Understanding antibiotic resistance
Understanding antibiotic resistance

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

Understanding antibiotic resistance

Week 3: How do bacteria become resistant to antibiotics?


In Week 2 you looked at how antibiotics target bacteria, either killing them or preventing their growth. But bacteria are constantly fighting back against this threat to their survival. Antibiotic resistance is the ability of pathogenic bacteria to resist the action of antibiotics so that they survive exposure to antibiotics that would normally kill them or stop their growth (CDC, 2017; PHE, 2017).

You could be forgiven for thinking that antibiotic resistance has been caused by our use, and misuse, of antibiotics. However, as you will see in the following video, bacteria that have not interacted with humans have acquired resistance to many of the antibiotic medicines we use to treat infections.

Video 1 Antibiotic resistance is a natural bacterial defence mechanism.
Interactive feature not available in single page view (see it in standard view).

You will return to look at how resistance has evolved and spread in Week 4. In this week, you will focus on how bacteria develop resistance in order to protect themselves from antibiotics. You will start by considering several mechanisms of antibiotic resistance before moving on to look at the differences between intrinsic and acquired antibiotic resistance. You will end the week by returning to the case study to explore the mechanisms responsible for resistance to third generation cephalosporins.

By the end of this week, you should be able to:

  • state what is meant by the term ‘antibiotic resistance’
  • recognise that antibiotic resistance evolved to protect bacteria
  • describe the three main mechanisms of resistance that bacteria have developed to counteract the action of antibiotics
  • give examples of these resistance mechanisms
  • distinguish between intrinsic and acquired antibiotic resistance.

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus