Text c. Antibacterials

An antibacterial is an agent that inhibits bacterial growth or kills bacteria. The term is often used synonymously with the term antibiotic(s). Today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic(s) has come to denote a broader range of antimicrobial compounds, including anti-fungal and other compounds.

The term antibiotic was first used in 1942 by Selman Waksman and his collaborators in journal articles to describe any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution. This definition excluded substances that kill bacteria, but are not produced by microorganisms (such as gastric juices and hydrogen peroxide). It also excluded synthetic antibacterial compounds such as the sulfonamides. Many antibacterial compounds are relatively small molecules with a molecular weight of less than 2000 atomic mass units.

With advances in medicinal chemistry, most of modern antibacterials chemically are semisynthetic modifications of various natural compounds. These include the beta-lactam antibacterials, which include the penicillins (produced by fungi in the genus Penicillium), the cephalosporins, and the carbapenems. Compounds that are still isolated from living organisms are the aminoglycosides, whereas other antibacterials (the sulfonamides, the quinolones, and the oxazolidinones) are produced solely by chemical synthesis. In accordance with this, many antibacterial compounds are classified on the basis of chemical or biosynthetic origin into natural, semisynthetic, and synthetic. Another classification system is based on biological activity. In this classification, antibacterials are divided into two broad groups according to their biological effect on microorganisms: bactericidal agents kill bacteria, and bacteriostatic agents slow down or stall bacterial growth.

Revision exercises on unit I

Ex. I. Answer the following questions:

1. What term was first used by Selman Waksman to describe any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution?

2. What compounds are classified on the basis of chemical/biosynthetic origin into natural, semisynthetic, and synthetic?

3. In accordance with what effect on microorganisms many antibacterial compounds are divided into two broad groups: bactericidal agents kill bacteria, and bacteriostatic agents slow down or stall bacterial growth?

4. What drugs are used along with analgesics to modulate the action of opioids when used against pain, especially of neuropathic origin?

5. What major classes of analgesics do you know?

Ex. II. Name the word.

1. Drugs or herbs that reduce fever, cause the hypothalamus to override an interleukin-induced increase in temperature, and make the body work to lower the temperature.

2. Pain relievers, e.g. ibuprofen and aspirin.

3. It has weak NMDA antagonist and no anticholinergic properties, and is used for moderate to strong pain.

4. It is effective in alleviating neuropathy and pain resulting from spinal injury and multiple sclerosis.

5. Sulfonamides and quinolones produced solely by chemical synthesis.

Ex. III. Fill in the blanks.

1. Many medications have antipyretic effects and thus are useful for fever but not … illness.

2. Rofecoxib, celecoxib and etoricoxib are equally effective … when compared with … , but cause less gastrointestinal hemorrhage in particular.

3. Compounds, isolated from living organisms, are the ….

4. … are produced solely by chemical synthesis.

5. Most of modern antibacterials chemically are semisynthetic modifications of various ….

6. Combination analgesics can often result in significant adverse events, including … , most often due to confusion which arises from the non-acting components of these combinations.

Antibacterials, natural compounds, heat, analgesics, aminoglycosides, accidental overdoses, NSAIDs.

Ex. IV. Find synonyms on the right to the words on the left:

	antibiotic(s)		stimulant that works against heavy sedation;
	opioids		drug that may elevate mood in distressed patients;
	caffeine		drug denoting a broader range of antimicrobial compounds, including anti-fungal;
	anesthetics		very effective analgesics with some unpleasant side-effects;
	antidepressant		painkillers acting on the peripheral and central nervous systems;
	analgesics		the non-steroidal anti-inflammatory drugs

Ex. V. Get meaningful sentences

1. Also, pain, the, is, choice, of, analgesic, determined, type, by.

2. Are, antibacterial, small, many, relatively, molecules, compounds.

3. Natural, chemically, in, chemistry, advances, most, semisynthetic, modern, antibacterials, medicinal, compounds, modifications, of, various, with, of, are.

4. Plants, in, referred, with, ethnobotany, as, naturally, commonly, febrifuges, occurring, antipyretic, properties, are, to.

5. Fever, or, bathing, with, heat, cool, those, water, illness, can, effectively, reduce, usually, body, in, with, sponging, but, not, in, temperature, with, those.

Ex. VI. Topics for discussion: Look through the list of plants that have been used as herbal medicine (Appendix B) and speak on their application.

Ex. VII. Translate into English paying attention on the etymology of medicinal herbs and plants.

Лекарственные растения (лат. Plantae medicinalis) — обширная группа растений, органы или части которых являются сырьём для получения средств, используемых в народной, медицинской или ветеринарной практике в лечебных или профилактических целях. Наиболее широко лекарственные растения представлены в народной медицине. В качестве лекарственных растений в начале XXI века широко используются аир обыкновенный, алоэ, брусника, девясил, зверобой, календула, каллизия, клюква, малина, мать-и-мачеха, мята, облепиха, подорожник, ромашка, солодка, тысячелистник, шалфей, шиповник и многие другие. По состоянию на начало 2013 года по данным Международного союза охраны природы (IUCN), было описано около 320 тысяч видов растений, из них лишь небольшая часть (21 тысяча видов) активно используется в медицине.