General Information about Acinetobacter baumannii

What is Acinetobacter?

Acinetobacter is a type of bacterium, which normally lives in the environment, for example in water and in soil. It can sometimes be found on the skin of healthy people, who carry it harmlessly. There are at least 30 different species of Acinetobacter, and a few of these, particularly a species called Acinetobacter baumannii, can cause infections in those hospital patients who are already very unwell. These 'hospital-adapted' strains of Acinetobacter baumannii are sometimes resistant to many antibiotics and the infections that they cause can therefore be difficult to treat.

How do people contract Acinetobacter infections?

Acinetobacter poses no risk to healthy people. Hospitalised patients, especially very ill patients on a ventilator or those with severe burns are at a greater risk of infection. Such patients are also more likely to be affected if they also suffer from chronic lung disease, weakened immune systems or diabetes. Acinetobacter can be spread on such wards to susceptible patients by person-to-person contact, or contact with contaminated surfaces or medical equipment and other exposure in the environment.

How can Acinetobacter be controlled and prevented from spreading in hospitals?

Acinetobacter can live on the skin and may survive in the environment for several days. Transmission can be reduced by careful attention to infection control procedures such as hand hygiene, environmental cleaning and disposal of exposed medical equipment after patient discharge.

Is Acinetobacter becoming resistant to all antibiotics?

Whilst resistance to antibiotics is not a new phenomenon for Acinetobacter, what is new is that since 2000 some strains have begun to develop resistance to the last effective group of active drugs called carbapenems. The Agency is aware of three such strains in the UK; The South East Clone, OXA-23 clone 1 and OXA-23 clone 2 of Acinetobacter baumannii, which have caused illness in patients.

There is still one type of drug (polymyxin) that is highly active in the laboratory, however this is an old antibiotic which is not routinely used and the HPA is currently studying how effective it really is in the treatment of Acinetobacter infections.

What is the HPA's involvement in controlling Acinetobacter?

The HPA monitors trends in these infections and has published interim infection control guidance. The HPA also offers advice and assistance to staff in hospitals as required.

The Agency provides a reference service that identifies the mechanisms of resistance and the strains that are prevalent. We are also initiating outcome studies to identify the most effective treatment.

Acinetobacter causes a variety of different illnesses. The Agency receives reports of blood poisoning due to these bacteria and conducts in-depth investigations into cases of infection and typing of the organism. It also alerted microbiologists to report outbreaks of multi-resistant Acinetobacter to their regional units of the HPA, and to send isolates to our reference labs for further investigation.

Last reviewed: 16 September 2009