culturemedia.pdf

culture media Prestented by, Pr. Namdeo Shinde Assistant Professor Department of Pharmaceutics, Satara College of Pharmacy, Satara- 415004 India 1  CULTUR...

culture media Prestented by, Pr. Namdeo Shinde Assistant Professor Department of Pharmaceutics, Satara College of Pharmacy, Satara- 415004 India 1  CULTURE AND THE MEDIUM CULTURE : Is the term given to microorganisms that are cultivated in the lab for the purpose of identifying and studying them. MEDIUM: Is the term given to the combination of ingredients that will support the growth and cultivation of microorganisms by providing all the essential nutrients required for the growth (i.e. multiplication) in order to cultivate these microorganisms in large number to study them. 2 The food material or substances required for growing microorganisms in vitro (outside the body) is called culture medium. Reasons for bacterial cultural: -subsequent clinical diagnosis. -studying its morphology and its identification. -Bacteria have to be cultured in order to obtain antigens from developing serological assay for vaccines. -Certain genetic studies and manipulations of the cells also need that bacteria be cultured in vitro. -Culturing on solid media is another convenient way of separating bacteria in mixture 9/20/2024 3  Microbiological culture: which are used for growing microorganisms, such as bacteria or yeast. The most common growth media for microorganisms are nutrient broths and agar plates Specialized media are sometimes required for microorganism and cell culture growth. 4  CULTURE MEDIA Used to grow bacteria Can be used to-  Enrich the numbers of bacteria.  Select for certain bacteria and suppress others.  Differentiate among different kinds of bacteria. 5  NEED FOR CULTURE MEDIA It is usually essential to obtain a culture by growing the organism in an artificial medium. If more than one species or type of organism are present each requires to be carefully separated or isolated in pure culture. 9/20/2024 6  BASIC REQUIREMENTS OF CULTURE MEDIA NUTRIENTS :  Energy source -Phototrophs-light-Rhodospirillum rubrum -Chemotrophs- chemical energy- E. Coli  Carbon source:CO2, organic complounds  Nitrogen source- atm./nitrate,nitrite MINERAL SALTS :  Sulphates, phosphates, chlorides and carbonates of K, Mg and Ca  A suitable pH- 7.2- 7.4 7  BACTERIAL GROWTH FACTORS ARGININE E.COLI GLUTATHIONE GONOCOCCI CHOLESTEROL MYCOPLASMA ARYL SULPHATE, AMIDE ATYPICAL MYCOBACTERIA GLYCEROL MYCOPLASMA HOMINIS SULFONAMIDES RIKETTSIA TRYPTOPHAN SALMONELLA TYPHI L-CYSTEINE LISTERIA MONOCYTOGENS SODIUM CHLORIDE VIBRIO PARAHAEMOLYTICUS FACTOR X & V H.INFLUENZAE 9/20/2024 8 9/20/2024 9 9/20/2024 10 9/20/2024 11  CLASSIFICATION BASED ON BASED ON BASED ON PHYSICAL STATE PRESENCE OF NUTRITIONAL MOLECULAR FACTORS OXYGEN AND REDUCING SUBSTANCES LIQUID MEDIA AEROBIC MEDIA SIMPLE MEDIA SEMISOLID MEDIA ANAEROBIC MEDIA COMPLEX MEDIA SOLID MEDIA SYNTHETIC MEDIA SPECIAL MEDIA 12  SPECIAL MEDIA A. ENRICHED MEDIA B. ENRICHMENT MEDIA C. SELECTIVE MEDIA D. DIFFERENTIAL MEDIA E. INDICATOR MEDIA F. TRANSPORT MEDIA G. SUGAR MEDIA 13  SIMPLE MEDIA Simple or basal media are culture media which contain the minimum adequate nutrition for non fastidious organisms Fastidious organisms: Only grow when specific nutrients are included in its diet. Example:- Nutrient broth/agar Peptone water Composition:- Lab-Lemco -10gm peptone-10gm NaCl- 5gm Distilled water-1000ml - When 2-3% agar is added ,then we have it as nutrient agar. - For semisolid media – agar concentration is 0.2-0.4% Uses:- 1. This is basis of most of the media used in the study at common pathogenic bacteria. 2. It is used for subcultures of certain organisms. 9/20/2024 15  NUTRIENT AGAR NUTRIENT BROTH SOLID SEMISOLID LIQUID MEDIA  PEPTONE WATER TYPE : Basic liquid media APPEARANCE : clear, colorless, watery, usually in test tube Composition : PEPTONE 10 g SODIUM CHLORIDE, NaCl 5g WATER 1 litre 17  USES OF PEPTONE WATER: The media is used chiefly as the basis for carbohydrate fermentation media. NUTRIENT BROTHS : may contain a small amount of sugar derived from meat and it is essential that the basal medium to which various carbohydrates are added for fermentation tests should be free from natural sugars. 9/20/2024 18  NUTRIENT BROTHS : It is also used to test the formation of indole. Culture of organisms for demonstration of motility 9/20/2024 19  COMPLEX MEDIA Complex media have added ingredients for bringing out certain properties or providing special nutrients required for growth of the bacteria. SYNTHETIC MEDIA  These are prepared from pure chemicals and the exact compositions of medium is very well known. Example :- Dubo’s medium SEMIDEFINED MEDIA  In these media the exact chemical composition of the constituents is not known because substances like meat and peptone are used.  Most of the culture media used for routine diagnostic work are semidefined culture media.  SPECIAL MEDIUM ENRICHED MEDIA  When basal medium is added with some nutrients such as blood, serum or egg is called enriched media.  They are used to grow bacteria which are more exacting in their nutritional needs. Examples:- Dorset’s Egg Medium.  It is a creamy coloured opaque slope kept in screw copped bottle  Selective medium for isolation of Mycobacterium tuberculosis.  