Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bacteriology > salmonella > Flashcards

salmonella Flashcards

1
Q

characteristics of salmonella

A
  • gram neg
  • rod shaped
  • facultatively anaerobic
  • motile with peritrichous flagella
  • non lactose fermenter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

is salmonella a zoonotic pathogen?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where does salmonella naturally reside?

A

GI tract of all animals, including fish, and reptiles. Very hardy animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are salmonella’s antigenic characteristics?

A
  • O-antigen
  • H-antigen
  • Vi (virulence or capsular) - S. Dublin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

which subspecies of salmonella is responsible for 99% of animal and human infections?

A

subspecies 1 (enterica)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the mode of infection of salmonella?

A
  1. oral transmission
  2. transovarian transmission (ovary to egg in poultry (yolk))
  3. flies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is a predisposing factor for salmonella

A

STRESS

-shipping, cold, overcrowding, surgery, antimicrobial therapy, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are two major sources of acquiring salmonella?

A

infected animals and asymptomatic carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the virulence factors of salmonella?

A
  • enterotoxins
  • cytotoxins
  • LPS
  • flagella
  • siderophore
  • heat shock proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the characteristics of the enterotoxins of salmonella?

A
  • cholera-like; (LT)
  • heat labile
  • induces fluid secretions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the characteristics of the cytotoxins of salmonella?

A
  • damage intestinal cells
  • three types:
    1. heat labile
    2. low MW protein
    3. cell associated hemolysin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the characteristics of the LPS of salmonella?

A
  • mutants that lack LPS are less virulent
  • cause vascular damage and thrombosis in the intestine
  • responsible for systemic signs: fever, DIC, circulatory collapse, and shock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the characteristics of the siderophores of salmonella?

A

-iron chelators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the characteristics of the HSPs of salmonella?

A
  • outer membrane proteins produces in response to stress

- essential for the survival in macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the two types of salmonella infections?

A
  • intestinal infections

- systemic infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the pathogenesis of intestinal infections?

A
  1. colonization of the intestine
  2. invasion and damage of the intestinal epithelium
  3. stimulation of fluid production and excretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the colonization of the intestine

A
  1. adherence to the enterocytes (receptor mediated)
  2. larger numbers of organisms are required to initiate the disease
  3. stress is a critical factor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe the invasion of the intestinal epithelium of salmonella

A
  1. enter the cells through the microvilli or via the junction complexes
  2. multiply and atack the adjacent cells
  3. enter lamina propria and are engulfed by macrophages
19
Q

what is a key feature to the salmonella’s invasiveness?

A

ability to survive and multiply inside phagocytes

20
Q

what is salmonella enteritis?

A

most often ileum is affected, later spreads to jejunum and colon

  • shortening and distortion of villi
  • degeneration of enterocytes
  • increased emptying of goblet cells (mucus productin)
  • neutrophilic infiltration and migration into the lumen (neutrophilic shedding in the feces)
21
Q

how does salmonella stimulate fluid production and excretion?

A
  1. net secretion of water, bicarbonate and chloride into the lumen
  2. loss of epithelial cells results in impaired absorption
    “diarrhea”
22
Q

what is the key virulence factor of salmonella?

A

LPS

23
Q

what does salonellosis cause?

A
  • enteritis
  • septicemia
  • abortion
  • food borne gastroenteritis in humans (diarrhea)
24
Q

what serotypes cause bovine salonellosis

A

S. Dublin and S. Typhinurium

25
Q

what serotypes cause equine salmonellosis

A
  • S. Typhimurium
  • S. Newport
  • S.Enteritidis
  • S. Heidelberg
26
Q

what serotypes cause swine salmonellosis?

A
  • S. Choleraesuis

- S. Typhimurium

27
Q

what serotypes cause ovine salmonellosis?

A
  • S. Abortusovis
  • S. Typhimurium
  • S. Dublin
28
Q

what serotypes cause canine and feline salmonellosis?

A
  • not very common

- racing greyhounds can get it from eating contaminated raw meat

29
Q

what causes avian salmonellosis

A
  • S. Pullorum
  • S. Gallinarum
  • S. Typhimurium (food poisoning)
30
Q

what are pullorum disease and fowl typhoid?

A
  • in chickens anturkeys
  • rare in commercial farms
  • septicemic diseases
  • transmitted through the egg “transovarian transmission”
31
Q

what causes pullorum disease?

A
  • salmonella pullorum
  • adult birds are resistant bu are carriers
  • excreted in feces
  • mode of infection: transovarian, ingestion, inhalation
  • lesions: caseous areas in the gizzard or lungs
  • diagnosis: serology (agglutination test)
32
Q

what causes fowl typhoid?

A
  • salmonella gallinarum
  • chickens and turkeys
  • excreted in feces
  • mode of infection: transovarian, ingestion, inhalation, or tick-borne
33
Q

what are the signs of fowl typhoid?

A
  • acute septicemic disease, weakness, hyperexcitability, paresis and diarrhea
  • lesions: meningitis, multiple small necrotic areas in the liver and heart
34
Q

what are a few mandatory reportable diseases by the National Eradication Program?

A

Pullorum and Fowl typhoid

35
Q

what causes avain salmonellosis?

A
  • S. Typhimurium

- S. Anatum

36
Q

what is the immunity toward salmonella?

A
  • both humoral and cell mediated
  • secretory IgA may provide local immunity
  • serum IgG against O-specific polysaccharide confers prodection
37
Q

what is the best protection against salmonella?

A

-live attenuated, orally administered vaccine

38
Q

how do you treat salmonellosis

A

antibiotics are useful (must conduct sensitivity test)

-fluid and electrolyte therapy

39
Q

why should you conduct a sensitivity test?

A
  • multiple antibiotic resistance is common
  • the wrong antibiotic may:
    • lead to systemic infection
    • prolong fecal shedding
40
Q

what are some control measures to prevent salmonellosis?

A
  • reduce contamination of the environment
  • eliminate source of infection
  • minimizing stress
41
Q

what are the three sources of salmonellosis in humans?

A
  • typhoid fever
  • enteric fever
  • gastroenteritis (most common)
42
Q

gastroenteritis characteristics

A
  • zoonotic disease

- symptoms: diarrhea, abdominal cramps, chills, fever, nausea, vomiting, headache

43
Q

what two serotypes are multi-drug resistant (MDR) Salmonella?

A
  • Typhimurium DT 104

- Newport

Bacteriology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions