Introduction
Antimicrobial is the general term for any product or ingredient that kills or inhibits bacteria, viruses, or molds. Antimicrobial agents are the one that interferes with the growth of and metabolism of microbes (Pelczar, JR, Chan & Krieg 2008). The microbes are controlled by: a) physical agents, b) chemical agent and c) antibiotics and other chemotherapeutic agents. Physical agent includes the temperature, desiccation, osmotic pressure, radiation, surface tension and filtration. Chemicals agents includes the alcohols, phenol and phenolic compound, halogens, heavy metals and their compounds, dyes, synthetic detergents, ammonium compounds, aldehydes.
In case of antibiotics and other chemotherapeutic agents, it is applied in two ways: natural and chemically synthetic. The microbes are controlled by many agents. Some are controlled by the natural occurring organism but some they are prepared chemically to prevent the microorganism
(infectious micro-organism). The importance is given more to the natural antimicrobial agents and it will mainly focus on natural rather chemically synthetic antimicrobial agents.
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Natural antimicrobial agent
Bacteria contain the genetic material to resist synthetic drugs and this does not seem to be the case with natural agents that have antibacterial properties (Spreen in Four antibacterial/antiviral agent, Sep 2010). And chemical antibiotics produced site effects in the long term whereas natural does not produce any harmful site effect. At present times they are looking for the alternatives to substitute the antibiotics with natural antibiotics
They used the in two different ways: a) They used as chemotherapeutic agent : some are chemically prepared but some also occur naturally b) They used as antibiotics : antibiotics are naturally and chemically prepared
But my interest is on the naturally occurring anti-microbial agents and will deals with it more specifically.
Chemotherapeutic agents
Pelczar, JR, Chan & Krieg (2008) said that the European used natural quinine from the bark of the cinchona tree to treat malaria as early as 1630. It is almost a history how the naturally occurring antimicrobial agents are used by the ancient people which have the significance importance in studies. Pelczar, JR et all also points that South American Indians, who relieved symptoms of malarial fever by chewing the bark of the cinchona tree. They practiced method before European has idea.
When I was young, my parents and relatives told us how to cure ourselves when we suffered from the sickness. For common cold they advice to take the extract from a chiruta plant (local name Khalu). Chiruta plants are exported to India and site income of our village. This we still used widely in our village and the extract is bitter. I think bitterness is two time than a bitter gourd. And for conjunctivitis urine is used as ailing agent. For the boil we used the paste from a plant (local name Ravana plant). The burn surface of our body parts are wrapped by rotten soya bean (local name Ye
’ pa used as species in the curry). And if the person has consumed the poison
(local name tshendug), excreta or Ye
’ pa is given as ailing agent. They have used widely from the ancient times and some still prevail. Our village ancestors have survived and practices are passed
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from the generation to generation. At modern era, above practices are decreasing as medicine came as substitute for it. When I reflect, the practices are natural chemotherapeutic agent. Even I have seen it and it does cure. But how it cures, remains as mysterious and lacks the scientific research. Of course there hasn’t done any research for such practiced in our community but I assure that some sort of natural chemicals (antimicrobial agent) are presents, responsible for curing it. Such kinds of practiced differ from region to region and they practiced different method and one kind is the codercep common in the high altitude.
Historical development of antibiotics
Some of the antibiotics are natural one. An antibiotic are chemical substance produced from one microorganism and has ability to inhibit micro-organism. Pelczar, JR et all suggests that antibiotic has come to refer to a metabolic product of one micro-organism that in a small amounts is detrimental or inhibitory to other organism. Definition defers but main idea remains the same. But some definitions are defined in the olden days and they are not compatible with present day. Waksman in Pelczar, JR et all (2008) proposed that chemical substances of the microbial origin which in small amounts exert antimicrobial activity. And Pelczar, JR et all
(2008) said that many years ago Chinese used moldy soybean curd for treatment of boils and controlled foot infection by wearing the sandals furry with molds. Actually human has been practicing the method of antibiotics but they have not realized it. Tyndall reported that cultures media cloudy with bacterial growth became clear when mold grew on the surface (Pelczar, JR et all, 2008). Metchnikoff recommended the use of the lactobacilli in the treatment of dysentery
(Pelczar, JR et all, 2008). His idea was based on the replacement method where harmless bacteria substitute disease cause bacteria. Modern action of antibiotics is not based upon the replacement method but utility of the active inhibitory principle.
