FSnet Aug. 20/08 -- III
BARFBLOG: 1
dead, dozens sickened in Canadian listeria outbreak: some
questions
ONTARIO:
Maple Leaf recalls meat, shuts plant
CANADA:
Public Health Agency of Canada statement on a listeria
monocytogenes outbreak
US: Mexican
peppers posing salmonella risk still being sold
AUSTRALIA:
New food safety laws to protect vulnerable people
IOWA: Scott
County reports hepatitis case
PORTUGAL:
Easing food safety standards for traditional products
FEDERAL
REGISTER: Residues of quaternary ammonium compounds, N-alkyl
(C12-18) dimethyl benzyl ammonium chloride on food contact
surfaces; Exemption from the requirement of a tolerance
Examination
of stress and virulence gene expression in Escherichia coli
O157:H7 using targeted microarray analysis
Methods and
tools for comparative genomics of foodborne pathogens
In Vivo
expression technology and signature-tagged mutagenesis
screens for identifying mechanisms of survival of zoonotic
foodborne pathogens
how to
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BARFBLOG: 1
dead, dozens sickened in Canadian listeria outbreak: some
questions
20.aug.08
barfblog
Doug Powell
http://barfblog.foodsafety.ksu.edu/2008/08/articles/listeria-1/1-dead-dozens-sickened-in-canadian-listeria-outbreak-some-questions/
Amy is 6 months pregnant: An outbreak of listeria in Canada
which has killed one and sickened dozens, is exactly why she
hasn’t eaten any cold cuts or smoked salmon for the past six
months.
http://www.marketwire.com/press-release/Public-Health-Agency-Of-Canada-891846.html
It has been thoroughly documented that many pregnant women
are not aware of the risks associated with consuming
refrigerated, ready-to-eat foods like cold cuts. Nor does
the literary dancing from various Canadian spokesthingies
inspire confidence.
http://barfblog.foodsafety.ksu.edu/2007/10/articles/culture-of-food-safety/pregnant-women-not-receiving-food-safety-info/
About 3 a.m. Sunday, Aug. 17/08, the Canadian Food
Inspection Agency (CFIA) and Maple Leaf Consumer Foods
issued an advisory warning the public not to serve or
consume Sure Slice brand Roast Beef and Corned Beef because
these products may be contaminated with Listeria
monocytogenes.
The press statement said,
“There have been no confirmed illnesses associated with the
consumption of these products.”
Usually, CFIA press releases say there have been no
illnesses associated with the product in question, if that
is indeed the case. The “confirmed illness” was a wiggle
phrase that Canadian media dutifully reported and then went
back to sleep.
Then, about 4 a.m. Wednesday Aug. 20/08, another press
release arrived from CFIA, this time announcing that Maple
Leaf was voluntarily recalling everything from the suspect
Toronto plant and that,
“… a number of the affected products … are part of a
listeriosis outbreak investigation.”
About the same time, Maple Leaf Foods put out a press
release stating,
“A small number of Sure Slice packaged meat products
produced at the Company's Bartor Road, Toronto facility,
predominantly for foodservice customers, have tested
positive to contain low levels of listeria monocytogenes.”
Always good to get someone else to read stuff to catch
grammatical errors, but there may not always be time.
http://www.newswire.ca/en/releases/archive/August2008/20/c5519.html
And maybe it wasn’t that small of a contamination, because
Wednesday afternoon, Ontario's Chief Medical Officer of
Health advised the public that there is an outbreak of
Listeriosis in the province.
http://www.newswire.ca/en/releases/archive/August2008/20/c5713.html
“In July 2008, routine surveillance conducted by the
Ministry detected a marked increase in cases of Listeriosis
being reported by Ontario health units.
“As of yesterday, there have been 29 cases associated with
the outbreak across 17 health units. Of these, 13 are
confirmed cases, and the rest are probable and suspect cases
which are under investigation by the local health units.
Outbreak associated cases of Listeriosis have also been
reported in British Columbia, Saskatchewan and Quebec.
Ontario is working with the Public Health Agency of Canada
and the other provinces in the investigation.”
