Cross-resistance

Definition

Cross-resistance occurs when a microorganism resistant to one antimicrobial drug also becomes resistant to another drug, often due to similar mechanisms of action or genetic factors. This phenomenon can complicate treatment options and contribute to the spread of multidrug-resistant infections.

5 Must Know Facts For Your Next Test

1. Cross-resistance often arises from the use of antibiotics with similar structures or mechanisms.
2. It can be caused by genetic mutations that confer resistance to multiple drugs.
3. Efflux pumps in bacteria are common contributors to cross-resistance by expelling various drugs out of the cell.
4. Horizontal gene transfer between bacteria can spread resistance genes, leading to cross-resistance.
5. Cross-resistance poses significant challenges in treating infections, particularly in hospital settings where multidrug-resistant strains are prevalent.

Review Questions

• What is cross-resistance and how does it affect antimicrobial treatment?
• Name two mechanisms by which bacteria develop cross-resistance.
• How does horizontal gene transfer contribute to cross-resistance?

Related terms

Multidrug Resistance (MDR): A condition enabling a microorganism to resist the effects of multiple antimicrobial drugs.

Efflux Pump: A protein that actively transports unwanted substances, including antimicrobial agents, out of cells.

Horizontal Gene Transfer: The movement of genetic material between organisms other than through vertical transmission (from parent to offspring).