Every body knows that first antibody was discovered by the Alexander Fleming in 1928.
Rosenberg (n.d) points that discovery of the first antibiotics was serendipity. He cultured bacteria in the petri-dish and left for the growth of the bacteria. Instead of bacteria he saw molds grown and no bacteria were found. From here he concluded that disappearance of the bacteria was presence of molds. Later he found out that chemical substance produced by the molds killed the bacteria. Chemical substance was the penicillin, the first antibiotics in the world and the oldest antibiotics. From his ideas similar antibiotics are discovered from different sources. The mold
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was identified as Penicillium species and Alexander Fleming called the antibiotics as penicillin.
Later series of antibiotics were discovered by different person. Rene Dubos isolated a culture of
Bacillus brevis from the soil which produced a substance that killed the micro-organism. Pelczar,
JR et all (2008) said that the cell free extract produced from bacillus brevis was found to contain two active chemical known as gramicidin and tyrocidine. Later on Selman Waksman discovered the streptomycin. Now several thousands of the antibiotics were isolated and their popularity was due ability to destroy the different kinds of pathogen and have no effect to the host when they take.
Penicillin
Penicillin is natural antimicrobial agent. It is the most useful and produce from the Penicillium notatum. Several penicillins are produced by biosynthesis in a single fermentation. Natural penicillin are prepared as the salts of sodium, potassium, procaine, and other bases. Crystalline sodium and potassium salts are freely soluble in water, ethyl alcohol, etc. Penicillin is colorless in pure crystalline form. The natural penicillin are unaffected by the saliva or bile. They are inactivated by heat, sodium hydroxide, hydrochloric acid, etc.
Bacitracin
Mixture of antimicrobial polypeptides produced by certain strains of Bacillus licheniformis or
Bacillus subtilis , the main components being bacitracins A, B1, B2 and B3. (BACITRACIN, Jan
2005). Bacitracin is produced by the bacterium Bacillus licheniformis. It was first described in
1945 when the producer Bacillus was isolated from a rapidly self healing wound from a human patient. Mathers (n.d) argue that Bacitracin is significantly different from other antibiotics

A natural peptide not an organic chemical

Made by an AAFCO-listed direct-fed microbe species often used in marketed animal probiotics

Manufactured using natural grains and salts as major ingredients in a controlled fermentation process, similar to probiotic- and enzyme-based products. Bacitracin products retain certain advantages over newer products in that
 They have proven positive effects on animal growth

Control bacterial disease for which it has approvals, both alone and in combination.
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Environmental Benefits of Bacitracin
As a peptide and salt molecule, bacitracin products degrade rapidly in composts and on soils to amino acids, thus have no impact on environment. It is used for skin irritations since has no adverse effect. Huyghe - baert and de Groote as cited in Mather (n.d) an additional advantage to the use of zinc bacitracin is the reduction in the amount of feces and increased nitrogen retention in broilers and swine. It will reduce the effluent invading the environment.
Bacteriocins
Chikindas, Cleveland and Montville ( 6 th
Nov, 2001) said that bacteriocins are antibacterial proteins produced by bacteria that kill or inhibit the growth of other bacteria. Many lactic acid bacteria
(LAB) produce a high diversity of different bacteriocins. Though these bacteriocins are produced by LAB found in numerous fermented and non-fermented foods, nisin is currently the only bacteriocin widely used as a food preservative. ( Chikindas, Cleveland and Montville 6 th
Nov, 2001)
Many bacteriocins have been characterized biochemically and genetically but the basic understanding of their structure–function, biosynthesis, and mode of action, are still unexplored.
And some are toxic in nature but research and their long-time intentional use strongly suggest that bacteriocins can be safely used.
Other natural antimicrobial agent
The over use of prescribe antibiotics has raised the concern by the health personal due to rise in the resistant strains of micro-organism. Can we substitute the antibiotics with the natural antimicrobial agent? Will bacteria withstand the antimicrobial action of natural antibiotics?
Many plant products (like coffee, tea, herbs and spices) have been shown to contain compounds that act as antimicrobial agents. (Cowan in natural antimicrobial agent, n.d). We can test the antimicrobial properties by culturing the bacteria in the presence of the extract of source.
Antimicrobial properties have been described by previous science fair investigators in some natural extracts, like garlic (Ashleigh and Rajasingham in natural antimicrobial agent, n.d) and honey (Monier in natural antimicrobial agent, n.d).
