Project Report 2023-24

CLASS-XII
BIOLOGY (044)
Project Name: A guide through
Antibiotics and it’s effects

DELHI PRIVATE SCHOOL, AJMAN

Submitted By:

Student Name : Sharank Santhosh Kumar

Register No :
Grade/Section : XII-M
Date : 20.08.2023

Signature of Internal Examiner:

Signature of External Examiner:

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 CERTIFICATE

This is to certify that SHARANK SANTHOSH KUMAR student of

class XII has successfully completed his/her Biology project titled
A GUIDE THROUGH ANTIBIOTICS AND IT’S EFFECTS The project
was completed under the guidance and supervision of
........................... as a requirement for the AISSCE PRACTICAL
EXAMINATION 2023-24.

Internal Examiner:
Date:

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 ACKNOWLEDGEMENT

In the accomplishment of this project successfully, many people have best owned upon

me their blessings and the heart pledged support, this time I am utilizing to thank all the

people who have been concerned with this project.

Primarily I would thank God for being able to complete this project with success. Then I

would like to express my sincere gratitude to my Principal Dr. VISHAL KATARIA, Head

Mistress Mrs. Khadija T.K and Supervisor Mrs. Anu Thomas for providing me with facilities

required to do my project. I am highly indebted to my Chemistry Teacher Mrs. Shajilla B.

for her valuable guidance which has promoted my efforts in all the stages of this project

work.

Then I would like to thank my parents and friends who have helped me with their valuable

suggestions and guidance has been very helpful in various phases of the completion of

the project.

Last but not the least I would like to thank my classmates who have helped me a lot.

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 INDEX

1. INTRODUCTION

2. HISTORY OF ANTIBIOTICS

3. TYPES OF ANTIBIOTICS AND ITS

CAUSES
4. WORKING OF AN ANTIBIOTIC

5. SIDE EFFECTS AND ALLERGIES

6. RECENT RESEARCH ON ANTIBIOTICS

7. CASE STUDY

8. BIBLIOGRAPHY

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 INTRODUCTION
You've most likely taken an antibiotic at least once in your
lifetime. From treatments for painful strep throat or ear
infections as a child, to burning urinary tract infections or
itchy skin infections as an adult, antibiotics are one of the
most highly utilized and important medication classes we
have in medicine.
Understanding the vast world of antibiotics and anti-infective
is no easy task. Anti-infective are a large class of drugs that
cover a broad range of infections, including fungal, viral,
bacterial, and even protozoal infections. Athlete's foot? That's
a common fungal infection. HIV? Antiviral medications are
always needed. Bladder infection? Yes, that may need a
common antibiotic. And head lice? A topical anti-parasitic can
alleviate the itching. There is no one type of antibiotic that
cures every infection. Antibiotics specifically treat infections
caused by bacteria, such as Staph., Strep., or E. coli., and
either kill the bacteria (bactericidal) or keep it from
reproducing and growing (bacteriostatic). Antibiotics do not
work against any viral infection.
(i)In 3500 BC the Sumerian doctors would give patients beer
soup mixed with snakeskins and turtle shells. (ii)Babylonian
doctors would heal the eyes by using an ointment made of frog
bile and sour milk. (iii)The Greeks used many herbs to heal
ailments. (iv)All of these "natural" treatments contained some
sort of antibiotic.

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 History of Antibiotics

1. Louis Pasteur was one of the first recognized physicians who

observed that bacteria could be used to kill other bacteria.
2. In 1929 Sir Alexander Fleming, a Scottish bacteriologist,
went on a action and left a petri dish of staphylococci
bacteria uncovered. When he returned, he noticed that
there was mold growing on it. Upon further examination, he
saw that the area around the mold had no bacteria growing.
He named the mold Penicillium, and the chemical produced
by the mold was named penicillin, which is the first
substance recognized as an antibiotic.
3. Almost immediately after penicillin was introduced,
resistance in certain strains of staphylococci was noticed.
4. In 1935, Domagk discovers synthetic antimicrobial chemicals
(sulfonamides). During World War II, because of need for
antibiotic agents, penicillin was isolated and further tested
by injection into animals. It was found to be extremely useful
in curing infections, and to have extremely low toxicity to
the animals. Because of these findings, use of penicillin
greatly increased. This also spurred a search of other
chemical agents of similar use.
5. In the late 1940's through the early 1950's, streptomycin,
chloramphenicol, and tetracycline were discovered and
introduced as antibiotics.

