Antibacterial Activity of Garlic Extract

against Escherichia Coli O157:H7

A Research Proposal

Presented to

Mrs. Lilia C. Tayco

at

Emiliano Tria Tirona Memorial National High School

in

Partial Fulfillment of the Requirement in Research I

by

Nicole L. Cerenio

III-Mangga

November-December 2010

APPROVAL SHEET

In partial fulfillment of the course requirement in Research I, this research

paper entitled Antibacterial Activity of Garlic Extract against Escherichia coli

O517: H7 was prepared and submitted to Mrs. Lilia C. Tayco, Emiliano Tria

Tirona Memorial National High School by Nicole L. Cerenio approved by the

committee on oral examination on with a grade of ________.

Panel of Examiners

Mrs. Lilia C. Tayco

Chairman

Mr. Celso L. Latosa Mrs. Maria Paula G. Reyes

Member Member

Mr. Arnel P. Reyes

Chairman

Accepted in partial fulfillment of the course requirement in Research I.

Recommended by:

Ms. Resurreccion Crisostomo Dr. Presenciana E. Pinazo Ed. D.

Head Teacher VI, Science Department Principal IV, ETTMNHS

ACKNOWLEDGMENT

The researcher would like to express his sincerest gratitude and

recognition to the following which made this research study successful and

worthwhile:

Foremost of all, to the ALMIGHTY GOD who gave him strength and

fortitude and served as his guiding light as he do the whole research study;

To his parents that served as his inspiration, for their moral and

financial support up to the very end and for their eternal affection;

To Mrs. Lilia C. Tayco, his teacher in Research I, for her whole-

hearted support, conveyance and arousing motivations that amplified his

determination and confidence in finishing this study; and

To his friends, classmates and fellow students who never

disappointed him in offering an overflowing support and tremendous

encouragement.

The researcher informs them his great appreciation for all their help

and participation because without having them, he might not have

accomplished this research study with all this success and great satisfaction.

ABSTRACT

The main objective of this research study is to get an extract from

garlic and test the activity of it to Escherichia coli O157:H7 bacteria.

The antibacterial activity of a chemical constituent of garlic was

studied, identified and derived.

Experimental variables were tested using the portion of organism

constituent parts focus on cell-forming bacteria.

The results were tabulated, interpreted and verified after the

experimentation.

Microbiological cultures determine pathogenic organisms or the type

of organisms that may cause infectious diseases. Incubation period of

inoculated liquid broths with bacteria was observed and analyzed.

One can determine the distinct advantage of frugality where

consumers are clamoring for cheap and common yet effective kind of

antibacterial product that can suit their health and nutritional needs.

DEDICATION

I, the researcher of this study, am conceitedly dedicating this to:

To the ALMIGHTY GOD,

To my ever-supportive parents,

To my brothers and sisters,

To my relatives,

To Mrs. Lilia C. Tayco,

To my former science teachers,

To my friends, classmates and fellow students,

And to you who will be benefited in this study…

Thank you for all the heart-lifting motivations.

Expressing my gratitude,

TABLE OF CONTENTS

TITLE PAGE

APPROVAL SHEET

DEDICATION

ABSTRACT

TABLE OF CONTENTS

CHAPTERS:

I. THE PROBLEM AND ITS BACKGROUND

A. Introduction

B. Background of the Study

C. Statement of the Problem

D. Assumptions and Hypotheses

E. Significance of the Study

F. Scope and Delimitation

G. Definition of Terms

II. REVIEW OF THE RELATED LITERATURE

III. METHODOLOGY

A. Materials

B. Equipment

C. Procedure

D. Flow Chart

BIBLIOGRAPHY

Chapter I

THE PROBLEM AND ITS BACKGROUND

A. Introduction

Allicin is an organosulfur compound obtained from garlic, a species in

the family Alliaceae. Garlic has been used throughout history for both

culinary and medicinal purposes. The garlic plant's bulb is the most

commonly used part of the plant. With the exception of the single clove

types, the bulb is divided into numerous fleshy sections called cloves.

Antibacterial activity of garlic extract was observed against

Escherichia coli which is known to be the cause of hemorrhagic fever.