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Olive leaf extract
The compound called flavonoids comes from the plant Olea europaea. Actually the extract is known as Oleuropein and has antimicrobial properties. It can protect tree against predatory organisms. Also called calcium elenolate, the substance has been officially tested as an antimicrobial agent. Olive leaf is even well known as an antioxidant.
Grapefruit seed extract
Natural antibiotic made from an extract grape fruit seed was made since grape fruit inhibit the bacteria for the extended time. It produces the chemical citricidal. The extract has been tested against a huge list of pathologic organisms. Resistance has not occurred against the substance, and it's even biodegradable
Ascorbic acid
Ascorbic acid (vitamin C) was use against viruses, bacteria and toxins from early 1930s by Fred
Klenner. His work showed a amazing success and was witnessed by his hospital personal. Many outsiders do not believe his work. Robert Cathcart uces very high doses of ascorbic acid and has been the nutrient for decades to get the AIDS patient normal in his clinic Los Altos, California.
Colloidal silver
Dr. Jonathan V. Wright's research has found that bacteria have an enzyme system that is disrupted by the presence of silver ions, causing the organism to die. He suggests adult doses of
"1 tablespoon of colloidal silver at a 40 ppm (parts per million) concentration at the first signs of any infection and 1-2 teaspoons three to four times daily until the infection is gone.” Water filters today are impregnated with silver to take advantage of the antibacterial effects
Natural antimicrobial agent to prevent food spoilage and damage
The chemist and food Scientist at Rutgers help to develop natural approaches to the prevention of food damage and spoilage. They used natural antimicrobial agent extracted from cloves, oregano, thyme and paprika. There aim was to create biodegradable polymers or plastics to block the formation of bacterial bioflims on food surfaces and packaging. The antimicrobial agent they prepared has many antimicrobial activities against many different kinds micro-organism. It has the broader spectrum of micro-organism than organism-specific drugs. It will avoid the potential
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of increasing the antimicrobial resistance of specific bacteria, due to over prescription of antimicrobial organism. These polymers are biodegradable due to their specific chemical composition and the nature of the bonds that hold them together.
Natural antimicrobial agent in MRSA treatment
Scientists are now afraid that even a treatment with vancomycin will fail in the future. There is clearly a need for alternative MRSA treatments. Nature itself developed powerful chemical defense mechanisms against all kinds of infections over millions of years. Chemical defense agents can be found in plants like the tea tree bush of New Zealand. MRSA skin infections can fortunately be cured without the use of antibiotics. Active Manuka Honey is the honey that is collected from the tea tree bush in New Zealand. When the bees collect their honey from the
Manuka flower of the tea tree bush they preserve a precious component (Unique Manuka
Factor). The antibacterial UMF is able to completely eliminate staph aureus and mrsa bacteria in wounds. Therefore Active Manuka Honey is considered a natural antibiotic. It has the strength of an antibiotic without the side effects of antibiotics. Active Manuka Honey has a long term treatment option. It can be used safely and without side effects until the infection is cleared.
Usnic acid
The evidence suggests that usnic acid, a secondary lichen metabolite, possesses antimicrobial activity against a number of planktonic gram-positive bacteria, including Staphylococcus aureus,
Enterococcus faecalis, and Enterococcus faecium. (Francolini, Norris, Piozzi, Donelli and
Stoodley, 11 th
July, 2004). Lichens are surface attached that produce the antibiotics (usnic acid) to defend themselves from colonization by other bacteria. Francolini, Norris, Piozzi, Donelli and
Stoodley (11 th
July, 2004) done experiment regarding the production of the usnic acid from the lichen and says:
They loaded (+)-usnic acid into modified polyurethane and quantitatively assessed the capacity of (+)-usnic acid to control biofilm formation by either S.
