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Microbiology Flashcards

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1
Q

Gram positive structure

A

Cell wall present; major surface antigen

Composition:

  • Peptidoglycan
  • Lipoteichoic acid–> TNF, IL-1 induction
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2
Q

Gram negative structure

A

No cell wall, only outer membrane
- Site of Endotoxin= LPS (lipopolysaccharide)= major surface antigen

Composition:

  • Lipid A–> activate macrophages–> increased TNF and IL-1
  • Antigen= O polysaccharide
  • Periplasm= space between cytoplasmic membrane and outer membrane; contains hydrolytic enzymes (beta-lactamases)
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3
Q

Spore structure

A

Resistant to dehydration, heat, chemicals
- Must autoclave (121 C for 15 min)

Composition:

  • Keratin-like coat
  • Dipicolinic acid core
  • Peptidoglycan

Seen in:

  • Soil: B. anthracis, Clostridium perfringens, c. tetani
  • Other: B. cereus, C. botulinum, Coxiella burnetti
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4
Q

Gram-positive cocci

A

Staphylococcus

Streptococcus

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5
Q

Gram-negative cocci

A

Neisseria

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6
Q

Gram-positive rod

A 
Clostridium
Corynebacterium
Bacillus
Listeria
Mycobacterium (high lipid= acid fast)
Gardenerella (gram variable)
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7
Q

Gram-negative rods

A

Almost everything else:

  1. Enterics:
    - E. Coli
    - Shigella
    - Yersinia
    - Klebsiella
    - Proteus
    - Enterobacter
    - Serratia
    - Vibrio
    - Campylobacter
    - Helicobacter (silver stain+)
    - Pseudomonas
    - Bacteroides
  2. Respiratory:
    - Haemophilus (pleomorphic)
    - Legionella (intracellular; silver stain +)
    - Bordetella
  3. Zoonotic
    - Francisella
    - Brucella
    - Pasteurella
    - Bartonella
    • resistant to Penicillin G (gram-negative outer membrane inhibits Pen G/Vanco from entering)
    • Susceptible to Ampicillin, amoxicillin
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8
Q

Spirochetes

A

Gram-negative (too thin)

  • Leptospira
  • Borrelia
  • Treponema
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9
Q

Pleomorphic bacteria

A

Giemsa-stain

  • Rickettsiae (intracellular)
  • Chlamydiae (intracellular, no muramic acid)
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10
Q

Bacteria with no cell wall

A

Mycoplasma= no staining

- Sterols with no wall

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11
Q

Giemsa-positive

A

Certain Bugs Really Try my Patience:

  • Chlamydia
  • Borrelia
  • Rickettsiae
  • Trypanosomes
  • Plasmodium
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12
Q

Carbol Fuschin stain (Ziehl-Neelsen)

A

Acid-fast organisms

  • Nocardia
  • Mycobacterium
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13
Q

India ink positive

A

Cryptococcus neoformans

- can also stain with mucicarmine

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14
Q

Exotoxin

A

Derived from gram + and gram -

  • Secreted from cell
  • Polypeptide
  • Located on plasmid/bacteriophage
  • Highly toxic
  • Antigenic= Induces antitoxins (titer antibodies)
  • Vaccine= toxoids
  • Destroyed at 60C (besides staph enterotoxin)

Seen in: Tetanus, botulism, diphtheria

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15
Q

Endotoxin

A

LPS= structural component of outer cell membrane in gram negative; released when lysed (NOT secreted)

Activates:

  1. Macrophages:
    - IL-1–> fever
    - TNF–> fever, hypotension
    - NO–> hypotension
  2. Complement
    - C3a–> hypotension, edema
    - C5a–> neutrophil chemotaxis
  3. Tissue factor
    - Coagulation cascade–> DIC
  • Located on Bacterial chromosome
  • Low toxicity
  • Causes: Fever, shock
  • Mode of action:Induces TNF and IL-l
  • Antigenic: Poorly antigenic
  • Vaccines= none
  • Stable at 100C for 1 hour

Seen in: meningococcemia, gram-negative sepsis

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16
Q

Obligate aerobes

A

Nagging Pests Must Breathe

  • Nocardia
  • Pseudomonas aeruginosa
  • Mycobacterium tuberculosis (apices of lung)
  • Bacillus
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17
Q

Obligate anaerobes

A

Can’t Breathe Air

  • Clostridium
  • Bacteroides
  • Actinomyces

Seen in GI tract, pathogenic anywhere else
** Can’t treat with aminoglycosides= need O2 to enter cell

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18
Q

Obligate intracellulars

A

Rickettsia

Chlamydia

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19
Q

Facultative intracellular

A

Now Listen Sally, Yer Friend Bruce Must Leave

  • Neisseria
  • Listeria
  • Salmonella
  • Yersinia Pestis
  • Francisella
  • Brucella
  • Mycobacterium
  • Legionella
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20
Q

Encapsulated bacteria

A

Positive Quellung reaction–> swelling

SHiNE SKiS

  • Streptococcus pneumoniae
  • Haemophilus infiuenzae type B
  • Neisseria meningitidis
  • Escherichia coli
  • Salmonella
  • Klebsiella pneumoniae
  • group B Strep.
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21
Q

Catalase-positive

A 
Degrades H2O2 before converted to microbicidal products by Myeloperoxidase (MPO)
PLACESS for your cats:
- Pseudomonas
- Listeria
- Aspergillus
- Candida
- E. Coli
- S. Aureus
- Serratia
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22
Q

Urease-positive

A

CHuck norris hates PUNKSS:

  • Cryptococcus
  • H. pylori
  • Proteus
  • Ureaplasma
  • Nocardia
  • Klebsiella
  • S. epidermidis
  • S. saprophyticus
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23
Q

