Survival and Persistence of Pathogenic Bacteria on Kitchen Sponge and Microfiber Towel in Restaurant and Foodservice Operations

Abstract

This study aimed to evaluate and assess the survival and persistence of pathogenic microorganisms on the kitchen sponge and microfiber towel after cleaning and sanitation in food service settings. For each replicate, 18 sponges and 9 microfiber towels were inoculated with a low concentration (104 CFU/cm2) cocktail of Salmonella spp., E. coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus, and were allowed to dry for 1h in a biosafety cabinet to ensure sufficient attachment. The inoculated samples were held at room temperature for 20 days. Before inoculation, each sponge was cut into two parts to result in a piece of approximately 5 x 5 cm2, and the towel was cut into four parts to result in a piece of approximately 10 x 10 cm2. Two sponges and two microfiber towels for each sample were taken at time zero, and 6 h post-inoculation and washed either with sterile water or sanitizer solution; the solution was made following the manufacturer’s instruction. Next, the washed liquid and samples were plated at each sampling time and incubated at 35 °C for 24 h. The same procedures were repeated on days 1, 2, 3, 7, 10, 13, 16, and 19. Results indicated that pathogenic E. coli, Salmonella, and S. aureus survive and persist for up to 16 days on the sponge and up to 13 days on microfiber towels. Therefore, there is a potential risk of contamination of food and food contact surfaces when proper sanitation practices are not followed. The kitchen sponge and towels should be changed frequently. The sanitizer solution also needs to be changed after each use. The results of this study will provide valuable information about the risk posed by the cleaning tools used in foodservice operations. The outcomes of the study will increase awareness on basic hygiene practices and training needs for employees working in the food service operations, frequent change of cleaning tools, current foodservice practices, and potential cross-contamination from these tools.

