‘Resistant bugs’: antibiotic resistance and multidrug-resistant organisms

This page explains about 'resistant bugs': antibiotic resistance and multidrug-resistant organisms (MDROs) and why this has become a worldwide public health issue. It explains how these organisms are passed on and how they can be treated. It also explains about things we are doing at Great Ormond Street Hospital (GOSH) to reduce the chance of them spreading.

Bacteria are tiny living beings (microorganisms, also commonly called bugs or germs). The human body contains huge amounts of ‘friendly’ bacteria that are either neutral or beneficial for us. They can help strengthen the immune system, secrete vitamins that benefit the health of the human body, and the ones that live in the gut help to digest food. Friendly bacteria also protect us from dangerous bacteria by occupying places in the body the types of bacteria that can cause disease want to attach to.

Antibiotics are types of medications that destroy or slow down the growth of bacteria. Antibiotics are used to treat infections caused by bacteria, they do not work against viral or fungal infections.

Antibiotic resistance is present in a bacterium when an antibiotic no longer has the ability to effectively control or kill it. This means that the bacteria have become ‘resistant’ to the antibiotic and continue to multiply even though there is a sufficient dose of antibiotic in the body.

Some bacteria are naturally resistant to some antibiotics and others have become resistant through selection of those with genetic changes due to use of the antibiotic. Some resistances can be passed from one bacterium to another, spreading resistance between different types of bacteria.

In the health care setting, a multi-drug resistant organism (MDRO) of concern is a bacterium that is resistant to several antibiotics, capable of causing infection and often adapted to spread easily. These bacteria are sometimes also called ‘superbugs’.

There are different types of bacteria that can become multidrug-resistant, especially:

• Gram-negative organisms (for example E.coli, Klebsiella or Pseudomonas).
• Gram-positive organisms (for example Vancomycin-resistant Enterococcus (VRE)).

A person can be either ‘colonised’ or ‘infected’ with a MDRO.

• ‘Colonised’ means that a person has the bacteria present on the skin, in body openings or in the gut, but has no signs of infection.
• 'Infected’ means that a person has signs of an infection, such as fever or pus from a wound.

Antibiotic resistance has emerged as one of the most pressing public health concerns. Almost every type of bacteria has become less responsive to antibiotic treatment. If a bacterium is resistant to many antibiotics, treating the infections it causes can become difficult or even impossible. Someone who is colonised or infected with a MDRO can pass this on to another person. In this way difficult to treat infections can spread from person to person.

There is no way of telling if someone has a MDRO, or not just by looking. The most reliable way of diagnosing a MDRO is by taking a faeces (poo) sample, a sample of other body fluids, such as sputum or urine or nose and throat swabs.

At GOSH, we ask for a stool sample from all children/young people that are admitted to the hospital, as gram negative MDROs are most commonly found in the gut.

The sample is sent to the microbiology laboratory to see whether any antibiotic resistant bacteria are present. If any bacteria are found, the laboratory staff will then do further tests to see the type of bacteria and to which antibiotics it is resistant.

At GOSH, the results of these tests are usually available within three to four days.

MDROs may develop in the body following the use of antibiotics or can be acquired from someone else. Any patient or parent, as well as staff, may, especially if they have had contact with health care before, be colonised with MDROs. The most common way of spreading the bacteria is by contact.

This can occur through contact with the hands from person-to-person. It can also occur though contact with objects such as equipment or toys that have not been cleaned properly. If your child has been in hospital or has had antibiotics recently, they are more likely to become colonised with a MDRO than other children.

Frequent hand washing or the use of alcohol gel and keeping the environment clean is the most important way to prevent the spread of a MDRO.

If the child is colonised with a MDRO, it is unlikely that they will experience any ill effects or symptoms.

If the child is infected with a MDRO the medical team caring for the child will discuss the treatment with the parents.

However, because both colonised and infected patients can spread the bacteria to other patients we will need to employ special precautions to reduce the risk:

• We will nurse the child in a separate room, if possible. On certain wards, such as Safari Ward and the intensive care units, the child may also be isolated in the bed space of a bay.
• We will use additional precautions, such as wearing gloves and aprons.
• We will also put an alert on the child’s computer record to indicate that they require, if possible, a separate room when coming to GOSH. This may impact on the timing of appointments or investigations, but your child will not be cancelled just because of this alert. 

In normal life these organisms are not usually a concern and there are no additional things you need to do at home or school. We always recommend good basic hygiene, such as hand washing before eating and after going to the toilet, and using separate towels. There is usually no need to inform anyone that the child has or has had a MDRO. The only circumstances where you might consider telling the child’s school is if there are other pupils who may need to go into hospital regularly.

As these bacteria can live harmlessly in the gut for long periods it is difficult to know when they are no longer present.

At GOSH, we declare a child free from MDROs if they meet the following criteria:

• They have not received antibiotics in the previous six months.
• They have three negative stool specimens taken one week apart. The last sample must be in or after the fifth month of the period where no antibiotics were given. If the MDRO was isolated from another area or sample, such as urine or sputum, then three specimens of urine or sputum would need to be negative, as well as three stool samples.
• They are not immuno-suppressed. 

GOSH has been working hard for a number of years to reduce the spread of MDROs. We screen every child that is admitted for MDROs so that we can put in place our control plans. We have low numbers of children with MDRO and when each case is checked, in most cases, the children have developed MDRO before they come to GOSH. We strongly encourage hand washing before and after patient contact, by providing alcohol hand rub (an alternative to soap and water) at the entrances to each ward. We encourage parents to ask any member of staff who visits the child whether they have washed their hands.

Finally, we are working with our cleaning contractors to improve levels of cleanliness in wards and general areas but we need your help too. There are posters and information leaflets in every ward about how you can help us keep the hospital clean.