IgA protease

A

Enzyme cleaving IgA–> colonize respiratory mucosa: SHiN

  • S. pneumoniae
  • H. influenza (B)
  • Neisseria

** These can all take up naked DNA from environment as well= Transformation

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24
Q

Protein A

A

S. Aureus

- Binds Fc region of Ig–> no opsonization/phagocytosis

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25
M Protein
Group A strep | - Prevents phagocytosis
26
Pigment-producing bacteria
Actinomyces Israelii= yellow (Israel= yellow sand) S. Aureus= yellow (pus/gold) Pseudomonas aeruginosa= blue/green (pyocyanin) Serratia marcescens= red (maraschino cherry)
27
Novobicin
Used to ID catalase-positive, coagulase-negative staphylococci - Staph Saprophyticus= resistant - Staph Epidermis= sensitive
28
Optochin
used to ID catalase-negative alpha-hemolytic streptococci: - Viridans= resistant - Penumoniae= sensitive
29
Bacitracin
Used to ID Catalse-negative, beta-hemolytic streptococci: - Agalactiae= resistant - Pyogenes= sensitive
30
Alpha-hemolytic bacteria
Partial hemolysis; green ring around colonies - Strep pneumo - Strep viridans
31
Beta-hemolytic bacteria
Complete hemolysis; clear ring around colonies: - Staph aureus - Strep pyogenes (group A) - Strep agalctiae (group B) - Listeria monocytogenes
32
Staphylococcus aureus
Gram positive cocci, Clustered Catalase positive Coagulase positive Virulence factor= Protein A (binds Fc-IgG--> prevents phagocytosis) Causes: 1. Inflammatory disease: skin infections, organ abscesses, pneumonia - Acute bacterial endocarditis - Osteomyelitis 2. Toxin-mediated disease: - Toxic shock syndrome (TSST-1)= superantigen, binds MHC II receptor--> T-cell activation--> IFN-gamma, IL-2 release - scalded skin (exfoliative toxin) - rapid-onset food poisoning (preformed enterotoxins) * * Activates T-cells (IL-2) and macrophages (IL-1, TNF) 3. MRSA: resistant to beta-lactams (altered penicillin-binding protein) Treatment: - Nafcillin (Naf for Staph- EXCEPT MRSA) - Vancomycin for MRSA THINK: - Pus, empyema, abscess - Surgical wound - chronic granulomatous disease (Catalase-positive microbes)
33
Staphylococcus epidermidis
Gram positive cocci Catalase positive Coagulase negative Novobicin sensitive (vs staph saprophyticus) Infects prostehetic devices, IV catheters (biofilm) - Seen in normal skin flora - Contaminates blood cultures Resistant to penicillins, tx with Vancomycin
34
Staphylococcus saprophyticus
Gram positive cocci Catalase positive Coagulase negative Novobicin resistant (vs staph epidermidis) Causes UTIs
35
Streptococcus pneumoniae
``` Gram positive cocci; lancet shaped Catalase negative alpha-hemolytic Capsule (+ quelling) Optochin sensitive (vs strep Viridans) IgA protease ``` Causes: - Meningitis - Otitis media - Pneumonia (rusty sputum) - Sinusitis - Sepsis, splenectomy in Sickle cell
36
Streptococcus viridans
``` Gram positive cocci Catalase negative alpha-hemolytic No capsule Optochin resistant (vs strep pneumo) ``` Causes: - Dental caries (normal flora in mouth= strep mutans) - Subacute bacterial endocarditis (strep sanguis)
37
Strep pyogenes
``` Group A strep Gram positive cocci Catalase negative beta-hemolytic Bacitracin sensitive (vs strep agalactiae) ``` M-protein (prevents opsonization--> blocking phagocytosis) Exotoxin= 1. streptolysin O - Protein degrades cell membrane (lyse RBCs)- test for ASO antibodies 2. Exotoxin A: brings MHC II and T-cell receptors together--> release IFN-gamma, IL-2 release--> Toxic shock-like syndrome 3. Streptokinase= plasminogen activator (blocks clotting) Causes: 1. Pyogenic: - Pharyngitis - Cellulitis - Impetigo (precedes glomerulonephritis, pharyngitis) 2. Toxigenic: - Scarlet fever (spares face, strawberry tongue, throat) - Toxic shock-like syndrome - Necrotizing fasciitis 3. Immunologic: - Rheumatic fever (polyarthritis, carditis, subcutaneous nodules, erythema marginatum, Sydenham's chorea) - Acute glomerulonephritis - Post strep glomerulonephritis= deficiency of complement due to fixation in renal tubules * * ASO titer to detect infection (antibodies to streptolysin O) * * Host antibodies to M-protein--> rheumatic fever
38
Strep agalactiae
``` Group B strep Gram positive coci Catalase negative Beta hemolytic (Produces CAMP factor--> increased hemolysis) Bacitracin resistant (vs strep pyogenes) Hippurate test positive ``` Causes: - Illnesses mainly seen in babies (due to colonization of vaginal flora): Pneumonia, meningitis, sepsis * * Screen women at 35-37 weeks - Prophylaxis with penicillin
39
Enterococci
``` Group D strep Gram positive cocci Catalase negative Non-hemolytic/variable hemolysis Grows in Bile and 6.5% NaCl ``` Enterococci faecalis, faecium: - Penicillin G resistant - Cause UTI, biliary tract infections, subacute endocarditis - Vancomycin-resistant strains= nosocomial infection
40
Streptococcus bovis
``` Group D strep Gram positive cocci Catalase negative Non-hemolytic Grows in Bile (no NaCl) ``` Colonizes gut - Colon cancer patients: subacute endocarditis, bacteremia
41
Corynebacterium diphtheriae
Gram positive rod (club-shaped) Black colonies in cystine-tellurite agar Metachromatic (blue and red) granules AB Exotoxin= (B=binds, A= active--> EF-2) - B-prophage encoded--> inhibits protein synthesis (ADP-ribosylates elongation factor= EF-2) - Test= Elek's test Causes: - Pseudomembranous pharyngitis (gray-white) - Lymphadenopathy - Myocarditis - Arrhythmias ** Toxoid vaccine= induces production of IgG against exotoxin B (toxin causes disease, not bacteria)
42
Clostridium tetani
Gram-positive rod Spore-forming Obligate anaerobe Exotoxin= Tetanospasmin - Tetanus toxin--> cleaves neurotransmitter-releasing proteins (SNARE) - Blocks glycine, GABA release (inhibitory neurotransmitters) from Renshaw cells in spinal cord - Causes spastic paralysis, trismus (lockjaw), risus sardonicus) Tx: passive vaccine
43
Clostridium botulinum
Gram-positive rod Spore-forming Obligate anaerobe Exotoxin= botulinum toxin - Cleaves SNARE proteins (blocking neurotransmitter release) - Inhibits ACh release at NM junction--> flaccid paralysis - Adults= ingest preformed toxin - Babies= spores in honey--> floppy baby) Tx: passive vaccine
44
Clostridium perfringens
Gram-positive rod Spore-forming Obligate anaerobe Exotoxin= alpha toxin (lecithinase= phospholipase) - Phospholipase degrades tissue, cell membranes--> - Causes myonecrosis (gas gangrene) - Hemolysis
