Infectious Disease Flashcards
What type of bacilli is seen in the shigella
Coliform bacilli(enteric Rods)
What type of anaerobes is the shigella
Nonmotile gram negative facultative anaerobes
What are 4 species of shigella
Shigella sonnei(mc in industrial )
Shigella flexneri (mc in developing countries)
Shigella boydii
Shigella dysenteriae
What kind of fermenting is shigella
Non lactose fermenting and also resistant to bile salt
Generic term for shigella is
Shigellosis
Low infectious dose
(10^2 -10^4 CFU)
Who are the reservoirs of shigella
Human Resource
How is shigella transmitted
Fecal oral route
Incubation period of shigella
1-3 days
What are the most common symptoms of shigella
Watery diahrea with fever ;changing to dysentery
Major causes of bacillary desentry (severe 2nd stage) in ped age grp
1-10yrs via fecal oral route
In shigella how many percentage leads to pediatric diarrhea
15%
Which is leading cause for infant diarrhea and mortality in developing countries
Shigella
An exotoxin with enteric activity that affects the intestinal tract
Enterotoxin
What is desentry
Inflammation of intestine with accompanying abdominal cramps
Tenesmus(straining to defecate)
Frequent and low volume stools containing blood,mucus and fecal leukocytes
Bacillary dysentery
Invasion of host cells and production of exotoxin
What are the two stages of shigellosis
Early stage
Second stage
Characteristics of early stage of shigellosis
Watery diarrhea Enterotoxic activity of shiga toxin Ingestion Non invasive colonisation Multiplication Production of enterotoxin in small intestine
Fever attributed to the neurotoxic activity of toxin
Second stage of shigellosis
Invasion of large intestine with dysentery
Cytotoxic activity of shiga toxin
Virulence attributable to
1) invasiveness (attachment and internalization)
2) exotoxin (shiga toxin)
3) intracellular survival and multiplication
Shigella penetrates in
Colonic epithelium And then into lamina propria
Shigella invades which cell
M cells
Shigella can Lyse
The phagocytic vacuole and replicate in cytoplasm
Shigella is contrast to
Salmonella