Exam 3: Salmonella

Question 1

What are the 2 species that the Salmonella genus is divided into?

Answer 1

Salmonella bongori

Salmonella enterica

Question 2

What are members of Salmonella enteric (subspecies I) associated with?

Answer 2

99% of Salmonella infections in human and warm-blooded animals

Question 3

Members of other Salmonella enterica subspecies are found in cold-bloodedanimals and the environment except for which?

Answer 3

Salmonella arizonae (subspecies IIIa)

Question 4

Where was Salmonella enterica arizona found?

Answer 4

Originally in reptiles, but it also occurs in fowl and other domestic animals

Question 5

Where is S. typhi found?

Answer 5

Humans

Question 6

Where is S. choleraesuis found?

Answer 6

Pigs

Question 7

Where is S. dublin found?

Answer 7

Cattle

Question 8

Where is S. pullout and S. galinarum found?

Answer 8

Poultry

Question 9

What are the most common sources of salmonella for people?

Answer 9

Animals and their products, especially meat and poultry, milk and pet turtles

Question 10

What did the FDA do in 1975? Why?

Answer 10

Banned the sale and distribution of turtles with a shell length of less than 4 inches in size as pets because they are often linked to salmonella infections, especially in young children

Question 11

What are the 2 major form of disease with salmonella?

Answer 11

Enteritis and septicemia (typhoid)

Question 12

What are major sings of the enteritis form of disease?

Answer 12

Fever
Anorexia
Depression
Foul-smelling, watery feces that often contains fibrin, mucus, and blood

Question 13

What may septicemia lead to?

Answer 13

Pneumonia
Meningitis
Polyarthritis in the young
Agalactia and abortion in adults

Question 14

What are the common species of salmonella in horses?

Answer 14

S. typhimurium (most common)

S. anatum

Question 15

What are the clinical signs of salmonella in horses?

Answer 15

Acute colitis with profuse diarrhea, sometimes abdominal pin

Usually febrile

Question 16

What makes horse more susceptible/predisosed to salmonella infections?

Answer 16

Highly contagious and adult horses are susceptible

Colic, GI surgery, and antimicrobial therapy predispose

Question 17

What can occur in neonate horses due to Salmonella?

Answer 17

Septicemia

Question 18

What are the serovars that cause enteritis in humans?

Answer 18

Typhimurium
Enteritidis
Newport

Question 19

What causes systemic disease in humans?

Answer 19

Typhi

Question 20

What are the serovars in cattle?

Answer 20

Typhimurium
Dublin
Newport

Question 21

What age is the most common for cattle to be infected?

Answer 21

4-6 weeks old

Question 22

What do the serovars cause in cattle?

Answer 22

Diarrhea,often with blood, usually with fever

Question 23

What does septicemia caused by Dublin in calves cause?

Answer 23

Pneumonia

Question 24

What are the serovars in pigs?

Answer 24

Typhimurium

Choleraesuis

Question 25

At what age is infection the most common in pigs?

Answer 25

Weaned pigs less than 5 months old

Question 26

What does Typhimurium cause?

Answer 26

Enterocolitis

Question 27

What does Choleraesuis cause?

Answer 27

Septicemia

Question 28

What are the 3 diseases in chickens and what causes them?

Answer 28

Paratyphoid: motile salmonella (anything but pullorum and gallinarum)
Pullorum disease: S. pullorum
Fowl typhoid: S. gallinarum

Question 29

What do S. typhimurium and S. enteritidis do?

Answer 29

Infect a wide range of animals and humans causing self-limited enteritis

Question 30

What does host adapted S. typhi cause?

Answer 30

Systemic illness in humans (typhoid)

Question 31

What is a major source of infection for salmonella?

Answer 31

Carrier state

Question 32

What are the virulence factors of salmonella?

Answer 32

Type III secretion system

Effector proteins

Question 33

Describe capsule-Vi antigen

Answer 33

Not antiphagocytic, but protect from complement

Question 34

What is the pathogenesis of intestinal infection for salmonella?

Answer 34

Oral route to intestine
Association with enterocytes mediated by fimbriae– M cells are the primary target
Invasion of enterocytes by receptor-mediated endocytosis by type III secretion system
Bacterial proteins disrupt enterocyte function and cause release of cytokines (IL8), which recruits neutrophils that invade and transcytose to intestinal lumen
Neutrophils release prostaglandins, causing adenylate cyclase activity in intestinal cells, increased cAMP, disrupts NaCl pumps
Diarrhea is secretory and exudative without enterotoxin production

Question 35

Describe the pathogenesis of systemic infection

Answer 35

Salmonella that persist in profession phagocytes are protected from antibody and can spread to cause systemic infection, particularly with host-adapted serovars
Survives in special Salmonella modified vacuoles that fail to fuse with lysosomes

Question 36

What provides the best protection against Salmonella? What does it stimulate?

Answer 36

Live vaccines

Stimulates CMI

Question 37

Is there antibiotic treatment for Salmonella?

Answer 37

It is controversial

Question 38

Describe a feature of Salmonella species in laboratory diagnosis

Answer 38

Most are non-lactose fermenters, except for S. arizonae group

Question 39

What animals is Salmonella enterica arozinae found in?

Answer 39

Reptiles
Chicks
Turkey poults

Question 40

What does Salmonella enterica arozinae cause?

Answer 40

An acute septicemic disease of young turkey poults known as arizonosis

Question 41

What does Klebsiella cause?

Answer 41

Pneumonia and pyosepticemia in foals

Mastitis in cows (coliform mastitis)

Question 42

What is Enterobacter-Serratia often lumped with?

Answer 42

Klebsiella as KES group

Question 43

What does Enterobacter-Serratia cause?

Answer 43

Mastitis in cows (coliform)