Micro Flashcards
Ventilator-associated pneumonia
pseudomonas aeruginosa
septic arthritis in young adult
neisseria gonorrhoeae
Waterhouse-Freidrichsen Syndrome
neisseria meningitidis
Cellulitis
S. aureus or S. pyogenes
Scalded Skin Syndrome
S. aureus (exfoliative toxin)
Gray-white membrane in the posterior pharynx of an unvaccinated child
C. diptheriae
Most common cause of meningitis
S. pneumoniae
Most common cause of osteomyelitis
S. aureus
Serious newborn infection
Listeria, E. coli, Group B Strep
Infant w/ poor muscle tone
C. botulinum
Diarrhea after ABX use
C. difficile
Respiratory distress in a postal worker
B. anthracis
Otitis media in children
S. pneumo
Spore formers
Clostridium, Bacillus, Coxiella burnetti
Tx of C. difficile colitis
Metronidazole or ORAL Vancomycin
GPR branching filmentous w/ sulfur granules
Actinomyces israelii
Rheumatic Fever
S. pyogenes
Subacute Endocarditis
Viridans Group Strep, Enterococci, S. bovis, coag (-) Staph, HACEK organisms
GI Sx after eating potato salad
S. aureus
GI Sx after eating reheated rice
B. cereus
Infections of indwelling foreign devices
S. epidermidis
Red pigment producer
Serratia marcescans
Blue-Green pigment producer
P. aeruginosa
Gold pigment producer
S. aureus
Yellow (sulfur) pigment producer
Actinomyces israelii
Dental procedure ->
Viridans Group Strep
Dental caries
S. mutans
Lipoteichoic acid
Capsule of G(+) induces TNF-alpha & IL-1
Acute Phase Cytokines
IL-1, IL-6, TNF-alpha
Fimbriae
mediates adherence
Pilus
Sexual conjugation (DNA transfer)
Capsule
elusion of phagocytosis
Quellung Reaction
capsule (+) –> swelling (+ anti-capsule serum)
Encapsulated bacteria
E. coli *S. pneumoniae Pseudomonas aeruginosa *Neisseria meningitidis Klebsiella pneumoniae *Haemophilus influenzae type B Salmonella typhi Group B Streptococcus
Meningitis in AIDS pts
Cryptococcus neoformans
Recombinant bacteria is made via
Transformation (DNA released by lysed cell -> picked up by another bacterium & incorporated in chromosomal DNA)
Transduction
phage infects bacterium (dirty - may pick up other DNA fragments)
Doesn’t Gram stain d/t high sterol composition & no cell wall
Mycoplasma
Doesn’t Gram stain d/t high Mycolic Acid composition
Mycobacteria
Spore-formers
Bacillus, Clostridium
Dark-Field Microscopy
Treponema
Atypical pneumonia d.t broken Air conditioner
Legionella pneumophila
PAS stain
Whipple Disease Dx (Tropheryma whipplei)
Ziehl-Neelson Stain (Carbolfuchsin AKA Acid-Fast)
Mycobacterium, Nocardia
India Ink Stain
Cryptococcus neoformans
Silver Stain
Pneumocystis jiroveci, Legionella pneumophila, Helicobacter pylori
Giemsa Stain
Chlamydia, Borrelia, Rickettsiae, Plasmodium, Trypanosomes, Histoplasma
Lipid A
G(-) outer membrane component that induces TNF-alpha & IL-1
Endotoxin
G(-) LPS
Transpeptidase
enzyme that cross-links the peptidoglycan layer of the cell wall
“O” antigen
LPS/Lipid A of G(-) Outer Membrane
Periplasm contains
b-lactamases
“H” antigen
Flagella
“K” antigen
Capsule
Capsule containing D-glutamate
B. anthracis
PAS stains which moclecules
glycogen & mucopolysaccharides
Chocolate agar + factors 5 (NAD+) & 10 (hematin)
Haemophilus influenzae
Thayer-Martin (or VPN) agar
Neisseria spp.
Charcoal yeast medium w/ Fe & cysteine
Legionella
Sabouraud agar
Fungi
pneumonia in Cystic Fibrosis pts
Pseudomonas aeruginosa
Anaerobes lack
catalase &/or dismutase -> oxidative damage
Which ABX is ineffective against anaerobes?
AminO2glycosides :)
Common ABX for anaerobic infections
Metronidazole or Clindamycin
Ventilator-associated pneumonia
Pseudomonas aeruginosa
Gamma hemolysis
Enterococcus
Beta Hemolysis
Group A Strep (S. pyogenes)
Group B Strep (S. agalactiae)
Alpha Hemolysis
Strep Viridans Group
S. pneumoniae
Endocarditis w/ _______________ warrants evaluation for Colon Cancer
S. bovis
Impetigo
S. aureus
What type of pt is at risk for severe infections by encapsulated bacteria?