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6. In 1953, during a Shigella outbreak in Japan, a certain strain
of dysentery bacillus was found to be resistant to
chloramphenicol, tetracycline, streptomycin, and the
sulfanilamides.
7. By the 1950's it was apparent that tuberculosis bacteria was
rapidly developing resistance to streptomycin, which had
commonly been used to treat it.

Antibiotics have revolutionized medical care in the 20th

century, but in recent years bugs have been winning We
haven't always relied on the latest new medicines to remedy
what ails us.

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Penicillin-THE FIRST MIRACLE
ANTIBIOTIC

Penicillin (sometimes abbreviated PC or pen) is a group of

Beta-lactam antibiotics used in the treatment of bacterial
infections caused by susceptible, usually Gram-positive
organisms. "Penicillin" is also the informal name of a
specific member of the penicillin group Penam Skeleton,
which has the molecular formula R-CHINO4S, where R is a
variable side chain.
Penicillin was first ever “true” anhbiohc and it was
discovered by a Scoish bacteriologist, Alexander Fleming
in 1928. It was widely used to treat the different types of
bacterial infechons that plagued man. Ironically, Penicillin
was an accidental discovery, but it was a landmark discovery
in the field of medicine. Penicillin is acquired from a mould

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 called Penicillium notatum (also known as Penicillium
chrysogenum).

Types of Penicillin
There are different types of penicillin, which are grouped based
on their effectiveness.
Penicillin VK and Penicillin G are natural Penicillin

• Penicillin VK – It is used to fight against bacterial infections.

Example: Ear infection.
• Penicillin G – More effective against gram-positive and
gram-negative cocci bacterial infections. Example:
susceptible bacterial infections in the stomach.

Penicillium chrysogenum

Penicillium chrysogenum, species of fungus in the

genus Penicillium (kingdom Fungi) that occurs across a variety of
habitats and is especially common in moist areas, including
forests and damp indoor environments. Penicillium
chrysogenum is very closely related to P. rubens and P.
notatum and has, at various times, been considered
synonymous with either or both.

P. chrysogenum is a source of the antibioticpenicillin. The

species was in fact the source from which
Scottish bacteriologist Alexander Fleming originally discovered
the antibiotic, although in 1928, at the time of Fleming’s
discovery, the strain was named P. notatum. P.

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chrysogenum also is a common contaminant of foodstuffs and
indoor environments, where its presence on surfaces or in the
air can have negative effects on human health.

In addition to penicillin, P. chrysogenum produces various other

substances. Among these substances are a yellow pigment
known as chrysogine and an antibiotic known as xanthocillin.

Penicillium chrysogenum

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 Types of Antibiotics and it’s
causes
1. Synthetic Antibiotics
2. Natural Antibiotics
3. Semi Synthetic Antibiotics

• Chemotherapeutic agents (Synthetic Antibiotics):

antimicrobial agents of synthetic origin useful in the
treatment of microbial or viral disease. Examples are
sulfonamides, isoniazid, ethambutol, AZT, nalidixic acid
and chloramphenicol. Note that the microbiologist's
definition of a chemotherapeutic agent requires that
the agent be used for antimicrobial purpose and
excludes synthetic agents used for therapy against
diseases that are not of microbial origin. Hence,
pharmacology distinguishes the microbiologist's
chemotherapeutic agent as a "synthetic antibiotic"
• Natural Antibiotics: antimicrobial agents produced by
microorganisms that kill or inhibit other
microorganisms. This is the microbiologist's definition.
A more broadened definition of an antibiotic includes
any of natural origin (from any type of cell) which has
the effect to kill or inhibit the growth of other types
cells. Since