Yet, as reported by Canwest News Service, health officials
in Ontario would not confirm a link between the cases and
the recall. Dr. Eleni Galanis with the B.C. Centre For
Disease Control said officials in that province had
interviewed the two confirmed cases and were satisfied there
was sufficient evidence to show a link.
http://www.canada.com/victoriatimescolonist/news/story.html?id=ae3479ad-ccbe-489b-9898-124788f674d2
"First, they have the same strain as the outbreak strain
that has been identified in Ontario and second they have
been exposed to the foods that are under recall. It does
seem that they are linked."
Galanis, who said B.C. is also reviewing three more
suspected cases, said she was particularly concerned for
people with compromised immune systems and pregnant women.
"In pregnant women it could result in still birth," she
said.
Despite the words of Dr. Galanis, the story has spun into
political nonsense, with the two major political parties
throwing barbs at each other, and one University of Guelph
type defending small agriculture by saying,
“That's not to say that a small butcher can't make mistakes,
but at best, he's going to kill off a few of his neighbours.
When you take that same mistake and you put it into a plant
that serves millions, the risk is vastly expanded.”
http://www.theglobeandmail.com/servlet/story/RTGAM.20080820.wrecall2ottawa21/BNStory/National/home
Wow. There’s a whole bunch of sick people out there. That’s
where the focus should be. And then, journos should ask, at
what point did health authorities make an epidemiological
link to Maple Leaf cold cuts? Would some illnesses have been
prevented if the warning Sunday morning had been expanded?
What is the process used to decide when to issue public
warnings? How much evidence is enough?
Oh, and the CFIA advice if you are pregnant or have a
weakened immune system?
“Although the risk of listeriosis associated with foods from
deli counters, such as sliced packaged meat and poultry
products, is relatively low, pregnant women and
immunosuppressed persons may choose to avoid these foods.”
http://www.inspection.gc.ca/english/fssa/concen/cause/listeriae.shtml
Here’s the advice from the U.S. Centers for Disease Control
for persons at high risk, such as pregnant women and persons
with weakened immune systems:
• Do not eat hot dogs, luncheon meats, or deli meats, unless
they are reheated until steaming hot.
-Avoid getting fluid
from hot dog packages on other foods, utensils, and food
preparation surfaces, and wash hands after handling hot
dogs, luncheon meats, and deli meats.
• Do not eat soft cheeses such as feta, Brie, and Camembert,
blue-veined cheeses, or Mexican-style cheeses such as queso
blanco, queso fresco, and Panela, unless they have labels
that clearly state they are made from pastuerized milk.
• Do not eat refrigerated pâtés or meat spreads. Canned or
shelf-stable pâtés and meat spreads may be eaten.
-Do not
eat refrigerated smoked seafood, unless it is contained in a
cooked dish, such as a casserole. Refrigerated smoked
seafood, such as salmon, trout, whitefish, cod, tuna or
mackerel, is most often labeled as "nova-style," "lox,"
"kippered," "smoked," or "jerky." The fish is found in the
refrigerator section or sold at deli counters of grocery
stores and delicatessens. Canned or shelf-stable smoked
seafood may be eaten.
The USDA risk assessment for listeria is ready-to-eat foods
is available here
http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/97-013F/ListeriaReport.pdf
and one from the World Health Organization is here.
http://www.who.int/foodsafety/publications/micro/mra_listeria/en/index.html
ONTARIO:
Maple Leaf recalls meat, shuts plant
20.aug.08
Toronto Star/AP/Reuters
Paolo Loriggio
http://www.thestar.com/News/Ontario/article/482049
Canwest News Service
Linda Nguyen, Tiffany Crawford and Becky Rynor
http://www.canada.com/victoriatimescolonist/news/story.html?id=ae3479ad-ccbe-489b-9898-124788f674d2
Globe and Mail
Public health officials are investigating whether an
outbreak of food poisoning that killed one person is linked
to contaminated cold cuts produced at a north Toronto plant.
Seventeen people, 13 of them in Ontario, have fallen ill
since June in an outbreak of listeriosis, a food-borne
disease caused by listeria bacteria. An Ontario resident
died of the illness.
Officials at the Public Health Agency of Canada say they
know little about the outbreak or its victims, but are
investigating a connection with a meat recalled by Maple
Leaf Foods, which supplies companies including McDonald's
and Mr. Sub.
The strain of listeria monocytogenes involved in the
outbreak is the same one found in the meat, but that doesn't
mean the two are related, said agency spokesperson Philippe
Brideau.
