Contact UsCareersNewsScienceContact Us
All You Need To Know About Antimicrobial ResistanceHomeYour HealthDisease and ConditionsAll you need to know about Antimicrobial Resistance

What is antibiotic resistance?

Antibiotic resistance is when germs (bacteria, fungi) develop the ability to defeat the antibiotics designed to kill them. It can happen when the bacteria decreases or destroys the effectiveness of antibiotics which can cure and prevent infections. As a result, the bacteria are able to survive and multiply in the presence of antibiotics, causing more harm. It does not mean your body is resistant to antibiotics.1,2

Can antibiotics be used to treat infections caused by viruses?

Bacteria and viruses can cause many different types of illnesses in humans. An antibiotic is a medication used specifically to treat bacterial infections. Antibiotics work by attacking the structures and functions inside bacterial cells, but have no effect against viruses. Your doctor will not prescribe antibiotics to treat a viral infection or illness not caused by bacteria.​​​​​​​

When do antibiotics work?

Antibiotics kill or reduce the growth of bacteria by attaching to specific targets on, or within the bacteria. Viruses are constructed differently from bacteria – a virus must get inside a living cell to grow and replicate.1​​​​​​​

Bacterial Vs Viral Infections8​​​​​​​

How does antibiotic resistance happen?

Antibiotics kill or hinder the growth of susceptible bacteria. When exposed to antibiotics, sometimes one of the bacteria can survive because it has found a way to counteract or evade the antibiotic attack. Even if one bacterium becomes resistant, it can multiply and replace all the bacteria that were killed.  This is called ‘selective pressure’ and it makes the surviving bacteria more likely to be resistant.​​​​​​​3There are several ways in which antibiotic resistance can happen. Random ‘mutations’ or changes can occur in the genetic material of the bacteria every time they reproduce and multiply. These changes may enable the bacteria to survive, protecting them from different types of antibiotics.​​​​​​​2   These genetic changes can also be passed on to other bacteria.​​​​​​​4Bacteria may develop the ability to counteract or ‘neutralize’ the antibiotic making it harmless.Some bacteria can even rapidly pump out the antibiotic before it can work. There is also a possibility of the bacteria changing their external structure so that there is no way for antibiotic to attach or penetrate inside bacteria.4

Why are bacteria becoming resistant to antibiotics?

Antibiotic resistance is a natural phenomenon caused by changes in the bacteria’s genes. Overuse and misuse of antibiotics can promote the development of antibiotic resistant bacteria.3 Sensitive bacteria are killed by antibiotic medications, but resistant bacteria can flourish and spread making antibiotics less effective.2,5 Using antibiotics when they are not needed or using them incorrectly can enable development of antibiotic resistance.​​​​1​ ​

Myths or facts on antibiotic use

Here are some common myths and truths regarding the use of antibiotics.2-6

1. Centers for Disease Control and Prevention. Antibiotic resistance threats in the United States. Available at: Antibiotic Resistance Threats in the United States, 2019 ( Accessed on 20th May 2022
2. European Centre for Disease Prevention and Control. Factsheet for the general public – Antimicrobial resistance. Available at: Accessed 20th May 2022
3. Centers for Disease Control and Prevention. Antibiotic resistance questions and answers. Available at: Accessed 20th May 2022 
4. Bennett PM. Plasmid encoded antibiotic resistance: Acquisition and transfer of antibiotic resistance genes in bacteria. Br J Pharmacol 2008; 153: S347-S357.
5. World Health Organization (WHO). Antimicrobial resistance. Global report on surveillance. 2014. Available at:;jsessionid=226100E0946A6CD70C8035A0D80F3429?sequence=1 Accessed 20th May 2022.
6. Shallcross JL, et al. Tackling the threat of antimicrobial resistance: From policy to sustainable action. Phil Trans R Soc B BiolSci 2015;370:20140082
7. Laxminarayan R, et al. Antibiotic resistance – the need for global solutions. Lancet Infect Dis 2013;13:1057-1098
8. Centers for Disease Control and Prevention. Viruses or bacteria. What’s got you sick? Available at: Accessed 20th May 2022.
Disclaimer:The content herein is meant for informational and awareness purposes only and should not be considered as a substitute for competent medical advice.

PP-ZVA-IND-0665 | 20/05/2022

About UsOur ScienceOur Community EffortsYour Health Career-Seekers News & MediaHealthcare ProfessionalsContact UsTerms And ConditionsPrivacy PolicyAdverse Event ReportingCopyright © 2002- 2022 Pfizer Inc. All rights reserved. This information—including product information—is intended only for residents of  India and strictly only for informational, educational, academic and/or research purposes and is not intended to substitute for professional medical advice, diagnosis or treatment. While due care and caution has been taken to ensure that the content here is free from mistakes or omissions, Pfizer makes no claims, promises or guarantees about the accuracy, completeness or adequacy of the information here. You may report an adverse event related to Pfizer products by emailing us at [email protected] or via Fax at: 000800100-5961 / +91-22 3919-771.