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 most clinically-useful antibiotics are produced by
microorganisms and are used to kill or inhibit infectious
Bacteria, we will follow the classic definition. Note also
(above), pharmacologists refer to any antimicrobial
chemical used in the treatment of infectious disease as
antibiotic.
• Semisynthetic antibiotics :are molecules produced my
a microbe that are subsequently modified by an organic
chemist to enhance their antimicrobial properties or to
render them unique for a pharmaceutical patent.

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 Working of an Antibiotic
Although there are a number of different types of antibiotic,
they all work in one of two ways:
• A bactericidal antibiotic (penicillin, for instance) kills
the bacteria; these drugs usually interfere with either
the formation of the cell wall of bacteria or its cell
contents.
• A bacteriostatic stops bacteria from multiplying, i.e.
retards its growth.

An antibiotic is given for the treatment of an infection caused

by bacteria. It is not effective against viruses. Most common
infections are caused by viruses, when an antibiotic will not be
of use. Even if you have a mild bacterial infection, the immune
system can clear most bacterial infections. For example,
antibiotics usually do little to speed up recovery from
bronchitis, or most ear, nose, and throat infections that are
caused by bacteria. So, do not be surprised if a doctor does not
recommend an antibiotic for conditions caused by viruses or
non-bacterial infections, or even for a mild bacterial infection.
However, you do need antibiotics if you have certain serious
infections caused by bacteria such as meningitis or pneumonia.
In these situations, antibiotics are often life-saving. When you
are ill, doctors are skilled at checking you over to rule out
serious illness and to advise if an antibiotic is needed. If you
have an infection, it is important to know whether it is caused
by bacteria or a virus. Most upper respiratory tract infections,

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such as the common cold and sore throats are caused by
viruses - antibiotics do not work against these viruses. If
antibiotics are overused or used incorrectly, there is a risk that
the bacteria will become resistant - the antibiotic becomes less
effective against that type of bacterium. A broad-spectrum
antibiotic can be used to treat a wide range of infections. A
narrow-spectrum antibiotic is only effective against a few types
of bacteria. Some antibiotics attack aerobic bacteria, while
others work against anaerobic bacteria. Aerobic bacteria need
oxygen, anaerobic bacteria do not. In some cases, antibiotics
may be given to prevent rather than treat an infection, as might
be the case before surgery. This is called 'prophylactic' use of
antibiotics. They are commonly used before bowel and
orthopedic surgery.

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 Side effects and Allergies
If you are experiencing a bothersome or serious antibiotic side
effect, you should contact
your health care provider to discuss your symptoms. The
outcomes may include:

• Staying on the same antibiotic and managing the side

effect
• Adjusting the dose
• Switching to a different antibiotic

Usually, antibiotic treatment should not be stopped without a

health care provider's
approval; all medication should be finished. Stopping
antibiotics early due to side effects
may allow the infection to worsen and may lead to antibiotic
resistance, making an
antibiotic less effective. Even if the infection appears to have
cleared up before all of the
medication is gone, the full course of antibiotic treatment
should always be completed
unless you are told otherwise by your doctor.

Antibiotic Allergies:

Antibiotic allergies or hypersensitivity reactions are some of

the most common side

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effects of antibiotics leading to emergency room admission.
Always tell your doctor of
any previous allergic reaction to any medication, including
antibiotics. Mild allergic
reactions may only result in a skin rash. A more severe allergic
reaction called
anaphylaxis is a medical emergency that requires immediate
medical attention.

Anaphylactic reactions due to antibiotics may include:

• Shortness of breath
• Wheezing
• Nausea/vomiting
• Light headedness, dizziness
• Fast heart rate
• Swelling of the face, lips or tongue
• Shock

Immediately call for medical help if any of these symptoms

should appear after taking an
antibiotic.

