The agents are Sh. They are gram negative non-motile rods facultative anaerobes placed in groups based on their O antigen and biochemical reactions. Organisms are transferred by fecal contamination of food and water. They are acid resistant and therefore survives in the stomach to reach the small and large intestine where they replicate and remain, causing ulcer and abscess. They rarely enter parenteral tissues.
Shigellosis is self limiting and requires the replacement of fluid and electrolytes.
Symptoms - Abdominal pain, fever, cramps and diarrhea. Treatment - Norfloxacin, tetracyclines, chloramphenicol, quinolones, cephalosporin and ampicillin, but there are resistant strains. Organisms can grow in alkaline pH. Sero type O1 is the agent for cholera and is characterized based on biochemical reactions, enterotoxin and O antigen. Transmission is by ingestion of contaminated water and uncooked food, especially fish. Symptoms - Vomiting, diarrhea and abdominal pain.