Boyd's dysentery bacterium

Microbiological description The dysentery bacillus is gram-negative, does not form spores, immotile, grows well at a temperature of 37°C, begins to grow on nutrient media 2-3 hours after sowing. During growth it produces hydrogen sulfide gas.

Dysenteric (Shigella) is a group of bacteria consisting mainly of four species - sh. dysenteriae, sh. flexneri, sh. heilani and sh. sonnei. There are also many serological types. The Shigella group is classified as the Shigella family in the subfamily of intestinal bacteria.

The human disease is caused by species sh. dysenteriae 2a and 1b, less often - other Shigella. Shigella has significant resistance in the external environment - it is secreted into cystogenic forms and survives in cold water for up to 7 months. They can live in environmental objects (mainly in water) for months, in waste water (15-30 days). Sh. dysenteriae for a long time, sometimes (in milk) can persist in food products for up to a year. Pathogenesis and infectious process The main route of infection is food, but water is also possible. When eating contaminated food, the microbe can be located in the large intestine, mucous membrane