Antibacterial

=Antibacterial =

__**What are antibacterials? **__
====In order to know what antibacterials are we have to understand the concept of bacteria. Bacterias are made up of single cell with a protective wall. This protective wall is made up of complex structures made of sugars bonded with peptides to lipids. ====

Bacterias have especial characteristics:

 * ====they have a single chromosome (one stand on DNA) ====
 * ====They are anaerobic (no need of oxygen) or aerobic (need oxygen) ====
 * ====Some cause diseases, others are beneficial ====

So we can deduce that antibacterial are a concentration of chemicals inhereted that prevent growth and multiplication of bacterias.
//Reference #1, #11//

//Reference #2, #11 //
 * Through out the years the most important discoveries of antibacterials are: **
 * ====Trypan Red: the first effective antibacterial developed by chemist Paul Ehrlich (1854-1915) in 1903 to cure sleeping sickness ====
 * ====Salvarsan (Arsohenammine): Antibacterial which contains arsenic, developed in 1908 to cure syphilis- By Ehrlich ====
 * ====“sulfa-drug” prontosil: first antibacterial commercially available against streptococcal bacterial discovered by Gerhard Domagk (1895-1964) in 1930’s ====
 * ====Penicillin: Alexander Fleming (1881 1955) discovered penicillin in 1928, which is an effective antibacterial for many diseases such as Syphilis and Staphylococcus. ====

**How they work... **
====Antibacterial targets are bacteria, and depending on the level of toxicity of the antibacterial the target changes. The principle targets are the cell walls (which animal cells do not have, but bacteria do), and intracellular organisms (but antibacterial efficiency varies depending on its capacity to penetrate the cell membrane). ====

The following are example of important antibiotics and their targets:
====<span style="font-family: Tahoma,Geneva,sans-serif;">In order to kill bacteria, the antibacterial needs to be in high concentration in the blood and stay in contact with bacteria long enough. Killing bacteria may depend on the concentration or on the time the antibiotic is exhibited. ====
 * < ====**<span style="font-family: Tahoma,Geneva,sans-serif;">Principle target **==== || ====**<span style="font-family: Tahoma,Geneva,sans-serif;">Antibiotic **==== ||
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">**Ce**ll wall ==== || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Penicillins ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Cephalosporins ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Glycopeptides ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Carbapenem ==== ||
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Ribosome ==== || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Chloramphenicol ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Macrolides ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Licosamides ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Fusidic acid ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Tetracyclines ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">amynoglycides ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Streptogramins ==== ||
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Cell membrane ==== || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Polymyxins ==== ||
 * ^  || ====<span style="font-family: Tahoma,Geneva,sans-serif;">Daptomycin ==== ||

**<span style="font-family: Tahoma,Geneva,sans-serif;">pH **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">pH influences the effect of the antibacterial on the bacteria. pH varies depending on the antibacterial. An example is macrolides; which decreases its effect on bacterial if pH falls below 7. ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Oxygen **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">For aerobic bacteria is imperative to be surrounded by oxygen in order to reproduce (found in respiratory system or surface areas such as skin) ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Microenvironment **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Antibacterial cannot pass through microenvironments prevent an effect on the bacteria. Microenvironments are formed by bacteria as protection. ====

//Reference #1// __ **<span style="font-family: Tahoma,Geneva,sans-serif;">Triclosan ** __

<span style="font-family: Tahoma,Geneva,sans-serif;">[[image:CHEM_triclosan.png width="331" height="148" align="right"]]

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">An antibacterial and antifungal. ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Organic compound, white aromatic powder which is soluble in some alcohols but not in water. ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">It is used basically in cleaning supplies because it shows antibacterial properties, for example: ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">﻿Toothpaste (to prevent gingivitis), deodorant, soaps, shaving cream, etc ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Medical Uses: **
====<span style="font-family: Tahoma,Geneva,sans-serif;">To identify the causes of bacteria(Empirically prior to identifying the causative bacteria when there is a wide differential and potentially serious illness would result in delay of treatment.) ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Used when bacteria is resistant to other drugs ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">In “super-infections” caused by diverse bacteria ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Advantages: **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Larger range of antibacterial activity (broader spectra) ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Less of a need (than narrow spectrum) to identify the germ that causes infection ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Disadvantages: **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Children who inhere these antibiotic during their first year of life are at increased risk of developing asthma ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">May give drug resistance ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Examples: **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Amoxicillin ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Levofloxacin ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Levofloxacin ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Tetracycline ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Chloramphenicol ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Medical Uses: **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">For infections, only when the bacteria is known ====

