Dr. Hofacre
4/5/2012
Why Do We Care About
Salmonella and Campylobacter?
Chuck Hofacre
The University of Georgia, College of Veterinary Medicine,
Department of Population Health
Poultry Diagnostic and Research Center,
953 College Station Road,
Athens, Georgia 30602-4875
U.S. Foodborne Illness
Illnesses recorded per 100,000 people in FoodNet surveillance:
Source
1996
2010
2010 Healthy People goal
2020 Healthy People goal
Campylobacter
23.6
13.6
12.3
8.5
Listeria
0.46
0.3
0.24
0.2
Salmonella
14.5
17.6
6.8
11.4
STEC O157
2.6
0.9
1
0.6
–
1
N/A
N/A
Shigella
8.9
3.8
N/A
N/A
Vibrio
0.15
0.4
N/A
1
0.3
N/A
STEC non-O157
Yersinia
0.2
0.3
FoodNet information provided by the CDC through reports on illness rates and the June 10 Morbidity and Mortality Weekly Report.
JAVMA, August 15, 2011
Who Wants Diarrhea
and Vomiting?
Who is Driving Food Safety
Change in the U.S.?
• Federal Government
⁻
⁻
⁻
⁻
Administration
CDC
FSIS
FDA
• Consumer Advocate Groups
• International Trade Partners
⁻ Codex Alimentarius (joint WHO/FAO)
“The Most Critical Factor in
Poultry Problems is the ‘Man’ in
Management!”
- Dr. Gross
Deep South Conference, 2012
Poultry meat
• Accounts for up to 50% of human illness
• Other sources include;






Water
Milk
Pork
Beef
Pets
Human to human
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Dr. Hofacre
4/5/2012
Which Salmonella?
New Campylobacter Standards
2007
2008
2009
S. enteritidis
16.9%
20.1%
19.2%
S. typhimurim
16.0%
16.0%
16.1%
S. newport
10.4%
10.1%
12.1%
S. javiana
5.5%
6.3%
8.5%
S. heidelberg
3.9%
----
3.6%
S. saintpaul
----
6.0%
2.5%
• No more than 8 positive samples in a 1 ml
rinse
• No more than 27 positive out of 51 (53%)
samples in the 30 ml or 1 ml rinse
* 2007 & 2009 CDC Foodnet
Old U.S. Salmonella Standards
for Broiler Chickens
USDA Inspector in Charge (IIC) notified time to
test
1.
2.
3.
4.
One carcass/day selected, rinsed and mailed to
USDA-FSIS lab
Testing continues for 51 days (51 carcasses)
13 or more positive (>23.5%) means Failure
3 categories of plants with line speed incentives for
lower Salmonella
New Salmonella Standards
• No more than 5/51 (10%) samples positive
• 3 categories of plants with plants’ names
posted on web for category 2 & 3
• Possibly S.E. testing??
Deep South Conference, 2012
USDA NPIP S.E. Monitored for
Parent Breeders
• Chicks from NPIP SE clean primary
breeder
• Drag swabs at 16-18 weeks and again at
40-45 weeks
• All national data will be complied by
USDA
Campylobacter in Chickens
• Chickens are usually culture positive after 3
wks of age
• Flock exposure may be due to horizontal
transmission from water or broiler house
environment
• Vertical transmission is possible but
controversial
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Dr. Hofacre
4/5/2012
Recent Campylobacter Research
at UGA
Epidemiology
SPECIES
• C. jejuni, C. coli positive breeders
• C.jejuni more commonly present in younger flocks.
• C.coli becomes more prevalent as birds get older, particularly breeders
or organic.
• Flocks will often be infected with both species (Waganaar et al.2008)
• Hatch eggs at UGA
• Broilers reared at UGA till 45 days of age
• Never isolated any campylobacter by
SEASONALITY
• Prevalence significantly higher in summer to fall months (Jacobs-Reitsma
et al.1994, van Asselt et al. 2008)
• Human rates also seasonal, but precede poultry curve (Newell et al. 2000).
