Lab 13 Bacterial cultivation Selective differential media Lab
![Lab 13 Bacterial cultivation Selective /differential media Lab 13 Bacterial cultivation Selective /differential media](https://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-1.jpg)
Lab 13 Bacterial cultivation Selective /differential media
![Lab activities: Demo selective and differentiation plates n Streaking bacteria on differentiation plates n Lab activities: Demo selective and differentiation plates n Streaking bacteria on differentiation plates n](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-2.jpg)
Lab activities: Demo selective and differentiation plates n Streaking bacteria on differentiation plates n
![Cultivation n The process of growing microorganisms in culture by taking bacteria from the Cultivation n The process of growing microorganisms in culture by taking bacteria from the](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-3.jpg)
Cultivation n The process of growing microorganisms in culture by taking bacteria from the infection site (in vivo or environment) and grow them in artificial environment in the laboratory (in vitro).
![Growth needs n Fastidious bacteria – relatively complex growth needs n Non-fastidious bacteria- relatively Growth needs n Fastidious bacteria – relatively complex growth needs n Non-fastidious bacteria- relatively](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-4.jpg)
Growth needs n Fastidious bacteria – relatively complex growth needs n Non-fastidious bacteria- relatively basic and straightforward growth needs
![Phases of growth media n Broth- Growth of bacteria will change the liquid from Phases of growth media n Broth- Growth of bacteria will change the liquid from](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-5.jpg)
Phases of growth media n Broth- Growth of bacteria will change the liquid from clear to turbid (cloudy). n Solid – Agar plates, slants – Bacterial cells inoculated on solid media will multiply enough to be seen by naked eye.
![Colony- (clone) n Colony- A bacterial population derived from one bacterial cell. The cells Colony- (clone) n Colony- A bacterial population derived from one bacterial cell. The cells](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-6.jpg)
Colony- (clone) n Colony- A bacterial population derived from one bacterial cell. The cells within the colony have identical, genus, species, genetic and phenotypic characteristics. n Pure bacteria - derived from a single colony. n Selection of a pure colony -most important for bacterial identification
![Media classification and function n Enrichment – Used to enhance growth of a particular Media classification and function n Enrichment – Used to enhance growth of a particular](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-7.jpg)
Media classification and function n Enrichment – Used to enhance growth of a particular pathogen n Supportive - support growth of most non fastidious bacteria
![Media classification and function n Selective - Contain inhibitory agents that are inhibitory to Media classification and function n Selective - Contain inhibitory agents that are inhibitory to](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-8.jpg)
Media classification and function n Selective - Contain inhibitory agents that are inhibitory to all organisms except those sought n Differential - Contain factors that allow bacterial species to manifest certain metabolic characteristics that distinguish them from other species. n Media can be both selective and differential based on the ingredients of the medium.
![Blood agar plate (BA) n Nutrient agar with 5% sheep blood n Cultivation of Blood agar plate (BA) n Nutrient agar with 5% sheep blood n Cultivation of](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-9.jpg)
Blood agar plate (BA) n Nutrient agar with 5% sheep blood n Cultivation of fastidious and non fastidious bacteria. n Differential – Identify hemolysis - Some bacteria secrete enzymes that lyse red blood cells (hemolysins) such that a clearing around the colony appears. ¨b hemolysis- complete clearing (white hemolysis) ¨a hemolysis – incomplete clearing (green hemolysis) ¨g hemolysis- no hemolysis
![](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-10.jpg)
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![Mannitol Salt Agar (MSA) n Both selective and differential medium. n High salt concentration Mannitol Salt Agar (MSA) n Both selective and differential medium. n High salt concentration](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-12.jpg)
Mannitol Salt Agar (MSA) n Both selective and differential medium. n High salt concentration - inhibits most bacteria. n Selective for Staphylococcus sp. n Differentiate between Staphylococcus sp. by the sugar mannitol fermentation. n Mannitol fermention produce acids that change the medium p. H. n n Peach color- neutral- no fermentation Bright yellow- Acidic – mannitol fermentation (Staph. coag. pos. - Staph. aureus)
![](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-13.jpg)
![Mac. Conkey Agar (MAC) n Selective and differential medium. n Selective - Gram positive Mac. Conkey Agar (MAC) n Selective and differential medium. n Selective - Gram positive](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-14.jpg)
Mac. Conkey Agar (MAC) n Selective and differential medium. n Selective - Gram positive bacteria are inhibited by the presence of bile salts and crystal violet inhibitors in the medium Most of gram negative bacteria will grow. n Differentiate- Between Gram negative bacteria by their ability to ferment lactose. n Pink colonies- Bacteria that ferment lactose (precipitation of some salts in media by acid production). n Pale colonies- Non fermenters
![](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-15.jpg)
![Eosine Methylene blue (EMB), n Differentiatial between lactose fermenting and non fermenting enteric bacteria Eosine Methylene blue (EMB), n Differentiatial between lactose fermenting and non fermenting enteric bacteria](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-16.jpg)
Eosine Methylene blue (EMB), n Differentiatial between lactose fermenting and non fermenting enteric bacteria
![Tellurite Glycine Agar (TGA) n Selective- Tellurite glycine and lithium inhibit most bacteria n Tellurite Glycine Agar (TGA) n Selective- Tellurite glycine and lithium inhibit most bacteria n](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-17.jpg)
Tellurite Glycine Agar (TGA) n Selective- Tellurite glycine and lithium inhibit most bacteria n Preferential growth of Staphyloccoci coagulase positive (Staphyloccocus aureus)
![Bacteria streaked in lab n n Staphylococcus aureus Staphylococcus epidermidis Salmonella pullorum, E. coli Bacteria streaked in lab n n Staphylococcus aureus Staphylococcus epidermidis Salmonella pullorum, E. coli](http://slidetodoc.com/presentation_image_h/b6b916e74554b2ef5756694cc05f2005/image-18.jpg)
Bacteria streaked in lab n n Staphylococcus aureus Staphylococcus epidermidis Salmonella pullorum, E. coli S. aureus S. pullurum S. epidermidis E. coli EMB and TGA
- Slides: 18