45
Clostridium difficile
Gram-positive rod Spore-forming Obligate anaerobe Exotoxins: 1. Toxin A = enterotoxin binding brushborder of gut) 2. Toxin B = cytotoxin binding enterocytes--> pseudomembranous colitis - Secondary to antibiotics (clindamycin, ampicillin) Treatment: - Metronidazole - Oral vancomycin
46
Bacillus anthracis
Gram-positive rod * Polypeptide capsule (D-glutamate containing) Spore-forming Exotoxin= anthrax (Edema factor) - Mimics adenylate cyclase (increased cAMP) - Calmodulin-dependent adenylate cyclase--> increases cAMP in smooth muscle--> vasodilation (edema), suppressed neutrophil funciton) Forms: - Cutaneous--> black eschar (painless ulcer)--> bacteremia, death) - Pulmonary--> flu-like symptoms--> fever, pulmonary hemorrhage, mediastinitis, shock (Woolsorter's disease)
47
Bacillus cereus
Gram-positive rod Spore-forming Obligate aerobe Enterotoxin= Cereulide - Food poisoning (enterotoxin in rice= "reheated rice syndrome) - Emesis: rice, pasta--> N/V in 1-5 hours - Diarrhea: GI pain, watery, non-bloody in 8-18 hours
48
Listeria Monocytogenes
Gram positive rod Facultative intracellular Catalase positive Beta hemolytic Forms "actin rockets"--> move cell to cell - Tumbling motility Ingested from unpasteurized milk/cheese, deli meats Causes: - Amnionitis - Septicemia - Spontaneous abortion - Meningitis in immunocompromised - Gastroenteritis in healthy (self-limited) Vaginal transmission Causes: - Granulomatosis infantiseptica - Neonatal meningitis * Tx= ampicillin
49
Actinomyces
``` Long, branching filament (resembles fungi) Gram-positive Anaerobe NOT acid-fast Found in normal oral flora ``` Causes: - Oral/facial abscesses that drain--> sinus tracts - Yellow "sulfur granules" Tx: Penicillin
50
Nocardia
``` Long, branching filament (resembles fungi) Gram-positive Aerobe Acid fast Found in soil ``` Causes: - Pulmonary infections in immunocompromised - Cutaneous infections (post-trauma) in healthy Tx: Sulfonamides
51
Mycobacterium tuberculosis
Gram-positive rod Carbol-Fuschin (Ziehl-Neelsen) stain Acid fast (lipid membrane) Obligate aerobe (lung apices) Facultative intracellular * Cord factor in virulent strain--> TNF-alpha release, inhibited macrophage maturation * Sulfatides (surface glycolipids) inhibit phagolysosomal fusion Primary TB: - Nonimmune host infected--> Ghon complex: 1. Heals (fibrosis)--> immunity/hypersensitivity 2. Progressive lung disease (immune compromised) 3. Severe bacteremia--> Miliary TB 4. Preallergic lymphatic/hematogenous dissemination--> dormant--> reactivate later in life Secondary TB: - Partially immune hypersensitized host (adult) reinfected) 1. Fibrocaseous cavitary lesion (upper lobes) 2. Reactivates Reactivated TB= Extrapulmonary TB - CNS (parenchymal TB/meningitis in base of brain) - Vertebral body (Pott's disease) - Lymphadenitis - Renal - GI Symptoms: - Fever, night sweats, weight loss, hemoptysis Tx: - Prophylaxis= Isoniazid (INH) - Therapy= Rifampin, Isoniazid, Pyrazinamide, Ethambutol (RIPE for tx)
52
Mycobacteria Kansasii
Gram-positive rod Carbol-Fuschin (Ziehl-Neelsen) stain Acid fast (lipid membrane) Obligate aerobe (lung apices) Facultative intracellular * Cord factor in virulent strain--> TNF-alpha release, inhibited macrophage maturation * Sulfatides (surface glycolipids) inhibit phagolysosomal fusion Pulmonary TB-like symptoms
53
Mycobacterium avium-intracellulare
Gram-positive rod Carbol-Fuschin (Ziehl-Neelsen) stain Acid fast (lipid membrane) Obligate aerobe (lung apices) Facultative intracellular * Cord factor in virulent strain--> TNF-alpha release, inhibited macrophage maturation * Sulfatides (surface glycolipids) inhibit phagolysosomal fusion Disseminated non-TB disease in AIDS, resistant to multiple drugs ** Prophylaxis with azithromycin (CD4+ < 50) Tx: Azithromycin, Rifampin, Ethambutol, Streptomycin
54
Mycobacterium leprae
Gram-positive rod Carbol-Fuschin (Ziehl-Neelsen) stain Acid fast (lipid membrane) Obligate aerobe (lung apices), likes cool temps Facultative intracellular * Cord factor in virulent strain--> TNF-alpha release, inhibited macrophage maturation * Sulfatides (surface glycolipids) inhibit phagolysosomal fusion Reservoir in USA= armadillos Causes Leprosy. 2 forms: 1. Lepromatous= lethal - Communicable - Low cell-mediated immunity, humoral Th2 response only Tx: Dapsone, rifampin, clofazimine (2-5 years) 2. Tuberculoid= hypoesthetic hairless skin plaques ("glove and stocking" loss of sensation) Tx: Dapsone, Rifampin (6 months)
55
Lactose-fermenting enteric bacteria
Gram-negative rods Grow pink colonies on MacConkey's agar: Fast fermenter= Lactose in KEE - Klebsiella - E. coli - Enterobacter Slow fermenter= - Citrobacter - Serratia
56
Neisseria Gonococci
Gram-negative diplococci Ferments Glucose (Gonococci) Produces IgA proteases Facultative intracellular Grown on special agar: Thayer-Martin agar (or VPN agar)—an agar plate containing antibiotics (vancomycin, colistin, nystatin, and TMP-SMX) - NO vaccine available (rapid antigenic variation in pilus) - STD Causes: - Septic arthritis - Neonatal conjunctivitis - PID - Fitz-Hugh-Curtis syndrome (adhesions due to PID; infection of liver capsule) Tx: Ceftriaxone (+ azithromycin/doxycyclin for chlamydia coinfection)
57
Neisseria Meningococci
``` Gram-negative diplococci Ferments Maltose and glucose (MeninGococci) Produces IgA proteases Facultative intracellular Encapsulated (polysaccharide capsule) ``` Grown on special agar: Thayer-Martin agar (or VPN agar)—an agar plate containing antibiotics (vancomycin, colistin, nystatin, and TMP-SMX) - Vaccine (none for Type B) - Found in respiratory, oral secretions Causes: - Meningococcemia - Meningitis - Waterhouse-Friderichsen syndrom Tx: Ceftriaxone, Pen G ** Rifampin, ciprofloxacin, ceftriaxone in close contacts
58
Haemophilus Influenza
``` Gram negative Coccoid rods Requires factor V and X to grow in culture (chocolate agar) IgA protease Encapsulated ``` - Vaccine= type B capsular polysaccharide conjugated to diphtheria toxoid (2-18 months) - Nontypable strains cause mucosal infections (no vaccine available) Causes: - Epiglottitis (cherry red) - Meningitis - Otitis media - Pneumonia Tx: Ceftriaxone (meningitis) * Rifampin prophylaxis in close contacts THINK: - Pediatric infection (epiglottitis)
59
Legionella pneumophilia
