Flashcards with Answers on Micro – Microbiology
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Unlock answersEncapsulated bugs |
Salmonella Streptococcus pneumoniae Haemophilus influenzae Neisseria meningitidis Klebsiella pneumoniae Group B Strep
"S SHiN" + GBS + Klebsiella" |
Passive Immunity given to pts after exposure to? (List 4)
-preformed abs |
"To Be Healed Rapidly" *Note: premature babies are also given passive immunization for RSV in winter mo |
Stain used to Dx Whipple's dz |
PAS ; *Tropheryma whippelii |
Facultative Intracellular Bacteria |
Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, ; Yersina (pestis and pseudotuberculosis) ; "Some Nasty Bugs May Live FacultativeLY" |
Corynebacterium diphtheriae toxin |
ADP ribosylating A-B toxin: inactivates EF-2 |
Pseudomonas exotoxin A |
ADP ribosylating A-B toxin: inactivates EF-2 |
Cholera toxin |
ADP ribosylation of Gs (permanent activation) ; adenylate cyclase activation ; ; cAMP ; ; Cl secretion and;; Na absorption, water follows ; voluminous rice-water diarrhea -encoded in a lysogenic phage ; |
ETEC toxins |
ADP ribosylating toxins: heat-labile toxin stimulates adenylate cyclase ; ; cAMP heat-stabile toxin stimulates guanylate cyclase ; *both cause watery diarrhea "Labile like the Air, Stabile like the Ground" |
Pertussis toxin |
ADP ribosylating toxin permanently disables G;i ;;; AC activation ;;; cAMP ; *whooping cough, inhibits chemokine receptor causing lymphocytosis "turns the off off" |
Clostridium perfringes toxin |
; toxin is a lecithinase that acts as a phospholipase to cleave cell membrane ; gas gangrene ; *double zone of hemolysis on blood agar |
Tetanospasmin toxin |
blocks the release of inhibitory neurotransmitters GABA and glycine |
Botulinum toxin |
blocks release of ACh -encoded in a lysogenic phage (certain strains) *CNS paralysis, esp. Cranial nerves *spores in canned foods *baby who eats honey ; floppy baby |
Bacillus anthracis toxin |
edema factor (part of toxin complex) IS an adenylate cyclase itself ; ; cAMP |
Shiga toxin (; Shiga-like toxin - aka Vero cytotoxin) |
cleaves host cell rRNA ; inactivates 60S ribosome (inh. of protein syn.) ;-encoded in a lysogenic phage *also produced by EHEC *also enhances cytokine release and toxic to renal endothelial cells ; HUS *production enhanced by Fe def. *Is an A-B toxin |
Yersinia enterocolitica enterotoxin |
activates guanylate cyclase ; *watery diarrhea and electrolyte loss |
Clostridium difficile exotoxins |
Toxin A (enterotoxin) - causes diarrhea; binds to brush border ; Toxin B (cytotoxin) - cytotoxic; destroys cytoskeleton (depolymerization of actin ; cell death; MOA by binding and inhibiting cytosolic GTPases??) *Dx C. diff by detecting one or both toxins in stool |
2 types of Transduction |
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Strep. pyogenes Erythrogenic toxin |
super antigen causes Scarlet Fever ; -encoded in a lysogenic phage |
;Is Staph. epidermidis Novobiocin sensitive or resistant? |
Novobiocin sensitive ; *Staph saprophyticus is novobiocin resistant "Fticus puts up a Fight" |
Tell me about Listeria monocytogenes |
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I say "rusty sputum", you say? |
Strep pneumo |
only bacterium w/ a polypeptide capsule? (what does it contain?) |
Bacillus anthracis ; *D-glutamate |
Actinomyces vs. Nocardia: How to differentiate b/t long branching filaments resembling fungi |
Actinomyces israelii: G+ anaerobe, normal oral flora, oral/facial abscesses (often after trauma), yellow "sulfur granules", tx w/ Penicillin ; Nocardia asteroides: G+ but also weakly acid-fast, aerobe, soil resident, pulm. inf. in immunocompromised, Tx w/ sulfa |
