What is antibiotic resistance? The overuse of antibiotics worldwide has resulted in the ability of harmful bacteria and other micro-organisms to adapt to the drugs and to resist the effects of an antibiotic to which they were once sensitive.
Taking an antibiotic kills the sensitive bacteria, but those bacteria that can resist the antibiotic manage to survive. In the right circumstances they can reproduce rapidly to become the dominant population of bacteria. These bacteria can cause infection that is more difficult to treat, as they are now resistant to the antibiotic. They can also be carried on the skin and transferred to other people, which is why infection control is vital in hospitals and visitors to high care units are required to use disinfectant hand wash at the entrances to these wards.
Antibiotic-resistant infections have become a common occurrence in hospitals due to invasive procedures, the clustering of patients, and the extensive use of antibiotics.
What is a superbug? Some bacteria are resistant to multiple types of antibiotics and are called “superbugs”, as they are hard to kill – and in extreme cases virtually impossible to kill. Examples of superbugs are MRSA (methicillin-resistant staphylococcus aureus), and multi-drug-resistant tuberculosis (MDR-TB).
How does antibiotic resistance work in the human body? At the cellular level in the body, antibiotic resistance may manifest through different evolving bacterial mechanisms such as:
- Bacteria can chemically modify the antibiotic to render it ineffective (a specific enzyme modifies the antibiotic to lose its activity),
- Bacteria can render the antibiotic inactive by physically removing or transporting it out of the cell, or
- Bacteria can modify the target site so that it is not recognized by the antibiotic, preventing the antibiotic from binding with the bacteria.
See illustration below of these bacterial mechanisms of antibiotic resistance:
Can antibiotic resistance be prevented?
- Doctors and patients should be sensitive not to overuse antibiotics – and use antibiotics only when it is the only and appropriate treatment for a bacterial infection.
- Unnecessary antibiotic prescriptions for which there is no value should be avoided. Antibiotics are not meant to be used for viral infections, such as for cold and flu, as antibiotics have no effect on viruses.
- Patients should strictly adhere to the prescribing guidelines and take antibiotics till they have completed the course.
- With a severe infection, antibiotic sensitivity testing should be done to determine the correct antibiotic to fight the infection.
Sources:
What you need to know about antibiotic resistance. Published 12 July 2016 on WebMD. (www.webmd.com)
The antibiotic resistance crisis. Published April 2015 in Pharmacy and Therapeutics. (www.ncbi.nlm.nih.gov)
Bacterial resistance to antibiotics. Published in the Online Textbook of Bacteriology. (www.textbookofbacteriology)
When will antibiotics stop working? Article based on information provided by Prof Marc Mendelson, head of the Division of Infectious Diseases and HIV Medicine at UCT, and co-chair of the South African Antibiotic Stewardship Programme. Published in Fairlady, February 2018.
HEALTH INSIGHT. MARCH 2018.