1. Salmonella infection

2. Salmonella infection
The genus Salmonella are Gram-negative, non-spore-forming rods.
Most species are motile, although a few such as S. gallinarum and S. pullorum are non-motile.
There are more than 2000 Salmonella serotypes, based on cell wall "O" and flagellar "H" antigens.
The genus comprises two species: S. enterica, which is subdivided into over 2000 serovars or serotype , and S. bongori.
Some serovars of S. enterica such as S. typhi cause systemic infections and typhoid fever, whereas others such as S. typhimurium cause gastroenteritis.

3. Some serovars such as S. typhi are specialists which infect only humans, but others such as S. typhimurium are generalists which can infect humans and many other animals.
Infection with bacteria of the genus salmonella is responsible for a verity of acute and chronic disease in poultry

4. Pullorum Disease
Was once of the most important disease in poultry, “Bacillary white diarrhea.”
Reportable disease.
Causative Agent
Salmonella Pullorum
Non motile – Gram (-) rod
Bacteria location
Chicks and poults – internal organs, yolk sac and blood stream.
Mature birds “carriers” – ovaries, testes and gall bladder.

5. Incubation Period 7 to 10 days Course of Disease 2 to 3 weeks Mortality In chicks and poults less than 2 weeks old, up to 100%
Method of Spread
“Carrier” layers – transovarian. This allows eradication.
Infected hatchers – automated incubators allowed pooling of eggs and lateral dissemination of pullorum.
Dead or moribund chicks in hatcher or dead in the shell.
MATURE BIRDS – seldom die.

6. Clinical Signs
Chicks and Poults
Some chicks may be moribund or dead soon after hatch – clinical presentation appears the same whether transovarian or hatchery transmission.
Mortality starts at 5-10 days old and peaks at 2-3 weeks of life.
Appear cold, anorexia, whitish diarrhea that causes pasted vent. Painful defecation.

7. Adults
Usually without signs
Fertility and hatchability reduced
Postmortem Lesions
Chicks and Poults
Peracute – lesions absent, rapid mortality.
Acute
-Liver – enlarged, congested, yellow streaks with hemorrhages. Use caution with interpretation because a yellowish tinge to liver is normal in young chicks.

8. -Omphalitis – solidified yolk.
This occurs because the bacteria digest the carbohydrates in the yolk.
This produces acid which coagulates the protein.
So young birds have problems absorbing the yolk.
-White nodules in heart, liver, lungs, ceca, large intestines, and gizzard muscle.
-Kidneys congested and urate filled.
-Swollen hock and wing joints filled with exudate.
-Caseous cecal cores.

9. Adults
-Misshapen, discolored, caseous ova.
-Nodular pericarditis.
-Peritonitis with internal ovulation.
-Testicular abscesses.
Differential Diagnosis
- Chilling or overheating.
- Omphalitis.
- Other Salmonellas and E. coli.
- In adults similar to other septicemic diseases.

10. Diagnosis
Suggestive Diagnosis – High mortality in chicks and poults during first two weeks of life plus lesions. Look for cecal cores.
Positive Diagnosis – Isolation and identification of causative agent.
Culture the gall bladder, yolk sac and gut. Non-motile
Serological Testing- Agglutination Blood Test – Indicates infected breeder flocks.
Tube agglutination test done after 16 weeks. Stained antigen whole-blood test accepted for chickens, not turkeys.

11. Control
Establish and maintain Pullorum-free breeders.
Serological testing – stained antigen whole blood test.
Purchase chicks and poults from healthy hatcheries.
Organism in hatchery can be killed by formaldehyde fumigation.
Non-pullorum reactors (false +) can occur on testing.
This problem is overcome by careful bacteriologic exam of suspicious reactors.

12. The false positives are usually caused by common cross-reactive antigens possessed by other bacteria.
Treatment I
Birds usually destroyed (killed) in U.S. and Canada
Treatment II
Drugs will not eliminate infection from a treated flock, and will perpetuate the carrier state.
Mortality can be controlled with:
Sulfonamides: i.e. Sulfamerazine can’t use sulfa in egg hens.
Antibiotics: tetracyclines, gentamycin, and spectinomycin.
Nitrofurans: effective but illegal in U.S.

13. Fowl Typhoid
A septicemia seen primarily in chickens, also in turkeys and other avian species, it looks very similar to pullorum disease.
This is common internationally due to lack of eradication programs.
This disease can continue for months and can be seen in young adults or mature fowl, due to the stress of coming into production.
Reportable

14. Causative Agent
Salmonella gallinarum
Closely related to S. pullorum but biochemically different, S. pullorum & S. gallinarum: Antigenically identical (complete cross agglutination) (S. enteritidis also cross-agglutinates).
Method of Spread
Vertical from carriers (Transovarian)
Lateral from carriers

15. Rats and wild birds
Human traffic
Incubation Period
4 to 5 days
Course of Disease 5 days in acute cases. Losses may extend over 2-3 weeks period. Mortality Variable, if acute may range up to 50%.

