Lecture 13 10/23/23

Question 1

What are the general characteristics of Salmonella sp.?

Answer 1

-inhabit GI tract
-two species
-many subspecies
-transmission through contaminated food

Question 2

What are the two species of Salmonella?

Answer 2

-S. enterica
-S. bongori

Question 3

What are the characteristics of Salmonella virulence/pathogenesis?

Answer 3

-facultative intracellular
-cause inflammation and systemic dissemination
-septicemia is major problem
-have LPS, flagella, fimbriae, pathogenicity islands
-type 3 secretion system that injects proteins into host cells

Question 4

What are the predisposition factors for Salmonella?

Answer 4

-age
-infectious dose
-alterations in normal flora

Question 5

What disease does S. dublin cause in cattle?

Answer 5

dry gangrene

Question 6

How can Salmonella be diagnosed?

Answer 6

-culture of fecal samples
-culture of blood
-liver, spleen, gall bladder culture
-selenite broth
-tetrathionate broth
-RV broth
-serology
-PCR

Question 7

What are the potential treatments for Salmonella?

Answer 7

-supportive therapy
-possible antimicrobials (controversial)

Question 8

What are the characteristics of Salmonella prevention?

Answer 8

-vaccines unsuccessful
-vx would need to induce both cellular and humoral immunity
-management/hygiene/isolation best practices

Question 9

What does Salmonella cause in horses?

Answer 9

infectious diarrhea

Question 10

Which Salmonella strains are common in horses?

Answer 10

-S. typhimurium
-S. muenchen
-S. newport

Question 11

What are the predisposing factors for horses getting Salmonella?

Answer 11

-stress
-history of surgery
-transport
-feed changes
-GI disorders
-concurrent disease
-antibiotic treatment

Question 12

How can Salmonella be treated in horses?

Answer 12

Polymyxin (binds to circulating endotoxin)

Question 13

How can Salmonella be prevented in horses?

Answer 13

-ID and isolation
-biosecurity practices
-serotyping/genotyping
-awareness and education

Question 14

What are the characteristics of S. pullorum in poultry?

Answer 14

-causes bacillary white diarrhea
-vertical, direct, or indirect transmission
-common in birds < 4 weeks
-survivors become asymptomatic carriers
-can cause septicemia, unabsorbed yolk sac, gray nodules in organs, and death
-testing and removal

Question 15

What are the charactersitics of S. gallinarum in poultry?

Answer 15

-causes fowl typhoid
-vertical or direct transmission
-similar lesions to S. pullorum
-seen in growing or mature flocks
-swollen, friable, bile-stained liver
-necrotic foci
-enlarged GI organs/inflammation
-testing and removal

Question 16

Which Salmonella sp. cause Avian Arizonosis?

Answer 16

S. arizonae and S. diarizonae

Question 17

What are the charactersitics of S. enteritidis?

Answer 17

-very common serotype
-inside eggs that appear normal
-silently infects ovaries of healthy-looking hens
-contaminates inside of eggs before shell formation

Question 18

What are the characteristics of Shigella sp.?

Answer 18

-cause bacillary dysentery
-fecal-oral transmission through contaminated food/water
-causes necrohemorrhagic periodontitis/gingivitis and arthritis
-low infectious dose

Question 19

Which Shigella sp. is important to humans?

Answer 19

S. dysenteriae

Question 20

What are the characteristics of Y. pestis?

Answer 20

-causes plague
-transmitted by wild rodents and their fleas
-bio-agent

Question 21

What types of disease can be caused by Y. pestis in humans?

Answer 21

-bubonic: local lymph node involvement
-septicemic
-pneumonic

Question 22

What does Y. pestis cause in mule deer?

Answer 22

ocular plague

Question 23

How is Y. pestis diagnosed?

Answer 23

-direct smear/staining
-culture
-PCR
-serology

Question 24

How is Y. pestis treated/prevented?

Answer 24

-antimicrobials (streptomycin, doxycycline, gentamicin, chloramphenicol)
-inactivated vx

Question 25

What are the characteristics of Yersinia psuedotuberculosis and Yersinia enterocolitica?

Answer 25

-infections in birds, rodents, and cats
-cause mesenteric lymphadenitis, terminal ileitis, gastroenteritis, and septicemia
-often in colder months
-culture or PCR for diagnosis

Question 26

What are the characteristics of Yersinia ruckeri?

Answer 26

-causes enteric red-mouth disease in fish
-hemorrhagic inflammation of organs causes death

Question 27

What are the characteristics of Enterobacteriaceae generally?

Answer 27

-opportunistic
-emerging antimicrobial resistance
-Proteus, Klebsiella, and Enterobacter sp.