Asplenics (opsonization is required for clearing infection)
People w/ Chronic Granulomatous Disease have recurrent infections w/ ______________ d/t a deficiency of ____________
Catalase (+) organisms;
NADPH oxidase deficiency
Facultative Intracellular organisms
Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia pestis
Obligate Aerobes
Nocardia
Pseudomonas aeruginosa
MycoBacterium tuberculosis
Gram Stain Limitations
Treponema -> Dark-Field Mycoplasma -> no cell wall Mycobacterium -> Acid-Fast Legionella pneumophila -> Silver stain Rickettsia -> Giemsa stain Chlamydia -> Giemsa stain
GNR Lactose Fermenters
Citrobacter – Fast Lactose Fermenter Klebsiella – Slow Lactose Fermenter E. coli - Slow Lactose Fermenter Enterobacter - Slow Lactose Fermenter Serratia - Fast Lactose Fermenter
Catalase (+) organisms
Pseudomonas Listeria Aspergillus Candida E. coli S. aureus Serratia
Catalase (+) organisms
Pseudomonas Listeria Aspergillus Candida E. coli S. aureus Serratia
Urease (+) organisms
Cryptococcus H. pylori Proteus Ureaplasma Nocardia Klebsiella S. epidermidis S. saprophyticus
Protein A is expressed by _________ & has what MOA
S. aureus;
binds Fc of IgG to prevent opsonization & phagocytosis
What structure protects against phagocytosis?
capsule
Plasmids are exchanged by?
Conjugation
Superantigen MOA
bind MHC class II -> activate TCR -> polyclonal T-cell expansion -> huge release of cytokines
What organisms secrete superantigens?
S. aureus & S. pyogenes
Diptheria toxin MOA
inactivates EF-2 -> cell death
Pseudomonas aeruginosa toxin
Exotoxin A
Exotoxin A of Pseudomonas aeruginosa MOA
inactivates EF-2 -> cell death
Shiga toxin MOA
cleaves host rRNA at Adenine base in 60S subunit -> prevents protein synthesis -> cell death
Shiga Toxin is expressed by
EHEC 0157:H7 & Shigella
Hemolytic Uremic Syndrome Sx
thrombocytopenia, hemolytic anemia, acute renal failure
HUS is caused by what organism
EHEC 0157:H7
ETEC heat-labile toxin MOA
activates adenylate cyclase -> increase cAMP
ETEC heat-stabile toxin MOA
activates guanine cyclase -> increase cGMP
Pseudoappendicitis
Yersinia enterocolitica
Anthrax toxin
3 components:
- Edema Factor (activates a.c. -> increase cAMP)
- Lethal Factor
- Protective Factor
Diptheria toxin MOA
inactivates EF-2
Heat-stabile toxin MOA; expressed by?
activates guanine cyclase -> increase cGMP;
ETEC & Yersinia entercolitica
Anthrax toxin
3 components:
- Edema Factor (activates a.c. -> increase cAMP)
- Lethal Factor
- Protective Factor
Traveler’s Diarrhea
E. coli
TSST-1 MOA
(S. aureus) causes release of cytokines -> TSS
“rice water” stools
Vibrio cholera
Botulinum toxin MOA
inhibits ACh release at NMJ -> flaccid paralysis
Tetanospasm toxin MOA
blocks release of GABA/glycine inhibitory NTs from Renshaw cells -> muscle contraction
Cholera toxin MOA
activates a.c. -> increase cAMP
Pertussis toxin MOA
inactivates the inhibitor of adenylate cyclase -> increase cAMP
Phospholipase causing gas gangrene (organism/toxin?)
C. perfringens - alpha toxin
Panton-Valentine Leukocidin MOA (organism?)
S. aureus - tissue destruction w/ MRSA, killing macrophages & neutrophils
Exfoliative toxin MOA (organism?)
S. aureus - disrupts zona granulosa -> flaccid bullae -> Scalded Skin Syndrome (newborns)
Woman on period using super-absorbent tampon–>
Toxic Shock Syndrome d/t S. aureus & TSST-1
Streptolysin O
S. pyogenes - O2-labile -> hemolysis
Streptolysin S
S. pyogenes - O2-stabile -> hemolysis
Scarlet Fever
S. pyogenes - pyrogenic exotoxins (A, B, C)
Biofilm production is esp pronounced in
S. epidermidis
IgA protease producers
(SHiN)
S. pneumo
HiB
Neisseria
M protein is produced by ______________ and has what MOA?
