Antibiotics are generally administered to kill pathogenic bacteria. Due to constant exposure to antibiotics, sometimes, these bacteria may develop resistance to antibiotics. Let us first take a look at what is meant by ‘antibiotic resistance’ and then find out more about these bacteria.
Some strains of bacteria can survive in spite of being exposed to particular antibiotics. This means they have developed antibiotic resistance and they do not succumb to the antibiotic drugs. The first antibiotic ‘penicillin’ was discovered by Alexander Fleming in 1929 and doctors started using it commercially in 1941. Since then, scientists have noticed that a bacterial strain soon becomes resistant to a number of antibiotic treatments but they were sure that they would be able to control the growth of that bacterial strain with at least one of the specially designed antibiotic drugs.
Now, the situation is serious as various strains of bacteria show resistance to multiple drugs. Researchers have already detected three strains of pathogenic bacteria resistant to more than 100 antibiotic drugs. Antibiotic resistance of bacteria may create a havoc because if pathogenic bacteria become immune to the entire antibiotic arsenal, devastating epidemics or pathogenic diseases will destroy the human race completely. The following section presents information on how do pathogenic bacteria become resistant to antibiotics.
Pathogenic Bacteria Turning Resistant to Antibiotics
The division and multiplication of bacteria through binary fission gives rise to daughter cells that are usually the exact copies of the parent cells. Occasionally, while copying the genetic material, a mistake or mutation may occur. Generally, genetic mutations do not promote any advantage or cause any disadvantage to the cell. Sometimes, they can be harmful to the cell but very rarely a genetic mutation enables an organism to generate a novel protein that is beneficial.
If we take into consideration the reproductive cycle of bacteria, it is easy to conclude that with such a fast rate of reproduction, advantageous mutations leading to creation of novel protein happen more often in bacteria than they would in an organism that reproduces slowly, such as humans. For example, the number of Escherichia coli (E. coli) can increase from one to one million cells, within 24 hours. An advantageous mutation enabling the bacteria to create new protein makes that bacteria less susceptible to the action of antibiotics.
Antibiotics are recognized as ‘miracle drugs’. They can work great for various dreadful diseases but they should be used sparingly and properly. The fact is that antibiotics are being overused and even misused. Let us see what happens when an antibiotic is administered. When the drug attacks the target, a group of bacteria, the cells that are susceptible, immediately die. Growth of the tolerant strains is stopped. The tolerant cells stop growing; but they are not completely killed.
Normally, when the growth of tolerant cells is stopped, the body’s own immune system can efficiently eliminate them. But if the prescribed dose of antibiotics is not taken and if the drug is discontinued too soon, the tolerant cells multiply to repopulate the entire colony. Moreover, resistant strains of bacteria continue to flourish even after coming in contact with the drug. After the end of antibiotic treatment, if there are any resistant cells left, they continue to grow and again cause another powerful attack of infection. This time, the previously used antibiotic drug won’t help control the infection.
While destroying the harmful bacteria, antibiotics interact with the non-harmful bacteria in the human body. Thus, non-pathogenic bacteria may become antibiotic-resistant and then they may be looked upon as good source of ‘resistance genes’ by newly invading harmful bacteria.
Extreme care has to be taken before prescribing antibiotics. Antibiotics should not be prescribed before verifying the presence of an infection. Doctors should confirm the diagnosis with the help of test results and then only they should prescribe antibiotic drugs. People taking the prescribed antibiotics, should never discontinue taking them, even though they feel better. Improper way of using antibiotics will not lead to complete elimination of the pathogenic bacteria. Instead, it will promote growth of both tolerant and resistant strains.
Do you know that almost 50% of all antibiotics produced are used in agriculture? Low doses of antibiotics are administered through feed to promote livestock growth or are sprayed over crops or fruit trees to prevent bacterial infestations. Antibiotics used in this way also encourage the development of resistant strains. These resistant strains of bacteria can easily enter a human body through unwashed hands or through ingestion of undercooked meat or unwashed fruits and vegetables.
Thus it can be concluded that overuse, misuse and non-medical use of antibiotics are mainly responsible for the development of pathogenic bacteria resistant to antibiotics. If you take a look at the pathogenic bacteria list, you will come to know that man had successfully controlled the growth of some harmful bacteria, for example, Yersinia pestis, which caused Black Plague in the middle ages. Proper care regarding personal hygiene and cleanliness can help control the growth of antibiotic resistant pathogenic bacteria.
Scientists have suggested that antibiotics should not be used for agricultural purposes. Researchers need to discover new affordable alternatives. Overexposure or overuse, can be minimized or eliminated by educating the people. Doctors should prescribe antibiotics only when they are required. Destruction of friendly bacteria by antibiotics should be avoided. All we can do is hope that within a few years, scientists will bring about a final solution to the problem of antibiotic resistant pathogenic bacteria.