1. Dr. Ban sahib abed al-nabi zoonotic disease unit post graduate lecture
Salmonella
Dr. Ban sahib abed al-nabi zoonotic disease unit post graduate lecture

3. Genus : Salmonella

4. Species In human
Diseases
1. S. typhi
Causes typhoid fever
2. S. para typhi
causes para typhoid fever
3. S. enteritidis
causes food poisoning
4. S. typhimurium
In cattle & sheep
1. S. dublin
Enteritis & septicaemia
2. S. typhimurium

5. Species in poultry & bird
Species in goat
Disease
1. S. typhimurium
causes enteritis
2. S. enteritidis =
3. S. hadar
Species in poultry & bird
1. S. pullorum
causes white diarrhoea
2. S. gallinarum
causes fowl typhoid
3. S. arizonae
causes enteritis,septicaemia
4. S. enteritidis =
5. S. typhimurium

6. Salmonella as pathogens Salmonella species are facultative   intracellular pathogens .  Many infections are due to ingestion of contaminated food.  Salmonella serovars can be divided into two main groups—typhoidal and nontyphoidal Salmonella.

7. Nontyphoidal serovars are more common, and usually cause self-limiting gastrointestinal disease. They can infect a range of animals, and are zoonotic, meaning they can be transferred between humans and other animals.

8. Morphology & S taining :
It is a Gram negative bacteria , cocco bacilli or straight rod with rounded ends .
some times they develop into pleomorphic forms or very short coccobacilli after prolonged culture on media .

9. Micro scopic appearance & Incubation period :
G ram stain
Negative
Morphology
cocco bacilli or straight rod with rounded end
Motility
by peritrichous flagella (actively motile) except S. pullorum & S. gallinarum
Capsule
observed with mucoid strains
Spore
Non
Temperature
37 c on media without any addition
Time
hours
Atmosphere
Aerobic & facultative an aerobic

10. Natural Habitat
Salmonellae live in the intestinal tracts of warm and cold blooded animals. Some species are ubiquitous. Other species are specifically adapted to a particular host.
In humans, Salmonella are the cause of two diseases called salmonellosis:
enteric fever (typhoid), resulting from bacterial invasion of the bloodstream
acute gastroenteritis, resulting from a foodborne infection .
The majority of infected animals become subclinical excretors .
Salmonella can survive for 9 months or more in the environment such as moist soil , water , faecal & animal feeds .

11. Isolation & Identification of salmonella :
1.Enrichment broth
Mannitol Selenite broth & Tetera thionate broth & Soy peptone broth for salmonella isolation from stool specimen .
These fluid a useful medium which allows the growth of salmonella but inhibits other enteric organisms .

12. 1. MacConkey agar & desoxy cholate citrate agar : (DCA)
The medium & colonies are pale yellow- straw smooth & non lactose Ferment .
lactose fermenting Non lactose Fermenting
Escherichia coli Salmonella spp
Klebsiella pneumoniae Shigella
proteus

13. 2. Salmonella- Shigella agar (ss agar) :
Its selective for salmonella .
Colonies are colorless with black center .
Non lactose ferment .

14. 3. Xylose lysine desoxy cholate (XLD) :
Red colonies with black centers of H2S producing . Non lactose ferment .

15. Red colonies & medium . Non lactose ferment .
4. Brilliant green agar :
Red colonies & medium . Non lactose ferment .
Smooth circular entire edges .

16. Colonies are black surrounding by metallic sheen on the surface.
5. Bismuth sulfite agar :
Is highly selective for salmonella & one of the most sensitive media to detect H2S production.
Colonies are black surrounding by metallic sheen on the surface.

17. 6. Hektoen enteric agar (HE) :
Colonies are blue-Green with black due to H2S production. Non lactose ferment .

18. Biochemicals test :
salmonella don’t ferment lactose, sucrose but ferment glucose, maltose , mannitol .
positive Negative

19. TSI/ p/y +H2S
simmon citrate +
Motility test/ motil +H2S

20. MR/ positive
VP/ Negative
Negative
urease test -