S. pyogenes;
helps prevents phagocytosis
Bull Neck
C. diptheriae
HUS is caused by what organism
EHEC 0157:H7 & Shigella
ETEC heat-labile toxin MOA
activates adenylate cyclase -> increase cAMP
-> increased Cl- secretion in GIT
Heat-stabile toxin MOA; expressed by?
activates guanine cyclase -> increase cGMP -> decreased NaCl resorption in GIT;
ETEC & Yersinia entercolitica
Botulinum toxin MOA
inhibits ACh release at NMJ (cleaves SNARE protein) -> flaccid paralysis
Tetanospasm toxin MOA
blocks release of GABA/glycine inhibitory NTs from Renshaw cells (cleaves SNARE protein) -> muscle contraction
Pertussis toxin MOA
inactivates the (Gi) inhibitor of adenylate cyclase -> increase cAMP
Bull Neck (severe LAD)
C. diptheriae
Painless black eschar
Cutaneous Bacillus Anthracis
Whooping cough
Bordetella pertussis
Impetigo
S. aureus & S. pyogenes
Superantigen MOA
bind MHC class II -> activate TCR -> polyclonal T-cell expansion -> huge release of IFN-gamma & IL-2
Diptheria toxin MOA
inactivates EF-2 (ADP ribosylator)
Whooping cough
Bordetella pertussis
“double zone” of hemolysis on blood agar
C. perfringens
ASO
(anti-Streptolysin O Ab) used to diagnose Rheumatic Fever (S. pyogenes)
LPS/Endotoxin activates (6)
- > macrophages ->TNF-alpha, IL-1, NO
- > complement -> C3a, C5a
- > tissue factor -> Coag cascade -> DIC
“rust-colored” sputum & lobar pneumonia
S. pneumoniae
Otitis Media
S. pneumoniae
Bacterial Toxins encoded by Lysogenic Phages
shigA toxin Botulinum toxin Cholera toxin Diptheria toxin Erythrogenic toxin of S. pyogenes
Organism associated w/ Acute Post-Strep Glomerulonephritis
S. pyogenes
Mediastinal widening
Bacillus anthracis (Inhalation Anthrax)
Which Streptococcus strain is susceptible to Optochin?
S. pneumo
Which Streptococcus strain is resistant to Optochin?
Viridans group
Cervicofacial Disease w/ draining sinus tracts
Actinomyces israelii
Contaminant of deli meats & unpasteurized milk products
Listeria
Obligate Anaerobes
Clostridium
Bacteroides
Actinomyces
Superantigen
TSST-1 (S. aureus) Exotoxin A (S. pyogenes)
Superantigen
TSST-1 (S. aureus) Exotoxin A (S. pyogenes)
2nd most common cause of UTI in young women
S. saprophyticus
Novobiocin Resistance
S. saprophyticus
Novobiocin Sensitivity
S. epidermidis
Sepsis in Sickle Cell pts or Asplenics
S. pneumoniae
S. pneumo is the MOST COMMON CAUSE OF
Meningitis
Otitis Media
Pneumonia
Sinusitis
MOST common cause of osteomyelitis
S. aureus
“Thumb Sign” on X-ray
Epiglottitis (H. influenzae type B)
Neonatal conjunctivitis
N. gonorrhoaea
Meningitis in young adults & children
N. meningitidis
Purpura Fulminans
N. meningitidis
Pontiac Fever
Legionella pneumophila
Hot Tub Folliculitis
P. aeruginosa
Burn victim wound infection
P. aeruginosa
GN diplococci, Oxidase (+) organism in COPD sputum sample
Moraxella catarrhalis
Diarrhea 1-3d following handling turtles
Salmonella
Osteomyelitis in a Sickle Cell pt
Salmonella
42C Culture
Campylobacter
Common cause of gastroenteritis & Guillain-Barre Syndrome
Campylobacter
Pneumonia in Alcoholics or COPD pts
Klebsiella pneumoniae
“Currant-jelly” sputum
Klebsiella pneumoniae
“Swarming” motility
Proteus
Struvite stones -> Staghorn Calculi
Proteus
E. coli causing HUS
EHEC O157:H7
Diarrhea d/t GN, non-motile, lactose nonfermenter
Shigella
Diarrhea d/t “S-shaped” organisms
Campylobacter jejuni
Diarrhea from household pets
Yersinia enterocolitica or Salmonella
Diarrhea d/t GN, motile, lactose nonfermenter
Salmonella
Traveler’s Diarrhea
ETEC
Diarrhea from undercooked hamburger meat
EHEC
Diarrhea mimicking appendicitis
Yersinia
Diarrhea after handling raw chicken or eggs
Salmonella or Campylobacter
Osteomyelitis in Sickle Cell pts
Salmonella
Osteomyelitis in Sickle Cell pts
Salmonella
“Comma” shaped GNR
Vibrio
“S” shaped GNR
Campylobacter
Which E. coli invades the intestinal wall?
EIEC
Infection caused by animal urine?
