Details

Autor(en) / Beteiligte

• Ahmed, N.M. (Univ. of Arkansas, Fayetteville, AR.)
• Conner, D.E

Titel

Evaluation of various media for recovery of thermally-injured Escherichia coli O157:H7

Ist Teil von

• Journal of food protection, 1995-04, Vol.58 (4), p.357-360

Ort / Verlag

Des Moines, IA: International Association of Milk, Food and Environmental Sanitarians

Erscheinungsjahr

1995

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Efficacies of plating media for recovering heated Escherichia coli O157:H7 were determined and compared. To compare populations of recovered cells, suspensions of cells (three isolates, four replications/isolate) were heated at 50, 55, or 60 degrees C, and then inoculated onto eight media: PCA-PA (plate count agar with 1% pyruvic acid [PA]), MSA (MacConkey sorbitol agar), MSA-Mg (MSA with 0.025% MgSO4), MSA-PA (MSA with 1% PA), MSA-MUG (MSA with 0.005% 4-methylumbelliferyl-beta-d-glucuronide (MUG), PRSA-MUG (phenol red sorbitol agar [PSRA] with 0.005% MUG), PRSA-PA (PRSA with 1% PA), and TSAPA (tryptic soy agar with 1% PA). Recovery was consistently higher (P 0.05) with PRSA-MUG and PRSA-PA. At 50, 55, and 60 degrees C, mean numbers (log10 CFU/ml) of recovered cells on PRSA-MUG were 4.42, 4.62, and 3.32, respectively, as compared to 2.78, 2.08, and 1.63, respectively, on MSA. PCA-PA and TSAPA were less effective than PRSA media, but better than MSA media. Thus, PRSA with MUG or PA was an effective medium for recovering heated cells of E. coli O157:H7; whereas MSA failed to detect sublethally injured cells. Furthermore, addition of Mg, PA, or MUG to MSA further compromised this medium