Full text

INTRODUCTION
•Foodborne illness outbreaks continue to pose a high risk to public
health and cause economic problems in the United States (1).
•Pathogenic microorganisms can transfer through cross-contamination
from food to the surfaces and vice versa.
•Commercial restaurants use sponge and microfiber towels for cleaning
and sanitizing food contact surfaces (2).
•These cleaning tools can provide an ideal condition for the growth of
bacteria, and may become a vehicle of pathogen transmission to food
and surfaces if proper sanitizing is not performed (3).
•Approximately 79% of foodborne illness outbreaks occur due to
inappropriate food handling and preparation practices in restaurants,
including poor hand-hygiene and cross-contamination (4).
•Presence of pathogens on the surface of cleaning tools (sponge and
towels) have been confirmed in peer reviewed publications (2, 5, 6,).
•However, there is a paucity of research on the persistence and long-
term survival of microorganisms on kitchen cleaning tools.
AIM
This project aimed to evaluate and assess the survival and persistence
of pathogenic microorganisms on kitchen sponge and microfiber towels
used commonly in commercial restaurants.
Lab
CONCLUSION
•Cleaning tools (sponge and microfiber towels) in
restaurant settings may be a vehicle of pathogen
transmission to food and surfaces.
•Results indicated that Salmonella spp. and E.
coli O157:H7 can survive for up to 16 days on the
kitchen sponge and up to ten days on microfiber
towels.
•L. monocytogens and S. aureus can survive up to
13 and 10 days on sponge and towels,
respectively.
•Proper cleaning and sanitizing of cleaning tools is
essential to reduce the risk of cross-contamination.
•Frequent change of cleaning tools is
recommended to avoid contaminating food
contact surfaces.
•The sanitizer solution is ineffective after 4 hours.
•Adequate preparation of the sanitizer solution is
vital to ensure the optimum disinfection of the
cleaning tools.
•The outcomes of the study will increase awareness
of the risk posed by cleaning tools in restaurants
and food service establishments.
RESULTS
REFRENCES
1. CDC , Global diahrrea burden, 2015. Available from:
http://www.cdc.gov/healthywater/global/diarrhea-burden.html/
2. Wolde T, Bacha K. 2016. Microbiological safety of kitchen sponges used
in food establishments. Int J Food Sci 2016.
3. Angelo KM, Nisler AL, Hall AJ, Brown LG, Gould LH. 2017.
Epidemiology of restaurant-associated foodborne disease outbreaks,
United States, 1998–2013. Epidemiol & Infect 145:523-34.
4. Mattick K, Durham K, Hendrix M, Slader J, Griffith C, Sen M,
Humphrey T. 2003. The microbiological quality of washing-up water and
the environment in domestic and commercial kitchens. J Appl Microbiol
94:842-8.
5. Rossi EM, Scapin D, Tondo EC. 2013. Survival and transfer of
microorganisms from kitchen sponges to surfaces of stainless steel and
polyethylene. J Infect Dev Ctries 7: 229-34.
6. Wolde T, Bacha K. 2017. Prevalence and antibiotics resistance patterns of
Salmonella isolated from kitchen sponges at Jimma town, Ethiopia.
African J Microbiol Res 11:631-636.
Zahra H. Mohammad, Sujata A. Sirsat
Conrad N. Hilton College of Hotel and Restaurant Management, University of Houston, Houston, Texas
Survival and Persistence of Pathogenic Bacteria on Kitchen Sponge and
Microfiber Towel in Restaurant and Foodservice Operations
ASM Microbe 2020
On sponge, Salmonella and E,
coli were recovered until day16
when washed with sterile water,
and L. monocytogens and S.
aureus was observed until day
10 post-inoculation. On
microfiber towels, Salmonella
and E, coli were survived until
day 13 when washed with
water, and
L. monocytogens and S. aureus
until day 10th. While, when
these tools washed with
sanitizer, no pathogens were
detected at time zero. But, E.
coli, Salmonella, and Staph
were recovered at days, 1,2, and
3.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h
Zero 1 2 3 7 10 13 16 19
Log (CFU/cm2)
Day
Sponge washed with water Sponge washed with sanitizer
Towel washed with water Towel washed with sanitizer
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h
Zero 1 2 3 7 10 13 16 19
Log (CFU/cm2)
Day
Sponge washed with water Sponge washed with sanitizer
Towel washed with water Towel washed with sanitizer
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h
Zero 1 2 3 7 10 13 16 19
Log (CFU/cm2)
Day
Sponge washed with water Sponge washed with sanitizer
Towel washed with water Towel washed with sanitizer
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h 0h 6h
Zero 1 2 3 7 10 13 16 19
Log (CFU/cm2)
Day
Sponge washed with water Sponge washed with sanitizer
Towel washed with water Towel washed with sanitizer
There were no significant
differences (P > 0.05) between
sponge and towels in terms of
microbial recovery when items
washed with water or sanitizer
solution. However, the
persistence and survival of each
microorganism were different
over 19 days analyses. The
results of E. coli, Salmonella,
LM, and S. aureus persistence
on sponge and microfiber towels
are shown in Figures 1-4,
respectively.
METHOD
Plated onto EMB, PALCUM, Bird Parker Agar & incubated at 35 C for 24 h
The same procedure were repeated on days 2, 3, 4, 7, 10, 13, 16, 19
Data analysis
Reviving microorganisms
(Salmonella spp., E. coli O157:H7, L.
monocytogenes, S. aureus)
Inoculum preparation (Incubate each organism onto TSB for 24 h)
Two consecutive transfers
Bacteria cocktail (mix all organisms)
10 fold dilutions in 1% PW (104 CFU/mL)
Each inoculated sponge cut into 2 parts (5 x 5 )cm2& towel into 4 parts (10 x 10) cm2
Inoculation of samples (sponge and microfiber towels) and left for one hour at 231
Inoculation of samples (sponges and microfiber towels), and left for one hour at 231
Two towel samples
Two sponge samples
Washed with sanitizer
solution at zero h
Washed with sterile
water at zero h Washed with sanitizer
Solution at zero h
Washed with sterile
water at zero h
Washed with sterile
water at 6 h
Washed with sanitizer
solution at 6 h
Washed with sterile
water at 6 h
Washed with sanitizer
Solution at 6 h The sanitizer solution’s efficacy
was tested at times 0, 4, 6, 8 h
and found that sanitizer is
effective only between 1-4 hours
At six hours, the sanitizer starts
losing its efficacy.
Figure 1. Survival of E. coli on sponge and microfiber towels after washing with water or sanitizer
Figure 2. Survival of Salmonella on sponge and microfiber towels after washing with water or
sanitizer
Figure 3. Survival of L. monocytogenes on sponge and microfiber towels after washing with water
or sanitizer
Figure 4. Survival of S. aureus on sponge and microfiber towels after washing with water or
sanitizer