Table 2.

Detection of nonproteolytic C. botulinum types B, E, and F by quantitative PCR analysis in sous vide-processed products with a low inoculum level (2.0 log CFU/kg) after storage at 4 and 8°C until sell-by date and 7 days after sell-by date

Product no. (recommended shelf life in days)No. of PCR-positive samples/no. of samples analyzeda
Sell-by date1 wk after sell-by date
4°C8°C4°C8°C
1 (14)0/30/30/30/3
2 (30)3/3 (1.19 ± 0.61; E, B)2/3 (0.83; E)0/30/3
3 (21)0/30/30/31/3 (0.41; E, B)
4 (14)0/30/30/31/3 (1.16; B)
5 (10)3/3 (0.41; E, F)2/3 (0.60; E)0/30/3
6 (30)0/30/30/30/3
7 (9)1/3 (0.41; E)1/3 (0.41; E)0/30/3
8 (21)0/30/30/31/3 (0.74; E)
9 (21)2/3 (0.83; E)1/3 (0.41; E)0/30/3
10 (21)0/30/31/3 (0.41; E)0/3
11 (21)1/3 (0.41; E)0/31/3 (0.90; E, B)1/3 (0.90; B)
12 (21)0/30/32/3 (0.41; E)2/3 (0.72; B, E)
13 (21)0/30/30/30/3
14 (30)0/30/30/30/3
15 (21)3/3 (0.74; E)1/3 (0.74; F)0/30/3
16 (21)0/30/30/30/3
  • a Data in parentheses are mean MPN log CFU per kilogram in PCR-positive samples (standard deviation of the cell counts is reported if more than two parallel samples were positive) and the serotype(s) detected, in diminishing order.