A resistance “cocktail” such as NDM-1

The past decade has seen a statistically significant uptick in reports of the bacterial strains known as “super-bugs,” so called not because of enhanced virulence, but because of their resistance to many antimicrobial agents. In particular, researchers have become alarmed about NDM-1 (New Delhi metallo-beta-lactamase), which is not a single bacterial species, but a transmittable genetic element encoding multiple resistance genes. A resistance “cocktail” such as NDM-1 could bestow immunity to a bevy of preexisting drugs simultaneously, rendering the bacterium nearly impregnable.

What is being said in the bold sentence?

A “cocktail” refers to a mixture of different elements - here it refers to a mixture of different genes that the bacteria has, making it immune to many drugs, and making it very difficult to kill.