M. avium-intracellulare prophylactic Tx in AIDS pts? (don't want disseminated dz) |
Azithromycin |
2 Disease types (leprosy) caused by Mycobacterium leprae: -and Tx |
Lepromatous: more serious (diffuse, can be lethal), pts have weak T-cell mediated immunity, Th2 (humoral), Leonine facies Tuberculoid: just a few nodules, intact T-cell response, Th1 response (CMI!) *M. leprae infects skin and superficial nn., armadillo reservoir Tx: long-term oral dapsone (hemolysis, methemoglobinemia), *watch for G6PD def. |
2 G- comma shaped bacteria: what are they and how do you differentiate? |
Campylobacter jejuni - grows in 42°C Vibrio cholera - grows in alkaline media
*both are ox+ |
prophylaxis for close contacts of Meningococci? |
Rifampin
*Rifampin prophylaxis is also used for close contacts of pts w/ H.inf type B meningitis |
Legionella pneumophila (facultative intracellular organism):
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VDRL false positives |
"VDRL"
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Chlamydia trachomatis serotypes |
A, B, & C: cause trachoma - blindness due to follicular conjunctivitis in Africa; chronic infection "ABC for Africa/Blindness/Chronic" D-K: urethritis/PID, neonatal pneumonia (staccato cough), neonatal conjunctivitis L1-3: lymphogranuloma venereum - swollen, painful inguinal nodes that coalesce, ulcerate, and rupture; leads to fibrosis and anogenital strictures (vs. donovanosis by Klebsiella granulomatis w/ painless, beefy red inguinal ulcers) *Tx all w/ azithromycin |
Which systemic mycoses is the exception to being a yeast in tissue? (not referring to cutaneous and opportunistic mycoses) |
Coccidoides imitis
*spherule in tissue - filled w/ endospores, much larger than RBCs |
Classic Triad of Congenital Toxoplasmosis: |
*Tx for Toxoplasmosis is Sulfadiazine + pyrimethamine |
What is the only ssDNA virus? |
Parvovirus B19 *ss, linear(-), and non-enveloped *aplastic crises, "slapped cheeks" (5th dz), crosses placenta |
Live attenuated viral vaccines |
Smallpox, yellow fever, chicken pox (VZV), Sabin's polio (oral), MMR, and intranasal influenza "Live one night only! See small yellow chickens get vaccinated w/ Sabin's and MMR" *influenza and yellow fever vaccines are egg based - allergic to egg? *live attenuated - humoral and cell mediated immunity *MMR is only live atten. that can be given to HIV+ pts |
Killed Viral vaccines |
Rabies, Influenza (IM), Salk Polio, HAV *humoral immunity only, need boosters "RIP Always" |
Recombinant viral vaccines |
HBV - antigen is HBsAg HPV - types 6, 11, 16, ; 18 |
3 DNA viruses that DON'T have linear genome |
Circular DNA genome
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Only dsRNA viruses |
Reoviridae (R. coltivirus - colorado tick fever) Rotavirus (#1 cause of fatal diarrhea in children)
*both are non-enveloped; linear genome |
Positive-stranded RNA viruses |
"I went to a RETRO TOGA party, where I drank FLAVored CORONA and ate HIPPY CALIfornia PICKLES" retrovirus, togavirus, flavivirus, coronavirus, hepevirus, calcivirus, picornavirus *equate the party to a positive (stranded) experience |
only diploid virus |
Retroviruses -2 identical ssRNA molecules
*all other viruses are haploid (1 copy of DNA or RNA) |
only DNA virus to not replicate in the nucleus |
Poxvirus
*also note poxvirus purified dsDNA is not infectious (same for HBV) |
only RNA viruses to NOT replicate in the cytoplasm |
influenza virus retroviruses |
Naked (non-enveloped viruses) |
"Naked CPR and PAPP smear + Hepevirus (HepE)" Calicivirus, Picornavirus, Reovirus, Parvovirus, Adenovirus, Papilloma, Polyoma, and hepevirus