aureus or Pseudomonas aeruginosa under laminar flow conditions by using image analysis. (+)-Usnic acid-loaded polymers did not inhibit the initial attachment of S. aureus cells, but killing the attached cells resulted in the inhibition of biofilm. Interestingly, although P. aeruginosa biofilms did
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form on the surface of (+)-usnic acid-loaded polymer, the morphology of the biofilm was altered, possibly indicating that (+)-usnic acid interfered with signaling pathways
Natural microbial agent in the skin
The stratum corneum of the skin of patients with atopic dermatitis is highly susceptible to colonization by various bacteria, including Staphylococcus aureus. The possibility that the increased colonization of bacteria found in patients with atopic dermatitis may result from a deficiency of sphingosine as a natural antimicrobial agent (Arikawa, Ichikawa, Imokawa,
Ishibashi, Kawashima, and Takagi 2002). The mechanism was carried out and Arikawa,
Ichikawa, Imokawa, Ishibashi, Kawashima, and Takagi (2002) summarized their result “the possibility that vulnerability to bacterial colonization in the skin of patients with atopic dermatitis is associated with reduced levels of a natural antimicrobial agent, sphingosine, which results from decreased levels of ceramides as a substrate and from diminished activities of its metabolic enzyme, acid ceramidase”
Honey as treatment of infected wounds
Honey is produced from many different floral sources and its antimicrobial activity varies with origin and processing. Dioscorides and Aristotle in Molan 2001 stated that a pale yellow honey from Attica was the best. At present they extract honey from different sources and have found out the medicinal value. Molan 2001 argues that honey is an ancient remedy for the treatment of infected wounds, which has recently been 'rediscovered' by the medical profession, particularly where conventional modern therapeutic agents are failing. Even in our village concume honey when we suffers from the sore in the mouth. They also take the maggots of wasps and believe that it have huge medicinal value.
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Conclusion
Since chemical antibiotics have adverse effects on the long run and micro-organism has ability to develop resistance although it cure the disease rapidly.. And now researchers’ fears that higher chemical antibiotics are needed as the micro-organism became resistance to antibiotics for same diseases to be cure. Now they focus on the natural antibiotics. Natural antibiotics are known very little at modern times. Natural antibiotics have no effect on the users and will not develop resistance. But it takes time to cure.
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Reference
Arikawa, J., Ichikawa, Y., Imokawa, G., Ishibashi, M., Kawashima, M., and Takagi, Y. (2002).
Decreased Levels of Sphingosine, a Natural Antimicrobial Agent, may be Associated with
Vulnerability of the Stratum Corneum from Patients with Atopic Dermatitis to Colonization
by Staphylococcus aureus .
Journal of Investigative Dermatology . Retrieved on 20 th Sep, 2011
from http://www.nature.com/jid/journal/v119/n2/abs/5601571a.html
BACITRACIN .(n.d). Retrieved on 20 th
Sep, 2011 from http://lib.njutcm.edu.cn/yaodian/ep/EP
5.0/16_monographs/monographs_a-c/Bacitracin.pdf
Chikindas, L. M., Cleveland, J., and Montville, J. T. (6 th
Nov, 2001. Bacteriocins: safe, natural
antimicrobials for food preservation. Retrieved on 20 th
Sep, 2011 from http://www.science
direct.com/science/article/pii/S0168160501005608
Donelli, G., Francolini, I., Piozzi, A., Norris, P., and Stoodley, P. (11 th
July, 2004). Usnic Acid, a
Natural Antimicrobial Agent Able To Inhibit Bacterial Biofilm Formation on Polymer Surfaces.
Retrieved on 20 th Sep, 2011 from http://aac.asm.org/cgi/content/abstract/48/11/4360
Four natural anti-bacterial/viral agent . (Sep 2010). Retrieved on 20 th
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www .annieappleseedproject.org/fournatanag.htm.
Mathers, J. (n.d). Bacitracin — Natural Peptide with Minimal Resistance Issues . Retrieved on
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Mathers.pdf
Molan, C. P. (2001) . Honey as a topical antibacterial agent for treatment of infected wounds .
retrieved on 9 th Oct, 2011 from http://www.worldwidewounds.com/2001/november/
Molan/honey-as-topical-agent.html
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MRSA Treatment – A cure for MRSA . (n.d). Retrieved on 20 th
Sep, 2011 from http://www
activemanukahoneyusa.us/Natural-MRSA-Treatment.htm
NATURAL ANTIMICROBAIL AGENT . (n.d). Retrieved on 20 th
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sciencebuddies.org/science-fair-projects/project_ideas/Pharm_p016.shtml?from=Home
Pleczar,JR, J. M., Chan, S. C. E., & Krieg, R. N. (2008). Microbiology . Tata Mcgraw-Hill
Publishing Company Limited: New Delhi
Rosenberg, J. (n.d). Alexander Fleming Discovers Penicillin. About.com, 20 th century history .
Retrieved on from http://history1900s.about.com/od/medicaladvancesissues/a/penicillin
.htm
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