What is the Difference Between Multidrug Resistance and Cross Resistance?

The difference between multidrug resistance and cross resistance lies in the extent of an organism's resistance to multiple antimicrobial drugs and the mechanisms involved.

Multidrug Resistance (MDR):

• MDR organisms carry one or more resistance mechanisms, making them resistant to multiple antimicrobials.
• MDR bacteria can be difficult to treat and complicate efforts to reduce resistance.
• MDR can occur when a bacterium has several different resistance genes, each providing resistance to a particular antibiotic, or when a single resistance mechanism gives resistance to more than one antibiotic.

Cross Resistance:

• Cross resistance is a phenomenon where a single resistance mechanism confers resistance to multiple antimicrobial drugs.
• This can happen when a bacterium uses a single pump to pump out several different antibiotics.
• Cross resistance corresponds to resistance to all the antibiotics belonging to the same class due to a single mechanism.

In summary, multidrug resistance refers to an organism's resistance to multiple antimicrobial drugs, while cross resistance is a specific type of multidrug resistance where a single mechanism provides resistance to multiple drugs within the same class. Both phenomena can be problematic, making infections difficult to treat and facilitating the spread of antibiotic resistance.

Comparative Table: Multidrug Resistance vs Cross Resistance

Here is a table comparing multidrug resistance and cross resistance:

In summary, multidrug resistance is a broader term that refers to resistance to multiple antimicrobial drugs in different classes, often due to multiple genetic changes in the pathogen. Cross resistance, on the other hand, is a more specific phenomenon where a single genetic change in the pathogen leads to resistance to multiple drugs in the same class.