Leptospira (water contaminated w/ urine)
Hantavirus (rodent urine)
“Target” shaped lesion is associated w/ what disease
Lyme’s Disease
Lyme’s Disease is transmitted by what vector
Ixodes tick
Lyme’s Disease is caused by what organisms
Borrelia burgdorferi
B/L facial n. palsy
Lyme’s Disease (disseminated)
Causes of rashes on palms & soles
Kawasaki Disease
Coxsackie A
Rocky Mountain Spotted Fever
Secondary Syphilis
External Otitis (Swimmer’s Ear)
Pseudomonas aeruginosa
Ecthyma Gangrenosum in immunocompromised
Pseudomonas aeruginosa
What allows S. sanguinis to bind to damaged heart valves?
Dextrans -> bind fibrin-platelet aggregates on damaged heart valves
S. pyogenes pyrogenic conditions
pharyngitis, cellulitis, impetigo
S. pyogenes toxigenic conditions
Scarlet fever, TSS-like, necrotizing fasciitis
S. pyogenes Immunologic conditions
Rheumatic Fever & Acute Post-Strep Glomerulonephritis
Ab to what S. progenies virulence factor gives rise to Rheumatic Fever?
Antibodies to M protein
Ab to what S. progenies virulence factor is used in the Dx of Rheumatic Fever?
Anti-Streptolysin Antibodies (ASO) - confirms prior S. pyogenes infection
“Strawberry tongue”
Scarlet fever d/t S. pyogenes
“Sandpaper-like” Rash
Scarlet fever d/t S. pyogenes
CAMP test or Hippurate Test is an important diagnostic test for?
S. agalactiae
Important cause of Biliary Tract Infections & UTIs?
Enterococci
Which Strep strain is resistant to Bacitracin?
group B Strep
Which Strep strain is sensitive to Bacitracin?
group A Strep
Lung abscess in aspiration pneumonia
Klebsiella pneumo
“rose-spots” on abdomen + fever + HA + diarrhea
Salmonella typhi
Salmonella typhi carrier state in which organ?
Gallbladder
Puppy poop
Yersinia enterocolitica
Weil’s Disease
Severe Leptospirosis - fever, hemorrhage, and anemia
Flu-like Sx in surfer
Leptospira interrogans
Flu-like Illness contracted from birds (parrots)
Chlamydophila psittaci
Flu-like Illness contracted from infected placenta or newborn farm animals
Coxiella burnetti
LAD + new kitten
Bartonella henslae
Recurrent Fever
Borrelia recurrentis
Spread by prairie dogs
Yersinia pestis
Spread by rabbits, squirrels, ticks
Francisella tularensis
Spread by armadillos
Mycobacterium leprae
Cat or Dog bite -> Cellulitis
Pasteurella multocida
Spread by the Dermacentor tick
Rickettsia rickettsii
Epidemic typhi
Rickettsia prowazekii (Lice)
Endemic typhi
Rickettsia typhi (fleas)
Spread by RABBITS, squirrels, ticks
Francisella tularensis
Endemic typhi
Rickettsia typhi (fleas)
Fish tank cellulitis
mycobacterium marinum
gray discharge + fishy odor
gardnerella vaginosis
Q fever Sx
acute flu-like Sx w pneumonia
Chronic –> endocarditis
Q fever agent
coxiella burnetti
Unpasteurized milk
Brucella or Coxiella burnetti
Animal placent
Coxiella burnetti
farm animal urine/feces –> air borne spread
Coxiella burnetti
Spread by Ixodes scapulars ticks
Anaplasma phagocytophilum & Borrelia burgdorferi
Spread by Lone Star tick
Ehrlichia chaffensis
Epidemic Typhus
Rickettsia prowazekii spread by lice
Endemic Typhus
Rickettsia typhi spread by flea
Chlamydia trachomatis A-C
Trachoma (eye infection -> blindness)
Chlamydia trachomatis D-K
Urethritis, cervicitis, PID
Reactive Arthritis
Chlamydia trachomatis, Campylobacter, Salmonella, Shigella, Yersinia
Pet parrot
chlamydophila psittaci
Common atypical pneumonia agents
legionella pneumoniae, chlamydophila pneumoniae, mycoplasma pneumoniae
Rickettsial triad of Sx
HA, fever, rash
Cold agglutinins
IgM
Mycoplasma pneumoniae Tx
Azithromycin
Bacterial vaginosis Tx
Metronidazole
Rocky Mountain Spotted Fever Tx
Doxycycline
Rocky Mountain Spotted Fever Sx
HA, fever, rash on palms/soles!!
