Modified agar medium for detecting environmental salmonellae by the most-probable-number method
| Autor: | D Hussong, Nancy K. Enkiri, W D Burge |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Salmonella
food.ingredient Xylose medicine.disease_cause Applied Microbiology and Biotechnology complex mixtures Microbiology Agar plate chemistry.chemical_compound food Most probable number Sewage sludge compost medicine Agar Food science Tetrathionic Acid Bacteriological Techniques Ecology biology Lysine biology.organism_classification equipment and supplies Culture Media Quaternary Ammonium Compounds chemistry Brilliant green Bacteria Food Science Biotechnology Research Article |
| Zdroj: | Applied and environmental microbiology. 48(5) |
| ISSN: | 0099-2240 |
| Popis: | Salmonellae in the environment remain a potential source of disease. Low numbers of salmonellae have been detected and enumerated from environmental samples by most-probable-number methods which require careful colony selection from a plated agar medium. A modified xylose lysine brilliant green medium was prepared to control the loss of selectivity caused by heating the brilliant green component. Added agar reduced colony spreading. The medium contained 47 g of xylose lysine agar base per liter; the agar content was adjusted to 2%, autoclaved, cooled to 50 degrees C, and then amended just before pouring to include H2S indicator and 7 ppm (7 ml of 1:1,000 brilliant green per liter) of unheated brilliant green dye. H2S-positive salmonellae were easily detected from sewage sludge compost to the exclusion of most other gram-negative bacteria. As a result, fewer non-salmonellae were picked for further most-probable-number analysis, greatly reducing the work load associated with the most-probable-number method. Direct plating was possible for enumerating salmonellae in laboratory composts containing ca. 10(3) or more salmonellae. |
| Databáze: | OpenAIRE |
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