Which type of bacteria is described as corkscrew shaped?

The correct choice is spirilla because this type of bacteria is recognized for its unique corkscrew shape, which allows it to move in a spiral-like motion. This shape is significant as it can influence how the bacteria interact with their environment and how they are able to swim through liquids. The spiral form is characteristic of certain species of bacteria within the larger group of spirillum, which are often associated with water or moist environments, and can sometimes be pathogens.

In contrast, staphylococci are generally round and tend to form clusters resembling bunches of grapes, which is a very different morphology. Bacilli are rod-shaped, and cocci are also round but typically form chains or pairs. Understanding the shape and structure of different bacteria can aid in their identification and help inform appropriate treatments in a clinical setting, as the morphology often correlates with their behavior and pathogenicity.