Which statement best describes Campylobacter pathogenesis?

• A. Complex nutritional requirements limit environmental growth.
• B. Adheres to the intestinal lining, invades cells, and may replicate intracellularly.
• C. LPS (endotoxin) and CDT (exotoxin) are involved in disease.
• D. Severity of disease is determined only by the number of organisms, with no host factors.

Answer: (B)

Campylobacter pathogenesis mainly involves sticking to the intestinal lining, invading the epithelium, and sometimes surviving or replicating inside cells. The bacteria use surface factors to adhere to mucosal cells, then cross or invade the epithelial layer, which triggers a strong inflammatory response and tissue disruption that leads to diarrhea. Toxins like CDT and the LPS endotoxin can contribute to disease, but the key driver of illness is this adherence and invasion process. Illness severity is not determined solely by bacterial numbers; host factors such as age, immune status, and gut environment play a big role. The organism’s fastidious, microaerophilic growth describes its growth needs outside the body, not the mechanism of disease once inside the host. So, adherence with invasion and possible intracellular activity best describes Campylobacter pathogenesis.