*Note Poxviruses and Paramyxoviruses are only 2 that start w/ P and are enveloped |
Enveloped viruses that acquire envelope from nuclear membrane (vs. all other from plasma membrane) |
Herpesviruses 1, 2, VZV, EBV, CMV, HHV-6 & 8 |
Where do you get Clostridium perfringens food poisoning from? |
reheated meat dishes *C. perfringens causes watery diarrhea and gas gangrene |
Salmonella food poisoning sources |
poultry, meat, eggs
*assoc. w/ pet reptiles (turtles, snakes) |
Osteomyelitis in diabetics and drug addicts |
Pseudomonas aeruginosa |
Osteomyelitis w/ a Hx of cat or dog bite/scratch |
Pasteurella multocida *"my bones hurt from chasing animals in the pasture" |
Positive nitrite test on urine analysis signifies? |
Gram negative bacterial UTI |
TORCHeS & their classic neonatal manifestations |
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Whipple's disease |
Tropheryma whippelii (a Gram+ actinomycete) MC Sx: arthralgias, diarrhea, abdominal pain, and weight loss; CNS involvement can occur ***small intestinal biopsy with periodic acid-Schiff (PAS);positive, and diatase-resistant granules in macrophages with characteristic bacillus |
Bactericidal Abx |
Vancomycin, Fluoroquinolones, Penicillin, Aminoglycosides, Cephalosporins, Metronidazole "Very Finely Proficient At Cell Murder" |
Tetracyclines used for? (tetracycline, doxycycline, demeclocycline, minocycline) |
"VACUUM THe BedRoom" Vibrio cholerae, Acne, Chlamydia, Ureaplasma Urealyticum, Mycoplasma pneumoniae, Tularemia, H. pylori, Borrelia burgdorferi, Rickettsia ; *use doxy in pts w/ renal failure (is fecally eliminated) |
Trimethoprim toxicities? How do you alleviate them? |
-megaloblastic anemia, leukopenia, granulocytopenia -leucovorin rescue - supplemental folinic acid (bypasses DHFR step) |
Polymyxins Examples? MOA? Use? Toxicity? |
-Polymyxin B, Colistin -Binds cell membranes and disrupts osmotic integrity (are cationic basic proteins acting like detergents) -resistant G- inf. ("last resort against multidrug resistant Pseudomonas" -neurotoxicity, acute renal tubular necrosis (ATN) |
TB prophylaxis and treatment |
Prophylaxis: isoniazid Treatment:
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MAI prophylaxis and treatment |
Prophylaxis: azithromycin (start when CD4 ;100) Tx: azithromycin, rifampin, ethambutol, streptomycin ; |
M. leprae Tx |
Dapsone (same MOA as sulfonamides - PABA antimetabolite inhibiting dihyropteroate synthetase) rifampin clofazimine (binds guanine bases of DNA preventing DNA use as a template, increases PLA2 activity) |
DOC for oral or esophageal Candidiasis (thrush)? |
Nystatin "swish and swallow" |
Tx for cryptococcal meningitis in AIDS pts? |
Initial Tx upon Dx is Amphotericin B, usu w/ addition of Flucytosine (ampho B does NOT cross BBB and must be given intrathecally) ; Maintenance Therapy for Life: Fluconazole -the azole that can cross the BBB |
The 3 NNRTIs in HIV therapy |
Nevirapine, Efavirenz, Delaviridine *non-competitive, do NOT require phosphorylation |
Superantigens and the bugs that produce them |
S. aureus: TSST-1 (TSS), enterotoxins (food poisoning), exfoliatin (SSSS) S. pyogenes: erythrogenic toxen (toxic shock-like syndrome) |
Common presentation of Legionnaire's Dz |
very HIGH fever in a smoker accompanied by diarrhea, confusion, and cough causing chest pain; radiographic evidence of pneumonia Tx w/ erythromycin *Legionella is a G- rod, but often no bacteria seen in sputum gram stain; test for anitgen in urine *more in eldery vs. Mycoplasma in young *NOT always going to see the assoc. w/ water in the ? |