A selective-differential medium is proposed for the preliminary recognition of Enterobacteriaceae from other Gramnegative bacteria direct.ly on the primary isolation plates. The modified medium, named MCPB, is constituted by a MacConkey agar base with 6-benzoyl-naphthyl-phosphate (as a substrate for the phosphatase activity), and a small amount of dextrose and aniline blue. On the MCPB medium all the enterobacteria and Xanthomonas maltophilia were phosphatase positive and developed red (lactose-negative), or violet (lactose-positive), colonies: all other Gram-negative bacteria formed colourless colonies. Therefore, it is possible to recognize enterobacteria from non-enteric bacteria on the basis of the growth colour and correctly choose the identification kit (either for enterobacteria or for non-enteric bacteria) without the aid of supplemental tests.
A modified MacConkey medium which allows the recognition of Enterobacteriaceae from other Gram-negative bacteria on primary culture plates / Raffaello, Pompei; Berlutti, Francesca; Maria C., Thaller; Angela, Ingianni; Giuseppe, Satta. - In: JOURNAL OF MICROBIOLOGICAL METHODS. - ISSN 0167-7012. - STAMPA. - 25:3(1996), pp. 271-278. [10.1016/0167-7012(95)00101-8]
A modified MacConkey medium which allows the recognition of Enterobacteriaceae from other Gram-negative bacteria on primary culture plates
BERLUTTI, Francesca;
1996
Abstract
A selective-differential medium is proposed for the preliminary recognition of Enterobacteriaceae from other Gramnegative bacteria direct.ly on the primary isolation plates. The modified medium, named MCPB, is constituted by a MacConkey agar base with 6-benzoyl-naphthyl-phosphate (as a substrate for the phosphatase activity), and a small amount of dextrose and aniline blue. On the MCPB medium all the enterobacteria and Xanthomonas maltophilia were phosphatase positive and developed red (lactose-negative), or violet (lactose-positive), colonies: all other Gram-negative bacteria formed colourless colonies. Therefore, it is possible to recognize enterobacteria from non-enteric bacteria on the basis of the growth colour and correctly choose the identification kit (either for enterobacteria or for non-enteric bacteria) without the aid of supplemental tests.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.