The agency is asking victims to trace back what they have
eaten in the past three months to see whether the outbreak
is linked to the recalled cold cuts. It can take from two to
90 days for symptoms to appear, he said.
Mark Nesbitt, spokesman for Ontario Health, said officials
were in the process of contacting all the long term care
homes and hospitals to confirm that they are aware of the
recall.
"There hasn't been any confirmation and the testing is
ongoing. It's quite difficult because Listeria has an
incubation period between two and 30 days and it has been up
to 90 days," he said.
Although health officials in Ontario would not confirm a
link between the cases and the recall, Dr. Eleni Galanis
with the B.C. Centre For Disease Control said officials in
that province had interviewed the two confirmed cases and
were satisfied there was sufficient evidence to show a link.
"First, they have the same strain as the outbreak strain
that has been identified in Ontario and second they have
been exposed to the foods that are under recall," said
Galanis.
"It does seem that they are linked."
Galanis, who said B.C. is also reviewing three more
suspected cases, said she was particularly concerned for
people with compromised immune systems and pregnant women.
"In pregnant women it could result in still birth," she
said.
This morning, Maple Leaf Foods expanded a nationwide recall
after bacteria was found in cold cuts produced at a Toronto
plant that supplies companies including McDonald’s and Mr.
Sub.
The Canadian Food Inspection Agency (CFIA) said the Maple
Leaf meats – including sliced cooked turkey, roast beef,
Bavarian smokes, corned beef, salami, ham and pepperoni –
may be contaminated with the bacteria listeria
monocytogenes.
The meats are sold under names including Schneiders, ML Sure
Slice, Deli Gourmet, MSD, Burns, ML and FS. They include
sliced turkey produced for McDonald’s and roast beef for Mr.
Sub.
CFIA spokesperson Garfield Balsom was cited as saying none
of the meat has been blamed for illnesses in humans, but
“quite a large amount of product” is affected.
In response, McDonald's has temporarily pulled the Turkey
BLT sandwich from its Canadian menu, said spokesperson Louis
Payette said.
Representatives of Mr. Sub and Maple Leaf could not be
reached for comment this morning.
There are about 60 cases of listeriosis reported each year
in Canada, but outbreaks are rare, Brideau said. About six
have been reported since 1981, the first outbreak on record.
Lists of the affected products are posted on the CFIA and
Maple Leaf websites.
Consumers can also call Maple Leaf Consumer Foods at
1-800-568-5801 or CFIA at 1-800-442-2342 for more
information.
A retired Health Canada microbiologist and food inspector
said Listeria contamination can cause serious illness and
the number of outbreaks is growing. Even so, he said, it
should not yet be considered a serious health issue.
"The number of incidents is still very low," said Bill
Riedel, also a member of the American Institute of Food
Technology. "The probability of getting diseases from the
bacteria is very, very remote."
CANADA:
Public Health Agency of Canada statement on a listeria
monocytogenes outbreak
20.aug.08
Public Health Agency of Canada
http://www.marketwire.com/press-release/Public-Health-Agency-Of-Canada-891846.html
OTTAWA, ONTARIO -- The Public Health Agency of Canada is
collaborating with provincial and local health authorities
in Quebec, Ontario, Saskatchewan and British Columbia,
Health Canada and the Canadian Food Inspection Agency (CFIA)
to investigate an increase in cases of Listeriosis with the
same genetic fingerprint (strain).
To date, there are 17 confirmed cases of the outbreak strain
of Listeriosis in four provinces (13 in Ontario, two in BC,
one in Saskatchewan and one in Quebec). One death in Ontario
has been attributed to this strain.
The Public Health Agency of Canada is working with its
partners to confirm the source of these infections. This
includes gathering epidemiological information from ill
individuals and assessing results of food testing.
Ready-to-eat meat products are being investigated as a
possible source. For information regarding recalled
products, please see the CFIA website:
http://www.inspection.gc.ca/english/corpaffr/recarapp/2008/20080819e.shtml
Listeria monocytogenes can be found in a variety of dairy
products, vegetables, fish and meat products. The disease
affects primarily older individuals, pregnant women,
newborns, and adults with weakened immune systems. A person
with listeriosis may experience fever, muscle aches, and
sometimes gastrointestinal symptoms such as nausea or
diarrhea. Deaths are uncommon, except in the very young, the
very old, or people with weakened immune systems. People who
believe they have experienced symptoms of illness are urged
to contact their health care provider.