B. Background of the Study

Garlic is widely used around the world for its pungent flavor as a

seasoning or condiment. It is a fundamental component in many or most

dishes of various regions, including East Asia, South Asia, Southeast Asia, the

Middle East, Northern Africa, Southern Europe, and parts of South and

Central America. The flavor varies in intensity and aroma with the different

cooking methods. It is often paired with onion, tomato, or ginger. It has been

proven that garlic has many uses.

Questions like “What might be the other uses of this plant except for

being a seasoning or a condiment” invades the researcher’s intuitive mind.

C. Statement of the Problem

The scientific study aims to:

1. Get extract from fresh garlic.

2. Test the effect or activity of this garlic extract against the growth of

Escherichia coli.

D. Assumptions and Hypotheses

Usually, when an ordinary person heard the word “garlic”, the first

thing that would come up into his mind is to sauté it with meat or any

related ingredient for it enhances the ingredient’s flavor. The concept that

the garlic has a content called allicin came to the researcher’s mind after he

had studied its phytochemical contents and health benefits.

Hi: Garlic (Allium sativum) contains chemical constituent called allicin.

Hi: Garlic (Allium sativum) extract really slowdown the growth of

Escherichia coli.

H0: Garlic (Allium sativum) extract has no distinct effect against the

growth of Escherichia coli.

D. Significance of the Study

The research study aims to determine the activity of garlic extract

against Escherichia coli. This study will be a great help to those people who

suffer from gastrointestinal diseases, in particular, hemorrhagic fever. Most

of the people nowadays are less fortunate. Instead of buying expensive

commercial medicines, they may get extract from garlic which is available in

cheaper prices.

F. Scope and Delimitation

This research study mainly focuses on comparing the growth of

Escherichia coli on:

1. garlic extract and agar; and

2. controlled agar only.

The study and experimentation lasted from November to December

2010 and was conducted at the researcher’s residence, Block 15, Lot 13,

Camia Street, Gardenville Subdivision, Barangay Pag-asa 2, Imus, Cavite.

G. Definition of Terms

1. Garlic- a plant with a bulb shaped like an onion, which has a strong taste

and smell and is used in cooking

2. Allicin- is the key ingredient responsible for the broad-spectrum of anti-

bacterial activity in garlic

3. Extraction- is a separation process consisting in the separation of a

substance from a matrix

4. Extract- is a substance made by extracting a part of a raw material, often

by using a solvent such as ethanol or water

5. Growth medium or Culture medium- is a liquid or gel designed to

support the growth of microorganisms or cells, or small plants like the moss

Physcomitrella patens

6. Agar or agar-agar- is a gelatinous substance derived from a

polysaccharide that accumulates in the cell walls of agarophyte red algae

Chapter II

REVIEW OF THE RELATED LITERATURE

Garlic (Allium sativum)

Allium sativum,

commonly known as garlic, is a

species in the onion family

Alliaceae. Its close relatives

include the onio n, shallot, leek,

chive, and rakkyo. Garlic has

Garlic (Allium sativum)

been used throughout history for both culinary and medicinal purposes. The

garlic plant's bulb is the most commonly used part of the plant. With the

exception of the single clove types, the bulb is divided into numerous fleshy

sections called cloves. The cloves are used for consumption (raw or cooked),

or for medicinal purposes, and have a characteristic pungent, spicy flavor

that mellows and sweetens considerably with cooking. The leaves, and

flowers (bulbils) on the head (spathe) are also edible, and being milder in

flavor than the bulbs, they are most often consumed while immature and

still tender. Additionally, the immature flower stalks (scapes) of the

hardneck and elephant types are sometimes marketed for uses similar to

asparagus in stir-fries. The papery, protective layers of "skin" over various

parts of the plant are generally discarded during preparation for most

culinary uses, though in Korea immature whole heads are sometimes

prepared with the tender skins intact. The root cluster attached to the basal

plate of the bulb is the only part not typically considered palatable in any

form. The sticky juice within the bulb cloves is used as an adhesive in

mending glass and china.

Allicin

Allicin is an organosulfur compound

obtained from garlic, a species in the family

Alliaceae. It was first isolated and studied in

the laboratory by Chester J. Cavallito and John

Hays Bailey in 1944. This colorless liquid has

Chemical Structure of Allicin

a distinctively pungent smell. This compound exhibits antibacterial and anti-

fungal properties. Allicin is garlic's defense mechanism against attacks by

pests.

