54 (4): 579-581.
About Author / Additional Info:
I am pursuing Ph.D and the broad area of my research is developing polymeric drug delivery vehicles and biomaterials.