For further information on Listeria:
http://www.inspection.gc.ca/english/fssa/concen/cause/listeriae.shtml
http://www.phac-aspc.gc.ca/msds-ftss/msds96e-eng.php?option=email
US: Mexican
peppers posing salmonella risk still being sold
20.aug.08
USA Today
Julie Schmit,
http://www.usatoday.com/money/industries/food/2008-08-20-peppers_N.htm?csp=34
Federal officials say fresh jalapeno and serrano peppers
from Mexico pose a salmonella risk, but the peppers are
still selling in the U.S. and for much less than their U.S.
rivals.
Buyers tend to be small Hispanic grocers and mom and pop
restaurants, while big supermarkets and restaurants shun the
Mexican supply, distributors say.
"Mexican peppers still are selling," says Raul Ramirez,
warehouse manager for Ramirez Bros., a Los Angeles-based
distributor. "Our customers are asking for them."
Mexican peppers "are growing in prominence," agrees Will
Steele, CEO of Frontera Produce, a large importer of Mexican
jalapenos. Frontera isn't importing them from Mexico now
because its buyers, large supermarket and restaurant chains,
don't want them, Steele adds.
The Food and Drug Administration warned last month that
consumers should avoid fresh jalapeno and serrano peppers
from Mexico, after salmonella saintpaul was found on
samples. Nationwide, 1,434 people have been sickened in the
outbreak, the largest for food in more than a decade. New
illnesses peaked in May and have slowed to a trickle. The
latest new illness started Aug. 8, says the Centers for
Disease Control and Prevention.
Forty-pound boxes of U.S.-grown jalapenos sold at wholesale
for $25 to $35 a box on Tuesday vs. $14 to $16 for Mexican
ones, Steele says. Before the warning, U.S. and Mexican
peppers cost about the same. Prices for U.S. ones are up.
Fresh jalapenos are often used in fresh salsas.
Many consumers and retailers may not be aware of the
warning, says Michael Doyle, director of the Center for Food
Safety at the University of Georgia.
Imported volumes are likely to be small, says John McClung
of the Texas Produce Association. Mexico supplies most of
the USA's peppers in winter, but California, North Carolina
and others supply a lot in August, he says.
The FDA hasn't banned the import of Mexican jalapenos and
serranos, but it has increased testing at border
checkpoints.
In recent weeks, it's restricted pepper imports from 12
Mexican firms because of salmonella, but not necessarily the
outbreak strain.
Future shipments from those firms must test free of
salmonella before the FDA will release them for sale.
AUSTRALIA:
New food safety laws to protect vulnerable people
21.aug.08
NSW Food Authority
James Ferre
http://www.ausfoodnews.com.au/2008/08/21/new-food-safety-laws-to-protect-vulnerable-people.html
New food safety standards that will give added protection to
people in hospitals and aged care facilities came into
effect on 18 August, 2008.The Vulnerable Persons Food Safety
Scheme will mean NSW’s 1,300 public and private hospitals
and aged care facilities will be required to have mandatory
food safety programs.
The new laws, which will protect vulnerable people in the
community including seniors and those that are unwell, mean
that hospitals and aged-care facilities will be subject to
regular food safety audits.
The scheme impacts on businesses such as hospitals, aged
care facilities, respite services, same-day aged care
services and certain delivered meal organisations such as
Meals on Wheels. For example, there will be strict
requirements about how different types of food can be
handled, prepared, transported and stored to minimise the
risk of food poisoning.
All affected vulnerable populations food businesses will
need to apply for a NSW Food Authority licence by 18 October
2008.
The Scheme also requires audited food safety programs to be
in place.
Audits of impacted businesses will commence from 1 March
2009. Same-day aged care services have extra time to
implement their food safety programs and be ready for audit
- audits for those services will commence from 1 September
2009.
New resources to help facilities implement the new
requirements include:
* Vulnerable Persons Food Safety Scheme Manual explaining
the requirements in detail, and;
* licence application and guide to applying for a licence
Details of the scheme and the new resources are available on
the NSW Food Authority website.
