Difco hektoen enteric agar selective isolation of enteric pathogens. Xylose lysine deoxycholate xld agar is a selective medium for the isolation of salmonella and shigella spp from clinical specimens and food samples. Under these conditions this medium has a shelf life of 7 weeks from the date of manufacture. Hektoen enteric agar is a selective as well as differential media for the isolation and differentiation of enteric pathogens from clinical specimens. Principles and explanation of the procedure microbiological method. Chocolate agar choc or chocolate blood agar cba is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. It improve d the detection of salmonella and shigella organisms compared to other enteric differentiating media. Macconkey agar is useful in isolating pathogens present in foods and coliforms in water samples. Hektoen enteric he agar is a medium that relies on the use of bile salts for selective inhibition and two indicator systems. Salmonellashigella agar detected 74 and 68%, respectively, and eosin methylene blue agar only 42 and 63%. Jul 06, 2011 hektoen enteric agar he is a selective and differential medium designed to isolate and differentiate members of the species salmonella and shigella from other enterobacteriaceae. Animal peptones and yeast extract provide the nutritive base. Hektoen enteric agar is a moderately selective medium used for the isolation and cultivation of gramnegative enteric microorganisms, especially shigella spp, from faeces, foodstuffs and other materials of sanitary importance.
The black or crystalloid colonies on the hektoen enteric he agar from stool samples were identified using the proposed method. Hektoen enteric agar hea has been widely used for this purpose since its. Hektoen enteric agar is formulated by king and metzger to isolate shigella and salmonella species. Jun 11, 2018 xylose lysine deoxycholate xld agar principle, uses, composition, preparation and colony characteristics. Hektoen enteric agar microbiology food and drug reference. Our hektoen enteric agar should be stored away from direct light at 4 to 8 c with the medium side uppermost to prevent excessive accumulation of moisture on the agar surface. Which ingredients in the hektoen enteric agar supply. Hektoen enteric agar, isolation techniques and selective media, a photographic atlas for the microbiology laboratory, purpose hektoen enteric he agar is used to isolate and differentiate salmonella and shigella species from other gramnegative enteric organisms. Hektoen enteric agar intended use hektoen enteric agar is a selective medium for the isolation and differentiation of pathogenic enterobacteria from biological samples of animal origin, water samples, dairy products and other food products. Comparison of brilliant green agar and hektoen enteric. Principle of xylose lysine deoxycholate agar xld agar. It is one of the earliest methods used to cultivate and identify enteric organisms. Principle and interpretation media that isolated a broader spectrum of enteric pathogens are less inhibitory to members of the nonpathogenic intestinal flora. The medium is particularly suited for the culture of shigella, and prevents invasion by proteus.
This chapter discusses that hektoee enteric he agar relies on the use of bile salts for selective inhibition and two indicator systems. The medium was introduced in 1968 by sylvia king and william i. Hektoen enteric agar he is for the selective isolation and differentiation of pathogenic gram negative enteric bacteria, such as the nonlactose fermenting salmonella species and shigella species normal stool flora, such as edehydrated microbiology culture media cultivate and isolate microorganisms for researching purposes. Bacteria categorized as lactosefermenting form pink colonies and have a zone. Summary and explanation hektoen enteric he agar was developed by king and metzger to produce a medium simultaneously conducive to. Hektoen enteric agar for microbiology sigmaaldrich.
The additional carbohydrates sucrose and salicin give better differentiation than lactose alone and the lower. The selective nature of bd bbl hektoen enteric agar is due to the incorporation of bile salts in the formulation. Hektoen enteric agar was originally developed by king and metzger 1, 2. Hektoen enteric he agar is a medium for the isolation of shigella and salmonella. It relies on the use of bile salts for selective inhibition and two indicator systems. King and metzger developed he agar in an effort to increase the recovery of salmonella and shigella species over the previously formulated salmonellashigella ss agar. Hektoen enteric he agar was introduced in 1968 by sylvia king and william i. Remel hektoen enteric he agar is a solid medium recommended for use in qualitative procedures for the isolation and differentiation of gramnegative enteric pathogens. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Without the help of any equipments, such as microscope, the red band corresponding salmonella could be visually detected.
