Food Protection Trends - November/December 2020 - 392

PEER-REVIEWED ARTICLE
Food Protection Trends, Vol 40, No. 6, p. 392-401
Copyright© 2020, International Association for Food Protection
2900 100th Street, Suite 309, Des Moines, IA 50322-3855

Rebecca M. Goulter,1* James S. Clayton,2
Robin Grant Moore,1 Justin M. Bradshaw,1a
Jason W. Frye,1 Esa J. Puntch1 and Lee-Ann Jaykus1
Dept. of Food, Bioprocessing and Nutrition Sciences, North Carolina State
University, Raleigh, NC 27603, USA
PDI Inc., 400 Chestnut Ridge Road, Woodcliff Lake, NJ 07677, USA
a
Current Affiliation: Johnston Community College, Smithfield, NC 27577, USA
1

Characterizing Microbial Cross-Contamination
on Large Surfaces Using a Traditional
"Cloth and Bucket" Disinfection Method
ABSTRACT
Use of buckets containing soiled disinfectant solutions
for disinfection is regularly practiced in food service
and other settings. This study characterized microbial
transfer of vegetative bacteria (Listeria innocua and
Escherichia coli), spores (Bacillus cereus), and a virus
(MS2 bacteriophage), to large surfaces, using a "cloth
and bucket" method with a commonly used quaternaryammonium compound (QAC) disinfectant (with or without
5% soil) and a phosphate-buffered-saline (PBS) control.
We also characterized concentrations of organisms in
the bucket solutions after wiping. With disinfectant (with
or without soil), there was little transfer of vegetative
bacteria. Transfer occurred readily with the PBS control
(4.8 ± 1.0 and 3.3 ± 0.9 log CFU/surface for Listeria
innocua and Escherichia coli, respectively). Spores were
transferred efficiently, regardless of whether PBS or
QAC was used or whether test was with or without soil
(range, 6.5 to 7.8 log CFU/surface). MS2 bacteriophage
appeared to be eliminated relatively quickly. When the QAC
did not inactivate the organism (regardless of soil load),

high microbial loads (> 87.9% of initial inoculum) were
detected in the bucket solution after wiping experiments.
This study suggests that reusable cloth can potentially
promote contamination of surfaces, sometimes in the
presence of disinfectant. This is concerning for food
service and other settings in which disinfection practices
rely on the cloth and bucket system.

INTRODUCTION
Continuous use of buckets containing soiled water
or disinfectant solutions for disinfection of surfaces is a
regular practice in food service establishments, schools,
and many other settings. It is not uncommon to use a single
sponge or cloth multiple times over a day or a shift to clean
environmental surfaces. However, little is known about the
safety of this practice, except that, microbiologically speaking,
it would be expected to be hazardous because of concerns
about consistent risk for cross-contamination.
There have been many studies to characterize the transfer
of microbes among surfaces, hands, and foods but very few
attempting to quantify this phenomenon as a function of

*Author for correspondence: Phone: +1 919.515.3019; Fax: +1.919.5157124; Email: rebecca_goulter@ncsu.edu

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