Litter
• Deep litter (re-used) – logical source of transmission.
• However; In a study, Campylobacter was not isolated from
experimental birds raised on litter obtained from a C.jejuni positive
broiler flock.(Payne et al.1999).
Darkling beetle
• Persist long time in litter.
• Implicated in vectoring other pathogens.
• Camplyobacter was cultured from beetles in a positive broiler
house (Bates et al.2004)
• One study was unable to culture C.jejuni from beetles more
than 72 hours after experimentally exposed. (Templeton et al.2006)
• Chickens fed beetles which had been exposed to
Campylobacter 7 days previously and were culture negative,
became colonized (Hazeleger et al.2008)
Campylobacter Risk Factors
AUTHOR
Bull
Guerin
Hansson
McDowell
Hue
Russa
COUNTRY
UK
Iceland
Sweden
N.Ireland
France
Holland
Decreased
Increased
culture/filtration
• PCR Negative
On Farm Interventions for
Campylobacter
• Hermans et al.2011 – Review of effect of on farm
interventions.
 Biosecurity can reduce the prevalence of colonized flocks,
but must be properly applied, and is not sufficient alone.
 Drinking water treatments – limited effect
 Feed additives – contradictory data
 Competitive exclusion – contradictory data
 Vaccination – further work required – Salmonella vectored
vaccine shows 6 log reduction(Wyszynska et al.2004)
 Prebiotics – limited potential observed
 Bacteriophages – potentially reduce load by 2 logs, further
work needed, concerns over long term efficacy
 Bacteriocins – promising, more research needed
Salmonella Control: Start at the
top!
RISK FACTOR
Season ‐ Summer to fall
Other livestock species on farm
Storing litter on farm
Spreading litter near house
Increased
Increased
Increased
Elites
Decreased
Increased
Increasing flock size
Increasing number of houses
Increased
Grandparents
Increased
Increased
Increasing flock age
Municipal or cholorinated water
Changing footwear 2x before entering
Changing disinfectant footbath regularly
Decreased
Parent Stock
Decreased
Decreased
Increased
Poor overall tidiness
Rodents observed in or around house
Thinning Poor flock health and welfare indicators
GGP
Increased
Turkeys
Broilers
Layers
Increased
Increased
Increased
Increased
Increased
NO EFFECT
Consumer
Increased
Deep South Conference, 2012
3
Dr. Hofacre
4/5/2012
Potential Sources of Salmonella
Water
Pest Management - Insects
Feed
Beetles
Wildlife
Insects
Litter
Rodents
Hatchery/
Bird Move
Fomites
S.T. can live at least 60 days
Humans
Vehicles
Alphatobius diaperinus
What is a Major Source?
Pest Management
Insects - Flies
•
•
•
•
Common house fly
Egg to adult in 7 days
Larvae need moisture
Travel 1-3 miles to
feed
Musca domestica
Pest Management
•
•
•
•
Insects
Rodents
Wildlife
Cats/Dogs
Pest Management - Rodents
Know how they
live
Water
Feed
Wildlife
Insects
Rodents
Poultry House
Litter
Roof rat
House mouse
Hatchery/
Bird Move
Fomites
Humans
•
Depopulation best time for control
• Location of baiting is determined by species
Vehicles
Norway rat
Deep South Conference, 2012
4
Dr. Hofacre
4/5/2012
Bait Box Salmonella Isolates from June 2009 - May 2011
Live Vaccines
• Will not make Salmonella positive chicks
negative
• Do not provide immunity to all serotypes
• Will reduce fecal shed
• Early protection almost like C.E.
• Don’t prime for the killed
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
20
18
16
14
12
10
8
6
4
2
0
• Protects pullet about 30 days
Kate Hayes, Aviagen, 2011
Drinking Water
• Source of Salmonella??
• Method of spread Wildlife
Insects
Rodents
Water
Killed Vaccines?
