Antibiotics
Antibiotics are a class of medications used to treat bacterial infections by either killing the bacteria or inhibiting their growth. They are produced naturally by microorganisms or synthesized in the laboratory. Antibiotics are a crucial tool in modern medicine for combating bacterial diseases and have significantly reduced the mortality and morbidity associated with such infections.
7 Key excerpts on "Antibiotics"
eBook - ePubAntibiotics and Antimicrobial Resistance Genes in the Environment
Volume 1 in the Advances in Environmental Pollution Research series
- Muhammad Zaffar Hashmi(Author)
- 2019(Publication Date)
- Elsevier(Publisher)
...Chapter 19 Antibiotics resistance mechanism Muhammad Naveed 1, Zoma Chaudhry 2, Syeda Aniqa Bukhari 2, Bisma Meer 3, and Hajra Ashraf 3 1 Department of Biotechnology, University of Central Punjab, Lahore, Punjab, Pakistan 2 Department of Biochemistry and Biotechnology, University of Gujrat, Gujrat, Punjab, Pakistan 3 Department of Biotechnology, Quaid-e-Azam University, Islamabad, Punjab, Pakistan Abstract Antibiotics are crucial in pharmaceuticals that are used against a broad range of bacteria to reduce their growth in living organisms. Antibiotics have been known for the last 30 years approximately according to their function and classification as Antibiotics have been around for a lot longer!!. In working, Antibiotics act as part of immune system and target bacterial cells specifically. Similarly, on detection of certain immune signals within living cells, Antibiotics detect harmful pathogens and act against them. Broad-spectrum Antibiotics affect both gram-positive and gram-negative bacteria, causing serious illnesses in human beings. But gradually, with passage of time, such bacteria have become resistant to these Antibiotics, resulting in prolonged bacterial infection and diseases. Resistance in bacteria is caused generally by means of self-medication, genetic variations, or mutations in bacteria and also by phenotypic variation such as β-lactams. As Antibiotics are specific to their targets, bacteria secrete certain enzymes to cleave chemical bonds within antibiotic structure. Furthermore, alteration in membrane permeability, antibiotic target modifications in bacteria, and resistant gene transfer to next generations also cause resistance to Antibiotics and, hence, bacteria such as Staphylococcus aureus and Neisseria gonorrhea, etc. have become resistant and cause lethal diseases in human beings...
eBook - ePub- David B. Wilson, Hermann Sahm, Klaus-Peter Stahmann, Mattheos Koffas, David B. Wilson, Hermann Sahm, Klaus-Peter Stahmann, Mattheos Koffas(Authors)
- 2019(Publication Date)
- Wiley-VCH(Publisher)
...8 Antibiotics and Pharmacologically Active Compounds Lei Fang 1, Guojian Zhang 1,2,3, and Blaine A. Pfeifer 1,2,3 1 University at Buffalo, The State University of New York, Department of Chemical and Biological Engineering, 904 Furnas Hall, Buffalo, NY, 14260‐4200, USA 2 Ocean University of China, Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Qingdao, 266003, People's Republic of China 3 Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, People's Republic of China CHAPTER MENU 8.1 Microbial Substances Active Against Infectious Disease Agents or Affecting Human Cells 8.2 β‐Lactams 8.3 Lipopeptides 8.4 Macrolides 8.5 Tetracyclines 8.6 Aminoglycosides 8.7 Claviceps Alkaloids 8.8 Perspectives 8.1 Microbial Substances Active Against Infectious Disease Agents or Affecting Human Cells 8.1.1 Distribution and Impacts Small molecule natural products have had a powerful impact on human health and follow‐up commercial development. In this chapter, a heavy emphasis will be placed on those small molecules that possess antibiotic activity, a capability that has particularly impacted modern medicine, in addition to alternative therapeutic activities associated with these same types of compounds. A common definition of an antibiotic (derived from “antibiosis,” which was first used by Vuillemin in 1889) is a chemical substance produced by a microorganism that can kill or inhibit the growth of other microorganisms. More broadly, an antibiotic may be any small molecule with antimicrobial activity. Microorganisms have developed metabolic pathways devoted to natural products that possess antibiotic activity. Such pathways are referred to as secondary metabolism, distinct from primary metabolism in that the final compounds (secondary metabolites) do not contribute to the primary growth and maintenance goals of the microbial cell...