IOWA: Scott
County reports hepatitis case
20.aug.08
Quad City Times
http://ads.qctimes.com/articles/2008/08/20/news/local/doc48ac5fc884ff9419329566.txt
A worker at a Davenport McDonalds has been diagnosed with
the infectious Hepatitis A, but health department officials
do not believe customers are at risk.
A news release from the Scott County Health Department
indicates that the food handler and the restaurant were
investigated, and the Iowa Department of Public Health was
consulted.
“It is highly unlikely that the restaurant’s patrons were
exposed to the infection, and patrons of the restaurant need
no further evaluation or preventive therapy,” the news
release states.
Louis M. Katz, medical director for the Scott County Health
Department, added, “McDonalds’ management has been very
cooperative with the Health Department’s investigation. They
are to be commended for their commitment to safe food
handling practices and monitoring of their employees’
compliance.”
The McDonalds case is the third report of Hepatitis A in
Scott County this year, health department officials said.
PORTUGAL:
Easing food safety standards for traditional products
20.aug.08
IPS
Mario de Queiroz
http://www.ipsnews.net/news.asp?idnews=43622
LISBON -- As the only alternative for preventing the
disappearance of small-scale farming, farmers’ markets,
rural slaughterhouses, taverns and traditional food
products, Portugal has decided to interpret the strict
European Union regulations on food safety with a domestic
slant.
The increasingly stringent EU regulations had begun to pose
a serious threat to a sector that is important to the
Portuguese economy: gastronomy based on home cooking and
artisanal products, for which, along with sun and beaches,
this southern European country is famous.
To remain in step with the EU, Lisbon created a special
police body, whose agents are the most feared and hated by a
populace accustomed to devouring tasty dishes often prepared
with food that comes from small producers.
Portugal went from a near total lack of food safety
oversight to the other extreme, furnishing the new Agency
for Food and Economic Security (ASAE) with exceptional
powers.
Armed ASAE officers who would show up wearing masks -- to
avoid being identified -- to carry out their inspections
began to shut down markets, small taverns, farms, and small
cheese shops and bakeries producing traditional delicacies.
But in the face of the public outcry in a country where laws
and regulations are not always so strictly enforced, the
government of socialist Prime Minister José Sócrates was
forced to backtrack, and decided to adapt EU food safety
regulations to the Portuguese reality -- and to the need to
continue attracting tourists.
Small-scale production will now be less complicated. Selling
eggs, honey or fish in small quantities will be simpler, and
will face fewer safety and hygiene restrictions. Artisans
and cottage industry food producers are now exempt from
having to secure special licences, and more flexible rules
will apply to the small-scale slaughter of livestock.
"A series of legislative measures, circulars, messages and
reports targeting small-scale, traditional producers and
artisans have come out in the last few days, with the aim of
improving their chances of survival," economic analyst Carla
Aguiar, an expert on the food industry with the Lisbon
newspaper Diario de Noticias, told IPS Tuesday.
But the great majority of traditional producers "are
unfamiliar with these new regulations and do not know how to
defend themselves from the ASAE," she added.
A joint communiqué issued by the economy and agriculture
ministries in late July explained the simplified hygiene
conditions that would enable small-scale food producers to
continue supplying their customers, which are mainly
taverns, restaurants and small shops.
To loosen the restrictions, Portugal invoked provisions of
the 2004 and 2005 EU regulations allowing member countries
to establish their own rules for small-scale producers in
the case of certain foods.
The new Portuguese government rules set upper limits on what
classifies as small-scale production for each product,
including homegrown eggs, honey, fish and seafood, beef,
poultry and wild game. Producers must also register with the
national veterinary office.
The nationally adapted EU regulations allow small producers
to make their products at home -- a provision that
especially favours the production of a broad range of
traditional cheeses and preserves.
But "the government initiative emerged after several
complaints from producers and the break out of the
controversy surrounding the ASAE," said Aguiar.
The modus operandi followed by the ASAE triggered howls of
outrage. In the fierce public discussion, respected
intellectuals, defending traditional products, pointed out
that culinary traditions form part of a country’s culture.
Some writers and filmmakers went to the extreme of comparing
the ASAE to the Polícia Internacional e de Defesa do Estado
(PIDE), the secret police that operated during Portugal’s
1926-1974 dictatorship.
Aguiar quoted Professor Xavier Malcata, director of the
department of biotechnology at the Catholic University of
Oporto, who said cases of food poisoning generally do not
involve traditional products.