<span style="font-family: Tahoma,Geneva,sans-serif;">**Advantages:**

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">It will kill less normal microorganisms of the body than the broad-spectrum antibiotic. ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">It will cause less resistance of the bacteria because it deals with only one family of bacteria ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Disadvantages: **

 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">It can only be used if the causative bacteria is determined ====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Need to be very accurate when choosing the antibacterial because it may not kill the actual causative bacteria ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">Examples: **
//<span style="font-family: Tahoma,Geneva,sans-serif;">Reference #8 //
 * ====__<span style="font-family: Tahoma,Geneva,sans-serif;">Azithromycin: __====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Used for bacteria causing middle-ear, throat and urinary tract infections, laryngitis, sinusitis ====
 * ====__<span style="font-family: Tahoma,Geneva,sans-serif;">Clarithmycin: __====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Used for bacteria causing acute bronchitis, acute sinusitis, pneumonia, skin infections ====
 * ====__<span style="font-family: Tahoma,Geneva,sans-serif;">Clindamycin: __====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Used for anaerobic bacteria causing infections of the respiratory track, skin, peritonitis, tissue; and causing bone and joint infections, ====
 * ====__<span style="font-family: Tahoma,Geneva,sans-serif;">Erythromycin: __====
 * ====<span style="font-family: Tahoma,Geneva,sans-serif;">Used for bacteria causing acute sinusitis, Otitis, pneumonia, conjunctivitis, skin infection ====

[[image:620px-Penicillin_core.svg.png width="188" height="136" align="left"]]
====<span style="font-family: Tahoma,Geneva,sans-serif;">Penicilin is a group of antibiotics which were the first drugs to be effective with many diseases such as syphilis. All penicillins are beta lactam antibiotics and are used in the treatment caused by susceptible, usually gram-positive, organisms. ====

**<span style="font-family: Tahoma,Geneva,sans-serif;">How Penicilin works... **
====<span style="font-family: Tahoma,Geneva,sans-serif;">Penicilin is a narrow spectrum anti-biotic that destroys the cell wall and other micro organism of the bacteria. It does this by inactivating an enzyme necessary for the cross linking of bacterial cell walls. The enzyme is known as transpeptidase. It accepts the penicillin as a substrate, it then takes a nucleophilic oxygen of the enzyme, making it inactive.Cell wall construction stops and the bacteria soon die. ==== ====

====

__**<span style="font-family: Tahoma; font-size: 11.5pt; line-height: 16.5pt; margin: 0cm 0cm 0pt; tabstops: list 36.0pt;">Historical development of Penicillin **__
> media type="youtube" key="7qeZLLhx5kU?fs=1" height="346" width="432" align="right" ====<span style="font-family: 'Tahoma','sans-serif';">Howard Florey (Australian, 1898-1968) and Ernst Chain (German, 1906.1979) planned a research project on “natural germ killing substances”. First they were able to purify penicillin which was still powerful but which did not cause any ill effect on animals. and to do clinical trials with partly purified penicillin, which were successful. ====
 * <span style="font-family: Tahoma; font-size: 11.5pt; line-height: 16.5pt; margin: 0cm 0cm 0pt; tabstops: list 36.0pt;">Tradition: use mould to prevent infections
 * ==== ** 1923 ** - Clodomiro Picado Twight (Costa Rican, 1887-1944) studied and recorded the action and growth of fungal // Penicillium sp //. in Paris. ====
 * ==== ** 1927 ** - Picado Twight pubished his work on the effect of // Penicillium sp. //on the growth of// Staphylococcus //and// Streotococcus, //but received little recognition ====
 * ==== The discovery of penicillin was attributed to bacteriologist Alexander Fleming (Scotsman, 1881-1955) who was interested in the treatment for wound infection. ====
 * ====**<span style="font-family: 'Tahoma','sans-serif'; font-size: 12pt; line-height: 115%;">1928 **<span style="font-family: 'Tahoma','sans-serif';">- Fleming was working with cultures of //Staphylococcus aureus//, which causes boils and other infections. When going away on a holiday, he left open a [|petri dish] containing one of the cultures. When he returned, a mould (//Penicillium notatum//) had grown in the petri dish, and the colonies that surrounded the mould were undergoing [|lysis], reducing growth of the bacteria. After doing tests Fleming inferred that //Penicillium notatum// produced what he called penicillin which even kills some of the most dangerous bacteria. Fleming noticed that penicillin was chemically unstable, and he was not able to purify it in order to inject it in the human body. ====
 * ====**<span style="font-family: 'Tahoma','sans-serif'; font-size: 12pt; line-height: 115%;">1929 **<span style="font-family: 'Tahoma','sans-serif';">- Fleming published his results, but he did not pursue his discovery. ====