Gram-negative rod Facultative intracellular Silver stain Grown on charcoal yeast extract with iron, cysteine - Aerosol transmission from water source - Detected in urine - Labs show hyponatremia Causes: - Legionnaire's disease= severe pneumonia, fever, GI, CNS symptoms - Pontiac fever= mild flu-like syndrome Tx: Macrolide (protein synthesis), quinolone (topoisomerase II)
60
Pseudomonas aeruginosa
``` Gram negative rod (enteric) Obligate aerobe Catalase positive Lactase NON-fermenting Oxidase positive Blue-green pigment, grape-like odor ``` Motile, oxidase positive Produces: - Endotoxin (fever, shock) - Exotoxin A (inactivates EF-2) - Elastase (breaks down vessel walls) ``` Causes: PSEUDOmonas - Pneumonia (chronic in CF pts due to biofilm) - Sepsis - External otitis - UTI - Drug use - Osteomyelitis (diabetic/drug user) + Hot tub foliculitis, wound/burn infections + MEO in diabetics ``` Tx: - Aminoglycoside + extended-spectrum penicillin (piperacillin, ticarcillin)
61
Enteroinvasive E. Coli (EIEC)
Gram-negative rod Lactose fermenting Virulence factors: - P fimbriae (cystitis/pyelonephritis) - K capsule (pneumonia, neonatal meningitis) - LPS endotoxin (septic shock) Mechanism: - Invades intestinal mucosa--> necrosis, inflammation Manifestation: similar to Shigella - Invasive - Dysentery (blood, pus in stool)
62
Enterotoxigenic E. Coli (ETEC)
Gram-negative rod Lactose fermenting Virulence factors: - P fimbriae (cystitis/pyelonephritis) - K capsule (pneumonia, neonatal meningitis) - LPS endotoxin (septic shock) Mechanism: - Labile toxin: overactivates adenylate cyclase--> increased cAMP--> Cl- secretion in gut--> H20 moves out of cells - Stable toxin: overactivates guanylate cyclase--> increased cGMP--> decreased resorption of NaCl /H20 in gut - NO inflammation/invasion Manifestation: traveler's diarrhea
63
Enteropathogenic E. Coli (EPEC)
Gram-negative rod Lactose fermenting Virulence factors: - P fimbriae (cystitis/pyelonephritis) - K capsule (pneumonia, neonatal meningitis) - LPS endotoxin (septic shock) Mechanism: - Adheres to apical surface, flattens villi - Prevents absorption Manifestation: - Pediatric diarrhea
64
Enterohemorrhagic E. Coli (EHEC)
Gram-negative rod Lactose fermenting Virulence factors: - P fimbriae (cystitis/pyelonephritis) - K-1 capsule (pneumonia, neonatal meningitis) - LPS endotoxin (septic shock) Mechanism: - O157:H7= most common--> Shiga-like toxin - Shiga-like toxin (SLT)= inactivates 60S ribosomal subunit by removing adenine from rRNA - Endothelial swelling, narrowed lumen--> hemolysis, reduced renal blood flow - Damaged endothelium--> thrombocytopenia Cuases: - Dysentery (Shiga-like) - Hemolytic-uremic syndrome (HUS) due to cytokine release in response to SLT--> vascular damage--> capillary thrombus formation--> anemia, thrombocytopenia, acute renal failure, increased bleeding time
65
Klebsiella
Gram negative rod Lactose fermenter Polysaccharide capsule (mucoid colonies) 4As: - Aspiration pneumonia - Abscess (lungs/liver) - Alcoholics - diAbetics * can also cause nosocomial UTI: positive urease test
66
Salmonella
``` Gram negative rod Lactose non-fermenter Oxidase negative Facultative intracellular Encapsulated ``` - Flagellated - Hematogenous dissemination - Animal reservoir - Produce hydrogen sulfide - Invades intestinal mucosa--> monocytic response Causes: - Bloody diarrhea - Non-typhoidal= appendicitis mimicker - Typhi= Typhoid fever (humans only): rose spots on abdomen, fever, headache, diarrhea - Osteomyelitis in sickle cell pts Tx: Antibiotics prolong symptoms
67
Shigella
Gram negative rod Lactose non-fermenter Oxidase negative Shiga toxin= inactivates 60S ribosomal subunit by removing adenine from rRNA - No flagella - Cell to cell transmission - Reservoir= humans/primates - Invades intestinal mucosa--> PMN infiltration - Shiga toxin--> Cytokine release--> HUS: due to cytokine release in response to Shige toxin--> vascular damage--> capillary thrombus formation--> anemia, thrombocytopenia, acute renal failure, increased bleeding time Tx: antibiotics shortens excretion of organism in feces
68
Campylobacter jejuni
Gram negative comma-shaped Oxidase positive Grows at 42C Transmitted through poultry, meat, unpasteurized milk Causes: - Bloody diarrhea (esp. children) - Guillain-Barre syndrome, reactive arthritis - Mimics appendicitis
69
Vibrio cholerae
Gram negative comma-shaped Oxidase positive Grows in alkaline media Mechanism: - Cholera toxin Activates Gs of adenylate cyclase--> increased cAMP--> increased Cl- secretion, H20 efflux Causes: - Profuse rice-water diarrhea (common in developing countries) Tx: rehydration
70
Yersinia enterocolitica
Gram negative rod Facultative intracellular Mechanism: - Transmitted from pet feces, contaminated milk, pork Causes: - Mesenteric adentitis (Crohn's, appendicitis mimicker)
71
H. Pylori
Curved Gram-negative rod Silver stain Urease positive (urease breath test)- alkaline environment created in stomach Causes: - Gastritis - 90% duodenal ulcers - Increased peptic ulcer, gastric adenocarcinoma, B-cell lymphoma risk Tx: triple therapy: - PPI - Clarithromycin - Amoxicillin/ Metronidazole
72
Spirochetes
Borrelia (BIG)= Wright/Giemsa stain Leptospira Treponema= dark field microscopy
73
Leptospira interrogans
Spirochete Water contaminated with animal urine (triathletes in tropics) Causes: - Flu-like symptoms - Jaundice - Photophobia with conjunctivitis - Weil's disease= icterohemorrhagic leptospirosis: severe; jaundice, azotemia (liver, kidney dysfunction), fever, hemorrhage, anemia
74
Borrelia Burgdorferi
Spirochete (visualized with Wright/Giemsa stain) Lyme disease: - Transmitted by Ixodes tick - Reservoir= wood mouse - Stages: 1. Erythemia migrans (bull's eye), flu-like 2. Neurologic (Bell's palsy), cardiac (AV node block) 3. Musculoskeletal (chronic monoarthritis, migratory polyarthritis), neurological (encephalopathy, polyneuropathy), cutaneous
75
Treponema Pallidum
Spirochete - Visualized by dark-field microscopy - Screened with VDRL, confirmed with FTA-ABS Syphillis: 1. Primary: localized painless chancre (treponemes) 2. Secondary: disseminated disease - Constitutional symptoms - Maculopapular rash - Condylomata lata (treponemes found on warty lesions) 3. Tertiary: - Gummas (chronic granulomas) - Aortitis (vaso vasorum destruction) - Neurosyphilis (tabes dorsalis) - Argyll-Robertson pupil (non-reactive, accomodative) - Signs: broad-based ataxia, + Romberg, Charcot joint, stroke w/o HTN - Treponemes in spinal tap Congenital syphilis: - Saber shins - Sadle nose - CNVII deafness - Hutchinson's teeth - Mulberry molars * * VDRL= nonspecific; can also indicate: - Viruses - Drugs - Rheumatic fever - Lupus, leprosy Tx: Pen G - Can lead to Jarisch-Herxheimer reaction (killed bacteria release pyrogens)- administer steroids, low dose antibiotics
