Listeria, Pseudomonas, Various Anerobes Flashcards
Describe the physical structure of Listeria monocytogenes
Thinnish G+ Rods
Hemolysis on Blood Agar
Listeria monocytogenes temperature preference?
Psychrophile
Listeria monocytogenes is motile at ________
Diptheroids is motile at ________
Room Temp, Not 37C
Not room temp, 37C
Listeria monocytogenes infection occurs where molecularly?
intracellular
Clinical presentation on Listeria monocytogenes
Native Flora in Animals
Infection following ingestion of infected food
Diarrhea, Dysentery, Meningitis, Bacteremia`
Who gets Listeria monocytogenes?
IC and Infants
Also, 2 perinatal versions
Clinical presentation of early onset perinatal Listeria monocytogenes
Stillbirth with granulomas
Clinical presentation of late onset perinatal Listeria monocytogenes
Infant bacterial meningitis
How is Listeria monocytogenes typically contracted?
Contaminated Food
Long term refrigerator storage of meats and cheese
Pathogenesis of Listeria monocytogenes?
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
Name two other bacterium that use Act A mechanism
Rikketsia and Shigella
How is Listeria monocytogenes treated?
Ampicillin preferred
Erythromycin will do in a pinch
No Vaccine because intracellular
Physical structure of pseudomonas aeruginosa
G- Rod with Single Polar Flagellum
Robust Metabolic Capacity
Fruity Aroma
Blue-green fluorescent pigments
Metabolism of pseudomonas aeruginosa?
Respiratory, but can use anerobic with NO3
Pseudomonas aeruginosa quorum sensing leads to….
Biofilm Formation
Clinical Presentation of Pseudomonas aeruginosa?
Opportunistic, Nosocomial Infections Skin Biofilms CF Patients Otitis Externa Eye Infections UTI Bacteremia/Sepsis (Leukemia Patients) Ecthyma gangrenosum Folliculitis
Who is most prone to develop Pseudomonas aeruginosa biofilms?
Burn Patients, Diabetics
What is ecthyma gangrenosum?
Erythematous, Non-pyogenic ulcerations
Two sources of Pseudomonas aeruginosa folliculitis?
Contaminated Water (Hot Tub) Acne
T or F. Pseudomonas aeruginosa is typically foundin the URT flora
F. Only in CF patients
Pathogenesis of Pseudomonas aeruginosa?
Adhesion pili Hypermutable and Persister Strains Biofilms deter Phagocytosis LPs endotoxin Type 3 secretion system secretes toxins
Toxins secreted by Pseudomonas aeruginosa
Exotoxin A and S – ADP ribosylation (s sigs apop)
Elastase – Destroy Elastins in the Lungs
Pyocyanin/Pyochelin – Make toxic O2 radicals
How is Pseudomonas aeruginosa controlled?
Sterile precautions with burn patients
Topical antimicrobials on wounds
Prevent BF formation
Best therapy usually for Pseudomonas aeruginosa?
Cipro + Aztreonam
What should you do before long-term Pseudomonas aeruginosa therapy?
Assess resistance profile
Significance of Acinetobacter baumanii?
Nosocomial infections
Ventilator associated pneumonia, septicemia
Highly Resistant
Significance of Burkholderia cepacia?
Similar to Pseudomonas aeruginosa
Catheter associated UTI
Anerobes typically have a _____ redox potential.
Negative
How are the low-redox potential regions preferred by anerobes typically maintained?
Facultative organisms like E. Coli
Physical structure of Bacteroides fragilis
G- Rod of the Colon
Virulence factors of Bacteroides fragilis?
Antiphagocytic Capsule
SOD and CAT (Not as badly affected by O2)
Extracellular Enzymes (Neurominidase, Heparinase)
Significance of Prevotella melaninogenicia?
Oral G- Coccobacillis
VF: Collagenase
Significance of Porphyromonas gingivalis?
Oral G-Rod
Gingivitis, Oral Abscess
Also infects other warm, moist areas
Significance of Fusobacterium?
Oral and Colonic
G- Fusiform
Infectious in osteomyelitis
Significance of Peptostreptococcus?
Colonic G+ Coccus
Infection of Blood and Pleura/Lungs
Significance of Propionibacterium acnes?
Epidermal G+ Pleomorphic Rod
Acne and Brain Abscesses
Pathogenesis of various anerobes?
Normal flora enter unprotected area via trauma
Production of tissue destructive enzymes causes an abscess
How to treat anerobes?
Drain accumulated fluid
Bacteroides/Prevotella – Metronidazxole and Clinda
Other – Pen G
