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

1.1 Natural antibiotics

Most natural antibiotics were discovered before the 1970s, using systematic non-target-based screening of soil samples. Relatively few antibiotics in use today are completely natural. Of these, about 20% are produced by fungi and 80% by a group of Gram-positive, filamentous soil bacteria called Streptomyces (Lo Grasso et al., 2016).

Two types of fungi – the Penicilliums and the Cephalosporiums – have proved good sources of antibiotics. For example, Penicillium notatum (Figure 1) was the source of the original penicillin discovered by Alexander Fleming in 1928. Cephalosporium acremonium gave rise to the first-generation cephalosporins (Clegg, 2015) .

Described image
Figure 1 Penicillium notatum – the source of penicillin

Natural antibiotics isolated from Streptomyces bacteria (Figure 2) include streptomycin, tetracycline, vancomycin, erythromycin and chloramphenicol (de Lima Procopio et al., 2012).

Described image
Figure 2 Streptomyces griseus – the source of streptomycin (Scale bar, 1 micrometre).
UAR_1

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 nearly 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