76
Bartonella
Cat scratch disease | - Can cause bacillary angiomatosis in immune compromised
77
Borrelia Recurrentis
Recurrent fever Source: Louse
78
Brucella
Gram negative rod Facultative intracellular Causes: Undulent fever Source: unpasturized dairy
79
Chlamydia psittaci
Obligate intracellular organism (cannot make own ATP) - Giemsa positive - Pleomorphic Elementary body= Enters cell via Endocytosis Reticulate body= replicates in cell via fission (seen on tissue culture) - Cytoplasmic inclusions on Giemsa, fluorescent antibody Psittacosis (pneumonia) Source: parrots, birds Tx: - Azithromycin (one time) - Doxycycline
80
Coxiella burnetii
Q fever Source: aerosol of cattle, sheep amniotic fluid - Survives in soil for years (spore) Tx: Doxycycline
81
Ehrlichia chaffeensis
Monocyte with morula (berry-like) inclusion in cytoplams Ehrlichiosis Source: lone star tick Tx: Doxycycline
82
Francisella tularensis
Tularemia Source: ticks, rabbits, deer fly
83
Pasteurella multocida
Cellulitis, osteomyelitis Source: animal bite (cat, dog)
84
Rickettsia prowazekii
Obligate intracellular Need CoA and NAD+ ``` Epidemic typhus (pro-WAr) - Rash sparing palms and soles ``` Source: louse Tx: Doxycycline
85
Rickettsia Typhi
Obligate intracellular Need CoA and NAD+ Endemic typhus Source: fleas Tx: Doxycycline
86
Yersinia pestis
Facultative intracellular Plague Source: fleas (rats/prairie dogs= reservoir)
87
Gardenerella vaginalis
Gram-variable pleomorphic rod "Clue cells" on vaginal swab KOH prep= fishy smell Causes: Bacterial vaginitis - Non-painful, smelly - Not STD (associated with sexual activity) Tx: Metronidazole
88
Rickettsia Rickettsii
Obligate intracellular Need CoA and NAD+ Causes: - Rocky Mountain Spotted Fever (Broad distribution) - Rash: wrists, ankles--> trunks, palms, soles - Headache, fever
89
Anaplasma
Anaplasmosis: | Granulocytes with morula in cytoplasm
90
Chlamydia trachomatis
Obligate intracellular organism (cannot make own ATP) - Giemsa positive - Pleomorphic Elementary body= Enters cell via Endocytosis Reticulate body= replicates in cell via fission (seen on tissue culture) - Cytoplasmic inclusions on Giemsa, fluorescent antibody ``` Causes: Reiter's syndrome: - Reactive arthritis - Conjunctivitis - Nongonococcal urethritis - PID ``` Serotypes: - A, B, C= chronic infection--> follicular conjuntivitis--> blindness (ABC= Africa, Blindness, Chronic infection) - D-K= Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), neonatal conjunctivitis) - L1, L2, L3= lymphogranuloma Tx: - Azithromycin (one time) - Doxycycline
91
Mycoplasma pneumoniae
No cell wall (no stain) - Sterol membrane (stability) Atypical "walking" pneumonia - Insidious onset, H/A, nonproductive cough, diffuse interstital infiltrate - IgM titer--> agglutinate, lyse RBCs Tx: macrolide, fluoroquinolone
92
Bordetella pertussis
Pertussis toxin - Overactivates adenylate cyclase--> increased cAMP (disables Gi)--> impairs microbial phagocytsosis Causes: - Whooping cough= cough on expiration, whoop on inspiration
93
Histoplasmosis
``` Dimorphic fungi (20C= cold mold, 37C= heat yeast) - Can mimic TB with no person-person transmission ``` Location: - Mississippi, Ohio river valleys - Bird/bat droppings in CAVES Causes: pneumonia - Hilar adenopathy Histo: Macrophage filled with histo (Histo hides in macrophages) Tx: - Local= fluconazole, itraconazole - Systemic= Amphotericin B
94
Blastomycosis
``` Dimorphic fungi (20C= cold mold, 37C= heat yeast) - Can mimic TB with no person-person transmission ``` Location: - States East of Mississippi river, Central America Causes: inflammatory, lung disease - Disseminates to skin, bone - Granulomatous nodules Histo: broad-based budding (Blasto Buds) Tx: - Local= fluconazole, itraconazole - Systemic= Amphotericin B
95
Coccidioidomycosis
``` Dimorphic fungi (20C= cold mold, 37C= heat SPHERULE) - Can mimic TB with no person-person transmission ``` Location: - SW USA, California (Valley fever) Causes: pneumonia, meningitis - Disseminate to skin, bone - Increased cases after earthquakes Histo: Spherule filled with endospores (larger than RBC) - Coccidio crowds Tx: - Local= fluconazole, itraconazole - Systemic= Amphotericin B
96
Paracoccidioidomycosis
``` Dimorphic fungi (20C= cold mold, 37C= heat yeast) - Can mimic TB with no person-person transmission ``` Location: Latin America (Paracoccdio parasails with Captain's wheel all the way to Latin America) Histo: - Budding yeast, captain's wheel formation Tx: - Local= fluconazole, itraconazole - Systemic= Amphotericin B
97
Tinea Versicolor
Malassezia furfur - Lipid degradation--> acids--> malanocyte damage--> hypo/hyperpigmented areas - Seen in hot, humid weather Histo: - "spaghetti and meatball" on KOH Tx: - Topical miconazole - Selenium sulfide (Selsun Blue)
98
Candida albicans
Tx: - Topical azole for vaginal infection - Fluconazole/capsofungin for oral/esophageal - Fluconazole, ampho B, caspofungin for systemic tx
99
Aspergillus Fumigatus
Invasive= immunocompromised, chronic granulomatous disease Allergic broncopulmonary (ABPA)= Asthma, CF Aspergillomas in lung cavities (post-TB) ** Produce aflatoxins= associated with Hepatocellular carcinoma
100
Cryptococcus neoformans
Encapsulated (crypt) yeast - Found in soil, pigeon droppings - Inhaled, hematogenous dissemination to meninges Culture: - Sabouraud's agar - India Ink stain - Latex agglutination= polysaccharide capsular antigen Can cause meningitis ("soap bubble lesions" in brain) in immune-compromised (AIDS patients with CD4+ < 50) Tx: - Amphotericin B + Flucytosine
101
Pneuomcystis jirovecii
PCP= diffuse interstitial pneumonia - bilateral CXR - Dx= biopsy, lavage - Disc-shaped yeast on methenamine silver stain Tx: TMP-SMZ, pentamidine, dapsone - Prophylax with CD4+ < 200
102
Sporothrix schenckii
Dimorphic Cigar-shpaed budding yeast "Rose-pickers" thumb= pustule, ulcer with nodules along lymphatic drainage Tx: itraconazole, potassium iodide (plant a rose in the pot)
103
Giardia Lamblia