Malcata, who has been studying food safety and protection
for two decades and was granted the International Leadership
Award by the International Association for Food Protection,
"has assumed the role of standard bearer in the defence of
traditional Portuguese products," said the analyst.
She again quoted Malcata, who described ASAE’s performance
as "autistic," and warned that overly ambitious oversight
could spell catastrophe for Portugal’s traditional heritage.
The professor specifically referred to sausage shops and
bakeries, "two gastronomic treasures associated with certain
regions, which have to do with centuries of cultural
evolution, with our own ethnic identity."
"Probiotic yoghurt," a fashionable, innovative product, only
offers economic gains to a few big companies, while "the
quality of traditional products, a factor that distinguishes
Portugal from other countries," is ignored, and current
legislation "favours foreign specialties," says Malcata.
The professor also laments "ASAE’s excesses with respect to
traditional products," and said that while oversight is
necessary, it must be carried out "in dialogue with us and
with associations of food producers."
He said the food safety police, who answer to the Economy
Ministry, should understand that "laws are not dogmas, and
should act with common sense and not be more papist than the
Pope."
He also recommends reasonable enforcement and oversight that
takes into account the fact that "large producers are the
main repeat offenders."
Aguiar agrees with Malcata that eating involves a certain
level of risk. "Food cannot be completely risk-free, and
eating is a calculated risk. Zero risk? Not even in Norway,"
she said.
FEDERAL
REGISTER: Residues of quaternary ammonium compounds, N-alkyl
(C12-18) dimethyl benzyl ammonium chloride on food contact
surfaces; Exemption from the requirement of a tolerance
20.aug.08
Federal Register (Volume 73, Number 162)
Page 49101-49107
DOCID:fr20au08-10
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
SUMMARY: This regulation establishes an exemption from the
requirement of a tolerance for residues of n-alkyl (C12-18)
dimethyl benzyl ammonium chloride (CAS No. 68424-85-1) on
food contact surfaces when applied/used in public eating
places, dairy processing equipment, and/or food processing
equipment and utensils. The regulation will exempt from the
requirement of tolerance residues in food resulting from
contact with surfaces treated with antimicrobial solutions
where the end-use concentration of active quaternary
compound does not exceed 400 ppm.
Examination
of stress and virulence gene expression in Escherichia coli
O157:H7 using targeted microarray analysis
01.aug.08
Food Borne Pathogens and Disease
Kevin J. Allen, Dion Lepp, Robin C. McKellar, Mansel W.
Griffiths
http://www.liebertonline.com/doi/abs/10.1089/fpd.2008.0100
Escherichia coli O157:H7 poses a threat to humans through
food- and water-borne transmission. To investigate how
environmental stresses affect the Escherichia coli O157:H7
transcriptome, we designed a targeted microarray consisting
of stress response and virulence genes (n = 125) to analyze
the impact of acidified (pH 3.5), cold (7.5°C), and fresh
tryptic soy broth (TSB) (37°C) on E. coli O157:H7 stress
response and virulence gene expression. Nutrient
replenishment with fresh TSB resulted in 72 differentially
expressed genes (≥1.5-fold change; p Kevin J. Allen
Department of Food Science and Canadian Research Institute
for Food Safety, University of Guelph, Guelph, Ontario,
Canada.
Current address: Bioniche Life Sciences, Belleville, ON,
Canada.
Dion Lepp
Food Research Program, Agriculture and Agri-Food Canada,
Guelph, Ontario, Canada.
Robin C. McKellar
Food Research Program, Agriculture and Agri-Food Canada,
Guelph, Ontario, Canada.
Mansel W. Griffiths
Department of Food Science and Canadian Research Institute
for Food Safety, University of Guelph, Guelph, Ontario,
Canada.
Methods and
tools for comparative genomics of foodborne pathogens
01.aug.08
Foodborne Pathogens and Disease
Arvind A. Bhagwat, Medha Bhagwat.
http://www.liebertonline.com/doi/abs/10.1089/fpd.2008.0117
A comparison of genome sequences and of encoded proteins
with the database of existing annotated sequences is a
useful approach to understand the information at the genome
level. Here we demonstrate the utility of several DNA and
protein sequence comparison tools to interpret the
information obtained from several genome projects.
