CULTURE OF SHIGELLA DYSENTERIAE ON BLOOD AGAR MEDIUM no hemolysis occurs on blood agar medium, the colonies are grayish-white and grows well. In Blood Agar medium, the Shigella dysenteriae shows gamma hemolysis i.e. In liquid culture media like Trypticase soy broth or Nutrient broth, the growth of the bacterium occurs as turbidity in the broth medium but the chances of contamination are high especially when the isolation is carried out from Feces specimen, commonly the Selenite F broth and Tetrathionate broth is used for the isolation of Shigella dysenteriae. PREPARATION OF MACCONKEY AGAR MEDIUM (MAC) IN LABORATORY Xylose Lysine Deoxycholate Agar (XLD) MediumĬheck out the preparation of MacConkey Agar medium in Laboratory Bile salts, Brilliant green dye, Sodium citrate & Sodium thiosulfate which selectively inhibit the growth of many gram-positive bacteria & coliform bacteria and supports the growth of Salmonella & Shigella sp.ĬULTURE CHARACTERISTICS OF SHIGELLA DYSENTERIAE (Sh. contains 4 key components that make it selective for Salmonella & Shigella i.e. ⇒ Similarly, the Salmonella – Shigella Agar medium is also a selective medium for Shigella dysenteriae & other species of Shigella as well as Salmonella spp. contains Deoxycholate and Citrate salts in a concentration that inhibits the growth of many gram-positive bacteria & most of the intestinal flora and supports the growth of Shigella dysenteriae. ⇒ The Deoxycholate Citrate Agar (DCA) medium is the Selective medium for Shigella dysenteriae & other Shigella Species as well as Salmonella Spp. MORPHOLOGY AND CULTURE CHARACTERISTICS OF SALMONELLA TYPHI (S. The Liquid medium (Trypticase Soy Broth, Nutrient broth, etc.)Ĭheck out the Morphology & Culture Characteristics of Salmonella typhi.Selenite F Broth ( Selective medium for Salmonella & Shigella).Xylose Lysine Deoxycholate (XLD) medium ( Selective medium for Salmonella & Shigella).Salmonella – Shigella Agar medium ( Selective medium for Salmonella & Shigella).Deoxycholate Citrate Agar (DCA) medium ( Selective medium for Salmonella & Shigella).
dysenteriae) in the laboratory and most commonly the MacConkey Agar medium, XLD medium and Selenite F broth medium is used which may vary as per the SOPs of the laboratory, the other media are as follows – ⇒ There are various culture media used for the cultivation of Shigella dysenteriae (Sh. grow best in the presence of oxygen and it is also a Facultative anaerobic organism i.e. dysenteriae) is an aerobic bacterium i.e. ⇒ Oxygen requirements – Shigella dysenteriae (Sh. Also, the pH requirement varies as per the strain of Escherichia col. dysenteriae cannot survive at acidic pH below 4.5, the maximum growth observed at 7.0 i.e. ⇒ Optimum temperature – Shigella dysenteriae ranges from 10–40☌ but the optimum temperature for most of the strains is 37☌ and usually cultivated at this temperature in laboratories. Commonly the MacConkey Agar medium & XLD medium is used for the cultivation of Shigella dysenteriae in the Laboratory. ⇒ Special requirements – Shigella dysenteriae have no complex nutritional requirements and readily grow in ordinary media like Nutrient Agar medium (NAM). MORPHOLOGY OF SHIGELLA DYSENTERIAE CULTURE REQUIREMENTS OF SHIGELLA DYSENTERIAE (Sh. Gram Staining Reaction – Shigella dysenteriae is a Gram -ve (Negative) bacterium.
dysenteriae is a Non-capsulated bacterium. Spores – The Shigella dysenteriae is a non–sporing bacterium.Ĭapsule – Sh. coli are non-motile.įlagella – Shigella dysenteriae is a non-flagellated bacterium. Motility – Shigella dysenteriae is a non-motile bacterium. Size – The size of Shigella dysenteriae is about 1–3 µm × 0.5 µm (micrometer).Īrrangement Of Cells – Shigella dysenteriae is arranged singly or in pairs. Shape – Shigella dysenteriae is a short, rod shape (bacillus) bacterium.