More Related Content Similar to Dr. Purnedu Vasavada - Current and Emerging Organisms in Raw Milk that Affect Public Health (20) Dr. Purnedu Vasavada - Current and Emerging Organisms in Raw Milk that Affect Public Health1. Current and Emerging Organisms in Raw Milk
that Affect Public Health
Dr. Purnendu C. Vasavada
Animal and Food Science Department
University of Wisconsin - River Falls
River Falls, WI 54022
Presented at
2010 NIAA Annual Meeting
Kansas City, MO.
March 15-17, 2010
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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2. Main Objective
To review current and emerging pathogens in raw
milk, including the “less recognized” and
“presumptive” pathogens in the context of safety and
public health risk associated with consumption of
raw milk and in milk products manufactured from
unpasteurized milk
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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3. Milk Mustaches… What, Me Worry?
Raw Milk: =
Alfred E. Newman
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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4. Outline
Introduction
Microorganisms in milk
Sources of microorganisms
Pathogens in Milk – Historical aspects
Current and Emerging Pathogens
Less recognized and presumptive pathogens
Summary
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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5. UW River Falls
UW River Falls
30 th UW River Falls
Food Microbiology Symposium and Rapid Methods in Food
Microbiology Workshop
River Falls, WI.USA , October 17-20, 2010
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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6. Significance of Microorganisms in Milk
Quality and shelf life
Regulatory and vendor compliance
Fermentation, starter cultures, flavor
organisms, adjunct flora, probiotic organisms
Safety - Pathogens, toxins, biosecurity
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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7. Microorganisms in milk
Bacteria
Yeast and molds
Viruses/Bacteriophages
Rickettsiae
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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8. Important spoilage microorganisms-
Bacteria
Bacillus* Achromobacter*
Corynebacterium Acinetobacter*
Clostridium Alcaligenes*
Enterococcus Enterobacter
Lactobacillus Escherichia
Listeria*
Flavobacterium
Microbacterium
Moraxella*
Micrococcus
Proteus
Pediococcus
Weisella
Schewanella
Psychrotrophic
Zymomonas
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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9. Important spoilage microorganisms -
Yeast and Molds
Yeasts Molds
Candida Alternaria
Cryptococcus Aspergillus
Debaromyces Aureobasidium
Rhodotorula Botrytis
Torulopsis Cladosporium
Yarrowia Geotrichum
Mucor
Penicillium
Rhizopus
Thamnidium
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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10. Sources of microorganism in Raw Milk
Milk from the healthy animal is usually sterile
Contamination may occur from
Cow (Mastitis, Systemic disease (Bovine Tuberculosis)
Skin microflora
Environmental contamination (air, soil,dus), water,
manure, bedding material (sawdust), silage
Equipment (milking equipment, pipe-line, utensils, drains,
transportation trucks
Vector ( insects , flies)
Humans ( personnel: milkers and milk handlers
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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11. Raw Milk and Public Health Threat
Raw milk recognized since early 1900s as a significant source
of diseases
Pasteurization introduced in 1906, PMO developed in 1924
Milkborne outbreak constituted 25% of all disease outbreaks
due to contaminated food and water, today, less than 1% of all
outbreaks attributed to contaminated milk and milk products.
Raw milk sales controlled or banned in over 40 states.
87% of raw milk outbreaks during 1973-1992 in states that
permit intrastate sale
Position statements and scientific consensus about public
health risk of raw milk
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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12. Public Health, Regulatory and Educational
Organizations’ Position on Raw Milk Issue
American Veterinary Medical Association (AVMA)
Association of Food & Drug Officials (AFDO)
Health Canada
National Association of State Departments of Agriculture
(NASDA)
National Association of State Public Health Veterinarians
(NASPHV)
National Conference on Interstate Milk Shipments
(NCIMS) program
State regulatory agencies
University cooperative extension programs
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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13. Raw Milk and Public Health Threat
Raw milk demand growing
Political pressure on relaxing/overturning milk
pasteurization regulations/allowing sale of raw
milk
Less then 0.5% of U.S. milk is consumed
unpasteurized.
