1. SHIGELLA

2. IT IS NAMED AFTER SHIGA ,WHO FIRST ISOLATED IT

3. IT IS A MEMBER OF ENTEROBACTERIACEAE
IN ENTEROBACTERIACEAE THERE ARE FOUR TRIBES
IT BELONGS TO TRIBE ESCHERICHIAE

4. DYSENTERY IS A CLINIC CONDITION OF MULTIPLE ORIGIN
IT IS CHARACTERIZED BY THE FREQUENT PASSAGE OF BLOODSTAINED,MUCOPURULENT STOOLS
TWO COMMON TYPES OF DYSENTERY ARE PRESENT
1. AMEBIC
2. BACILLARY

5. THE CASATIVE AGENTS OF BACILLARY DYSENTERY BELONG TO THE GENUS SHIGELLA
THE OTHER BACILLI WHICH ALSO PRODUCE THE CLINICAL PICTURE OF DYSENTERY ARE
EIEC
VIBRIO PARAHAEMOLYTIUS
CAMPYLOBACTER

6. MORPHOLOGY SHIGALLAE ARE SHORT ,GRAM-NEGATIVE RODS
THEY ARE NONMOTILE,NONSPORING AND NONCAPSULATED
FIMBRIAE MAY BE PRESENT

7. CULTURAL CHARACTERISTICS
THEY ARE AEROBES AND FACULTATIVE ANAEROBES
THEY GROW ON ORDINARY MEDIA
AFTER OVERNIGHT INCUBATION,COLONIES ARE SMALL,CIRCULAR,CONVEX,SMOOTH AND TRANSLUCENT

8. CONTD
COLONIES ON MACCONKEY AGAR ARE COLOURLESS DUE TO THE ABSENCE OF LACTOSE FERMENTATION
BUT Sh Sonnei FERMENTS LACTOSE AND FORMS PALE PINK COLONIES
SELECTIVE MEDIA-DCA

9. RESISTANCE SHIGALLE ARE NOT SPECIALLY RESISTANT
THEY ARE KILLED AT 56 C IN ONE HOUR
BY 1% PHENOL IN 30 MINUTES
IN FECES THEY DIE WITHIN A FEW HOURS DUE TO THE ACIDITY PRODUCED BY THE GROWTH OF COLIFORMS
Sh sonnei IS MORE RESISTANT THAN OTHER SHIGELLA SPECIES

10. BIOCHEMICAL REACTIONS
SHIGALLAE ARE MR POSITIVE
REDUCE NITRATES TO NITRITES
DO NOT FORM H2S
CATALASE IS PRODUCED, EXCEPT by sh dysenteriae Type 1

11. CONTD GLUCOSE IS FERMENTED WITH THE PRODUCTION OF ACID WITHOUT GAS
NEWCASTLE AND MANCHESTER BIOTYPES OF
Sh flexneri TYPE 6 AND SOME STRAINS OF Sh boydii FORMS GAS
BASED ON THE FERMENTATION OF MANNITOL SHIGELLAE ARE DIVIDED INTO MANNITOL FERMENTING AND NON FERMENTING SPECIES

13. ANTIGENIC STRUCTURE IT POSSESS SOMATIC O ANTIGENS
SOME STRAINS POSSESS K ANTIGENS
FIMBRIAL ANTIGENS ARE ALSO PRESENT