The high content of carbohydrate and peptone in the medium neutralise the inhibitory effects of the bile salts and. Bd hektoen enteric agar is a moderately selective and differential medium for the isolation and cultivation of gramnegative enteric microorganisms, especially. Macconkey agar composition, principle, uses, preparation and colony morphology. Xylose lysine deoxycholate xld agar principle, uses. The high peptone content offsets the inhibitory effect of bile salts on shigella species in particular. Macconkey agar is a selective and differential media used for the isolation and differentiation of nonfastidious gramnegative rods, particularly members of the family enterobacteriaceae and the. Comparison of chromagar salmonella medium and hektoen. Culture media notes page 3 of 7 online microbiology notes. They formulated he agar medium while working at the hektoen institute in chicago, to increase the recovery salmonella and shigella from clinical specimens. Food and drug administration 10903 new hampshire avenue silver spring, md 20993 1888infofda 18884636332 contact fda. Weber scientific 2732 kuser road hamilton, nj 08691.
It is a selective medium for the isolation of salmonella and shigella spp from clinical specimens and food samples. Macconkey agar composition, principle, uses, preparation and. Hello fellow wikipedians, i have just modified one external link on hektoen enteric agar. Brilliant green bg agar and hektoen enteric he agar media were compared for their efficiency in isolating salmonellae from various food products. Xld agar was originally formulated by taylor for the isolation and identification of shigella from stool specimens the pathogens are differentiated not only from the nonpathogenic lactose fermenters but also from many non. Hektoen enteric agar he is for the selective isolation and differentiation of pathogenic gram negative enteric bacteria, such as the nonlactose fermenting salmonella spp. Jun 11, 2018 macconkey agar composition, principle, uses, preparation and colony morphology.
Apr 14, 2018 xld agar principle xylose lysine deoxycholate agar sugars xylose, lactose and sucrose provide sources of fermentable carbohydrates, xylose is mainly incorporated into the medium since it is not. Thermo scientific remel he agar hektoen enteric agar facilitates isolation and differentiation of gramnegative enteric microorganisms. Hektoen enteric agar was developed in 1967 by king and metzger of the hektoen institute in order to increase the. Principle and interpretation hektoen enteric agar, a selective and differential medium designed to isolate and differentiate members of the species salmonella and shigella from other enterobacteriaceae and was developed by king and metzger 1,2. Apr 14, 2018 chocolate agar choc or chocolate blood agar cba is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. Summary and explanation through the years many media have been devised for the isolation of enteric pathogens. Hektoen enteric he agar for stool cultures for the. Hektoen enteric he agar is a modrately selective medium used in qualitative procedures for the isolation and cultivation of gramnegative enteric microorganisms, especially shigella, from a variety of clinical and nonclinical specimens.
Hektoen enteric agar he is a differential and selective plating medium for culture of enteric pathogens. Rapid identification of salmonella using hektoen enteric. The presence of the bile salts and dyes inhibit most grampositive organisms allowing only gramnegative rods to grow on he agar. Hea contains indicators of lactose fermentation and hydrogen sulfide production. Macconkey agar composition, principle, uses, preparation. Other notes plating medium for the isolation of enteric pathogens. Hektoen enteric agar is a selective and differential media for the isolation and differentiation of enteric pathogens from clinical specimens. Hektoen enteric agar he is a selective and differential medium designed to isolate and differentiate members of the species salmonella and shigella from other. When compared with other selective medium, this medium inhibits the growth of salmonella andshigellavery slightly. Hektoen enteric he agar is a medium that relies on the use. Hektoen enteric agar culture media online microbiology notes. Hektoen enteric agar is a type of primary standard media, which may be commonly used in the selective detection and isolation of salmonella in food microbiology labs and in human stool specimens.