Yet, raw milk and cheese result in approximately
twice the outbreaks as conventional products
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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14. Growing Demand for Raw Milk
and activism
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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15. Hearing Held About Legalizing Raw Milk
Mar 10, 2010
EAU CLAIRE, Wis. (AP) -- Hundreds of people packed a
legislative hearing in Eau Claire Wednesday on legalizing
the sale of unpasteurized milk.
The proposed legislation would allow consumers to buy
raw milk directly from a farm and give dairy farmers
immunity from liability if someone got sick drinking the
unpasteurized product.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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16. © Dr. P.C. Vasavada.2010 All Rights Reserved.
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18. Pathogens identified in unpasteurized dairy
Products associated illness outbreaks, U.S.,
1990-2006
• Source: SCPI Outbreak Alert! Database, 2008.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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19. Bellingham company recalls raw milk due to
E. coli fears
Posted on February 24, 2010 by Drew Falkenstein
a Bellingham, Washington company called
Jackie's Jersey Milk recalled raw milk
product due to possible contamination by
E. coli O157:H7.
The contamination was detected during
routine sampling and testing of the
company's products by the Washington
State Department of Agriculture.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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20. © Dr. P.C. Vasavada.2010 All Rights Reserved.
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21. Tuesday, March 16, 2010 • WALWORTH COUNTY, WI
State orders Elkhorn farm to stop raw milk sales
through cow-share program
ELKHORN — State agriculture officials have ordered an Elkhorn farm to stop
selling raw milk through a cow-share program after more than two dozen
people fell ill.
The order against Zinniker Farm Inc., says 35 people from Walworth,
Waukesha and Racine counties have been diagnosed with campylobacter
jejuni since Aug. 13. That’s a bacterial infection that causes diarrhea, cramping
and vomiting.
All the victims said they had consumed raw milk. Thirty of them said they got it
from the Zinniker farm. Tests matched campylobacter jejuni found in 29
victims’ feces to campylobacter jejuni found in cow feces on the farm.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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26. E. Coli in raw milk sends kids to the hospital
December 13, 2005
By Brian Barker
and KATU Web Staff
VANCOUVER, Wash. - If you or your children have been
drinking unpasteurized milk or been experiencing diarrhea, you
might want to get checked out by a doctor.
The Clark County Health Department says
they have confirmed six cases of E. coli have
in children between the ages of 5 and 19.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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27. FDA Warns Consumers to Avoid
Drinking Raw Milk
E coli outbreak in Washington
blamed on raw milk
Raw milk distributors targeted
by regulators
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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28. © Dr. P.C. Vasavada.2010 All Rights Reserved.
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29. E. coli 0157:H7 infection associated with
Unpasteurized Goat’s Milk
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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30. UK: Threat of E-coli contamination spreads
23 Dec 2005
Source: just-food.com
Fears that certain brands of camembert may be
infected with the dangerous strain of E-coli, 026, have
spread to include other raw milk products imported
from France, the Food Standards Agency (FSA)
announced yesterday (23 December).
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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31. © Dr. P.C. Vasavada.2010 All Rights Reserved.
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32. Pathogens in Raw Milk -
Historical aspects
M. tuberculosis
C. diptheriae
C. burnetii
Staph. aureus
Salmonella
Streptococci
Brucellae
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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33. Pasteurization statutes - 1906/ PMO adoption
“TB Free” and “Brucella Free” status of dairy herds
“Certified” milk movement
Refrigeration of milk
On-farm hygiene and milk quality programs
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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34. Current and Emerging Pathogens
Salmonella spp. Emerging Pathogens are infectious
E. coli 0157:H7 agents whose incidence in humans has
increased dramatically within the past two
Listreia monocytogenes*
decades, or one that has the probability
Yersinia enterocolitica* of increasing in future
Staphylococcus aureus CDC (1994)
Clostridium spp.
