TABLE 3

Survival of NEO water-treated Y. enterocolitica, E. coli O157:H7, and S. Enteritidis populations after being exposed to additional temperature, NaCl, bile salt, and pH stresses

Organism and NEO water concnFree chlorine concn (ppm)Count (log CFU/ml)a
NEO onlyNEO + tempNEO + NaClNEO + bile saltsNEO + pH
Y. enterocolitica
    008.68 ± 0.05 Aa8.66 ± 0.02 Aa8.68 ± 0.03 Aa8.67 ± 0.02 Aa8.67 ± 0.04 Aa
    31.88.67 ± 0.01 Aa8.65 ± 0.05 Aa8.69 ± 0.02 Aa7.79 ± 0.02 Bb8.63 ± 0.03Aa
    63.58.57 ± 0.04 Aa6.98 ± 0.17 Cb8.14 ± 0.01 Bb6.78 ± 0.06 Cc8.47 ± 0.05 Aa
    105.97.39 ± 0.05 Ab4.86 ± 0.23 Dc6.70 ± 0.07 Bc5.69 ± 0.19 Cd7.13 ± 0.22 ABb
    158.96.07 ± 0.16 Ac3.60 ± 0.31 Cd5.66 ± 0.08 Ad4.61 ± 0.10 Be6.01 ± 0.04 Ac
    2514.84.12 ± 0.09 AdND Ce3.20 ± 0.49 Be2.68 ± 0.26 Bf3.45 ± 0.26 ABd
E. coli O157:H7
    008.76 ± 0.01 Aa8.75 ± 0.02 Aa8.74 ± 0.02 Aa8.73 ± 0.04 Aa8.75 ± 0.02 Aa
    31.88.73 ± 0.03 Aa8.56 ± 0.03 Bb8.72 ± 0.02 Aa8.65 ± 0.02 ABa8.68 ± 0.03 Aa
    63.58.00 ± 0.05 Ab5.01 ± 0.19 Bc7.96 ± 0.11 Ab7.71 ± 0.07 Ab7.89 ± 0.05 Ab
    105.97.12 ± 0.07 AcND Dd7.10 ± 0.03 Ac6.76 ± 0.03 Cc6.90 ± 0.02 Bc
    158.94.97 ± 0.13 AdND Cd3.69 ± 0.27 Bd4.00 ± 0.24 Bd4.74 ± 0.10 Ad
    2514.83.02 ± 0.00 AeND BdND BeND BeND Be
S. Enteritidis
    008.53 ± 0.03 Aa8.50 ± 0.04 Aa8.52 ± 0.03 Aa8.50 ± 0.04 Aa8.52 ± 0.04 Aa
    31.88.49 ± 0.03 Aa8.01 ± 0.04 Bb8.46 ± 0.04 Aa8.50 ± 0.03 Aa8.02 ± 0.11 Bb
    63.57.67 ± 0.10 Ab7.11 ± 0.04 Bc6.98 ± 0.07 Bb6.18 ± 0.07 Db6.51 ± 0.04 Cc
    105.95.87 ± 0.15 Ac3.39 ± 0.24 Dd5.40 ± 0.11 ABc4.56 ± 0.05 Cc5.08 ± 0.21 BCd
    158.93.44 ± 0.37 AdND Ce2.75 ± 0.19 BdND Cd2.81 ± 0.16 ABe
    2514.8ND eND eND eND dND f
  • a The limit of enumeration was 1.62 CFU/ml. Different capitalized letters within each row represent significant differences when comparing the numbers with each other in the same row, while the different lowercase letters represent significant differences within a column (P < 0.05). ND, the surviving cell numbers were below the limit of enumeration.