Macconkey agar is a modified neutral red bile salt agar by alfred theodore macconkey. Hektoen enteric agar hektoen enteric agar is a selective and differential medium designed to isolate and differentiate members of the species salmonella and shigella from other enterobacteriaceae. Hektoen enteric he agar is a medium that relies on the use of. Bile salts and the dyes bromthymol blue and acid fuchsin inihibit the growth of most gram positive organisms. An effort to develop a medium which would be conducive to growth of shigellae and inhibitory to normal intestinal flora was reported by king and metzger. Principle of xylose lysine deoxycholate agar xld agar ii. Hektoen enteric agar is a selective and differential medium designed to isolate and differentiate members of the species salmonella and shigella from other enterobacteriaceae.
Hardy diagnostics hektoen enteric he agar is a selective and differential medium used for the isolation and differentiation of gramnegative enteric pathogens. Cystinelactoseelectrolytedeficient cled medium, first described by sandys and later modified by mackey and sandys, is generally used for diagnostic routine urinary bacteriology as a nonselective medium capable of supporting the growth of most urinary pathogens. Lactose, sucrose, and salicin provide fermentable carbohydrates to encourage the growth and differentiation of enterics. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple faq for additional information. Which ingredients in the hektoen enteric agar supply carbon. Of the 11,226 food specimens examined, 1,662 or 14. It is a variant of the blood agar plate, containing red blood cells that have been lysed by slowly heating to 80 c giving the medium a chocolate brown color reason why it is called chocolate agar. Hektoen enteric agar he is a selective and differential medium designed to isolate and differentiate members of the species salmonella and shigella from other enterobacteriaceae. The selective and differential aspects of this complex medium are due to presence of the dyes acid fuchsin and bromthymol blue, the sugars lactose, sucrose and salicin, and the compounds sodium thiosulfate and ferric ammonium citrate and bile salts. Optically clear polystyrene for distortion free viewing.
Comparison of brilliant green agar and hektoen enteric agar. Microbiology hektoen enteric agar free medical atlas. Bd hektoen enteric agar is a moderately selective and differential medium for the isolation. Hektoen enteric he agar was developed by king and metzger to simultaneously grow salmonella and shigella and inhibit normal intestinal flora. Hektoen enteric agar, media microbiological for selective.
Hektoen enteric agar, a selective and differential medium designed to isolate and differentiate members of the species. Hektoen enteric agar, a selective and differential medium designed to isolate and differentiate members of the species salmonellaandshigella from other enterobacteriaceae and was developed by king and metzger 1,2. Macconkey agar plate, purpose, ingredients and principle. The high concentration of bile salts partially or fully. Hektoen enteric agar hek, he or hea is a selective and differential agar primarily used to recover salmonella and shigella from patient specimens. Hektoen enteric agar is a selective and differential bacterial media used for salmonell spp. Hektoen enteric agar is currently used as direct and indirect plating medium to recover gastrointestinal pathogens, such as salmonella and. Macconkey agar is a selective and differential media used for the isolation and differentiation of nonfastidious gramnegative rods, particularly members of the family enterobacteriaceae and the genus pseudomonas. The incorporation of larger quantities of peptone to counteract the. Bd hektoen enteric agar he agar intended use bd hektoen enteric agar is a moderately selective and differential medium for the isolation and cultivation of gramnegative enteric microorganisms, especially for the isolation of shigella and salmonella species from fecal specimens. Sucrose, lactose, and salicin are added to help differentiate pathogens. Principle meat peptone supplies essential nutrients to support bacterial growth. The numbers of false positives accruing to each medium, however, showed hektoen enteric and salmonellashigella agars to produce more than twice as many falsepositive plates as xld.
774 273 1503 451 63 963 310 1457 333 1315 472 355 1104 1407 1390 1324 499 100 902 25 641 1208 917 1218 1409 672 1127 1226 943 1240 1345 454 445