Comparisons are presented between closely related strains of
Escherichia coli commensal isolates, different isolates of
O157:H7, and Shigella spp. It is expected that comparative
genome analysis will generate a wealth of data to compare
pathogenic isolates with varying levels of pathogenicity,
which in turn may reveal mechanisms by which the pathogen
may adapt to a particular nutrient supply in certain foods.
These genome sequence analysis tools will strengthen
foodborne pathogen surveillance and subsequent risk
assessment to enhance the safety of the food supply.
Arvind A. Bhagwat
Produce Quality and Safety Laboratory, Henry A. Wallace
Beltsville Agricultural Research Center, Agricultural
Research Service, USDA, Beltsville, Maryland.
Medha Bhagwat
National Center for Biotechnology Information, National
Institute of Health, Bethesda, Maryland.
In Vivo
expression technology and signature-tagged mutagenesis
screens for identifying mechanisms of survival of zoonotic
foodborne pathogens
01.aug.08
Foodborne Pathogens and Disease
Edward G. Dudley
http://www.liebertonline.com/doi/abs/10.1089/fpd.2008.0104
High-throughput genetic screens provide great insights into
the biochemistry and molecular biology of how bacteria
sense, respond to, and propagate within their environments.
Genomics era techniques such as microarrays and proteomics
have great potential to increase our understanding of how
foodborne pathogens grow and survive within animal and human
hosts, in the environment and foods, and during thermal and
nonthermal inactivation protocols. While these techniques
are incredibly useful for studying gene expression in
simplified in vitro conditions, it is much more challenging
to pursue similar studies within more complex experimental
models such as in vivo, within the food matrix, or within
heterogeneous microbial populations. Techniques such as in
vivo expression technology (IVET) and signature-tagged
mutagenesis (STM) provide alternatives for studying
bacterial gene expression and growth requirements within
these settings. These techniques are used extensively by the
medical, veterinary, and plant research communities for
identifying genes promoting the colonization and disease
process, factors mediating commensalism between bacteria and
their host, and genes that promote survival of environmental
bacteria within natural settings. Research into the
transmission and survival of foodborne pathogens from
farm-to-fork would likely benefit from these techniques,
however there are few reports describing their use for such
purposes. This review will briefly cover the methods of IVET
and STM, discuss how these techniques improved our
understanding of the interactions between zoonotic foodborne
pathogens and their animal hosts, and ask whether these
techniques could be further exploited to better understand
the survival of foodborne pathogens within the environment,
within food matrices, and during inactivation protocols.
Edward G. Dudley
Department of Food Science, Penn State University,
University Park, Pennsylvania.
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International Food Safety Network at Kansas State
University, and is supported at the Gold Fork level by:
Marler Clark.
FSnet is supported at the Sterling Fork level by: CropLife
Canada, Ontario Ministry of Agriculture, Food and Rural
Affairs , New Zealand Food Safety Authority, Monsanto
Canada, and the Ontario Cattlemen's Association.
Fsnet is supported at the Silver-plate Fork level by: The
National Restaurant Association, Unilever, Sholl Group/Green
Giant Fresh, Feedlot Health Management Services, McDonald's,
and Syngenta Crop Protection Canada.
The Food Safety Network presents a unique opportunity to
bring together all those associated with agriculture and
food, to enhance the safety of the food supply. To provide
financial support to the Food Safety Network, please visit
http://www.foodsafety.ksu.edu/en/donations.php. For
information on collaboration or fee-for-service
opportunities, please contact Dr. Doug Powell:
dpowell@ksu.edu
To subscribe to the html version of FSnet, send mail to:
(subscription is free)
listserv@listserv.ksu.edu
leave subject line blank
in the body of the message type:
subscribe fsnet-L firstname lastname
i.e. subscribe fsnet-L Doug Powell
(replace fsnet-L with fsnettext to subscribe to the text
version)
To unsubscribe to the html version of FSnet, send mail to:
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leave subject line blank
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For more information about the FSnet research program,
please contact:
Dr. Douglas Powell
associate professor
dept. diagnostic medicine/pathobiology
Kansas State University
Manhattan, KS
66506
cell: 785-317-0560
fax: 785-532-4039
dpowell@ksu.edu
http://www.foodsafety.ksu.edu
archived at
http://archives.foodsafety.ksu.edu/fsnet-archives.htm
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