Composition: Hen’s egg, Nutrient broth  BLOOD AGAR TYPE : Enriched media. APPEARANCE : Red color. COMPOSITION : Sterile Nutrient agar + Defibrinated sheep blood USES :  Routine culture  Widely used in medical bacteriology  It is also an indicator medium showing the haemolytic properties of bacteria such as Streptococcus pyogenes. 22  CHOCOLATE AGAR Also called Heated blood agar. TYPE : Enriched media. APPEARANCE : Chocolate brown color. PROCEDURE: Melt the desired amount of nutrient agar. Cool it in a water – bath at 75º C. Add 10 ml of sterile blood. Allow the medium to remain at 75º C. Mixing the blood and agar by gentle agitation from time to time until the blood become chocolate brown in color, within about 10 min. Then pour in plates.  USES: CULTURE OF Neisseria , Haemophilus influenzae, Pneumococcus 23  ENRICHMENT MEDIA  In this media, it has a stimulating effect on the bacteria to be grown or inhibits its competitors.  This result in an absolute increase in the number of wanted bacteria related to other bacteria.  Example:- Selenite F broth  It is enrichment medium for culture of Salmonella typhi and paratyphi bacilli from stool sample  Principle:-  At neutral pH solution acid salinity has high toxicity to coli form group of bacteria and not to most of the salmonella groups. SELENITE F BROTH Alkaline peptone water  SELECTIVE MEDIA  It is a medium in which certain substances are present which inhibit all other bacteria except the desired bacteria.  It encourages the growth of particular species from a mixed inoculum. Example:- TCBS -It is light green translucent medium kept in petridish -It is selective medium for Vibrio cholera -Principle:- Bile salt inhibit the growth of normal commensals (unwanted bacteria).  Vibrio chloerae produce acid by fermentation of sucrose which acts on bromothymol blue (indicator) producing yellow colonies. Salmonella Shigella Agar with DCA Salmonella-Shigella agar plate (SS)  DIFFERENTIAL MEDIA MAC CONKEY AGAR MacConkey agar is a culture medium designed to grow Gram-negative bacteria. It is a useful medium for the cultivation of enterobacteriacea. It shows lactose fermenter as red colonies while non-lactose fermentor as white/pale colonies. 28 MacConkey agar showing both lactose and non- lactose fermenting colonies. Lactose fermenting colonies are pink whereas non- lactose fermenting ones are colourless or appear same as the medium. 29  Gram-negative bacteria growing on the media are differentiated by their ability to ferment the sugar lactose. Lactose fermenter cause the pH to drop and is detected by neutral red, (red at pH's below 6.8.) which appear as bright pink to red colonies on the agar. 30  Uses Acting as a visual pH indicator, the agar distinguishes those Gram-negative bacteria that can ferment the sugar lactose (Lac+) from those that cannot (Lac-). This medium is also known as an "indicator medium" "low selective medium". Absence of electrolytes serves to inhibit swarming by Proteus species 31  Lac+ By utilizing the lactose available in the medium, Lac+ bacteria such as Escherichia coli Enterobacter spp. Klebsiella spp. will produce acid, which lowers the pH of the agar below 6.8 and results in the appearance of red/pink colonies 32  CLED (Cystine Lactose Electrolyte Deficient medium) It is a valuable non-inhibitory growth medium used in the isolation and differentiation of urinary organisms. Being electrolyte deficient, it prevents the swarming of Proteus species 33 Description: Lactose & non lactose fermenters on CLED medium. 34  INDICATOR MEDIUM  These media contain an indicator which changes colour when bacteria grow on them.  Example:- Wilson and Blair medium  For isolation of Salmonella typhi and S. paratyphi  They appear as black colonies  Principle:- The black colour of colonies is due to the ability of these organisms to reduce bismuth sulphite to sulphide in the presence of glucose coliforms are inhibited by brilliant green and bismuth sullphite  TRANSPORT MEDIUM These are used for the temporary storage of specimens being transported to the laboratory for cultivation. Such media ideally maintain the viability of all organisms in the specimen without altering their concentration. Transport media typically contain only buffers and salt. The lack of carbon, nitrogen, and organic growth factors prevents microbial multiplication. Transport media used in the isolation of anaerobes STUART TRANSPORT BROTH must be free of molecular oxygen.  CHARACTERISTICS OF TRANSPORT MEDIA: It should be non-toxic It should not promote or inhibit the bacterial growth It should be easy to carry and transport Examples: 1. Venkatraman Ramakrishnan medium 2. Buffered glycerol saline transport medium 3. Cary and Blair medium Cary and Blair medium  ANAEROBIC MEDIUM These media are used to grow anaerobic organisms. Examples:-  Thioglycollate broth  Robertsons Cooked Meat Medium  Mueller-Hinton agar Mueller-Hinton agar is an microbiological growth medium that is commonly used for antibiotic susceptibility testing. Originally formulated for isolation of Neisseria species. It is also used to isolate and maintain Neisseria and Moraxella species. 39 9/20/2024 40 9/20/2024 41 9/20/2024 42 9/20/2024 43 9/20/2024 44 9/20/2024 45 9/20/2024 46