16. Clinical Signs
Chicks and Poults – Similar to pullorum
Infected eggs yield moribund and dead chicks
Whitish pasty vents, Anorexia, Labored breathing,
Growing and Mature Birds Drop in feed consumption, Depressed and pale
High fever (up to 112ºF), Normal body temperature – 104ºF
Greenish diarrhea – catarrhal enteritis
Death in 4 to 10 days after exposure

17. Postmortem Lesions
Same as pullorum with a tendency for enlarged (2-3x) dark spleens in acute cases and mahogany or greenish-bronze livers in subacute and chronic cases.
Focal areas of necrosis in the heart and grayish lungs are also apparent.
Comment
This disease is usually very acute, and dead birds will be found on the nest and on the floor. These birds may not have lesions.

18. Differential Diagnosis
Abscesses in lungs and viscera in chicks unique to typhoid and pullorum
In adults similar to other septicemic diseases (fowl cholera, AI,ND)
Reaction to agglutination test helpful in chronic cases

19. Diagnosis
Suggestive Diagnosis – High mortality in hens, showing described lesions
Positive Diagnosis – Isolation and identification of the causative agent from liver and/or spleen.
Serological testing – stained antigen whole blood test.
Control Program
Voluntary regulatory program reactors must be disposed of under supervision of state regulatory agency.
Flock usually destroyed.
Premises decontaminated.
Culture Methods
Similar to other Salmonellae except:
Slow to variable H2S production
Non-motile

20. Treatment
Same as S. pullorum treatment I. (destroy) & II. (Treat to control mortality).
Prevention
An attenuated vaccine strain 9R of S. gallinarum is being using with success in some foreign countries that do not have successful eradication programs.

21. Paratyphoid Infections
All Salmonella infections in poultry other than S. pullorum, S. gallinarum, and S. arizona.
They are not host specific and infect many types of animals.
Public health significance is more important than bird health – these cause food-borne illness.

22. Causative Agent
Many species of Salmonella.
Have somatic and flagellar antigens.
These Salmonella are motile.
Survive and multiply in most environments.
S. typhimurium most frequently isolated from young poultry.
This is more common in turkeys than in chickens.

23. Comment
Salmonella paratyphoid: approximately 200 serotypes found in poultry.
Approximately 10 or 12 serotypes cause most problems.
S. enteritis, S. typhimurium (most frequently involved), S. Montevideo, S. newport 75% of all poultry infected at some time in life with one or more serotypes.
Important problem in hatchery sanitation. It serves as a barometer of egg shell and chick quality problems.
These organisms are motile so are more common.

24. Comment
S. enteritidis important in human outbreaks.
It is most severe in old, very young, and immuno-compromised people.
Large percentage of the outbreaks related to consuming eggs.
This organism is found contaminating chicken ovaries.
Rats and mice strongly involved in epidemiology.
S. enteritidis, S. pullorum, and S. gallinarum are all type D Salmonella, so testing protocol for pullorum and typhoid also detects S. enteritidis.

25. Clinical signs
Signs usually are seen only in young birds (less than 7 weeks),
profuse diarrhea followed by dehydration, pasting or wetting of the vent area, drooping wings, shivering,
there usually is high morbidity and mortality although these are variable.

26. Lesions
There may be few lesions in birds that die after a short septicemic course, perhaps a few petechial hemorrhages.
Dehydration and marked enteritis, often with focal necrotic lesions in the mucosa of small intestine.
Occasionally there are necrotic foci in the liver. In young birds there often is unabsorbed yolk material in the yolk sac.
Less frequently lesions include blindness, arthritis or swollen eyelids.

27. Avian Arizonosis
Similar to other Salmonella infections, seen mainly in turkeys less than three weeks of age.
Causative Agent
Salmonella arizona
This organism differs from other salmonellas biochemically and serologically.
It is motile.
Incubation Period 4 to 5 days
Course of Disease 5 days in acute cases with losses extending over 2-3 weeks

28. Mortality
5-10% in young birds.
Occasionally up to 60% if exposed at hatching time.
No mortality in adult birds; they become carriers.
Method of Spread
Transovarian transmission in turkeys
Egg shell contamination
Hatchery contamination – lateral transmission
Carrier birds, fecal contamination
Biological vectors – rats and mice

29. Clinical Signs
Similar to other Salmonellas –diarrhea, listless, huddling, mortality.
Often blindness and nervous signs are seen in poults.
Opacity of anterior chamber of eye in poults
None in adult carriers

30. Postmortem Lesions
Same as other Salmonellas; Eye lesions (opacity) in poults very common
Omphalitis, Cecal cores
Diagnosis
Isolation and serotyping.
Culture Methods
Similar to other Salmonellas

31. Treatment
Injection of streptomycin, spectinomycin, or gentamycin at the hatchery is used in some countries. Formerly in-feed medication with nitrofurans was also used.
Prevention
Eradicate from breeder population, fumigation of hatching eggs, good nest and hatchery hygiene, inject eggs or poults with antibiotics and monitor sensitivity.
Control
Controlled by egg-dipping (Gentamycin).
Turkey breeders vaccinated at weeks. Use autogenous bacterins.