1. Salmonella

2. Characteristics of Salmonella enterica
Named after D. E. Salmon
Enterobacteriaceae (many characteristics like E. coli)
Gram negative rod, ~ 1 mm in length.
Facultative anaerobe
Non-spore-forming
Typically motile
Lactose negative
Forms H2S
Is nationally notifiable

3. Nomenclature of Salmonella
S. enterica
Subspecies enterica (I), salamae (II), arizonae (IIIa), diarizonae (IIIb), houtenae (IV), indica (VI)
S. bongori (V)
Salmonella enterica subsp. enterica
Salmonella enterica subsp. I

4. Serovar (serotype) designation
2,541 serovars, 1,504 are within S. enterica subsp. enterica
Kauffman and White
Salmonella enterica subsp. enterica serovar Typhimurium
ser. Typhimurium
Salmonella enterica subsp. enterica 4,5,12 : i : 1,2

5. Salmonella enterica subsp. enterica groups
Common O-antigen
Examples
Antigenic designation A 2
ser. Paratyphi A
1,2,12 : a : - B 4
ser. Typhimurium
1,4,5,12 : i : 1,2 C1 6
ser. Montevideo
6,7 : g,m,s : - C2 8
ser. Newport
6,8 : e,h : 1,2 D 9
ser. Enteritidis
1,9,12 : g,m : - E
3, 10, 15, 19
ser. Senftenberg
1,3,19 : g,s, t: - F 11
ser. Aberdeen
11 : i : 1,2 G
13, 22
ser. Cubana
1,13,22 : z29 : -

6. Top nine Salmonella serovars (CDC, 2006)
Rank
Serovar
No. of cases % 1
Typhimurium
6,982
19.3 2
Enteritidis
6,730
18.6 3
Newport
3,295
9.1 4
Heidelberg
1,903
5.3 5
Javiana
1,324
3.7 6
4, 5, 12: i :-
822
2.3 7
Montevideo
809
2.2 8
Muenchen
733
2.0 9
Saintpaul
683
1.9
% of total cases
64%

7. Growth and survival characteristics
pH range (5.4 acetic acid, 4.0 HCl)
Temperature range for growth (5-47C, opt. 37C)
Heat tolerance
ser. Senftenberg
Vary dependent upon the matrix
Water activity
Effect on heat resistance
Reservoirs

8. Outbreaks (2014, CDC investigated)
Food/other implicated
ser. Braenderup
Nut butter
ser. Newport, Hartford, Oranienburg
Organic sprouted chia powder
ser. Heidelberg
Tyson chicken
ser. Stanley
Raw cashew cheese

9. Disease symptoms Infectious dose Incubation time
Enterocolitis; nonbloody diarrhea; abdominal pain
Duration
Treatment

10. Serovars of particular note
Salmonella enterica subsp. enterica serovar Typhi
Group D; serovar 9,12,Vi : d : -
Salmonella enterica subsp. enterica serovar Paratyphi
Group A, B, and C (Paratyphi A, Paratyphi B, Paratyphi C)
Human specific
Disease can be invasive
Mary “Typhoid” Mallon

11. Serovars of particular note (con’t)
Salmonella enterica subsp. enterica serovar Enteritidis
Particular issue with eggs

12. Schematic view of egg system and potential routes of SE transmission
Breeder house
water
Layer house
Feed
Processing plant
Wash water
Cooling
Packing
Humans

13. Serovars of particular note (con’t)
Salmonella enterica subsp. enterica serovar Enteritidis
Particular issue with eggs
Pennsylvania Egg Quality Assurance Program (PEQAP)
Sample birds, drag swabs of environment
Screen on campus for group D
Submit positive samples to U. Penn for serotyping
Food and Drug Administration mandating for facilities with >3,000 birds

14. Sunland, Inc peanut butter outbreak
Sept 22-25, 2012
CDC investigating ser. Bredeney outbreak, 30 infected, 19 states
63% under the age of 10 (two reasons why)
Oct 5: Traditional epidemiology study
28 interviewed; 21 shopped at Trader Joe’s
19 purchased TJ’s Salted PB with Sea Salt
2 consumed TJ’s Salted PB with Roasted Flaxseed
S. Bredeney isolated from container in patient’s home
Oct 15: Molecular epidemiology
FDA isolates S. Bredeney from Sunland processing facility
PFGE matches isolate from PB container
Recall expanded to include in-shell peanut products from Portales, New Mexico processing plant

17. How did this happen? Maybe clues from another prominent outbreak
Peanut Corporation of America (Georgia)
; 691 ill in 46 states; involved 3,913 products made by 361 companies
Jan 2009 inspection found:
Foot-long gaps in roof of the facility (birds)
Holes in walls (rodents)
Dead insects near peanuts
“retest until negative”

18. Other notable Salmonella outbreaks
Schwan’s ice cream outbreak (1994)
224,000 infected with ser. Enteritidis
Cross contamination of pasteurized ice cream mix with ser. Enteritidis containing liquid eggs
Jewel Company pasteurized milk (1985)
6149 reported ill; ser. Typhimurium
Cross contamination with raw milk
Regents Chocolate outbreak (1974)
200 ill; ser. Eastbourne
Contaminated cocoa beans (resisted roasting and conching)
Tests suggest contamination present at 2.5 cfu/g

19. Control points Farm environment Processing facility At home:
Basic sanitation, hygiene, separating animals from produce
Monitoring programs for ser. Enteritidis
Processing facility
Sanitation
Of plant as well as equipment (ie. harborage sites)
Rodent and bird control
At home:
Separating poultry from non-cooked foods;
Wash your hands after handling reptiles.