Consequences of Antibiotic Resistance (Cambridge (CIE) AS Biology)

Consequences of Antibiotic Resistance

• Antibiotic-resistant strains are a major problem in human medicine; incidence of resistance is increasing due to antibiotic use in humans and in livestock farming when they are not needed

  • By using antibiotics frequently, a selection pressure is exerted on the bacteria, which drives selection of resistant individuals

• Commonly prescribed antibiotics are becoming less effective against some bacterial strains

• Some strains of bacteria can be resistant to multiple antibiotics, making diseases very difficult to treat

  • These bacteria are commonly known as superbugs

  • The most common example is a strain of Staphylococcus aureus that has developed resistance to an antibiotic called methicillin, and is now known as MRSA (Methicillin-resistant Staphylococcus aureus)

• Infections caused by resistant strains of bacteria often need to be treated using multiple antibiotics, resulting in complicated and expensive treatments that may not be available to all

Reducing antibiotic resistance & its impact

• Ways to prevent the incidence of antibiotic resistance include:

  • tighter controls in countries where antibiotics are sold without a prescription

  • doctors prescribing antibiotics only when needed, e.g. antibiotics not being used for viral infections

  • avoiding the blanket use of ‘wide-spectrum’ antibiotic, and instead prescribing specific antibiotics for different types of infection

  • tighter control of antibiotics in agriculture

• The spread of already-resistant strains can be limited by:

  • ensuring good hygiene practices, such as handwashing and the use of hand sanitisers, especially in clinical environments

  • isolating infected patients to prevent the spread of resistant strains, in particular in surgical wards where MRSA can infect surgical wounds

• Scientists need to find new antibiotics to which bacteria have not yet been exposed, as well as antibiotic alternatives, but this process is expensive and time-consuming