Agents that cause rash on palms & soles
Coxsackie A, Rocky Mountain Spotted Fever, Meningocococcus, Secondary Syphilis
Rocky Mountain Spotted Fever agents
Rickettsia rickettsiae
Bird & bat droppings
Histoplasmosis
Broad-based fungus found near MS, OH river basins
Blastomycoses
HSV-1 may cause
Temporal lobe encephalitis
Gingivostomatitis
Oral herpes labialis
Keratoconjunctivitis
HSV-2 may cause
Genital Herpes
Multiple, painful vesicles
latent infection in sacral n. root
HSV-2 spread
sexual contact, genital-oral contact (mucosa)
HSV-2 to neonate
through canal
primary inf. increases risk of spread to neonate
ZVZ
primary: chickenpox, encephalitis, pneumonia
Secondary: latent in dorsal root ganglia -> shingles (U/L single dermatome rash)
ZVZ spread
contant, respiratory, direct contact to active lesions, airborne if disseminated in immunodeficient
Tzanck smear
open vesicle sample, multinucleate giant cell, HSV-1, -2, VZV; low specificity
Intranuclear eosinophilic inclusions
Cowdry A inclusions
EBV
infectious mononucleosis
EBV spread
oral secretions, 15-24yo, kissing disease
EBV infects
B cells, T-cell response
Downey cells
atypical lymphocytes seen in EBV (reactive T-cells)
infectious mononucleosis
fever, sore throat, posterior cervical LAD, exudative pharyngitis
When you give Amoxicillin to infectious mononucleosis pt –>
maculopapular rash (trunk, ext) NOT ALLERGIES
infectious mononucleosis complications
splenomegaly, rupture (no contact sports)
infectious mononucleosis Dx
Monospot test (heterophile Ab) IgG IgM Ab to EBV
Heterophile negative mononucleosis
CMV > HIV > Toxoplasmosis
EBV is assoc. w/ what malignancies?
Hodgkin, Burkitt, Nasopharyngeal carcinoma, Diffuse Large B cell, Hairy leukoplakia
CMV spread
congenital, close contact
CMV cuases
Heterophile negative mononucleosis
Transplant pts
AIDS w/ CMV
retinitis, GI ulcers, Candida esophagitis
CMV infects
mononuclear cells & polynuclear cells infected for life
HHV-6 causes
roseola in children, 6th Ds, exanthum rubitum
HHV-6 Sx
3-5d Fever, maculopapular rash, +/- Febrile seizures
HHV-7
Roseola-like virus, almost all ppl are infected by 5
HHV-8
Kaposi Sarcoma, MSM, HIV
Acyclovir
guanosine analog (activated by thymidine kinase) inhibits DNA polymerase; useful for HSV-1, -2, VZV
Parvovirus B19
ssDNA
Sickle cell pts + Parvo
Transient aplastic crisis
Parvo B19 in children
Slapped cheek! erythema infectiosum
Adults w/ Parvo B19
inflammatory arthritis
Parvo B19 in utero
Hydrops fetalis & miscarriage
HPV-1, -2
common warts
HPV-6, -11
genital warts
HPV-16, -18
genital cancer
Adenovirus
dsDNA, URI -> conjunctivitis + diarrhea; hemorrhagic cystitis, pneumonia,
Smallpox
enveloped variola virus
Cowpox
Milkmaid’s blisters,
provides immunity to smallpox
Molluscum contagiosum
benign umbilicalized flesch-colored lesins
JC virus
PML in HIV pts
Hepatitis B virus (Hepadnavirus)
partial dsDNA, circular enters nucleus, makes RNA, uses RT to make DNA
Rotavirus
fatal diarrhea in children -> severe diarrhea, electrolyte imbalance
Rotavirus case
infant, winter mos, daycare child
Coltivirus
CO tick fever in west US, spread by wood tick
Picornavirus
small RNA virus
Enterovirus
Poliovirus, Coxsackie, Echovirus
Poliovirus
infects gray matter of anterior horn & motor horns
Salk vaccine
injected, killed Polio vaccine
Sabin vaccine
Oral, live Polio vaccine
Echovirus
Aseptic meningitis, myocarditis, URIs
Echovirus
Summer outbreaks, detected by PCR of CSF
Coxsackie virus
Aseptic meningitis, myocarditis, Hand-foot-mouth disease, pericarditis
Hepatitis A virus transmission
fecal-oral
Rhinovirus
common cold (Coronavirus too)
Norwalk Virus
Calcivirus; viral gastroenteritis - vomiting, diarrhea; outbreak on ships & nursing homes
Hepatitis C is in which viral family
Flavivirus
Yellow Fever
Flavivirus, Aedes mosquitoes spread, sub-saharan Africa
Yellow Fever Sx
High fever, hemorrhagic ds, jaundice, coffee-ground emesis, gum bleeding, purpura
