This document discusses Shigella bacteria and shigellosis. It covers the classification of Shigella as a genus of Gram-negative, facultative anaerobic bacteria closely related to Salmonella. Four common types of Shigella that cause shigellosis are described. Shigellosis is an infectious disease typically causing diarrhea, fever, and abdominal pain. It is transmitted through the fecal-oral route and spreads easily in areas with poor sanitation. Prevention methods include water purification, insect control, food hygiene, and vaccination.

1. Prepared by: Umair Khan
B.S Pathology 3rd semester 03149714825

2. Shigella and its classification
Shigellosis and its symptoms
 Life Cycle andTransmission
Cultural characteristics and Prevention.
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3. Shigella is a genus of Gram-negative ,
facultative anaerobic , non-spore-forming
, non-motile, rod-shaped bacteria closely
related to Salmonella.
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5. Kingdom: Bacteria
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Enterobacteriales
Family: Enterobacteriaceae
Genus: Shigella
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6. 1- S. boydii
2- S. dysenteriae
3- S. flexneri
4- S. Sonnei
Shigella Dysentery is the most common.
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7. Shigellosis, also known as bacillary
dysentery or Marlow Syndrome.
Shigellosis is a disease caused by bacteria
of the genus Shigella.
Shigellosis rarely occurs in animals other
than humans.
It is usually resolves in 5-7 days.
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8. Shigellosis Cont....
 Shigella is one of the most common infectious
bacteria and infection will cause when we ingest
100-200 organism.
 Shigella can servive up to 30 days in Milk, Egg
and Cheese.
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9. The global burden of shigellosis has been estimated
at 165 million cases per year,
of which 163 million are in developing countries.
More than one million deaths occur in the
developing world yearly due to Shigella infection. By
one estimate, Shigella infections are responsible for
300,000 illnesses and 600 deaths per year in the
United States
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10. Common symptoms
 Fever
 Diarrhoea
 Abdominal Pain
 Stomach pain
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11. Fecal-oral transmission is the main route of
Shigella infection. Other modes of
transmission include ingestion of
contaminated food or water, contact with
infected objects, or sexual contact. Outbreaks
of Shigella infection are common in places
with poor sanitation standards.
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12. The Shigella life cycle begins with penetration of
colonic mucosa.
This results in degradation of the epithelium and
acute inflammatory colitis in the lamina propria.
This causes leakage of blood, inflammation in the
colon, and mucus into the intestinal lumen.
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15.  All memeber of shigella aerobic and facultative
anerobes.
 Grow readily in culture media at pH 6.4 to 7.8 at 10-40
Oc.
 After incubation of 24 hours, shigella collinies reaches a
diameter of 2mm.
 In XLD medium they appear pinkish to reddish colonies
while in Heaktoen Enteric Agar ( HEA), they give green to
blue green colonies
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17.  Supply of pure water.
 Insects control.
 Food Hygiene.
 Vacccine- 6 months
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