Final answer:
The motility of Listeria monocytogenes differs from Shigella spp. as Shigella lacks flagella and is generally non-motile, while L. monocytogenes is motile through actin polymerization that enables intracellular movement and cell-to-cell spread.option c is correct.
Step-by-step explanation:
The motility of Listeria monocytogenes differs from that of Shigella spp. because Shigella species are generally non-motile due to the absence of flagella, which are required for bacterial mobility. On the other hand, E. coli, Salmonella spp., and Shigella spp. are all Gram-negative enteric bacilli, but E. coli and Salmonella typically exhibit motility through the use of flagella.
L. monocytogenes, known for its ability to cause severe infections like meningitis and to cross the body's important barriers using internalins and proteins such as listeriolysin O and ActA, also exhibits motility but in a different manner from these other bacteria, primarily through actin polymerization which facilitates intracellular movement and cell-to-cell spread.