Listeria, Pseudomonas, Various Anerobes Flashcards Preview

Micro Exam #2 > Listeria, Pseudomonas, Various Anerobes > Flashcards

Flashcards in Listeria, Pseudomonas, Various Anerobes Deck (38)
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1
Q

Describe the physical structure of Listeria monocytogenes

A

Thinnish G+ Rods

Hemolysis on Blood Agar

2
Q

Listeria monocytogenes temperature preference?

A

Psychrophile

3
Q

Listeria monocytogenes is motile at ________

Diptheroids is motile at ________

A

Room Temp, Not 37C

Not room temp, 37C

4
Q

Listeria monocytogenes infection occurs where molecularly?

A

intracellular

5
Q

Clinical presentation on Listeria monocytogenes

A

Native Flora in Animals
Infection following ingestion of infected food
Diarrhea, Dysentery, Meningitis, Bacteremia`

6
Q

Who gets Listeria monocytogenes?

A

IC and Infants

Also, 2 perinatal versions

7
Q

Clinical presentation of early onset perinatal Listeria monocytogenes

A

Stillbirth with granulomas

8
Q

Clinical presentation of late onset perinatal Listeria monocytogenes

A

Infant bacterial meningitis

9
Q

How is Listeria monocytogenes typically contracted?

A

Contaminated Food

Long term refrigerator storage of meats and cheese

10
Q

Pathogenesis of Listeria monocytogenes?

A
Siderophores that bind Fe
Intracellular -- uptake via Internalin
low pH of lyso activated listerilysin O
Break out of lysosome
ActA causes actin to propel Listeria to other cells
11
Q

Name two other bacterium that use Act A mechanism

A

Rikketsia and Shigella

12
Q

How is Listeria monocytogenes treated?

A

Ampicillin preferred
Erythromycin will do in a pinch

No Vaccine because intracellular

13
Q

Physical structure of pseudomonas aeruginosa

A

G- Rod with Single Polar Flagellum
Robust Metabolic Capacity
Fruity Aroma
Blue-green fluorescent pigments

14
Q

Metabolism of pseudomonas aeruginosa?

A

Respiratory, but can use anerobic with NO3

15
Q

Pseudomonas aeruginosa quorum sensing leads to….

A

Biofilm Formation

16
Q

Clinical Presentation of Pseudomonas aeruginosa?

A
Opportunistic, Nosocomial Infections
Skin Biofilms
CF Patients
Otitis Externa
Eye Infections
UTI
Bacteremia/Sepsis (Leukemia Patients)
Ecthyma gangrenosum
Folliculitis
17
Q

Who is most prone to develop Pseudomonas aeruginosa biofilms?

A

Burn Patients, Diabetics

18
Q

What is ecthyma gangrenosum?

A

Erythematous, Non-pyogenic ulcerations

19
Q

Two sources of Pseudomonas aeruginosa folliculitis?

A
Contaminated Water (Hot Tub)
Acne
20
Q

T or F. Pseudomonas aeruginosa is typically foundin the URT flora

A

F. Only in CF patients

21
Q

Pathogenesis of Pseudomonas aeruginosa?

A
Adhesion pili
Hypermutable and Persister Strains
Biofilms deter Phagocytosis
LPs endotoxin
Type 3 secretion system secretes toxins
22
Q

Toxins secreted by Pseudomonas aeruginosa

A

Exotoxin A and S – ADP ribosylation (s sigs apop)
Elastase – Destroy Elastins in the Lungs
Pyocyanin/Pyochelin – Make toxic O2 radicals

23
Q

How is Pseudomonas aeruginosa controlled?

A

Sterile precautions with burn patients
Topical antimicrobials on wounds
Prevent BF formation

24
Q

Best therapy usually for Pseudomonas aeruginosa?

A

Cipro + Aztreonam

25
Q

What should you do before long-term Pseudomonas aeruginosa therapy?

A

Assess resistance profile

26
Q

Significance of Acinetobacter baumanii?

A

Nosocomial infections
Ventilator associated pneumonia, septicemia
Highly Resistant

27
Q

Significance of Burkholderia cepacia?

A

Similar to Pseudomonas aeruginosa

Catheter associated UTI

28
Q

Anerobes typically have a _____ redox potential.

A

Negative

29
Q

How are the low-redox potential regions preferred by anerobes typically maintained?

A

Facultative organisms like E. Coli

30
Q

Physical structure of Bacteroides fragilis

A

G- Rod of the Colon

31
Q

Virulence factors of Bacteroides fragilis?

A

Antiphagocytic Capsule
SOD and CAT (Not as badly affected by O2)
Extracellular Enzymes (Neurominidase, Heparinase)

32
Q

Significance of Prevotella melaninogenicia?

A

Oral G- Coccobacillis

VF: Collagenase

33
Q

Significance of Porphyromonas gingivalis?

A

Oral G-Rod
Gingivitis, Oral Abscess
Also infects other warm, moist areas

34
Q

Significance of Fusobacterium?

A

Oral and Colonic
G- Fusiform
Infectious in osteomyelitis

35
Q

Significance of Peptostreptococcus?

A

Colonic G+ Coccus

Infection of Blood and Pleura/Lungs

36
Q

Significance of Propionibacterium acnes?

A

Epidermal G+ Pleomorphic Rod

Acne and Brain Abscesses

37
Q

Pathogenesis of various anerobes?

A

Normal flora enter unprotected area via trauma

Production of tissue destructive enzymes causes an abscess

38
Q

How to treat anerobes?

A

Drain accumulated fluid
Bacteroides/Prevotella – Metronidazxole and Clinda
Other – Pen G