Guidance

Extended-spectrum beta-lactamases (ESBLs): FAQs

Published 1 December 2013

Extended-spectrum beta-lactamase (ESBL)-producing E. coli are antibiotic-resistant strains of E. coli.

E. coli are very common bacteria that normally live harmlessly in the gut. ESBL-producing strains are bacteria that produce an enzyme called an extended-spectrum beta-lactamase, which makes them more resistant to antibiotics and makes the infections harder to treat. In many instances, only two oral antibiotics and a very limited group of intravenous antibiotics remain effective.

1. What illnesses do ESBL-producing E. coli cause?

E. coli are one of the most common bacteria causing infections in humans, particularly urinary tract infections (UTIs). These infections can sometimes progress to cause more serious infections such as blood poisoning which can be life threatening. ESBL-producing strains are more difficult to treat because of their antibiotic resistance.

2. Are some people more at risk than others?

Most of the infections have occurred in people with other underlying medical conditions who are already very sick, and in elderly people. Patients who have been taking antibiotics or who have been previously hospitalised are mainly affected.

3. Is this the type of E. coli that causes severe food poisoning?

No. There are very specific strains of E. coli including E. coli O157, that cause food poisoning and sometimes kidney failure when people eat undercooked meat. These are completely different strains. ESBL-producing E. coli are usually associated with urinary tract infections (UTIs) rather than food poisoning.

4. How do people contract it?

Further research is needed to look at the risk factors associated with different strains of ESBL-producing E. coli and how they are transmitted between patients and also in the community. Public Health England (PHE) is currently doing research to address some of these issues.

5. Is it treatable?

The important factor is quick diagnosis and recognition that the bacteria causing infection are resistant to some antibiotics, so that the most appropriate treatment can be prescribed quickly. There are only two oral antibiotics and few intravenous antibiotics that are effective against such infections.

6. Which antibiotics are these infections resistant to?

Most ESBL-producing E. coli are resistant to cephalosporins, penicillins, fluoroquinolones, trimethoprim, tetracycline and some other antibiotics, leaving very limited options for oral treatment in the community, usually only nitrofurantoin and fosfomycin.

7. Is PHE monitoring ESBL-producing E.coli?

There is voluntary national surveillance of blood poisoning caused by E. coli poisoning, including ESBL-producing strains.

8. How can the spread be controlled?

Robust infection control measures are always important to prevent the spread of infection. These include interventions, such as, hand washing and patient isolation. It is also important to ensure that antibiotics are prescribed only when needed, in the right dose, for the right duration, so as to reduce resistance developing in bacteria.

9. What else is PHE doing about the problem?

There are a number of ongoing initiatives. These have included advice and assistance in treatment and management of patients; awareness raising through presentations and publications; development of guidance on detection of such organisms and studies into patient risk factors for infection outcome; and research through externally funded projects.