2.2.3 Multidrug resistance
Bacteria can acquire multiple resistance mechanisms, making them resistant to multiple antibiotics. This is known as multidrug resistance (MDR). MDR bacteria are often known as ‘superbugs’ (although it is important to note that being resistant does not make bacteria more pathogenic, just that it will be harder to treat) and they are a major concern because they severely limit available treatment options.
Multidrug resistance is increasing globally, both in human healthcare and in farm animals. The issues in human healthcare are obvious, but multi-drug resistance in the food chain could have a severe impact on our ability to treat animals, as well as consumers of affected meat, in the future.
Activity 7: Acquiring multidrug resistance
In this activity you are asked to read a short article and answer some questions about it. One article is relevant to animal health and the other to human health; select the article that is most appropriate for your job and your interests.
Animal health
Read the Medical News Today article ‘Antibiotic resistance in farm animals is rising fast’ [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] , which highlights that, although multidrug resistance is rare, it is increasing and could cause significant problems for treatment of both animals and humans in the future.
While you read the article, note down the answers to the following questions.
- What percentage of antibiotics used in human treatment are routinely used in meat production?
Answer
73% are used in animals raised for food.
- Which countries have the largest number of multidrug resistance cases among farm animals?
Answer
India and north-east China have the most cases. Kenya, Uruguay and Brazil follow close behind.
- How much has the use of antibiotics in the last ten years affected resistance of bacteria found in samples from cattle, chickens and pigs?
Answer
The quantity of antimicrobials that bacteria found in cattle are resistant to has doubled. For chickens and pigs, the resistance is almost three times higher.
Human health
Read the BBC article ‘Bug resistant to all antibiotics kills woman’, which highlights that, although multidrug resistance is rare, it can have a devastating impact.
While you read the article, note down the answers to the following questions.
- Which bacterium caused the patient’s infection?
Answer
The patient’s infection was caused by the Gram-negative bacterium Klebsiella pneumoniae.
- How many antibiotics was the infection resistant to?
Answer
It was resistant to 26 different antibiotics, including the ‘drug of last resort’: colistin.
- Is resistance to all antibiotics a common occurrence?
Answer
No. Infections that are resistant to all antibiotics are uncommon.
2.2.2 Introducing acquired resistance
