Transcript Document

¹ Master’s student Clemson
University. Contact:
[email protected]
² Clemson University. Contact:
[email protected]
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Clemson University. Contact:
[email protected]
Graph 2. Displays the aerobic organism count and Staphylococcus aureus count during non-busy hours
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Public surfaces have been studied extensively for bacterial contamination and foodborne diseases, these
surfaces are mainly the food contact surfaces. Some non-food contact surfaces such as restaurant menus
are not routinely evaluated for microbial contamination thus can be a potential contamination risk.
6 subjects
covered
hands w/
luminescent
cream
Menus
held under
black light
and
analyzed
Menus
held as in
restaurant
setting
Protocol
made
based on
test results
Cleanliness of a restaurant is assessed by the eye and therefore the menu is visually assessed by the
consumer and hence microscopic organisms may be present and potentially transferred to consumers
hands and food and eventually the digestive system. The restaurant maybe not to blame, a previous
consumer may have transferred bacteria to the menu that was then transferred to another consumer
resulting in food poisoning (Griffith and Moore, 2002)
Swab fluid
plated on
TPC,
Staphylococcus. Spp
Petrifilms
Petrifilms
counted
after 24, 48
hrs
accordingly
statistically
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To detect bacteria on restaurant menus
To Test the rate of bacteria transfer from menus to consumers’ hands
To test the survival of bacteria on the menu surfaces after 24, 48 hrs
Preliminary tests: To determine where to sample on a menu, how to measure the transfer rate of bacteria
from a menu to a consumers hand and to measure he survival of bacteria after 24 and 48 hours,
pretest were done. These pretest aided in the tailoring of the main study tests. Modifications to pretest
were made until these pretests were made into the study's’ main tests.
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TPC 2
150
Staph 2
100
Bacteria
was
cultivated
and
harvested
and media
made
Test menus
were made
to
resemble
restaurant
menus
Menus
contaminated with
inoculum
fluid and
left to dry
8 subjects,
each held
menu for 1
minute in
restaurant
setting
Menus, hands
were washed
w/ 0.1%
peptone (w/v)
recovery
water, for 30 S
each
Recovery
wash water
plated for
bacterial
count
Bacterial
count after
24 hrs
incubation
at 37oC
Data
analyzed
statistically
and
compared
with each
other
Adjustment
to method
made as
required
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The results of the menu hygiene sampling proves the presence of bacteria on the restaurant menus
(Graph1, 2). The average mean of TPC was 19.38 CFU/Menu during busy periods and 10.59 CFU/Menu
during less busy periods. The Staphylococcus count had an average mean of 4.21 CFU/Menu during busy
periods and 1.53 CFU/Menu during less busy periods.
Research has found that 70% of consumers will never return to an establishment at which they have
contracted food poisoning (Food Safety Agency, 2009), so cleanliness should be paramount for any
establishment.
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Data
analyzed
CFU/Menu
The menus at restaurants are not like silverware and dishes; they are not cleaned, washed, steamed and
rarely wiped after each use. There is the occasional wipe down of food from menus that have had a
considerate amount of food fallen on them. Restaurant inspections generally don’t include a thorough
assessment of the concentration of bacteria on menus since these tests take up to 48 hours to complete
and indicate if there are bacteria (Almanza et al, 2011).
It is estimated that an average income American eats 1 out of 4 meals at a restaurant and this may differ
between consumer to consumer depending on income indicating that this number may be
underestimated (Americans’ Dining-Out Habits) .
3M swabs
used for
swabbing
menu 25
strokes
across
menu
surface
Menus at
local
restaurants
were
swabbed
according
to protocol
Bacteria
was
cultivated
and
harvested
and media
made
Menus
contaminated with
inoculum
fluid and
left to dry
Test menus
were made
Menus were
washed for
30 S with
0.1%
peptone
recovery
water
Recovery
wash water
plated for
bacterial
count
Bacterial
count for
2nd 3
menus
after 24 hrs
at 27oC
Bacterial
count for
1st 3 menus
at initial
time
Bacterial
count for
3rd 3
menus
after 48 hrs
at 27 oC
Graph1. Displays the aerobic organism count and Staphylococcus aureus count during busy hours
Restaurant menu sampling: The samples from local restaurant menus were a total of 378 samples done
over a period of two semesters, which means that seasonality was put into consideration. There was a
total of 208 in the fall and 170 during January and December. The high traffic and low traffic samples
were a total of 158, and 50 respectively. during the fall period. There were a total of 128 and 42 for the
high traffic periods and the low traffic periods respectively during the month of January and December.
8 Subjects participated in the transfer rate study 3 times in a restaurant setting.
Data
analyzed
statistically
and
compared
in-between
Testing the survival of bacteria yielded 1.389835%, 2.057413% after 24 hrs as the mean and the standard
deviation respectively and 1.341937%, 1.891689% after 48 hrs as the mean and the standard deviation
respectively.
The results of the transfer rate study showed that bacteria did transfer from the menu to the hands of the
participants. The transfer rate test showing values of 11.16599%, 10.44717% as the mean and the standard
deviation respectively. The results of the 8 participants transfer rates indicate that some of them
experienced greater transfer rates than others. This was due to their hand preference and/or hand size
affected by gender. The right-handed participants transferred larger numbers of bacteria with their right
hands than their left hands and the same for left-handed participants, as their left hand results were higher
in colony count.
The data that has been collected shows that there is bacteria content on menus from local restaurants.
Some of the numbers of bacteria colonies prove that there is evidence that restaurant menus have
bacteria that is viable enough to cause a food-borne illness. The presence of Staphylococcus aureus may
cause illnesses if ignored. In conclusion, results produced from this study prove that restaurant menus
harbor bacteria, bacteria can transfer from these menus to the customers’ hands at a certain rate and
that bacteria survive on a sterile menu after 48 hours at room temperature.
Future research may include standard sanitation procedures to reduce possible cross contamination
from menus. The producing of such a technique and implementing it may prove to decrease incidences of
food-borne illnesses. Studying transfer rate with different types of menu materials and their ability to
harbor bacteria
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References
Almanza, B., Choi, J., and Nelson, D. 2011. A Strategic Cleaning Assessment Program: Cleanliness of the Menu at Restaurants.
[Online]. University of Massachusetts. MA.
Americans’ Dining-Out Habits. [Online] Availble from
http://restaurant.org/tools/magazines/rusa/magarchive/year/article/?articleid=138.html [accessed 1 January 2013].
Food Safety Agency (2009). Scores on the Doors. Available from http://www.food.gov.uk/multimedia/pdfs/board/fsa080306.pdf.
[accessed 10 January 2013.]
Griffith, C., and Moore, G. 2002. Monitoring Surface Hygiene within The Food Industry: An Industry Trial a Comparison of
Traditional and Recently Developed Methods for Monitoring Surface Hygiene Within The Food Industry: An Industry Trial.
International Journal of Environmental Health Research (12): 317–329.