Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
11 Cards in this Set
- Front
- Back
|
Frank vs. Opportunistic Pathogens
|
Frank = attack you when you are "normal"
Opportunistic = low invasiveness, need an opportunity to hurt, can be really bad once they get cookin |
|
|
3 Factors leading to a "compromised host"
|
1. Damage to skin or mucous membranes
2. Modern medical technologies (surface for colonization) 3. Opportunistic pathogens |
|
|
Pseudomonas aeruginosa
|
Gram neg. rod w/ single polar flagellum, aerobe, very non-fastidious
Lactose NON Fermenting (white colonies on MacConkey) Green color on slides: Pyocyanin (blue, toxic) Pyoverdin (yellow, fluorescent under UV) Ubiquitous (everywhere), low invasiveness but highly virulent. MOST COMMON. Infections: 1. Pulmonary Infections (especially in CF patients or people on ventillators) 2. Bacteremia/Fatal sepsis (ppl. on immunosupressive drugs, burn/wound patients 3. Ecthyma Gangrenosum follows bacteremia, necrotic black ulcers 4. Otitis externa 5. UTI (cathederization) 6. Meningitis (LP) 7. Septic arthritis/endocarditis (IV drug users) 8. Eye infections (ulcerative Keratitis) Virulence Factors: 1. Exotoxin A (UDP-ribose to EF2) 2. Exoenzyme S 3. Proteases 4. PLC - lyses cells 5. Pyocyanin = kills cells via toxic O2 intermediates 6. Antibiotic tolerance 7. Pili - adhesion 8. Endotoxin = LPS (less toxic) 9. Capsule (alginate) = antiphagocytic, BIOFILM Tx: Gentamycin + piperacillin For UTIs, give ciprofloxacin |
|
|
Why are people with CF more predisposed to an infection by Pseudomonal aeruginosa?
|
CFTR is normally a receptor for P. aeruginosa, allowing the epithelium to internalize the bacteria and then get sloughed off. Without CFTR in patients with CF, you cant get rid of the bacteria.
P. aeruginosa also adapts by undergoing a mucoid conversion in vivo, further resisting phagocytosis. |
|
|
?
Burkholderia pseudomallei |
Gram neg. opportunisitc infection
Melioidosis = inhalation --> pneumonia Tropical Tx: imipenem, ceftazidime |
|
|
?
Burkholderia cepacia |
Gram neg. opportunisitc infection
Pulmonary infections in CF Tx: trimethoprim/sulfamethoxazole |
|
|
?
Acinetobacter |
Gram neg. opportunisitc infection
Nosocomial infections Tx: imipenem or meropenem |
|
|
Legionella pneumophila
"Legionaires' Disease" |
Facultative intracellular parasite, likes to live in protozoa in fresh water
Gram neg, hard to stain, no person-to-person spread Diseases: 1. Legionare's Disease = Savere toxic pneumonia leading to resp. failure 2.Pontiac Fever = nonpneumonic febrile illness. SELF-LIMITING Risk factors: smoking, age, immune suppression Inhaled and enter into alveolar macrophages, causing lung damage Common in urban environments where water sits and isnt purified Tx: azithromycin or fluoroquinolone/rifampin |
|
|
Klebsiella pneumoniae
|
Lac+ enterobacteriaceae, worry about infection during surgery
1. Pneumonia, savere 2. Bacteremia (2nd most common behind E. coli) 3. UTI 4. Burn wound infections Virulence: 1. Capsule, resistance to antimicrobial agents Tx: 3rd gen. cephalosporins |
|
|
Serratia sp.
|
Bright RED
Lac+ enterobacteriaceae Serious hospital infections, especially in newborns Rx: imipenem or meropenem |
|
|
Proteus vulgaris
|
Very motile, "SWARM" on agar plate
Makes UREASE, inc. urine pH --> renal stones UTIs Rx: cefotaxime, ceftriaxone, cefepime, or ceftazidime (all 3rd gen. cephalosporins) |