- Halldor Thormar, Halldor Thormar(Authors)
- 2010(Publication Date)
- Wiley(Publisher)
...Introduction There has recently been a renewed interest in the antimicrobial effects of natural compounds which were commonly used as health remedies in the Western world until the advent of antibiotic drugs in the 1940s and 50s. After the emergence of Antibiotics many previously fatal infections and infectious diseases were brought under control and millions of lives were saved. Due to the dramatic effect of the new synthetic drugs, some health professionals even believed that the threat to mankind of pathogenic microorganisms had finally been eliminated. The great success of chemotherapy, using synthetic Antibiotics against bacterial and fungal infections and nucleoside analogues against viral infections, discouraged researchers and the pharmaceutical industry from making serious efforts to develop drugs containing simple natural compounds. However, this may now be changing, with the increasing problem of drug-resistant bacterial and viral strains, partly caused by drug overuse. Because the development of new drugs has not in all cases kept up with the emergence of new resistant strains of pathogens, such strains cause thousands of deaths annually, many in hospitals. Also, most synthetic drugs have more or less severe side effects, which affect a considerable number of patients. In spite of these drawbacks, the health benefits of Antibiotics to humans and their domestic animals can hardly be overestimated. It has become apparent to many medical microbiologists and health professionals that besides synthetic drugs, which inhibit the replication of pathogenic microorganisms in a specific way, there may be a place for less specific antimicrobial compounds, microbicides, which kill the pathogens on contact. Microbicides could act in concert with specific Antibiotics, launching a two-pronged attack on the invading pathogens. Direct killing, in addition to growth inhibition of pathogens, might make the formation of antibiotic-resistant strains less likely...
- Frank M. Aarestrup, Stefan Schwarz, Lina Maria Cavaco, Jianzhong Shen, Stefan Schwarz, Lina Maria Cavaco, Jianzhong Shen(Authors)
- 2018(Publication Date)
- ASM Press(Publisher)
...4 Mechanisms of Bacterial Resistance to Antimicrobial Agents Engeline van Duijkeren, 1 Anne-Kathrin Schink, 2 Marilyn C. Roberts, 3 Yang Wang, 4 Stefan Schwarz 2 INTRODUCTION With regard to their structures and functions, antimicrobial agents represent a highly diverse group of low-molecular-weight substances which interfere with bacterial growth, resulting in either a timely limited growth inhibition (bacteriostatic effect) or the killing of the bacteria (bactericidal effect). For more than 60 years, antimicrobial agents have been used to control bacterial infections in humans, animals, and plants. Nowadays, antimicrobial agents are among the most frequently used therapeutics in human and veterinary medicine (1, 2). In the early days of antimicrobial chemotherapy, antimicrobial resistance was not considered as an important problem, since the numbers of resistant strains were low and a large number of new highly effective antimicrobial agents of different classes were detected. These early antimicrobial agents represented products of the metabolic pathways of soil bacteria (e.g., Streptomyces, Bacillus) or fungi (e.g., Penicillium, Cephalosporium, Pleurotus) (Table 1) and provided their producers with a selective advantage in the fight for resources and the colonization of ecological niches (3). This in turn forced the susceptible bacteria living in close contact with the antimicrobial producers to develop and/or refine mechanisms to circumvent the inhibitory effects of antimicrobial agents. As a consequence, the origins of bacterial resistance to antimicrobial agents can be assumed to be in a time long before the clinical use of these substances...
eBook - ePub- José-Luis Capelo-Martínez, Gilberto Igrejas, José-Luis Capelo-Martínez, Gilberto Igrejas(Authors)
- 2019(Publication Date)
- Wiley(Publisher)
...Dis.1: 512–522.19Nontraditional Medicines for Treatment of Antibiotic ResistanceAna Paula Guedes Frazzon, Michele Bertoni Mann, and Jeverson FrazzonFederal University of Rio Grande do Sul, Porto Alegre, Brazil19.1 IntroductionThe success of the discoveries of the physician and microbiologist Alexander Fleming gave rise to “antibiotic era” brought a great relief for the medical and scientific community in the postwar period, since the treatment of bacterial infections were deemed as a historical milestone. However, less than 100 years after and, warned by the researcher himself that his discovery would have a limited time, the life span of Antibiotics seems to have its days over.However, even before the discoveries of antimicrobials, some substances were already used in the treatment of bacterial diseases. Generally, essential oils from plants have been used in the treatment of infections throughout history. Further, at the end of the nineteenth century and the start of the twentieth century, physicians and bacteriologists Emil Adolf von Behring and Shibasaburo Kitasato showed the first experimental evidence of the use of antibodies, along with the possibility of using immunoglobulins as to neutralize diphtheria toxin, a fact that has generated a great revolution in the scientific thinking at that time. Afterward, a German physician and bacteriologist, Paul Ehrlich, proposed the theory of side chain of antibody formation, quite similar to the current idea on cell surface receptors. These antibodies were called “magic bullets” due to their ability to find the target antigen through specific interactions and to neutralize and destroy the antigen. The therapeutic potential of antibodies had been unveiled.Taking into consideration the definition of “traditional approaches” as therapeutic agents using small molecules acting directly on the target bacterial component exerting a bactericidal or bacteriostatic effect...
