Skip to main content

Video

You are here

Killer Diseases: Antibiotic Resistance

16 November 2017

Antibiotic resistance isn’t an illness, but it is a major public health issue. Antibiotic resistance is when bacteria multiply—despite the presence of an antibiotic. 
Some bacteria are naturally resistant to certain antibiotics, while others that are usually antibiotic-sensitive can become resistant.

There are two mechanisms that may explain this phenomenon. 
In the first case, the chromosome that carries the bacteria’s genetic material mutates for no reason. Antibiotics work by targeting specific sites in bacterial cells. But when a bacteria’s chromosome mutates, the target sites are modified thereby preventing the antibiotic from binding with the bacteria to destroy it.

When resistant bacteria multiply, the antibiotic resistance gene is transmitted to their clones.

In the second case, the bacteria use another tactic to resist antibiotics. When resistant bacteria encounter non-resistant ones—even of a different strain—they can transmit their resistance gene. 

In both cases, when antibiotics are overused or used incorrectly, they become selective. When an antibiotic is present, resistant bacteria multiply while so-called antibiotic-sensitive bacteria are destroyed.

A person infected with resistant bacteria can transmit them, and therefore the resistant gene, to people around them.

Hospitals are high risk environments due to the risk of infection during and after surgery and patients' lowered immunity,.

Resistant Staphylococcus aureus bacteria is a major concern for hospitals as it can compromise many treatments. Patients risk developing a life-threatening infection such as septicicaemia, or blood-poisoning. 

Widespread use of antibiotics in livestock is partly responsible as resistant bacteria found in meat are transmitted to humans. 

The antibiotic avoparcin, used to stimulate growth in animals, is responsible for the worldwide development of resistance to vancomycin, its equivalent used to treat humans. Vancomycin is one of the few remaining antibiotics that is effective against staphylococcus aureus.