Trophozoite Giardiasis: bloating, flatulence, foul-smelling, fatty diarrhea Transmission: cysts in water Dx: stool: trophozoites, cysts Tx: Metronidazole (GET on the Metro: G= giardia, E= entamoeba, T= Trichomonas)
104
Entamoeba histolytica
Trophozoite Amebiasis: bloody diarrhea (dysentery), liver abscess (anchovy paste exudate), RUQ pain (flask-shped ulcer if submucosal colon abscess ruptures) Transmission: cysts in water Dx: Serology, trophozoites (with phagocytosed RBCs) or cysts (multinucleated) in stool Tx: Metronidazole (GET on the Metro: G= giardia, E= entamoeba, T= Trichomonas) - Iodoquinol for asymptomatic carriers
105
Cryptosporidium
AIDS patients: severe diarrhea - Milder (watery diarrhea) in immunocompetent Transmission: Cysts in water) Dx: Cysts on acid-fast stain Tx: Prevent (filter water) - Nitazoxamide in immunocompetent
106
Toxoplasma Gondii
HIV: brain abscess (ring-enhancing lesions) Congenital: Triad= chorioretinitis, hydrocephalus, intracranial calcifications Transmission: cysts in meat, cat feces Dx: Serology, biopsy Tx: Sulfadiazine, pyrimethamine
107
Naegleria Fowleri
Rapidly fatal meningoencephalitis Transmission: swimming in freshwater lakes, Netti pot (cribiform plate--> brain) Dx: Amoebas in CSF Tx: Amphotercin (maybe?)
108
Trypanosoma brucei gambiense
West African Sleeping sickness: - Slowly progressive fevers, wasting, late neuro symptoms - Recurrent fevers: due to Variable Surface Glycoproteins (change with each generation--> immune system can't keep up) Transmission: Tsetse fly (painful bite) Diagnosis: blood smear Tx: Blood borne= Suramin CNS= Melarsoprol "Sure is nice to go to sleep. Melatonin helps with sleep"
109
Trypanosoma brucei rhodesiense
East African sleeping sickness: - More severe, rapid progression (recurrent fevers--> neurological disease--> coma--> death) Transmission: Tsetse fly (painful bite) Diagnosis: blood smear Tx: Blood borne= Suramin CNS= Melarsoprol
110
Plasmodium vivax/ovale
Malaria: fever, H/A, anemia, splenomegaly - 48 hr cycle (fever on 1st, 3rd day) - Dormant form in liver Transmission: Mosquito Diagnosis: Blood smear - Trophozoite ring - RBC schizont with merozoites Tx: - Chloroquine (blocks heme ploymerase) - Mefloquine for resistant strains - Life-threatening: IV quinidine (test for G6PD) - **Add primaquine (test for G6PD) to kill hypnozoites in liver
111
Plasmodium falciparum
Malaria: fever, H/A, anemia, splenomegaly - Severe, irregular fever - Parasitized RBCs occlude brain capillaries--> cerebral malaria, kidneys, lungs Transmission: Mosquito Diagnosis: Blood smear - Trophozoite ring - RBC schizont with merozoites Tx: - Chloroquine (blocks heme ploymerase) - Mefloquine for resistant strains - Life-threatening: IV quinidine (test for G6PD)
112
Plasmodium malariae
Malaria: fever, H/A, anemia, splenomegaly - 72 hour cycle of fever Transmission: Mosquito Diagnosis: Blood smear - Trophozoite ring - RBC schizont with merozoites Tx: - Chloroquine (blocks heme ploymerase) - Mefloquine for resistant strains - Life-threatening: IV quinidine (test for G6PD)
113
Babesia
Babesiosis: fever, hemolytic anemia - Seen in NE USA - Increased risk of severe disease in asplenia Transmission: Ixodes tick Diagnosis: blood smear (ring form, "Maltese cross), PCR Tx: Atovaquone + azithromycin
114
Trypanosoma cruzi
Chagas' disease: dilated cardiomyopathy, megacolon, megaesophagus Transmission: Reduviid bug ("kissing bug")- painless bite--> feces enter wound Diagnosis: Blood smear Tx: Nifurtimox
115
Leishmania donovani
Visceral leishmaniasis: spiking fevers, hepatosplenomegaly, pancytopenia Transmission: sandfly Diagnosis: macrophages with amastigotes Tx: sodium stibogluconate
116
Trichomonas Vaginalis
Vaginitis: foul-smelling, greenish discharge - Itching, burning Transmission: sexual (must have host- no cyst form) Diagnosis: Trophozoites (motile) on wet mount - Strawberry cervix Tx: Metronidazole (patient and partner) (GET on the Metro: G= giardia, E= entamoeba, T= Trichomonas)
117
Enterobius Vermicularis
Pinworm Intestinal infection--> anal pruritis ("Scotch tape test") Transmission: food contaminated with eggs Tx: Bendazoles, pyrantel pamoate ("Bendy" worms)
118
Ascaris Lumbricoides
Giant roundworm Intestinal infection Transmission: Fecal-oral; see eggs under microscope Tx: Bendazoles, pyrantel pamoate
119
Strongyloides stercoralis
Intestinal infection: N/V, diarrhea, anemia Transmission: **larvae in soil penetrate skin** Tx: Albendazole, ivermectin
120
Ancylostoma duodenale, Necator Americanus
Old world, new world hookworm Intestinal infection--> anemia (suck blood) (microcytic anemia) Transmission: **larvae penetrate skin** Treatment: Bendazoles, pyrantel pamoate
121
Dranunculus medinensis
Skin inflammation, ulceration Transmission: drinking water Tx: slow extraction of worm
122
Onchocerca volvulus
"River blindness": microfilariae migrate to eye--> die--> inflammatory response--> opacity - Hanging groin - Lymphadenopathy - Allergic reactions Transmission: Female black fly Tx: Ivermectin (Iver for River blindness)
123
Loa Loa
Swelling in skin, pain and edema in eye (worm in conjunctiva) Transmission: female deer fly (horse, mango fly) Treatment: Diethycarbamazine
124
Wucheria bancrofti
Blocks lymphatic drainage--> elephantiasis (~1 year after bite) Transmission: female mosquitoes (night) Tx: Diethylcarbamazine
125
Toxocara canis
Visceral larval migrans: granulomas in viscera (including CNS)--> death from respiratory failure, cardiac arrhythmias, brain damage Transmission: food contaminated with eggs (carried by cats, dogs) Tx: Albendazole, mebendazole
126
Taenia Solium
Cestode (tapeworm) 1. Ingestion of larvae in undercooked pork--> Intestinal infection Tx: Praziquantel 2. Ingestion of eggs (fecal-oral)--> Cysticercosis, neurocysticercosis Tx: Praziquantel, bendazoles for neurocysticercosis
127
Diphyllobothrium latum
Cestode (tapeworm) Vitamin B12 deficiency (tapeworm competes for B12 in intestine)--> anemia Transmission: Ingestion of larvae from raw freshwater fish Treatment: Praziquantel
128
Echinococcus granulosus
Cestode (tapeworm) Ingestion of eggs (dog feces) Cysts in liver (anaphylyaxis if released--> pretreat with ethanol injection before removing) Tx: Bendazoles
129
Schistosoma
Trematode - Liver and spleen granulomas, fibrosis, inflammation * * S. haematobium--> SCC of bladder * * S. Mansoni--> portal HTN Transmission: Snails= host--> cercariae penetrate skin Tx: praziquantel
