Skip to main content
hpa logo
Topics A-Z:
Search the site:

General Information

Extended Spectrum Beta Lactamases - Frequently Asked Questions Description

  What are Extended-Spectrum Beta-Lactamase (ESBL) producing E.coli?

What illnesses do ESBL-producing E. coli cause?

Are some people more at risk than others?

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

How do people contract it?

Is it treatable?

How many of these infections are reported to the HPA?

Which antibiotics are these infections resistant to?

Is the HPA monitoring ESBL-producing E.coli?

How can the spread be controlled?

What else is the HPA doing about the problem?

What are Extended-Spectrum Beta-Lactamase (ESBL) producing E.coli?

ESBL (Extended-Spectrum Beta-Lactamase) 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 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.

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 ones more difficult to treat because of their antibiotic resistance.

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.

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

No. There is a very specific strain of E. coli called E. coli O157, which causes food poisoning and sometimes kidney failure when people eat undercooked meat. That is a completely different strain. The ESBL-producing E. coli are associated with UTIs rather than food poisoning.

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.

Is it treatable?

The important factor is quick diagnosis and recognition that the bacteria causing infection are resistant to 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.

How many of these infections are reported to the HPA?

This is an emerging problem and surveillance needs to be adapted to monitor ESBL-producing E. coli infections.
The surveillance we have of E. coli bacteraemias from 1994 to 2004 indicates a year on year increase in the number of these infections. Total numbers of E. coli bacteraemias have more than doubled in the last decade from 8,640 to 17, 416 cases in 1994 and 2004, respectively. The increasing numbers in the early part of this period are thought to be due mainly to better reporting of cases.
The percentage of which are multi-resistant to antibiotics and therefore likely to be ESBL-associated is 2% in 2001, 3% in 2002 and 4% in 2003.

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.

Is the HPA monitoring ESBL-producing E.coli?

Currently there is voluntary national surveillance of blood poisoning caused by E. coli poisoning, but surveillance needs to be extended to look for ESBL-producing E. coli as a cause of blood poisoning and also of UTIs in the community.

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.

What else is the HPA doing about the problem?

Since the HPA first identified this 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.
For further recommendations, please see the HPA's Report on the emergence of multi-drug resistant ESBL-producing E. coli causing infections in England.