Micro High Yield Flashcards
6 bugs that don’t gram stain well
Treponema palladium (visualize on darkfield microscopy) Rickettsia (intracellular) Mycobacteria (acid fast) Mycoplasma (no cell wall) Legionella (sliver stain) Chlamydia (intracellular)
Bugs that stain with Giemsa stain
Chlamydia, Borrelia, Rickettsia, Trypanosomes, Plasmodium
Ziehl Neeson is a stain that correlates with what type of bacteria
Acid fast bacteria
Typical bug that stains with India Ink
Cryptococcus neoformans
Bugs that stain with silver stain
fungi, Legionella, H. pylori
What makes up Thayer-Martin Agar and what grows on it?
VPN (vancomycin, polymixin, nystatin) and it grows Neisseria
Agar that grows Clostridium diptheriae
Tellurite Lofflers
Fungi grow on this type of agar
Sabaroud dextrose
Legionella grows on this type of agar
Charcoal yeast with cysteine and iron
These bugs grow on Hektoen Enteric agar
Salmonella, Shigella, E. coli, Klebsiella
Vibrio cholera grows on
TCBS
Aminoglycosides are ineffective against these types of organisms
obligate anaerobes (AG’s need O2 to work)
Organisms that are catalase positive
Pseudomonas, Listeria, Aspergillus, Candida, E. coli, Staph A, Serratia
Toxins that inhibit protein synthesis
C. diptheria, Pseudomonas (both inactivate IL2); Shigella, EHEC (both inactivate 60s ribosome)
Toxins that increase cAMP
Vibrio cholera (increase Cl secretion-"rice water") Bacillus anthracis (edema) ETEC (labile-increases Cl secretion; stabile- decreases NaCl absorbtion) Bordetella pertussis (disables Gi, impairs phagocytosis)
Toxins that affect nerve transmission (cleave SNARE)
C. tetani- rigidity, lockjaw, no release of GABA or glycine
C. botulinum- flaccid paralysis, inhibits release of Ach.
toxins that lyse membranes
C. perfringens: alpha toxin, myonecrosis
Strep pyogenes: streptolysin O lyses RBC
Superantigens of Strep pyogenes and Staph A causing TSS.
Strep: Exotoxin A
Staph: TSST1
How to differentiate Beta hemolytic strep
Sensitive to Bacitracin: Strep pyogenes
Resistant to Bacitracin: Strep agalacticae
How to differentiate Alpha hemolytic strep
Sensitive to Optochin: Strep pneumo
Resistant to Optochin: Viridians strep
How to differentiate Coagulase negative strep
Sensitive to Novobiocin: Staph Epidermis
Resistant to Novobiocin: Staph Saprophyticis
Strep pneumo is the most common cause of these 4 diseases
MOPS: meningitis, otitis media, pneumonia, sinusitis
Strep bovis has a high association with
colon cancer
Common infections caused by and characteristics of Pseudomonas
Acronym: PSEUDOmonas Pneumonia (CF patients) Sepsis External otitis UTI Drug use Osteomyelitis (in diabetics) (hot tub folliculitis)
Differentiate between Salmonella and Shigella
Salmonella: H2S +
Shigella: H2S -
E. coli strain responsible for Traveler’s diarrhea (watery)
ETEC; labile and stable toxins. No mucosa invasion.
E. coli strain responsible for Hemolytic uremic syndrome (anemia, thrombocytopenia and renal failure)
EHEC O157:H7 virulence factor is the Shiga-like toxin (doesn’t ferment sorbitol unlike other E. colis!)
Most common cause of bloody diarrhea in kids, temperature it grows in and high yield clinical sequelae
Campylobacter jeujeni, grows at 42 degrees C, can cause Guillian Barre syndrome
H. pylori is the predominant cause of ulcers located where?
duodenum
Clinical consequence of Leptospira infection
Weil disease: jaundice, renal failure, liver and kidney shutdown, fever, hemorrhage, anemia
Sign of primary syphillis
painless chancre (tx: penicillin)
Signs of secondary syphillis
maculopapular rash on palms and soles, condyloma lata
Signs of tertiary syphillis
CNS manifestations: tabes dorsalis, ataxia, Argyll Robertson pupil
gummas (chronic granulomas), charcot joints
Description of Argyll Robertson pupil
Accommodates but doesn’t react (prostitute pupil)…GET IT???
