L/O/G/O
Student : Usmanova Assel .
Group:207 “A” pharmacy
South Kazakhstan State Pharmaceutical
Academy
Foreign languages department
Contents
Introduction
Antibiotics
Properties/classification
Conclusion. Literature
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Introduction
- The word "antibiotics" comes from the Greek anti ("against") and bios ("life"). The noun “antibiotic” was suggested in 1942 by Dr. Selman A. Waksman, soil microbiologist .
- Antibiotics are used in medicine widely and frequently as a remedy for healing many diseases.
- An antibiotic is a drug that kills or slows the growth of bacteria. Antibiotics are one class of antimicrobials, a larger group which also includes anti-viral, anti-fungal, and anti-parasitic drugs. Antibiotics are chemicals produced by or derived from microorganisms (i.e. bugs or germs such as bacteria and fungi). The first antibiotic was discovered by Alexander Fleming in 1928 in a significant breakthrough for medical science. Antibiotics are among the most frequently prescribed medications in modern medicine.
Functions
- Antibiotics are used to treat many different bacterial infections. Antibiotics cure disease by killing or injuring bacteria. Bacteria are simple one-celled organisms that can be found, by the billions, all around us: on furniture and counter-tops, in the soil, and on plants and animals. They are a natural and needed part of life. Bacteria cause disease and infection when they are able to gain access to more vulnerable parts of our bodies and multiply rapidly. Bacteria can infect many parts of the body: eyes, ears, throat, sinuses, lungs, airways, skin, stomach, colon, bones, genitals.
Antibiotics
- Some antibiotics are 'bactericidal', meaning that they work by killing bacteria. Other antibiotics are 'bacteriostatic', meaning that they work by stopping bacteria multiplying.
- Each different type of antibiotic affects different bacteria in different ways. For example, an antibiotic might inhibit a bacterium's ability to turn glucose into energy, or its ability to construct its cell wall. When this happens, the bacterium dies instead of reproducing.
types
- Some antibiotics can be used to treat a wide range of infections and are known as 'broad-spectrum' antibiotics. Others are only effective against a few types of bacteria and are called 'narrow-spectrum' antibiotics.
Antibiotic resistance
- Antibiotics are extremely important in medicine, but unfortunately bacteria are capable of developing resistance to them. Antibiotic-resistant bacteria are germs that are not killed by commonly used antibiotics. When bacteria are exposed to the same antibiotics over and over, the bacteria can change and are no longer affected by the drug.
Antibiotic resistance
- Bacteria have number of ways how they become antibiotic-resistant. For example, they possess an internal mechanism of changing their structure so the antibiotic no longer works, they develop ways to inactivate or neutralize the antibiotic. Also bacteria can transfer the genes coding for antibiotic resistance between them, making it possible for bacteria never exposed to an antibiotic to acquire resistance from those which have. The problem of antibiotic resistance is worsened when antibiotics are used to treat disorders in which they have no efficacy (e.g. antibiotics are not effective against infections caused by viruses), and when they are used widely as prophylaxis rather than treatment.
Antibiotic resistance
- Resistance to antibiotics poses a serious and growing problem, because some infectious diseases are becoming more difficult to treat. Resistant bacteria do not respond to the antibiotics and continue to cause infection. Some of these resistant bacteria can be treated with more powerful medicines, but there some infections that are difficult to cure even with new or experimental drugs.
Antibiotics classification
- Although there are several classification schemes for antibiotics, based on bacterial spectrum (broad versus narrow) or type of activity (bactericidal vs. bacteriostatic), the most useful is based on chemical structure. Antibiotics within a structural class will generally have similar patterns of effectiveness, toxicity, and allergic potential.
Antibiotics classification
- The main classes of antibiotics are:
- Beta-Lactams
- Penicillins
- Cephalosporins
- Macrolides
- Fluoroquinolones
- Tetracyclines
- Aminoglycosides
Antibiotics classification
- Most commonly used types of antibiotics are: Aminoglycosides, Penicillins, Fluoroquinolones, Cephalosporins, Macrolides, and Tetracyclines. While each class is composed of multiple drugs, each drug is unique in some way.
Penicillins
- The penicillins are the oldest class of antibiotics. Penicillins have a common chemical structure which they share with the cephalosporins. Penicillins are generally bactericidal, inhibiting formation of the cell wall. Penicillins are used to treat skin infections, dental infections, ear infections, respiratory tract infections, urinary tract infections, gonorrhea.
Penicillins .History of discovery
Usage
Cephalosporins
- Cephalosporins have a mechanism of action identical to that of the penicillins. However, the basic chemical structure of the penicillins and cephalosporins differs in other respects, resulting in some difference in the spectrum of antibacterial activity.
- Cephalosporins are used to treat pneumonia, strep throat, staph infections, tonsillitis, bronchitis, otitis media, various types of skin infections, gonorrhea, urinary tract infections Cephalosporin antibiotics are also commonly used for surgical prophylaxis. Cephalexin can also be used to treat bone infections.
Fluoroquinoloness
- Fluoroquinolones (fluoridated quinolones) are the newest class of antibiotics. Their generic name often contains the root "floxacin". They are synthetic antibiotics, and not derived from bacteria
- Fluoroquinolones are used to treat most common urinary tract infections, skin infections, and respiratory infections (such as sinusitis, pneumonia, bronchitis).
Usage
Tetracyclines
- Tetracyclines got their name because they share a chemical structure that has four rings. Tetracycline antibiotics are broad-spectrum bacteriostatic agents, which inhibit bacterial protein synthesis. Tetracyclines may be effective against a wide variety of microorganisms, including rickettsia and amebic parasites.
- Tetracyclines are used in the treatment of infections of the respiratory tract, sinuses, middle ear, urinary tract, skin, intestines.
Macrolides
- The macrolide antibiotics are derived from Streptomyces bacteria, and got their name because they all have a macrocyclic lactone chemical structure. The macrolides are bacteriostatic, binding with bacterial ribosomes to inhibit protein synthesis. Macrolide antibiotics are used to treat respiratory tract infections (such as pharyngitis, sinusitis, and bronchitis), genital, gastrointestinal tract, and skin infections.
- Macrolide antibiotics are:
- erythromycin
- clarithromycin
- azithromycin
- dirithromycin
- roxithromycin
- troleandomycin
Usage
Aminoglycosides
- In 1943, Selman Waksman, together with his co-workers, discovered that a fungus Streptomyces griseus produced an antibiotic substance which they named "streptomycin." Selman Waksman was awarded the Nobel Prize in Physiology or Medicine in 1952 for his discovery of streptomycin.
- Aminoglycoside antibiotics are<span style=" font-family: 'Times New Roman', 'Arial'; font-size: 20pt