Bacillus cereus*
* Pyschrotrophic
Campylobacter jejuni
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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35. Pathogens in raw milk
Several well designed studies to assess incidence of
pathogens in raw milk
Steel et al. 1997 Ontario Bulk Tank Raw Milk
Jayarao and Henning 2001. Bulk tank milk in SD and
Western Mn
Waak et al. 2002. Listeria monocytogenes in raw milk in
Swedish dairy
Karns et al 2005. Salmonella enterica in bulk tank milk by
PCR
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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36. Pathogens in Bulk Tank Milk
Pathogen %
Campylobacter 2 – 9.2%
E. coli O157:H7 0 - 0.75%
Listeria monocytogenes 2.8 - 7.0%
Salmonella spp 0 – 11%
Shiga-toxin E. coli Oliver et-al (2009
2.4 3.96%
Yersinia enterocolitica 1.2 – 6.1%
Oliver et al (2009)
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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37. Pathogens in raw milk*
Pathogen % positive
Campylobacter jejuni 0.4 – 12.3 %
E. coli 0157:H7 0.8 – 3.8%
Salmonella spp. 0.2 – 8.9%
L. Monocytogenes** 1.0 – 12.6 %
Y. enterocolitica 11.3 - 89%
• Compiled from Several International studies, Oliver et al. 2005.
** Incidence of L.M. in raw milk varies from 0 %- 45.3 %
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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40. Less Recognized and Suspected Pathogens
Changing Paradigm –
Microorganisms: The Good Bad and Ugly
Beneficial Organisms
Spoilage Organisms
Recognized and emerging pathogens
New category:
Less recognized/ presumptive /opportunistic
pathogens
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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41. Less Recognized and Suspected
Foodborne Pathogens
Enterobacteriaceae
Helicobacter and Arcobacter
Spore forming organisms
Lactic acid bacteria
Coryniform and Mycobacteria
Zoonotic organisms
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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42. Less Recognized and Suspected Foodborne
Pathogens
Enterobacteriaceae
Citrobacter spp., 5 outbreaks 3 attributed to
milk
Klebsiella. Isolated from milk, milk products,
water, vegetation
Spore forming organisms
Bacillus cereus, B. brevis, B.licheniformis
Clostridium perfringens
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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43. Enterobacter sakazakii
Linked to deaths of premature infants in neonatal
intensive care units
Reconstituted infant formulae
Several recalls of infant formulae
Environmental contamination
C. sak
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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44. E. Sakazakii
Necrotizing enterocolitis, sepsis,
meningitis in neonatal infants
Powdered milk-based infant formulae
recognized as a vehicle for infection
Outcome poor (fatality rate 40 - 80%)
Wide spread in environment
Variable heat resistance
Biofilm production
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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45. E. sakazakii - Heat Resistance
Thermal Death Time Curves for
2 E. Sakazakii Heated at 58°C
D = 591.9 sec
D = 30.5 sec
E. sakazakii- Biofilm Formation
Stainless Steel: Adherent Micro-Colonies
Hoescht Stain of ES after attachment (1:10 TSB – 4 h, RT),
rinsing and Incubation (TSBReserved. and 48 h at 37oC)
© Dr. P.C. Vasavada.2010 All Rights – 24 h
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46. Less Recognized and Suspected
Foodborne Pathogens
Zoonotic pathogens
Mycobacterium paratuberculosis
Brucellosis
Q fever
Leptospirosis
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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47. Mycobacterium paratuberculosis (MAP)
Johne’s and Crohn’s disease
Detection and isolation of M. paratb.
Heat inactivation of MAP
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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48. Other Mycobacterium spp.
M. bovis
M. scrofulaceum
Associated with infected lymph nodes
in children
isolated from raw milk
M. gordonae
“tap water bacillus”
Isolated from raw milk and water
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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49. Brucellosis
Zoonoses affecting farmers, Vets
Undulant fever, Malta fever
B.abortus, B. melitensis, B.suis
Brucellosis outbreak associated with soft
cheese from unpasteurized sheep and
goat’s milk and travel to endemic areas
Trends in Raw milk/Cheese consumption
Disease making a come back?
