Antibiotics have become an indispensable part of our medicine cabinet today. They play a paramount role in combating a large number of infectious diseases against which one was virtually powerless in the past.
Importance
Antibiotics play a weighty role in combating infectious diseases. Since the introduction of penicillin, for example, success has been achieved in the treatment of blood poisoning, certain forms of meningitis, and venereal diseases, far eclipsing anything previously known. Streptomycin represents a significant enrichment of options in the treatment of tuberculosis, and chloromycin is effective against typhoid-like diseases. In addition, antibiotics have also become very important in surgery. Here they are used to prevent wound infections during and after operations. As early as 1900, it had been observed on several occasions that nutrient solutions in which certain bacteria or fungi had grown could contain substances that inhibited the development of other bacteria and fungi. This phenomenon was then called antibiosis (anti = against, bios = life).
Composition
By antibiotically active substances, in short antibiotics, one has to understand thus substances which are formed by living beings (mostly microorganisms) in the course of their life activity, and which already in very small concentration inhibit other microorganisms in their development or even kill them. These are therefore substances that are formed in nature and are certainly important for the biological balance, for example in the soil, where many microorganisms live side by side. The decisive upswing in the development of antibiotics began with the discovery of penicillin by the English researcher Sir Alexander Fleming in 1929. However, at that time it was not possible to extract this metabolic product of the fungus Penicillium notatum from the nutrient solution on which the fungus was grown, and for some time it was thought that the product was too unstable to be captured chemically. But in 1940, the Englishman Florey and his team at Oxford succeeded in obtaining pure penicillin. This paved the way for a development that has since assumed unimagined proportions.
Treatment
After the first reports of the sometimes astounding treatment successes with penicillin became known, an intensive search began throughout the world for particularly powerful penicillin formers and, equally, for other microorganisms that formed other antibiotics. Very quickly, suitable methods were developed that allowed antibiotic activity to be tested. The tests revealed that many of the tested bacterial strains had the ability to produce certain antibiotic substances. Further, it turned out that this ability is by no means limited to certain groups of the microbial kingdom, but that there are antibiotically active representatives among bacteria and ray fungi, in almost all groups of molds, and even among algae. However, most of these antibiotics are not practically applicable, because a medically usable antibiotic must meet a number of requirements that are often not fulfilled. In many cases, for example, the quantities of the antibiotic in question that would be needed to cure a particular infectious disease are already toxic to the human or animal body. Then treatment is either not possible at all, or at best only to a very limited extent with local, external application. In other cases, there are difficulties in obtaining the substances from the nutrient solutions that have not yet been overcome.
Forms
However, of many hundreds of antibiotic substances mentioned in the literature in recent decades, at least a dozen or so have entered medical practice with the greatest success. In addition to penicillin, which, as mentioned, is produced by Penicillium notatum and some other molds, it is primarily the ray fungi (actinomycetes) that produce valuable antibiotics. The most important substances here are aureomycin, chloromycin, erythromycin, streptomycon and terramycin. For local application, some antibiotic substances produced by spore-forming bacteria play a certain role. Bacitracin, gramicidin and polymyxin should be mentioned.Penicillin and the actinomycete antibiotics mentioned are produced biologically on an industrial scale. For this purpose, there are directly extensive factory facilities, which had to be developed especially for the needs of the antibiotics industry. The antibiotics are grown in huge tanks. In the process, they secrete the active substances into the nutrient solution, from which the antibiotics are then chemically extracted. It was already indicated at the beginning that the individual antibiotics are particularly suitable for the treatment of certain diseases. This is due to the fact that each antibiotic is only effective against a limited group of pathogens. While chloromycin strongly inhibits typhoid bacteria, penicillin is virtually ineffective against this type of pathogen. On the other hand, penicillin can be used effectively to combat the pathogens of gonorrhea, against which chloromycin is unsuccessful. Penicillin and chloromycin are ineffective against tuberculosis bacteria, whereas streptomycin proves effective in this case. These few examples should show that there are no miracle cures among antibiotics. Through the sensationally presented articles in earlier media and certain professional journals, many readers have gained the impression that in penicillin, for example, the physician has a preparation in his hand with which practically every infectious disease can be effortlessly cured.
Correct use
This is completely false, and with such reports only an unfortunate confusion has been brought to the general public. The physician must know exactly whether the pathogens are actually sensitive to the antibiotic in question before treating them with antibiotics. Furthermore, the antibiotic selected for treatment must be administered in a quantity that, if necessary divided into individual doses, ensures a sufficiently high concentration in the body over a certain period of time. Therefore, the patient must follow the doctor’s instructions to the letter, often receiving tablets or injections over several days, because only in this way is it possible for bacteria to be inhibited in their development and for the body’s natural defenses to destroy the pathogens that are no longer able to multiply. If the antibiotic is administered in too small a quantity or irregularly, there is a risk that the pathogens will become accustomed to it and then even subsequent, higher doses, which would originally have been sufficient to cure the infection, will remain practically ineffective. The extent to which people have already harmed themselves through the reckless use of these agents is shown by a comparison: 20 years ago, about 70 percent of all pus-causing bacterial strains were sensitive to penicillin; today, only 34 percent are. The indiscriminate use of antibiotics harbors yet another danger: every human being harbors, especially in the gastrointestinal tract, a large number of microorganisms that are instrumental in breaking down food substances and are therefore indispensable for normal digestive processes. The killing of a large part of the intestinal bacteria by antibiotics during the treatment of an infectious disease can lead to serious illness. The danger can be reduced if artificially cultured intestinal bacteria are returned to the organism in the form of certain preparations during or after antibiotic treatment. These examples show how much care the physician must take in the proper use of antibiotics so that these drugs remain with us as an effective weapon against infectious diseases. Insufficient insight on the part of the patient can jeopardize the success of treatment and even become a danger to the general public. The search for new antibiotics is still in full swing. After all, there are still bacterial and viral infections that largely defy treatment with antibiotics. Moreover, pathogens are adapting more and more to antibiotics and becoming resistant. Diseases that cannot yet be cured or treated with antibiotics include spinal polio, rabies and some influenza diseases. Furthermore, highly effective antibiotics against pathogenic fungi are still lacking. So, although excellent results have been achieved with antibiotics, much remains to be done. Physicians, biologists, chemists and technicians are working closely together to advance development in this field.