130
Clonorchis sinensis
Trematode= Chinese liver fluke - Biliary tract inflammation--> pigmented gallstones * Associated with cholangiocarcinoma Transmission: undercooked fish Tx: Praziquantel
131
Paragonimus Westermani
Trematode - Lung inflammation; secondary bacterial infection--> hemoptysis Transmission: undercooked crab meat Tx: Praziquantel
132
Live, attenuated vaccines
``` Smallpox Yellow fever Chicken pox (VZV) Sabin's polio virus MMR (only one can be given to HIV+ patients without immune deficiency) Influenza (flumist nasal spray) ```
133
Killed vaccines
Rabies Influenza Salk Polio HAV
134
Recombinant vaccine
HBV: antigen= recombinant HBsAg HPV: 6, 11, 16, 18
135
RNA viral genomes
* All are ssRNA except Reoviridae * All replicate in cytoplasm except Retrovirus (diploid ssRNA), influenza + ssRNA: I went to a RETRO(virus) TOGA(virus) party, where I drank FLAVored(flavivirus) CORONA(virus) and ate Hippy(hepevirus) CALIfornia (calcivirus) PICkles (picornavirus)
136
DNA viruses
All dsDNA, linear, icosahedral, replicate in nucleus: ``` Hepadna (circular, incomplete) Herpes Adeno Pox (complex, has DNA-dependent RNA polymerase--> replicates in cytoplasm) Parvo (ssDNA) Papilloma (circular, supercoiled) Polyoma (circular, supercoiled) ```
137
Herpesviruses
Enveloped dsDNA, linear ``` HSV1= oral, Spontaneous temporal lobe encephalitis, keratoconjunctivitis HSV2= genital HSV3= VZV= chickenpox HSV4= EBV= mono, Burkitt's, Hodgkin's, nasopharyngeal carcinoma HSV5= CMV= AIDS retinitis, congenital defects (latent in mononuclear cells= "owl's eyes") HSV6= roseola HHV7= roseola (less common) HHV8= Kaposi's sarcoma ``` Diagnosis: 1. PCR (#1) 2. Tzanck test= smear of opened vesicle (used for HSV1, 2, VZV) - See **intranuclear Cowdry A inclusions** 3. Monospot (EBV): heterophile antibodies on agglutination of sheep/horse RBCs - Atypical lymphocytes= reactive cytotoxic T cells
138
Hepadnavirus
Enveloped dsDNA, partial circular Hep B: - Acute or chronic (incubation= months) - Vaccine= recombinant (HBsAg) - Contains reverse transcriptase (NOT retrovirus)= DNA-dependent DNA polymerase - Uses host RNA polymerase--> viral proteins Transmission: Parenteral, sexual, maternal-fetal Serology: - HBsAg= infected (acute/chronic) - Anti-HBs= immunity (vaccine/recovered) - HBcAg= antigen to core (infected) - Anti-HBc= positive during infection (IgM= acute/recent, IgG= prior/chronic) - HBeAg= Active (acute/chronic) - Anti-HBe= Window, chronic (low infectivity, recovery) * * Risk of HCC * * ALT > AST (vs alcoholics: AST > ALT
139
Adenovirus
Non-enveloped dsDNA, linear Pharyngitis, hemorrhagic cystitis Pneumonia Conjunctivitis
140
Parvovirus
Non-enveloped ssDNA, linear negative (smallest DNA virus) B19= "slapped cheeks" (erythema infectiosum), 5th disease - In SC pts--> aplastic crisis - In uteros--> hydrops fetalis - Adults: RBC aplasia, RA symptoms
141
Papillomavirus
Non-enveloped dsDNA, circular HPV: 1, 2, 6, 11= warts 16, 18= CIN, cervical cancer ** Recombinant vaccine Diagnosis: - Koilocytes on Papanicolaou smear (pap smear)
142
Polyomavirus
Non-enveloped dsDNA, circular - JC virus= PML in HIV - BK virus= transplant patients, kidney targeted (Bad Kidney)
143
Poxvirus
Enveloped dsDNA, linear (largest DNA virus) Smallpox= germ warfare Vaccinia= cowpox Molluscum contagiosum= flesh-dome lesion with central dimple
144
Reovirus
Nonenveloped dsRNA, linear Icosahedral Coltavirus= colorado tick fever (arbovirus) Rotavirus: - villus destruction, atrophy--> decreased Na absorption, loss of K+
145
Picornavirus
Non-enveloped ssRNA+, linear Icosahedral PERCH: Poliovirus Echovirus (aseptic meningitis) Rhinovirus (common cold) Coxsackievirus (aseptic meningitis, herpangina, hand foot mouth disease, myocarditis) HAV (acute Hep A virus): asymptomatic, acute, alone (no carriers) ** All but Rhino (acid-labile) are fecal-oral enteroviruses
146
Hepevirus
Non-enveloped ssRNA+, linear Icosahedral Hep E - Transmission= fecal-oral (waterborne epidemics) - No carrier state, short incubation, no HCC - Enteric, Expectant mothers (bad), Epidemic
147
Calcivirus
Non-enveloped ssRNA+, linear Icosahedral Norovirus
148
Flavivirus
Enveloped ssRNA+, linear Icosahedral Hep C: - Transmission= blood, IVDU, post-transfusion - Long incubation - HCC risk - Chronic, Cirrhosis, Carcinoma, Carrier Yellow fever (arbovirus): fever, black vomit, jaundice Dengue (arbovirus) St. Louis Encephalitis (arbovirus) West Nile (arbovirus)
149
Togavirus
Enveloped ssRNA+, linear Icosahedral Rubella (German measles) - Postauricular lymphadenopathy, arthralgias, truncal rash (head--> trunk) - Mild in children, serious congenital disease Eastern Equine Encephalitis (arbovirus) Western Equine Encephalitis (Arbovirus)
150
Retrovirus
Enveloped ssRNA+, linear Icosahedral (HTLV--> T-cell leukemia) Complex conical (HIV--> AIDS) ** contain reverse transcriptase HIV: * envelope proteins acquired by budding from host plasma membrane= ENV - Env glycosylation--> gp160--> cleaved in ER/golgi--> gp120, gp41 1. gp120= docking glycoprotein*; - attach to host CD4+ cell (early= CCR5, late= CXCR4) - attach to CCR5/CD4 on host macrophages - CCR5 mutation--> immunity (homo), slow course (hetero) 2. gp41= transmembrane protein*; fusion and entry 3. p17= matrix protein 4. p24= capsid protein: GAG 5. reverse transcriptase: POL Diagnosis: 1. ELISA= rule out (high false-positive) 2. Western Blot= rule in (high false-negative) 3. PCR for viral load 4. CD4+ count (< 200= AIDS) or CD4/CD8 < 1.5
151
Coronaviruses
Enveloped ssRNA+, linear Helical Corona= common cold, SARS
152
Orthomyxoviruses
Enveloped ssRNA- , linear, 8 segmented Helical Influenza: - Hemagglutin= viral entry - Neuraminidase= progeny virion release - Genetic shift/antigenic shift= pandemics (high frequency recombination) ex: swine and human virus recombine - Genetic drift= epidemics (minor, random mutation)
153
Paramyxovirus
Enveloped ssRNA-, nonsegmented Helical Parainfluenza (croup) RSV (bronchiolitis in babies, Rx= Ribavirin) Measles: - Cough--> conjunctivitis-> spots--> Maculopapular rash: head to toe - Koplik spots (buccal mucosa) - Delayed encephalitis (SSPE) - Giant cell pneumonia (immune suppressed) Mumps: (makes your parotids and testes as big as POM poms) - Parotitis - Orchitits - Meningitis * * surface F (fusion) protein= respiratory epithelial cells fuse--> multinucleated cells - Use Palivizumab (MAB against F) to prevent RSV in premies)