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Recent research on Antibiotics
About the study

In the present study, researchers sub-cultured colonies detected

after 12 weeks of incubation on agar plates overlaid
with Staphylococcus aureus. Bioassay-guided fractionation of
the extract from these microbial colonies yielded Kalimantan, a
previously known antibiotic originating
from Pseudomonas and Alcaligenes. Initially, kalimantacin was
more abundant in the extract; however, when the researchers
disrupted the first gene in the kalimantacin/batumin operon,
viz. bat1, it reduced kalimantacin production below detectable
levels. Further fermentation yielded a novel depsi-peptide
compound like teixobactin with a unique mass of 903.5291
[M+H]+, which the researchers named clovibactin.

Study findings

Structurally, clovibactin featured two D-amino acids, d-alanine,

and d-glutamic acid, in its four amino acid long linear N terminus
and D-3-hydroxy asparagine, a unique amino acid residue.
Sequencing of the E. terrae ssp. carolina genome revealed 19
predicted biosynthetic gene clusters (BGCs) in clovibactin, and
BLASTN alignment revealed 72% identity between the
clovibactin and teixobactin BGCs. Clovibactin was active
against Bacillus subtilis, unlike kalimantacin. To exert its
antibiotic effects, it blocked cell wall synthesis by binding the

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pyrophosphate (PPi) moiety of multiple cell wall lipid precursors,
including undecaprenyl phosphate (C55PP), lipid II, and lipid
IIIWTA(wall teichoic acid). Clovibactin molecules antiparallelly
arranged themselves to selectively bind to the PPi moiety of lipid
precursors, resulting in a supramolecular complex that
subsequently oligomerized into a stable higher-order fibrillar
assembly using its short N terminus acts as oligomerization
domain. These supra-structures appear to be an essential part of
the killing mechanism of clovibactin. However, a detailed
structural analysis of clovibactin could only uncover how it
manages to bind PPi of lipid II tightly and selectively. Another
striking feature of clovibactin was its exceptional ability to cause
cell lysis in a mechanistically distinct manner from teixobactin.

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 CASE STUDY
A 25-year-old woman reporting an allergy to penicillin

During rouhne antenatal screening of a 25-year-old woman in

her first trimester of pregnancy, posihve results are obtained on
serologic teshng for syphilis, and aver inveshgahon, late latent
syphilis is diagnosed. Standard treatment for this stage of syphilis
in pregnancy consists of three weekly intramuscular injechons of
penicillin G benzathine.1 The pahent reports that her mother told
her she had an allergic reachon to penicillin as a child, the details
of which neither can recall.

On the basis of her history, is this patient likely to have an allergy

to penicillin?
Allergy to penicillin is self-reported by about 10% of the general
populahon, but only 10% of those reporhng an allergy have a
posihve result on penicillin skin teshng. When assessing a pahent
with reported penicillin allergy, the clinician must obtain a
detailed history. Important queshons to be asked are listed in Box
1. Commonly, as in this pahent, the history of allergic reachons
is remote and difficult to recall. Features of hypersensihvity
reachons mediated by immunoglobulin E (IgE) (i.e., type 1
reachons) include urhcaria, angioedema, gastrointeshnal

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symptoms and bronchospasm. These reachons usually occur
within one hour of exposure and can lead to anaphylaxis. Some
IgE-mediated reachons may occur 1–72 hours aver
administrahon. Delayed (non–IgE-mediated) reachons occur
hours to days aver exposure.

How can a type 1 allergic reaction to penicillin be excluded in this

patient?

When a clear history cannot be elicited, skin testing is currently

the method of choice for excluding type 1 reactions to
penicillin. This most often requires the help of an expert in
allergy. Penicillin skin testing consists of prick testing followed by
intradermal instillation of small quantities of major (penicilloyl–
polylysine) and minor (penicillin G, penicilloate and penilloate)
determinants and observation for a wheal.

