Name a bacterial infection that can lead to septic shock.

Neisseria meningitidis is known to cause septic shock, particularly due to its ability to enter the bloodstream and induce a severe systemic response. This bacterium can lead to meningococcemia, a condition characterized by the presence of the bacteria in the blood, which can ultimately result in rapid and life-threatening septic shock. The pathogenic mechanisms of Neisseria meningitidis include the production of lipooligosaccharides (LOS), which can trigger potent inflammatory responses, leading to vascular collapse and shock.

Other bacterial infections listed, while they can cause serious illness and complications, are less commonly associated with septic shock in the same way. For example, while Streptococcus pneumoniae can lead to severe pneumonia and bacteremia, not all infections result in shock. Clostridium difficile primarily affects the gastrointestinal tract and leads to colitis, and Escherichia coli, although capable of causing septic instances through certain strains (like urosepsis), does not typically carry the same level of association with septic shock as Neisseria meningitidis does. Thus, the unique virulence factors and mechanisms of Neisseria meningitidis make it a notable cause of septic shock.