Signs of congenital syphillis
Saber shins, saddle nose, CN VIII deafness, mulberry molars, “hutchinson teeth” (notched)
3 infections causing rash on palms and soles
Coxsackie A, Rickettsia (RMSF) and syphillis
4 fungal pneumonias in immunocompetent patients
- Histoplasmosis
- Blastomyces
- Coccioides
- Paracoccioides
Histoplasmosis is found in this geographic area and is associated with exposure to…
Mississippi/Ohio river valley, assoc with caves, bats, demolition projects. The fungi hides in the macrophages
Blastomyces is found in this geographic area, characteristics of what you see on microscopy
Mississippi and eastward, on microscopy you see broad based budding yeast.
Coccioides is associated with this geographical area and has what characteristic on microscopy?
Desert SW, especially after an earthquake. Microscopy shows Spherules containing endospores
Paracoccioides looks like this and is found where?
Captains wheel and found in Latin America
This cutaneous fungi looks like “spaghetti and meatballs” on KOH prep
Tinea Versicolor (Malasezzia furfur)
cigar-shaped fungi associated with vegetation, causes pustule/ulcer
Sporothrix -“rose gardener” disease
Protozoa causing malabsorption, flatulence, diarrhea, associated with campers and hikers.
Giardia Lambia: treated with metronidazole
Parasite causing bloody diarrhea, RUQ pain, liver abcess. Contains multinucleated cysts
Entamoeba histolytica
aka pinworm
Enterobius vermicularis
Nematode causing intestinal infections, knobby looking eggs
Ascaris lumbricoides
Trichuris trichuria (whipworm) causes what type of infection?
Intestinal: bloody diarrhea, football shaped eggs w/ operculated ends
Cestode responsible for neurocystisarcosis and intestinal infection from undercooked pork.
Taenia solium (tx: praziquantel)
Cestode that competes for B12 in intestines and causes anemia
Diphyllobothrium- from raw fish
Schistosome that causes portal HTN and liver issues
Schistosome mansoni
Schistosome that causes bladder CA
Schistosome hematobilium
Protozoa causing rapidly fatal meningioencephalitis. Found in freshwater lakes, enters cribiform plate.
Neigleria fowleri
Congenital toxoplasmosis infection triad found in babies
chorioretinitis, hydrocephalus, intracranial calcifications
Trypanosoma brucei is transmitted by what
tse tse fly (no amastigotes-those are only cruzi)
T. brucei causes this disease
African sleeping sickness: swollen lymph nodes, recurring fever, somnolence, coma.
Tx: suramin
Mode of Plasmodium transmission
Anopheles mosquito
Transmission of Babesiosis
Ioxodes tick (coinfects with Borellia)
What you see on microscopy in Babesiosis infection
Ring form (ddx: malaria) and Maltese cross (rules out malaria)
Tx for Babesiosis
Atovaquone and azithromycin
Transmission of Trypanosome cruzii
reduvid bug (amastigotes seen)
Clinical signs/sx of T. cruzi infection
Chagas disease: dilated cardiomyopathy, megacolon, megaesophagus
Paragnomius westermani causes
lung inflammation, TB like sx, hemoptysis (lung fluke)
Clinical sign of infection with Paragnomius westermani
“coffee bean shape” operculated eggs, “rusty” color.
recent ingestion of undercooked seafood/crab
Tx: praziquantel
List of live vaccines
VZV, smallpox, yellow fever, Sabin’s polio, MMR, Intranasal influenza, rotavirus
only DNA virus that is single stranded
parvovirus (part-of-virus -silly mnemonic)
only RNA virus that is double stranded
reovirus
RNA viruses:
Retrovirus, Togavirus, Flavivirus, Coronavirus, Hepevirus, Calicivirus, Picornavirus, Orthomyxovirus, Paramyxovirus, Rhabdovirus, Bunyavirus
7 DNA viruses:
Herpesvirus, Hepadnavirus, Adenovirus, Parvovirus, Papillomavirus, Polyomavirus, Poxvirus
High fever then when fever stops you get a rash
Roseola
Roseola is caused by what virus?
HHV6
How can you identify Herpes Simplex virus for diagnostic purposes? (just HSV1 and HSV2)
Tszank test and visualization of cowdry bodies
Hepadnavirus causes what disease?
Hepatitis B
Virus responsible for aplastic crisis in sickle cell patients, “slap cheek fever”/erythema infectiosum (5th disease) in kids
Parvovirus B19
Subtypes of HPV responsible for cervical cancer
HPV 16 and 18
Virus responsible for Progressive multifocal leukoencephaly in HIV patients
JC virus (polyomavirus)
Poxvirus is responsible for these diseases
smallpox and molluscum contagiosum