A negative result on skin testing with both major and minor

determinants has a negative predictive value for an immediate
hypersensitivity reaction nearing 100%. For safety reasons, a
negative skin test result is typically followed by a graded
challenge, which involves administration of several incremental,
subtherapeutic doses of penicillin. For patients who tolerate this
graded challenge, penicillin can be prescribed. Skin testing or
graded challenges should not be performed in patients with a
history suggestive of severe delayed hypersensitivity reactions
such as Stevens–Johnson syndrome. Skin testing can be safely
performed in pregnancy.

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If this patient has a positive result on skin testing for penicillin
allergy, can she still be treated safely with penicillin?

The positive predictive value of a penicillin skin test ranges from

40% to 100%. Therefore, if a patient has a positive skin test
result, penicillin can still be administered through a carefully
observed desensitization process, which would be performed by
an allergy expert. Desensitization involves administering
incremental doses of the drug in a monitored setting until the
therapeutic dose is achieved. The purpose of desensitization is
to induce tolerance without triggering adverse effects, and this
is maintained only if the drug is administered continually.
Desensitization can be safely performed in pregnancy.

If this patient has a positive result on skin testing, can she be

treated with other β-lactam antibiotics in the future?

It was previously believed that individuals with penicillin allergy

had a 10% risk of immediate hypersensitivity with the
administration of cephalosporins. However, this belief was
based on studies in which the cephalosporin administered
contained trace amounts of penicillin. Currently, it is believed
that the rate of cross-reactivity is closer to 1%. Data suggest that
characteristics of the side chains, and not the β-lactam ring itself,
are most responsible for cross-reactivity between various β-
lactam antibiotics. Patients with a prior history suggestive of IgE-
mediated penicillin allergy have only a 2% risk of IgE-mediated
reaction to carbapenems. Aztreonam does not cross-react with
other β-lactam agents except for ceftazidime. If a patient has a

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positive result on penicillin skin testing and treatment with a
cephalosporin or carbapenem is indicated, he or she can
undergo a graded challenge.

The case revisited

The pahent was referred to an allergist for penicillin skin teshng,

the result of which was negahve. This was followed by a graded
challenge, which was tolerated. The pahent was subsequently
treated with intramuscular penicillin G benzathine for her late
latent syphilis, without adverse event. Her allergy history was
updated in her clinic records to indicate that she did not have an
allergy to penicillin.

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 CONCLUSION
In conclusion, antibiotics stand as indispensable agents in
modern medicine, revolutionizing the treatment of bacterial
infections and significantly improving overall public health.
Their discovery marked a transformative milestone, rendering
once-fatal diseases treatable and surgery safer. However, the
escalating concern lies in the emergence of antibiotic-
resistant strains, a consequence of overuse, misuse, and
inadequate regulatory measures. This resistance jeopardizes
the effectiveness of antibiotics, creating a pressing global
health crisis.

To mitigate this threat, a comprehensive and collaborative

approach is imperative. Implementing judicious antibiotic
stewardship programs, educating healthcare professionals
and the public on responsible use, and fostering research into
alternative therapies are crucial steps. International
cooperation is essential to address the transboundary nature
of antibiotic resistance. Additionally, incentivizing
pharmaceutical research for novel antibiotics and promoting
sustainable agricultural practices can contribute to reducing
the selective pressure driving resistance.

As we confront the challenges of antibiotic resistance, a

concerted effort is needed to strike a delicate balance
between the benefits and risks associated with these life-

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saving drugs. The future hinges on our ability to implement
multifaceted strategies, ensuring the continued efficacy of
antibiotics and preserving the foundation of modern
medicine for generations to come.

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 BIBLIOGRAPHY
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592298/

https://byjus.com/biology/antibiotics/

https://www.slideshare.net/guest08f61f/project-
antibioticsbyharkiran-presentation

https://www.slideshare.net/riyarc/antibiotics-84457188

https://www.youtube.com/watch?v=CFVyvlQH-oc

https://en.wikipedia.org/wiki/Antibiotic

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