<span style="font-family: 'Tahoma','sans-serif'; font-size: 15px; line-height: 22px;">

 * ====<span style="font-family: 'Tahoma','sans-serif';">Florey tested the partly purified penicillin in mice which were earlier injected with the bacteria //Streotococcus//, and those who were given the penicillin lived. ====
 * ====<span style="font-family: 'Tahoma','sans-serif';">Chain discovered another method to fully purify penicillin dissolving it on ether in order to inject and try it on humans, which resulted successful. ====
 * ====**<span style="font-family: 'Tahoma','sans-serif'; font-size: 12pt; line-height: 115%;">1941 **<span style="font-family: 'Tahoma','sans-serif';">- Florey and Chain used penicillin to cure a policeman who was dying of septicemia (blood poisoning). Improvements on the policeman’s condition were drastic but unfortunately he died because Florey and Chain ran out of supply. ====
 * ====<span style="font-family: 'Tahoma','sans-serif';">Since Britain was at war (World War II), the industrial development of penicillin was carried out by the United States where penicillin was grown in containers holding corn-steep liquor. Penicillin started to be mass produced by the industry Merck & Co. During World War II Penicillin helped to prevent deaths and amputation that may have been caused by infected wounds. But since 80% of penicillin inhered is excreted in 3-4 hours, it was needed to find a solution to retain penicillin. Researchers found a molecule, called uricosuric, which competes with penicillin to be excrete first. ====
 * ====**<span style="font-family: 'Tahoma','sans-serif'; font-size: 12pt; line-height: 115%;">1945 **<span style="font-family: 'Tahoma','sans-serif';">- Fleming, Florey and Chain received the Noble Prize in Physiology/Medicine ====
 * ====**<span style="font-family: 'Tahoma','sans-serif'; font-size: 12pt; line-height: 115%;">1950’s **<span style="font-family: 'Tahoma','sans-serif';">- Dorothy Crowfoot Hodgkin determined penicillin’s structure, facilitating chemists to synthesis different types of penicillin and other antibacterial derived from mould. ====

//<span style="font-family: 'Tahoma','sans-serif';">Reference #9, #10, #11 // ====

====

**Resistance to penicilin**
====Certain types of bacteria were resistant to penicilin and were able to multiply. this was becacause the bacteria had an enzyme called penicillinase, that deactivated penicilin. eventhough chemist tried to overpass this obstacles, bacterias, as superbugs, developed and mutated into a new resistant breed. some examples would be staphylococcus auereus or mycobacterium tuberculosis which cause tuberculosis. so in order to treat this infections they had to drink a large amount of antibiotics to prevent but with a risk of further resistance developing. This cause an over prescription====

**Overprescription of penicilin**
====Through historym when it was first available to all public, the doctors easily prescribed this antibacteria to cure minor diseases, like sore throat. however the public had an overprescription which led to side effects and death. The largest side effect would be hypersensitivity which is an allergy that causes rashes and anaphylaxis (another type of allergy). Other side effects may be an inflmmation of the kidney tubules, depletion of white blood cell, coagulation of blood and nervous system toxicity.==== ====Healthy animals were given antibiotics to prevent risk of disease, however this contributed to the resistnat process because it passed thorugh its dairy products and meat and this increases the amount of resistnat bacteria and a festar death.====

__**Important facts of antibacterials**__
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**Honey Natural antibacterial**
====A natural antibacterial is [|honey], which cures infected wounds. The strongest one called manika, comes from new zealand which still stops bacteria growth when it is at the 100th part of its original power.==== //Reference #3//

__**References**__
> ====<span style="color: #000000; font-family: 'Calibri','sans-serif'; font-size: 11pt; line-height: 115%;">[] ====
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 * 6) <span style="font-family: 'Calibri','sans-serif'; font-size: 11pt; line-height: 115%;">[]
 * 7) <span style="font-family: 'Calibri','sans-serif'; font-size: 11pt; line-height: 115%;">[]
 * 8) []
 * 9) []
 * 10) IB Chemistry book. Option D:medicines and drugs- pg.31

D6 Antibacterials 2 hours Assessment statement Obj Teacher’s notes D.6.1 Outline the historical development of penicillins.

D.6.2 Explain how penicillins work and discuss the effects of modifying the side-chain.

D.6.3 Discuss and explain the importance of patient compliance and the effect of  penicillin overprescription.