Dengue Virus Sx
break bone fever, severe HA, retro-orbital pain
Dengue hemorrhagic fever
Tourniquet Test -> excess petechiae = increased vascular wall fragility
West Nile Virus
spread from birds -> mosquitoes -> humans
West Nile Virus Sx
flu-like illness
West Nile Virus complications
meningitis, encephalitis, flaccid paralysis (ant. horn infection like polio)
West Nile Virus Dx
IgM anti-WNV Ab
St. Louis Encephalitis virus
Arbovirus (arthropod vector)
Rubella virus
mild fever, rash, arthralgias
Congenital Rubella syndrome
cardiac defects, cataracts, deafness, PDA, pulmonic stenosis
Coronavirus
common cold (rhinovirus)
HTLV-1 is a
RNA RT
Influenza virus
orthomyxovirus, enveloped, ssRNA, hemagluttinin, neuraminidase
Influenza Sx
Viral pneumonia, secondary bacterial infection (S. pneumo, S. aureus)
Genetic shift
reassortment of viral genome, exchange genetic material -> complete shift -> pandemic
Genetic drift
mutated or rearranged -> seasonal epidemics
Influenza vaccine
trivalent (2 A & 1 B)
quadravalent (2A & 2B)
injectable or live intranasal
Recommendations for flu vaccine
everyone > 6mo
Avian influenza
H5N1, bird-to-human
Avian influenza Sx
URI, GI sx, pancytopenia, fever, ALT & AST elevated
Swine Influenza
H1N1
Neuraminidase inhibitors
Zanamivir, Oseltamivir for influenza pts at high risk, must be used w/in first 24h
Parainfluenza virus
Croup -> barking seal cough, steeple sign (laryngo-tracheo-bronchitis)
Parainfluenza virus Tx
cold air, mist, Epi, steroids, O2
RSV
Bronchiolitis +/- pneumonia in winter in premature infants
URI, brassy cough
RSV Px
palivizumab for premature infants
Ribavirin
guanosine analog
RSV, Hep C (IFN-alpha)
S/E Hemolytic anemia, teratogen
Measles aka
Rubeola
Measles Sx
Coryza, cough, conjunctivitis, Koplik Spots (buccal mucosa) -> maculopapular rash (head down)
Measles Complications
Fetal loss, premature delivery, encephalitis, giant cell pneumonia
Subacute Sclerosing Pnacephalitis
Complication of Measles
Mumps
Parotitis, Orchitis, Aseptic Meningitis
Rabies virus
bitten by infected animal -> peripheral nn. to CNS
Negri bodies
Rabies Virus
Bullet-shaped capsid
Rabies
Rabies Sx
fever, malaise, n/v, strange behavior, hallucinations, hydrophobia, coma, death
Hantavirus
hemorrhagic fever, pulmonary syndrome, respiratory failure
Hantavirus
aerosolized mouse urine (deer mouse)
Hemorrhagic fever
Ebola, Marburg
Ebola
spread through infected blood, secretions
Ebola Sx
fever, HA, myalgias, v/n, diarrhea, fluid-loss, shock, death
Ebola prevention
sweat, tears, urine, feces - ISOLATION!!
Screening HIV test
ELISA (high Sens)
Confirmatory Test for HIV
Western (high Spec)
Viral Load HIV testing
PCR, quantifies HIV RNA, monitor effectiveness, confirm diagnosis (early detection 1-2mo in window period)
Most common opportunistic infection in HIV pts
pneumocystic jiroveci pneumonia
Pneumocystic jiroveci (PCP) in AIDS pts
interstitial infiltrates on CXR
Opportunistic infection in HIV pts
PCP, TB, MAC –> pneumonia
Histoplasma capsulatum -> systemic disease, HSM, fever
Cryptococcal meningitis
Toxoplasmosis (ring-enhancing lesions)
Primary Lymphoma
CMV retinitis (cotton-wool spots)
PML JC virus
Cryptosporidiosis
C. albicans -> thrush, esophageal candidiasis
Oral hairy leukoplakia (can’t scrape off)- EBV
HSV, CMV oral infections
Progressive Multifocal Leukoencepalopathy
reactivation of JC virus
HIV pts are at risk for what malignancies
Kaposi sarcoma (purple lesions), Primary CNS lymphoma (ring lesions) Large B cell EBV Squamous Cell Carcinoma cervix/anus
Bacillary angiomatois
purple lesions
Prophylaxis for AIDS pts
TMP-SMX for PCP at CD4
Causes cat scratch fever
Bartonella henslae
Causes lyme disease
Borrelia burgdorferi
Causes recurrent fever from variable surface antigens
Borrelia recurrentis
Causes bloody diarrhea
Campylobacter (puppies, livestock, fecal-oral)
Causes Q fever
