Plate count agar pdf
Please forward this plate count agar pdf screen to 208. Salmonella and Shigella from patient specimens.
The definitive use of HEK is to discriminate between Shigella and Salmonella, although many other species may grow on these plates. However, while the other bacteria may be clinically relevant, the assay does not discriminate among them. Effectively, HEK uses a metabolic assay to divide colonies into “Salmonella and Shigella” and “everything else”. Shigella or Salmonella, but the medium also includes peptone which can be used as a carbon source. Few sulfur-reducing bacteria exist other than Salmonella, which can be isolated from the intestines.
Most of these are inhibited on HEK plates by the inclusion of bile salts, so encountering a black colony that is not Salmonella is unusual, although not unheard of. Comparison of brilliant green agar and Hektoen enteric agar media in the isolation of salmonellae from food products”. Diagnostic and public health dilemma of lactose-fermenting Salmonella enterica serotype Typhimurium in cattle in the Northeastern United States”. This page was last edited on 25 November 2017, at 17:36. An agar plate is a Petri dish that contains a solid growth medium, typically agar plus nutrients, used to culture small organisms such as microorganisms.
Several methods are available to plate out cells. One technique is known as “streaking”. Another way of plating organisms, next to streaking, on agar plates is the spot analysis. A third used technique is the use of sterile glass beads to plate out cells. In this technique cells are grown in a liquid culture of which a small volume is pipetted on the agar plate and then spread out with the beads. In 1881, Fanny Hesse, who was working as a technician for her husband Walther Hesse in the laboratory of Robert Koch, suggested agar as an effective setting agent, since it had been commonplace in jam making for some time. Agar plates may be formulated as either permissive, with the intent of allowing the growth of whatever organisms are present, or restrictive or selective, with the intent of only allowing growth a particular subset of those organisms.