Escherichia coli

Escherichia coli (commonly abbreviated E. coli; pronounced /ˌɛʃɨ

r ki ko la /, named after Theodor Escherich) is a Gram negative rod-ˈ ɪ ə ˈ ʊ ɪ

shaped bacterium that is commonly found in the lower intestine of warm-

blooded organisms (endotherms). Most E. coli strains are harmless, but

some, such as serotype O157:H7, can cause serious food poisoning and

hemorrhagic fever in humans, and are occasionally responsible for product

recalls. The harmless strains are part of the normal flora of the gut, and can

benefit their hosts by producing vitamin K2, and by preventing the

establishment of pathogenic bacteria within the intestine.

E. coli are not always confined to

the intestine, and their ability to

survive for brief periods outs ide the

body makes them an ideal indicator

organism to test environmental

samples for fecal contamination. The

bacteria can also be grown easily and

its genetics are comparatively simple

and easily manipulated or duplicated through a process of metagenics,

Escherichia coli

making it one of the best-studied prokaryotic model organisms, and an

important species in biotechnology and microbiology.

E. coli was discovered by German pediatrician and bacteriologist

Theodor Escherich in 1885, and is now classified as part of the

Enterobacteriaceae family of gamma-proteobacteria.

Antibiotic Activity of Garlic

Louis Pasteur commented on the bactericidal (bacteria – killing) effect

of fresh garlic juice when dropped onto growing bacterial colonies. Over the

years studies have shown that fresh garlic juice inhibits the growth of

Staphylococcus (wound infection), Brucella (brucellosis), Salmonella

(Typhoid) and several other bacteria. The action was comparable in vitro (in

the laboratory) with that of several antibiotics including penicillin,

streptomycin, chloramphenicol, tetracycline and erythromycin.

Agar

Agar or agar-agar is a gelatinous

substance derived from a polysaccharide

that accumulates in the cell walls of

agarophyte red algae. Historically and in a

modern context, it is chiefly used as an

ingredient in desserts throughout Asia and

Putting an agar solution in a petri dish

also as a solid substrate to contain culture medium for microbiological work.

The gelling agent is an unbranched polysaccharide obtained from the cell

walls of some species of red algae, primarily from the genera Gelidium and

Gracilaria, or seaweed (Sphaerococcus euchema). Commercially it is derived

primarily from Gelidium amansii.

Agar (agar-agar) can be used as a laxative, a vegetarian gelatin

substitute, a thickener for soups, in jellies, ice cream and other desserts, as a

clarifying agent in brewing, and for paper sizing fabrics.

Chapter III

Methodology

A. Materials

garlic cloves, agar powder, beef broth

B. Equipment

mortar and pestle, cheese cloth, container, 10 petri dishes, graduated

cylinder, ruler, slide, microscope

C. Procedure

1. Preparation of garlic extract

a. Gather all the materials needed.

b. Pound the garlic cloves.

c. Cut the pound garlic into smaller pieces.

d. Put it into a cheese cloth.

e. Squeeze the cloth to get the garlic extract.

f. Store the extract into a clean and dry container.

2. Preparation of agar and Escherichia bacteria culture

a. Boil water.

b. Add agar and beef broth.

c. Mix thoroughly.

d. Transfer agar solution to 10 petri dishes.

e. Cool until gelatin consistency is attained.

3. Testing stage

a. Set aside 5 petri dishes for garlic extract environment and 5 petri

dishes for controlled environment.

b. Put 5ml of garlic extract on each 5 petri dishes.

c. Place a small sample of E. coli in the center of each petri dishes.

d. Start timing the observation at daily intervals for 5 days.

e. Measure the diameter in centimeter (cm) of E. coli.

4. Microscopic Observation

a. Prepare slides of treated and untreated E. coli.

b. Examine under microscope.

C. Flow Chart

Gathering

Extracting

Storing

the extract

Agar Preparatio

n

Incubation

Period

Measuring and

Macroscopic Observation

BIBLIOGRAPHY

Internet Sources

http://www.wikipedia.comhttp://www.google.comhttp://www.yahoo.comhttp://www.encarta.comhttp://www.eternalhealth.comhttp://msn.com

Reference Books and Periodicals

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