MANGALPUR, BALURGHAT, SOUTH
DINAJPUR, WEST BENGAL
PROJECT REPORT SUBMITTED BY
SUBHORAJ SAHA
CLASS – XII
ROLL NO. –
YEAR – 2019 – 2020 {CLASS XII SESSION}
SUBJECT –BIOLOGY [SUB CODE –044]
Bona fide certificate
This is to certify that this project entitled“study of
drug resistance in bacteria using
antibiotics”by Subhoraj Saha of class-xii,
Roll no. – _____________ ,
Registration no. – ____________ ,
Academic session – 2019-2020
Submitted in fulfillment to ‘ class – xii biology (044)
project’ , is bona fide record of work carried out
under my guidance and supervision.
______________
Signature
Name – suparna Bhattacharjee
Designation – PGT
Department – Biology
School – Techno India Group Public school
Date – ______________
Acknowledgement
1) I would like to express my special thanks
of gratitude to my biology teacher
“Mrs. –suparna Bhattacharjee” for
their able guidance and support in completing
my project.
2) I would also like to extend my gratitude to
my parents for providing support and
helping me in completing the project.
________________
Signature of candidate
Subject –Biology
Subject code – 044
Roll no. – ___________
Contents
SR.NO TITLE PAGE
NO
1) Introduction 1-5
2) History of antibiotics 6
3) What is drug 7
resistance?
4) Why do bacteria 8
become resistant to
antibiotics?
5) Aim of project 9
6) Materials 10 - 12
7) Procedure 13
8) Method 14 - 15
9) Observation 16
10) Result 17
11) conclusion 18
12) precaution 19
13) bibliography 20
Introduction -
Antibiotics are drugs that are used in the
treatment or prevention of bacterial
infection. Strictly speaking ,antibiotics are
natural substance produced by
microorganisms to kill other organisms or
retard their growth.
Penicillin, Tetracycline, Streptomycin are
few drugs used to treat various diseases.
HISTORY OF ANTIBIOTICS
ANCIENT
In 3500 BC,the Sumerian doctors would give
their patients,beer soup with snakeskin and
turtle shells.
Modern History -
Louis Pastures was the first to recognize that
bacteria could be used to kill other bacteria.In
1929 Sir Alexander Fleming discovered
Penicillum Notatum.It is effective again range
of bacteria.Then Streptomycin discovered.
What is drug
resistance ?
Antibiotics resistance occurs when an
antibiotics has lost its ability to effectively
control or kill bacterial growth; in other
words, the bacteria are”Resistance”and
continue to multiply in presence of
therapeutic levels of an antibiotic.
Why do bacteria
become resistant to
antibiotics?
Antibiotics resistance is a naturalphenomenon. When an
antibiotics is used, bacteria that can resist that antibiotics
have a greater chance of survival than those that are
“Susceptible”.
Susceptible bacteria are killed or inhibited by an antibiotics,
resulting in a selective pressure for the survival of resistant
strains of bacteria.
In some countries and over Internet, antibiotics can be
purchased without a doctor’s prescription. Patients
sometimes take antibiotics unnecessarily, to treat viral illness
like common cold.
Aim of the
project-
In this project the aim is to
investigate the Study of
development of drug
resistance in bacteria using
antibiotics.
Materials-
BUNSEN BURNER FORCEPS
SOAP PARAFILM
ISOPROPANOLCOTTON SWAB
MATCHES BROTHCULTURES
OF
S.EPIDERMIDIS
TSA PLATES BENT GLASS ROD
FINE TIPPED MARKING ANTIBIOTICS
IMPREGNATD DISCS
Procedure-
It involes the following steps :
To compare how effective one effective one
antibiotic is to another, or to measure the degree
of antibiotic resistance in a bacterium a procedure
called the Kirby-Bauer test can be done.
To do this,
1) A pure strain of bacteria is isolated from an
infected person.
2) This pure strain is then spread over the surface of a
special medium ,called Mueller-Histon Agar ,to
create a lawn ,or carpet of bacteria.
3) Small filter paper discs ,impregnated with
standardised amounts of antibiotics ,are gently
pressed on to the surface of the agar.
4) The plates are then incubated overnight ,the
antibiotics diffuses from the disc and into the
agar.This antibiotics diffusing into the agar will
inhibit the growth of susceptible bacteria.
Method -
1) Clean your work area and sterilize it with
70% isopropanol.
2) Swirl the contents of the brothculture of
S.Epidermis until it is equally murky
throughtout.Use the sterile cotton swab and
glass rod to create a lawn ,or carpet of
S.epidermis on 2 of the plates of TSA.
Don’t forget to hold the cap in your pinky and to
flame the mouth of the test tube before and after
dipping the sterile swab into it.
3)Label the bottom of petric dish with your name
,the date be sure to write small and only around
the edges of the bottom petri dish.
4) Use the second sterile swab to repeat step two
,expect substitute E.coli for S.epidermis. Also
,label this E.Coil dish.
5) Select two different antibiotics discs. Place
them on oppsite side of a petri dish containing
S.epidermis ,with the code side facing up. T ap
them gently with sterile forceps to stick them to
the agar.
6) Using the second plate ,repeat step 5 ,again
using two different antibiotics discs. You should
have four different antibiotics discs on two plates
of S.epidermidis.
7) Repeat steps 5 and 6 using the plates of E.coli.
Be sure to use the same types of antibiotics discs
as were used in steps 5 and 6.
8) Warp parafilm around all four plates and place
the plates on their lids and in the incubator at
37˚C for 24 hours.
9) After 24 hours in the incubator ,check for the
presence of antibiotics activity.
Observations -
THE AREA AROUND THE ANTIBIOTIC DISCS IN
THE PETRIDISH WILL BE CLEAR.IN OTHER
AREAS,COLONIES OF BACTERIA WILL BE
OBSERVED.EXAMINE THE CLEAR AREA IN EACH
PETRIDISH FOR FEW MORE DAYS.A FEW VERY
SMALL COLONIES MAY APPEAR IN THE CLEAR
AREAS.THESE ARE THE COLONIES OF RESISTANT
STRAINS OF THE BACTERIA.
.
CONCLUSION:-
ANTIBIOTIC DRUGS KILLED MOST OF THE BACTERIAL
STRAIN,HENCE THE AREAS APPEARED
CLEAR.HOWEVER,A FEW STRAINS WHICH WERE
RESISTANT IN THE BACTERIAL POPULATION
SURVIVED AND PRODUCED COLONIES LATER.THIS
PROVES THE RESISTANT STRAIN TO ANTIBIOTICS
WERE PRESENT IN THE BACTERIAL POPULATION.
PRECAUTIONS-
A microbiology lab is potentially a very dangerous
place.For this reason it is extermely important
that you follow safety guidelines and always
practice sterile technique when handling microbes
,unless instructed otherwise.
1) There should be no books or paper at your
workstation except this lab packet.
2)Never have any food or drinks at your
workstation.
3)Never open a petri dish after you have
inoculated it and have allowed it to incubated
overnight.
4) Always dispose of used material in the biohazer
bag unless instructed otherwise.
BIBIOLGRAPHY –
https://en.wikipedia.org/wiki/Drug_resistance
https://aidsinfo.nih.gov/understanding-hiv-
aids/glossary/212/drug-resistance
https://www.niaid.nih.gov/research/antimicrobial-resistance-
definitions
https://www.sciencedirect.com/topics/neuroscience/drug-
resistance
https://www.medicinenet.com/script/main/art.asp?articlekey
=3120