- Henry Philippsborn(Author)
- 2006(Publication Date)
- Elsevier Science(Publisher)
...to biochemical origin and production of Antibiotics, in contrast to chemotherapeutics, which are of chemical (synthetic) origin.) d Antibiotika npl als Stoffwechselprodukte von Mikroorganismen f antibiotiques mpl comme substances métaboliques des micro-organismes p antibióticos mpl como substâncias metabólicas dos microorganismos 481 Antibiotics forestall the formation of the bacterial wall (Ant.) (See also entry: mucopeptide; peptidoglycan; murein.) d Antibiotika npl verhindern die Bildung der Bakterienwand f antibiotiques mpl empêchent la formation de la paroi bactérienne p antibióticos mpl impedem a formação da parede bacteriana 482 Antibiotics of biological origin (Ant.) (Biological origin: predominantly fungi; applied biotechnology.) d Antibiotika npl biologischen Ursprungs f antibiotiques mpl d’origin bioloqique p antibióticos mpl de origem biológica 483 Antibiotics of semisynthetic. substances (Ant.) (Antibiotics of modified natural products: Biotechnology.) d Antibiotika npl halbsynthetischer Stoffe f antibiotiques mpl des substances semi-synthéthiques p antibióticos mpl de substâncias semi-sintéticas 484 Antibiotics, synthesis inhibitors of the bacterial cell wall (Ant.) (Way of action of Antibiotics.) d Antibiotika npl, Synthesehemmer der Bakterienzellwand f antibiotiques mpl, inhibiteurs de la synthèse de la paroi cellulaire bacterienne p antibióticos mpl, inibidores da síntese da parede celular bacteriana 485 Antibiotics with narrow spectrum of action (Ant.) (E.g. ref. to certain cephalosporin type, predominantly active on (Gram-negative) pseudomonas.) d Antibiotika npl mit schmalem Wirkungsspektrum f antibiotiques mpl à un spectre étroit d’action p antibióticos mpl de espectro estreito de ação 486 Antibiotics with selective toxicity (Ant.) (Ref...
eBook - ePubHandbook of Natural Toxins
Food Poisoning
- Anthony Tu, Anthony Tu(Authors)
- 2019(Publication Date)
- Routledge(Publisher)
...However, the search for newer and better drugs for use on entire herds or flocks of animals that can be administered through feedstuffs or drinking water is a continuous process. It is estimated that over 100 million kg of these drugs are being used worldwide annually (Steele and Beran, 1984). The impact of these vast amounts of drugs on human and on animal health, agriculture, ecology, and the environment are exceedingly important as they often lead to potential drug residues in foods and the environment. III. SUBTHERAPEUTIC USE OF ANTIMICROBIAL DRUGS IN ANIMALS The administration of sulfonamides, principally sulfamethazine and sulfathiozole, and Antibiotics such as tetracyclines, penicillin, virginiamycin, and tylosin, in subtherapeutic doses to livestock through feed and/or water is well described in the literature (Nichols and Keys, 1984). These drugs exert then-effects on animals in at least four different ways: (1) direct growth promotion, (2) metabolic activity, (3) nutrient sparing effect, and (4) disease control. The Antibiotics thus not only help increase the rate of weight gain and improve feed efficiency, but also prevent many potential diseases in animals. A. Growth Promotion Antibiotics, e.g., penicillin, inhibit the growth of many gram-positive organisms, which consequently leads to development of increased numbers of Escherichia coli and other intestinal bacterial flora that play an important role in the synthesis of essential vitamins and amino acids. As animals are given antimicrobial drugs in feeds on a continuous basis, their intestinal wall structures become thinner and more absorptive. Because of this, these drugs are employed mainly to improve and contribute to the production of beef, lamb, poultry, and pork (Steele and Beran, 1984). B. Metabolic Effect There is evidence to suggest that Antibiotics contribute to modification of metabolic reactions...
