Table 2

Percentages of bacterial spore recovery after filtration steps

Sample% spore recovery after:
PrefiltrationaCapture filtration onlybDARE procedurec
Control (no sample)975956
Baking powder787654
Baking soda935649
Bentonite467016
Cement766541
Chalk706333
Coffee559449
Cornstarch897564
Dust787452
Flour
    All purpose897463
    Whole wheat737346
Laundry detergent876451
Milk powder (skim)1025052
Nondairy creamer824022
Plaster665521
Probiotics937760
Salt (NaCl)876350
Silica915748
Soil1034952
Sugar
    Granulated1007676
    Powdered1057681
Talcum627537
Tea978380
Tobacco898675
Avg ± SD84 ± 1668 ± 1351 ± 17
  • a With a 5-μm-pore-size Millex-SV filter.

  • b With a 0.45-μm-pore-size Millex-HV filter; calculated as 100% − (% recovery after prefiltration − % recovery after the DARE procedure).

  • c With 5-μm- and 0.45-μm-pore-size Millex filters.