Final answer:
Salmonella enterica serovar Typhi causes typhoid fever by entering epithelial cells through induced membrane ruffling and surviving in macrophages. It spreads systemically via the bloodstream and lymphatic system and occasionally produces an enterotoxin. Hygiene and cooking are key preventive measures.
Step-by-step explanation:
How does Salmonella Carry Out Invasion in Enteric Fever?
Salmonella enterica serovar Typhi is a Gram-negative, rod-shaped gamma proteobacterium responsible for typhoid fever. The infection starts when the bacteria are ingested; they then multiply within the intestines. Salmonella has unique strategies for invading host cells. Using effector proteins, it induces membrane ruffling in epithelial cells, a process that facilitates endocytosis and allows the bacteria to enter the cells. Inside the body, Salmonella can survive in the phagosomes of macrophages and can spread to the bloodstream and lymphatic system, causing systemic infection. Some strains also produce an enterotoxin which contributes to the disease process.
Salmonella's ability to cause disease depends on various factors, such as the serotype, size of the inoculum, and the host's health. Preventative measures include handwashing and thorough cooking, which are effective due to the bacteria's inability to withstand high temperatures. The impact of typhoid fever remains significant, with the disease still causing many cases and deaths annually, as well as examples of asymptomatic carriers spreading the disease.
Understanding the pathogenesis of Salmonella, including its methods of invasion and survival within the host, is essential for preventing and controlling the spread of typhoid fever and other forms of salmonellosis.