154
Rhabdovirus
Enveloped ssRNA-, linear Helical RABIES!: - Bullet-shaped - Negri bodies= cytoplasmic inclusions in neurons (Purkinje of Cerebellum) - Post-exposure prophylaxis= Wound cleansing + Rabies Ig - Bite--> nerve axons--> CNS--> salivary glands
155
Filovirus
Enveloped ssRNA-, linear Helical Ebola/Marburg hemorrhagic fever
156
Arenaviruses
Enveloped ssRNA-, circular segments Helical Lymphocytic Choriomeningitis Virus (LCMV) Lassa Fever encephalitis (mouse-borne)
157
Bunyaviruses
Enveloped ssRNA-, circular segmets Helical California encephalitis (Arbovirus) Sandfly/Rift valley fever (Arbovirus) Crimean-Congo hemorrhagic fever (Arbovirus) Hantavirus--> hemorrhagic fever, pneumonia
158
Delta virus
Enveloped ssRNA-, cricular Hep D: Defective (needs HBV for coinfection) - Transmission: parenteral, sexual, maternal-fetal - Short superinfection, long coinfection
159
Negative stranded viruses
``` Must transcribe negative strand to positive: Always Bring Polymerase Or Fail Replication - Arenavirus - Bunyavirus - Paramyxovirus - Orthomyxovirus - Filovirus - Rhabdovirus ```
160
Segmented viruses
RNA viruses: BOAR - Bunyaviruses - Orthomyxoviruses - Arenaviruses - Reoviruses
161
Systemic symptoms of HIV infection
Histoplasma capsulatum (pulm symptoms only in immune competent): low grade fever, hepatosplenomegaly, tongue ulcer - CD4 < 100 - Oval yeast cells in macrophages
162
Dermatologic symptoms of HIV infection
C. albicans (thrush): cottage-cheese lesions - oral: CD4 < 400 - esophageal: CD4< 100 - Pseudohyphae Bartonella henselae: superficial vascular proliferation - Neutrophilic inflammation
163
GI symptoms of HIV
Cryptosporidium: chronic watery diarrhea - CD4 < 200 - Acid-fast cysts in stool
164
Neurologic symptoms of HIV
JC virus: encephalopathy - CD4 < 200 Toxoplasma: abscesses - CD4 < 100 Cryptococcus neoformans: Meningitis - CD4 < 50 CMV: Retinitis - CD4 < 50 Dementia due to HIV
165
Oncologic processes in HIV
HHV8: Kaposi's sarcoma - Lymphocytic inflammation EBV: 1. hairy leukoplakia (tongue); 2. non-Hodgkin's lymphoma (large cell)- seen on Waldeyer's ring 3. CNS lymphoma (focal or multiple) HPV: Squamous cell carcinoma (anus, cervix)
166
Respiratory processes in HIV
CMV: Interstitial pneumonia - Owl's eye intranuclear inclusions Aspergillus: invasive - pleuritic pain, hemoptysis, infiltrate on imaging Pneumocystis jirovecii: Pneumonia - CD4 < 200 Mycobacterium aviium intracellulare: TB-like - CD4 < 50 - Prophylax with azithromycin
167
CD4 < 200
1. Pneumocystis jirovecii: Pneumonia 2. JC virus: encephalopathy 3. Cryptosporidium: chronic watery diarrhea
168
CD4 < 100
1. C. albicans (esophageal thrush): cottage-cheese lesions 2. Toxoplasma: abscesses 3. Histoplasma capsulatum (pulm symptoms only in immune competent): low grade fever, hepatosplenomegaly, tongue ulcer
169
CD4 < 50
1. CMV: Retinitis | 2. Cryptococcus neoformans: Meningitis
170
Prion diseases
PrPc= normal cellular prion protein PrPsc= Beta-pleated form; transmissible - Accumulation--> spongiform encephalopathy (dementia, ataxia, death) Creutzfeld-Jacob= sporadic, rapidly progressive dementia Gerstmann-Straussler-Scheinker= inherited Acquired= Kuru, New Variant CJD
171
Normal flora in body
Skin= staph epidermidis Nose= staph epidermidis, colonized by s. aureus Oropharynx= viridans group strep Dental plaque= strep mutans Colon= Bacteroides fragilis > e. coli Vagina= lactobacillus; colonized by e. coli and group B strep
172
Bugs causing food poisoning
Vibrio parahaemolyticus, vulnificus= contaminated seafood (wounds for vulnificus) Bacillus cereus= reheated rice S. aureus= meats, mayonnaise, custard; preformed toxin Clostridium perfringens= reheated meat C. botulinum= improperly canned food E. coli= undercooked meat (O157:H7) Salmonella= poultry, meat, eggs
173
Bloody diarrhea
``` Campylobacter Salmonella Shigella EHEC EIEC Yersinia enterocolitica Entamoeba histolytica ```
174
Watery diarrhea
``` ETEC (Stable and Labile toxins) Vibrio C. Diff (can also have blood) C. perferingens Protozoa (giardia, crypto) Noro, Rotavirus ```
175
Common causes of pneumonia neonates
Group B strep | E. coli
176
Common causes of pneumonia: children
``` RSV/ viruses Mycoplasma Chlamydia trachomatis C. pneumoniae Streptococcus pneumonia ``` "Runts May Cough Chunky Sputum"
177
Common causes of pneumonia: adults 18-40
Mycoplasma C. pneumoniae S. pneumoniae
178
Common causes of pneumonia: adults 40-65
``` S. pneumoniae H. influenzae Anaerobes Viruses Mycoplasma ```
179
Common causes of pneumonia: elderly
``` S. pneumoniae Influenza Anaerobes H. influenzae Gram-negative rods ```
180
Common causes of meningitis: newborns
Group B strep E. coli Listeria
181
Common causes of meningitis: children (6 months-6 years)
Strep pneumo N. meningitidis H. flu type B Enteroviruses
182
Common causes of meningitis in 6-60 year olds
S. pneumo N. meningitidis Enteroviruses HSV
183
Common causes of meningitis in 60+ years
S. pneumo Gram-negative rods listeria
184
Meningitis: CSF findings
Bacterial= normal pressure, PMNs, increased protein, decreased sugar Fungal/TB= normal pressure, Lymphocytes, increased protein, decreased sugar Viral= normal pressure, lymphocytes, normal/elevated protein, normal sugar
185
UTI findings
Predisposition: - Women (10x more common) - Males= congenital defects in infants, vesicoureteral reflux - Elderly males= enlarged prostate Diagnostics: - Bacterial UTI= positive leukocyte esterase - Gram-negative UTI= positive nitrite test Causes: 1. E. coli 2. Staph saprophyticus 3. Klebsiella pneumoniae (urease positive) - Serratia marascens= nosocomial, drug resistant - Enterobacter cloacae= nosocomial, drug resistant - Proteus mirabilis= motile, "swarm" in agar; urease positive--> struvite stones - Pseudomonas= nosocomial, drug resistant
186
ToRCHeS
Toxoplasma: - triad: chorioretinitis, hydrocephalus, intracranial calcifications Rubella: - triad: Septal defects/PDA/pulmonary artery hypoplasia or stenosis, cataracts, deafness (+/- "blueberry" rash) CMV: - Hearing loss, seizures, petechial rash, "blueberry" rash HIV: - Recurrent infections, chronic diarrhea Herpes Simplex Virus 2: - Encephalitis, herpetic lesions Syphillis: - Stillbirth, hydrops fetalis, facial abnormalities (Hutchinson's teeth, saddle nose, short maxilla), saber shins, deafness (CNVIII)
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