Question

Salmonella are a genus of pathogenic bacteria that can cause infections through the gastrointestinal tract. How could Salmonella poisoning be initiated if a human were to ingest these bacteria?

Salmonella are a genus of pathogenic bacteria that can cause infections through the gastrointestinal tract. How could Salmonella poisoning be initiated if a human were to ingest these bacteria?

The bacteria survive the acidic environment of the stomach and resist lysosomal degradation in macrophages.

The bacteria release chemical messengers that make them resistant to phagocytosis.

There is a delay in selection of the population of eosinophils that recognize and fight these bacteria.

The combination of foods eaten at a meal increases the pH of the stomach sufficiently so that ingested bacteria are not destroyed.

Answer 1

Answer- The bacteria survive the acidic environment of the stomach and resist lysosomal degradation in macrophages.

Explanation-

The outer capsule of Salmonella protects it from acid of stomach.

The mode of entry of Salmonella in gut lumen varies according to type of cell encountered on the gut epithelium. The M cells take up the bacteria by means of receptor mediated endocytosis, whereas dendritic cells engulf them by phagocytosis. The membrane of epithelial cells is modified by the action of SPI1 to facilitate the entry of bacteria. Once inside the gut lumen, Salmonella is being taken up by macrophages, T cells, B cells, neutrophils, etc.

Salmonella resists lysosomal degradation by action of SPI2

Immune evasion strategies of Salmonella is represented by following diagram-