Bacterial Resistance To Antibiotics - part 2 Multi-resistant bacteria How do bacteria build up resistance? Are bacteria able to retaliate?

Bacterial Resistance To Antibiotics - part 2

Multi-resistant bacteria

During the latter part of the 1950s, a very amazing thing occurred in a hospital in Japan which caused panic among the entire scientific community. It was the birth or origin of a multiple drug resistance. A number of patients admitted to this hospital have been suffering from Shigella dysentery. The bacteria responsible for this infection were also resistant to the sulphonamides, tetracycline, chloramphenicol and streptomycin. Before this incident, people were unaware of multiple-resistance. And now, it sent shock waves across the globe all of a sudden.

Later, by 1966, several countries began reporting multiple drug resistance. Fifty per cent of the E. coli bacteria isolated from the feces and urine of patients admitted to a hospital in South Africa showed that they were resistant to one or more antibiotics. The resistance information was transmitted by the plasmids (units of DNA that reproduce within the cell separately of the chromosomal DNA) inside the bacterial cell. These plasmids were passed on to other bacteria, enabling them to become multi-resistant too. Precisely speaking, it has been found that the resistant bacteria share their aptitude to overcome antibiotics with other bacteria that are still not multi-resistant.

Whether one agrees or not, the fact remains that drug resistance has genuinely turned out to be major problem globally. Although to different extents, presently the entire planet virtually has a problem with antibiotic-resistant infections. In fact, this problem is no more specific to developed or developing nations of the world. Today, it is affecting each and every one of us and in some way, it also unites us to fight the menace.

How do bacteria build up resistance?

The method used by bacteria to defeat the actions of antibiotics, supposedly known as 'magic bullet', is captivating indeed. In fact, we can only be in fear of these variable and resistant microorganisms as well as the manners which they adopt to defeat our endeavours to eliminate them.

Our restricted thoughts as well as lack of awareness regarding nature are presently compelling us to see things in a different perspective. We need to acknowledge that even the disease-bearing or pathogenic bacteria play a positive as well as significant role in nature. It is not necessary for us to comprehend the exactness of their role; we simply need to respect it. In fact, respect is the key to resolving the menace of bacterial resistance to antibiotics.

It appears that healthcare practitioners in the underdeveloped or developing nations have this respect. Apparently, many of them have a perception regarding the interrelation that exists among all the living things and, hence, they are endeavouring to work with nature by complying with its laws all the time. In effect, these people do not consider or perceive them to be different from or superior to the remaining aspects of nature. Conversely, people belonging to the Western civilization have a tendency to view humans as all-important, different in some way from the rest of nature, and, hence, are able to surmount nature and control it. However, the ordinary single-celled organisms (bacteria) have educated us regarding the mistakes of our ways. They are not only capable of eluding the 'magical bullets' (antibiotics), but their aptitude to be able to do this can also teach us an extremely important lesson. In fact, it is important that all of us learn this lesson and, thereby, change the way we think regarding control - control of nature, control of people, and control of land - as this would enable us to live in agreement with nature.

Are bacteria able to retaliate?

Over the centuries, bacteria have been successful in surviving despite the antibiotics by means of a procedure called spontaneous mutation. Now and then, genetic material metamorphose (mutates) or changes and produces a gene that can help the bacteria to stay alive in the face of any poisonous substance in the ecosystem, counting antibiotics. When the antibiotic usage is low, this is the only thing needed for survival. When antibiotics are present, they eliminate the bacteria that are vulnerable to it. However, some bacteria, which possess genetic substance that has undergone mutation in such a manner that they become resistant to the antibiotics, are left behind. Such resilient bacteria are subsequently left alive and they reproduce copiously and at a random pace. Subsequently, the gene that is resilient to antibiotics is passed on from one generation of antibiotic-resilient bacteria to the next. Since the bacteria that are susceptible to antibiotics die, they leave behind a population of bacteria that is made up of naught, but the primarily rare antibiotic-resistant bacteria.

The noted Scottish biologist, Dr. Alexander Fleming had detected such mutant bacteria during his researches and cautioned people against them way back in the 1940s. In those days, Dr. Fleming had forecast that the more extensive use of antibiotics would result in more extensive and more numerous of these mutant forms of bacteria. By means of spontaneous mutation, the genes of bacteria are able to become accustomed, facilitating them to stay alive even in the most unfriendly conditions. This is rather incredible and it demonstrates the manner in which a shift in the ecosystem is able to cause unseen transformations in the bacterial world.

Random use of antibiotics has resulted in the bacteria turning out to be ever more adjustable. This has led the bacteria to develop new, improved methods of staying alive in the form of plasmids.

It may be noted that plasmids are mini chromosomes that have the ability to replicate by them. They can also be described as pieces of genetic material that are present in the cell of a bacterium. However, plasmids are quite apart from the chromosomes. Occasionally, a plasmid transforms (mutes) and from this mutation an antibiotic-resilient gene is born. Plasmids enclosing these mutated genes then carry new information regarding the manner in which they can survive even in the presence of an earlier lethal substance. Even as we have been making antibiotics available extensively and giving us kudos for it or the excellent advance made by us in medical science, the bacteria were active in developing more effectual methods of protecting them. In fact, the plasmids are constantly changing their forms. They are recurrently losing genes that are no more useful for the survival of the bacterial cell and, simultaneously, they are getting new genes. In fact, the environment is responsible for dictating as well as selecting the genes that are valuable and require retaining, and the genes that are not need any longer for the survival of the cell.

Owing to the misuse of antibiotics by us, we have actually ensured the development of plasmids as well as their constant significance. The primary role of plasmids is to protect bacteria from being eliminated by antibiotics.

One of the exceptional properties of plasmids is that they are able to transfer from one bacterial cell to another and even from one species of bacterium to another. This, in fact, enables the bacteria to become resilient to a drug quite rapidly.

In effect, there appears to be no maximum to what bacteria can do in the war against antibiotics and to survive. As if producing plasmids was not sufficient, now bacteria have developed transposons which actually passes on properties like antibiotic resistance between the genetic substances. Compared to plasmids, transposons are very small bits of DNA or the genetic material. As the name of these tiny pieces of genetic material suggests, they have the aptitude to leap from one bit of genetic material to another - transposition. The transposons have the ability to leap from a plasmid to a chromosome and the other way around too. Each time the transposons pass on from one genetic material to another, it reorganizes the DNA of the bacterial cell where the transposons come to rest. In this fashion, the transposons can transfer resistance genes inside a bacterial cell or from one bacterial cell to another very easily. In fact, this is considered to be a more rapid and further effectual manner of spreading resistance genes among bacterial population. The bacteria employ three major methods to be able to survive even in the presence of antibiotics and they include spontaneous mutations, development of transposons as well as production of plasmids. Precisely speaking, these are the three means that have resulted in the epidemics of bacterial resistance to antibiotics, which is presently plaguing several sophisticated hospitals across the globe.


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