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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50. Less Recognized and Suspected
Foodborne Pathogens:”LAB”
Streptococci
S.pyogenes, S. agalactiae S. zooepidemicus
Enterococci
E. durans, E, feacium, E. fecalis
Lactobacillus, Lactococcus,
Leuconostock &
Pediococci
All isolated from human infection
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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51. Less Recognized and Suspected
Foodborne Pathogens
Streptobacillus moniliformis
Pleomorphic Gram negative rods
Acute illness associated with rat- bite fever
1926 Haverhill fever traced to raw milk
consumption
Coryniform bacteria
C. diptheriae, C. bovis, C. ulcerans
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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52. Less Recognized and Suspected
Foodborne Pathogens
Protozaon parasites
Cryptosporidium
Giardia
Toxoplasma gondii – Raw Goat’s milk
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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54. Q Fever in The Netherlands
December 16, 2009 An outbreak of Q fever
2,293 human cases have been confirmed
in 2009, including 6 deaths
Part of the ongoing outbreak of Q fever in
the Netherlands since 2007
190 cases (2007)1,000 cases in 2008.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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55. Coxiella burnetii
a highly infectious agent
resistant to heat, drying, and many
common disinfectants, allowing it to
survive for a long time in the environment.
can become airborne and inhaled by
humans.
could be developed for use in biological
warfare and is considered a potential
terrorist threat.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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56. Q Fever - Recommendation-
Eat only milk and dairy products that have
been pasteurized.
Do not drink raw milk or eat raw milk
products.
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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57. Summary
Raw milk is a recognized source of pathogen
Inadequate Some organisms pose special
challenge due to their slow growth, low occurrence
or special characteristics
Detection challenges and approaches
Education, awareness and implementation of
preventative strategies (HACCP)
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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58. Emphasis on Dairy Products
Quality and Safety
Quality Control
Quality Assurance
TQM
Quality Systems
HACCP
TQM
GMPs
HACCP
Hygiene
On-Farm HACCP ?
Microbes play a significant role in food quality and safety
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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59. Detection Challenge
Many suspected pathogens are :
Slow growing fastidious organisms
VNC
Similar to other contaminating flora
Do not grow readily on microbial media
….and hence the need for novel
approaches and methods
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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60. Detection Challenge: MAP, Parasites and
viruses
On-farm “quick tests” in most cases have
not been tested or approved for use in milk
Assays typically do not have the sensitivity or
specificity to detect/indentify pathogens such as
E. coli O157:H7
Multiplex detection not possible
Molecular methods?
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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61. PCRs, Biosensors and Microarrays:
MAP, Parasites and viruses detection
Rapid Progress made in
and characterization methods and
approaches
Symposia, workshops worldwide for
research dissemination and training
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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62. UW River Falls
Food Microbiology Symposium
30 th UW River Falls You are invited!!!
Food Microbiology Symposium and Rapid
Methods in Food Microbiology Workshop
River Falls, WI.USA
October 17-20,2010
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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63. Conclusion
Raw milk and unpasterurized milk product
consumption continues to cause illness and
outbreaks
Inadequate regulations restricting raw milk and
unpasterurized milk product
Unpasteurized product outbreaks are more
common and cause more severe illness than
pasteurized product outbreak
Educate consumers, public health partners and
legislators about health risks of consuming
unpasteurized products
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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64. Raw Milk Safety : Control of Pathogens
“First priority in producing dairy foods: produce safe foods.”
“To produce safe dairy products, it is vital to understand the
causes of foodborne illness and the peculiarities of the
organisms involved”
Elmer H. Marth, Emeritus Professor , UW- Madison
‘It is very difficult to get a person to understand something
when his/her salary depends on not understanding it.’
Upton Sinclair from The Jungle
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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65. Acknowledgement
Thank You !! Any Questions ???
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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66. See you in Wisconsin !!
© Dr. P.C. Vasavada.2010 All Rights Reserved.
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