Coxiella burnetii (livestock placenta, tick feces)
Cause tularemia
Francisella tularensis (Rabbits)
Causes leptospirosis
Leptospira (animal urine)
Causes cellulitis and osteomyelitis from cat or dog bites
Pasteurella multocida
Tx for CMV retinitis
Ganciclovir > Foscarnet
Oral hairy Leukoplakia
EBV
Aplastic anemia in a sickle cell pt
Parvovirus B19
Child w/ fever + slapped cheek rash
Parvovirus B19
Congenital Rubella Cardiac Defects
PDA, aortic stenosis
Coryza, cough, conjunctivitis
Measles
blue-gray spots on buccal mucosa surround by a base of red
Koplik spots w/ Measles
Travel to Africa + fever, vomiting, diarrhea
Ebola
Can cause conjunctivitis or diarrhea
Adenovirus
Can cause fever + jaundice + black vomit
Yellow Fever
Can cause enlarged cell w/ “owl’s eye” inclusions
CMV
Can cause “barking seal” cough
Parainfluenza virus
Can cause bronchiolitis w/ cough/wheezing in babies
RSV
Can cause negri bodies
Rabies
Hides in trigeminal ganglia
HSV-1
Diarrhea in child during winter months
Rotavirus
2 most common causes of the common cold
Rhinovirus > Coronavirus
Downey Cells are seen w/
EBV
Common cause of aseptic meningitis
Enterovirus
gag gene in HIV encodes
p24 capsid protein
pol gene in HIV encodes
RT & integrase
env gene in HIV encodes
gp120, gp41
Meningitis in AIDS pt
Cryptococcus neoformans
Pseudoappendicitis
Yersinia colitis
C. albicans - oral thrush Sx
white, cottage-cheese like patches on tongue
C. albicans - oral thrush is seen in
AIDS, immunodeficient, asthmatics w/ inhaled steroids, neonates
C. albicans - oral thrush vs oral hairy leukoplakia
oral thrush can be scraped off
C. albicans - Vuvlovaginitis
acidic pH, severe itching, cottage cheese discharge
Diaper rash
C. albicans
C. albicans - Intertrigo
skin infections in folds
C. albicans - Bloodstream infections are seen in
pts w/ central lines, drug users, immunocompromised
C. albicans - complications in immunocompromised
Endopthalmitis, Endocarditis
C. albicans - Dx
germ tubes, budding yeast
C. albicans - Tx
Topical Nystatin, Clotrimazole, Fluconazole
Cryptococcus neoformans is seen mostly in
Aids pts as meningitis
Cryptococcus neoformans Dx
Sabouraud’s agar, narrow-based budding yeast
Cryptococcus neoformans is found in what environment
soil & in pigeon droppings
India ink stain
Cryptococcus neoformans
Soap-bubble lesion in the brain
Cryptococcal meningeal encephalitis
Pneumocystis jiroveci is most commonly seen
in AIDS pts as atypical pneumonia
Pneumocystis jiroveci - pneumonia
Diffuse interstitial
Pneumocystis jiroveci Dx
Silver stain or CXR w/ “ground-glass” appearance
Pneumocystis jiroveci Tx
TMP-SMX
Aspergillus fumigatus is found
ubiquitous in food, soil, air
Aspergillus fumigatus Dx
narrow-septate branching at acute angles
Mucor & Rhizopus Dx
Broad, irregularly shaped, non-septate hyphae branching at right angles
Mucor & Rhizopus in Diabetics
Rhinocerebral mucormycosis: facial pain, HA, necrotic lesions
“Ringworm” aka
Tinea capitis or Tinea corpora
Thickened, discolored nails
Tinea unguium (Onychomycosis)
Malassezia furfur Sx
hypo pigmented spots on trunk
Malassezia furfur Tx
Topical azole, topical selenium sulfide
Malassezia furfur Dx
KOH prep - “spaghetti & meatball” appearance
Organism assoc. w/ cat feces
Toxoplasma
Organism assoc. w/ dog feces
Yersinia entercolitica
Organism assoc. w/ bird or bat poop
Histoplasma capsulatum
Organism assoc. w/ OH & MS river valley
Histoplasma capsulatum
Histoplasma capsulatum enters lung and is engulfed by
macrophages
Blastomyces dermatitidis is found
MS, OH river basins & Central America (East of River)
Blastomyces dermatitidis Dx
broad-based yeast forms
Coccidioides immitis in environment
dimorphic -> mycelial or arthroconidia in soil
Coccidioides immitis in human lung
Spherules - larger than a RBC
Coccidioides immitis is found
SW US & increased in incidence after windstorms
What organism is assoc w/ rose thorns?