• Birds respond poorly to bacterial vaccines
Feed
Litter
Poultry House
Fomites
Humans
Hatchery/
Bird
Move
• Need 2 injections before lay
• Will take 1 year to be effective
Vehicles
Flocks given chlorinated water at least once/week had significantly less
Salmonella (Jones, 1991).
What Controls Have I Tried?
• Vaccination
• Live
• Inactivated
• Water Treatment
Deep South Conference, 2012
Bird Type
Sample
Liners
NO-VAX
0.0%
VAX
0.8%
Pullets
Environment
40.7%
40.6%
0.987
Feed
2.6%
8.0%
0.006
0.617
• Antibiotic Treatment
• Competitive Exclusion • Combinations
• Defined
• Undefined
Correlation Between Vaccination of Pullet Flocks and
Salmonella Prevalence in Broiler Chicken Meat Birds
for Two Poultry Integrators
Breeder
Broiler
P Value
0.033
Total
17.2%
16.5%
Environment
34.0%
35.4%
0.741
Ceca
57.9%
26.2%
<0.001
Liners
Environment
33.8%
30.5%
18.5%
15.1%
<0.001
<0.001
Feed
5.6%
0.0%
0.246
Ceca
29.1%
17.0%
<0.001
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Dr. Hofacre
4/5/2012
Second Vaccination Study
Manipulating Intestinal Flora
6 vaccinated
• 12 breeder flocks
6 not vaccinated
• 4 Drag swabs and 4 Boot socks at 35 and 45 weeks of
age
•
29 from vaccinated
• 58 broiler flocks
29 from not vaccinated
• 4 Drag swabs and 4 Boot socks 1 week before kill
• Ceca at rehang
Results
2nd
Vaccination Study
How Can We Alter the Normal
Flora?
• Undefined C.E.
Breeders:
• Defined C.E. / probiotic
• No difference in Salmonella environmental samples or MPN
per sample
• Yeast or yeast cell wall (MOS)
• Broilers:
•
•
•
• Antibiotics
Vaccinated 14.1% positive
Not vaccinated 25.5%
Vaccinated 50% lower in ceca (MPN = 0.3 log 10 lower)
• Organic Acids
• Controlling intestinal disease, i.e. coccidia,
Clostridium perfringens
* Note – Boot socks again better than Drag Swabs
Defined C.E.
S. heidelberg Counts
Comparison of Salmonella Cecal Culture Challenge
Results After Final Culture
100%
12
100 b
100
86%
98%
90%
10
92%
83%
Vaccinated
Challenge
75%
60
58%
NonVaccinated
Challenge
40
Log 10 S. heidelberg counts
80
% o f P o s itiv e B ir ds
94%
92%
Ceca (CFU)
80%
Drag Swabs %
70%
8
60%
42 a
6
2x
50%
105 b
40%
4
30%
2 x 102 a
20
2
0
0
20%
10%
S. hadar
S. kentucky
S. heidelberg
S. enteritidis
0%
C.E.
Control
C.E.
Control
42 day old broilers
* Bacillus subtilis
Deep South Conference, 2012
6
Dr. Hofacre
4/5/2012
Organic acids in Drinking
Water
•
•
•
•
Used as food preservatives
Spectrum of activity varies with carbon length
Most of effect is in the crop - ↓pH
Theory on function is modify gut flora by
affecting what survives to colonize lower in the
intestine
(J. Dibner 2002,
J. Appl. Poult. Res. 11:453)
Cocci, N.E. and Salmonella
Treatment
Cecal
Cocci
Score
N.E.
Mortality
(%)
D.S. % +
(42 day)
Ceca % +
(42 day)
Negative Control
0.2
0
67
67
N.E. Positive Control
0.5
38
33
7
0
21
0
0
BMD
0.2
16
33
13
Roxarsone + BMD
0.1
12
0
0
Roxarsone
Hofacre, 2007, J. Appl. Poult. Res.
Prevention of Salmonella
• No silver bullet
• No magic potion
• No single remedy
Deep South Conference, 2012
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