Sporothrix schenckii
What organism is assoc w/ SW US
Coccidioides immitis
Paracoccidioides brasiliensis is found
Latin America
What organism is assoc w/ East of the MS River
Blastomyces dermatitidis
Barrel-shaped arthroconidia
Coccidioides immitis
Amphotericin B MOA
binds ergosterol -> permeability
Cryptosporidium - Sx
chronic watery diarrhea in AIDS pts
Giardia lamblia in found
in nature in fresh-water streams
Giardia lamblia Sx
gas, bloating, acute fatty & foul-smelling diarrhea
Giardia lamblia Dx
pear-shaped trophozoite or oocyte
Giardia lamblia Tx
Metronidazole, Tinidazole
Entamoeba histolytica Sx
amoeba dysentery invades colon +/- liver cysts
Flask-shaped lesions in GIT
Entamoeba histolytica
Entamoeba histolytica Dx
trophozoites or cysts in stools
Entamoeba histolytica Tx
Metronidazole & Iodoquinol to kill cysts
Trichomonas vaginalis Sx
greenish, foul-smelling discharge
Trichomonas vaginalis Dx
trophozoites w/ flagella
Toxoplasma gondii is found
cat feces or undercooked cysts in meat
Toxoplasma gondii Sx
ring-enhancing lesions on MRI in AIDS pts
Congenital Toxoplasma gondii
Chorioretinitis, hydrocephalus, intracranial calcifications
Naegleria fowleri - Sx
meningoencephalitis
Naegleria fowleri is found
swimming in freshwater lakes
Naegleria fowleri Tx
Amphotericin B
Trypanosoma brucei Sx
Fever, LAD, somnolence —> encephalitis, coma, death
Trypanosoma brucei are found
Africa
Trypanosoma cruzi is found
S. America
Trypanosoma cruzi is transmitted by
reduvid bug
Trypanosoma brucei is transmitted by
Tsetse fly
Chagas Disease
Trypanosoma cruzi –> dilated cardiomyopathy, megacolon, megaesophagus
Leishmania donovani - Visceral
fevers, HSM, pancytopenia
Leishmania donovani - Cutaneous
ulcerating papules slow to heal
Malaria vector
Anopheles mosquito
Malaria Sx
cyclin fever (48h ovale & vivax, 72h malaria)
Most severe form of Malaria
p. falciparum
Banana-shaped gametocyte
p. falciparum
Babesia Sx
ring-form trophozoite
maltese cross merozoite
Babesia vector
Ixodes tick
Most common helminthic inf. in the US
Enterobius vermicularis
Ascaris lumbricoides Life cycle
ingest egg -> larvae hatch -> penetrate bowel -> lung -> migrate up trachea to oropharynx -> swallowed & mature in colon
Ascaris lumbricoides - Sx
Loffler eosinophilic pneumonitis
Ascaris lumbricoides - Tx
Mebenzdazole, Albendazole, Pyrantel pamoate
Undercooked game meat (bear)
Trichinella spiralis
Trichinella spiralis life cycle
larvae migrate from GIT to muscles
Trichinella spiralis Sx
myositis, fever, eosinophilia, periorbital edema
Strongyoides stercoralis infect humans via
infactive larvae penetrate skin from soil
Strongyoides stercoralis life cycle
larvae migrate to lung -> swallowed -> GI inf
Strongyoides stercoralis Tx
Ivermectin, Mebendazole
Ancylostoma & Necator infect humans via
penetrate skin of feet
Ancylostoma & Necator cause
abd discomfort (hookworm sucks blood) -> anemia
Ancylostoma & Necator Tx
Albendazole, Mebendazole, Pyrantel pamoate
Undercooked pork
Taenia solium
Taenia solium Sx
GI Sx or Myositis, Neurocysticercosis
Taenia solium infects humans via
adult tapeworm infects GIT or
ingestion of eggs -> larvae invasion of tissues (myositis, neurocysticercosis)
Neurocysticercosis
black ring lesion on CT
Immigrant presents w/ new CNS Sx (AMS, confusion, etc)
neurocysticercosis
Taenia solium Tx
Praziquantel, Albendazole + Dexamethasone (Neurocysticercosis)
Diphyllobothrium latum -> deficiency of
Vitamin B12 -> megaloblastic anemia
Ingestion of raw fish (tapeworm)
Diphyllobothrium latum
Tapeworm spread in dog feces
Echinococcus granulosus
Echinococcus granulosus Sx
cysts in liver or lung
Schistosoma life cycle
eggs ingested by snails -> cercaria penetrate skin of humans -> “swimmers itch” -> migrate to lungs or liver
Which parasite resides in the lower GU?
Schistosoma haematobium
Which parasite resides in Mesenteric vessels?
Schistosoma mansoni
Helminths + portal HTN + splenomegaly
Schistosoma eggs stuck in portal v.
Schistosoma haematobium can cause what malignancy?
Squamous cell carcinoma of bladder
Paragonimus westermani Sx
chronic bronchitis, hemoptysis
Undercooked crabmeat
Paragonimus westermani
Clonorchis sinensis - Sx
lives in biliary tract -> inflammation, pigmented gallstones, cholangiocarcinoma
Undercooked fish - fluke
Clonorchis sinensis
Wuchereria bancrofti Sx
elephantiasis, hydrocele “filariasis”
Scabies are found typically
interdigital webs