Micro Flashcards
what do Lipid A (outer mem of g-) and Lipoteichoic acid (outer layer of g+ cell wall) induce?
both serve as major surface antigens and induced TNF and IL-1.
where are b-lactamases found?
Periplasmic space
define Glycocalyx
network of polysachharides that mediates adherence to surface, i.e. as a biofilm to cathether
G+ rods
Bacillus, Clostridium, Corynebacterium diptheria, Lactobacillus, Propionibacterium, Listeria, Mycobacterium
Camplyobacter classification
G- enteric
Giemsa stain organisms
Chlamydia, Rickettsia, Borrelia, Plasmodium. these are pleomorphic.
Chlamydia: high or low muramic acid?
low
carbol-fuchsin aka Ziehl-Neelsen stain
Acid fast: bacteria = Nocardia, Mycobacterium. protozoa = cryptosporidium.
auramine-rhodopsin is an alternative
silver stain organismis
PCP, Legionella, H Pylori
PAS
Whipples: Cardiac sx, Arthralgias, and Neuro sx + malabsorption. Foamy macrophages in intestinal LP.
describe Thayer-Martin agar
Chocolate agar + antibiotics. AKA VPN (p =polymyxin). But we know it cantains Very Nice Chocolate Treats. Vanco (G+), Nystatin (fungi), Colistatin (G- except Neisseria), Trimethoprim .
Sabourad agar
Fungi. Sab is a fun guy!
Anaerobic bacteria lack___________and are susceptible to __________damage
lack Catalase/SOD. oxidative damage. they are foul smelling.
Clostridium, Actinomyces, Bacteroides, Fusobacterium.
________ ineffective against clostridium
Aminoglycosides are ineffective against Anaerobic organisms
keep nocardia and actinomyces 02 req straigth
nocardia: the air bellow even though inside. its Aerobe
actinomyces
how do conjugate vaccines enhance immunogenicity
Promote t cell activation and class switching
urease positive organisms (list)
Cryptococcus, H pylori, Proteus, Klebsiella, Straph epidermidis/saprophyticus, Nocardia!, Ureaplasma
Stones from organisms such as Crptococcus, Klebsiella, Nocardia
Urease + organisms cause struvite aka ammonium magneisum phosphate kidney stones –> staghorn calculi
people with recurrent catalase + infections (dont forget serratia)
Chronic granulomatous disease (NADPH oxidase deficiency)
f(x) of protein A (dont confuse with IgA protease)
expressed by staph aureus. binds Fc of IgG.
Prevents opsonization/complement/phagocytosis
organisms that express IgA protease
Strep pneumo, H flu, Neisseria –> helps to colonize respiratory mucosa (SHiN)
f(x) of M protein
prevent phagocytosis (strep pyo aka GAS)
Type 3 injectisome secretion system
Shigella, Salmonella, E coli, Pseudomonas
Exotoxin vs Endotoxin
Exo: polypeptide, secreted from cell, genes on plasmid/bacteriophage. low ID50 = highly fatal/toxic. Destroyed with heat.
Endo: polysachharadie, no secreted, released upon lysis, low toxicity, induces TNF, IL-1, IL6, can cause DIC, stable at 100 C heat.
extoxins that inhibit protein synthesis
Inactivate EF-2: Diptheria and Exotoxin A(PSEUDOmonas)
Inactivate 60S by removing adenine from rRNA = Shiga and Shiga-like toxin (EHEC)
difference btwn Shiga and Shiga-like toxin (E coli)
both inactivate protein synthesis by removing adenine from 60S rRNA. “60$ for A # 9 HUS burger”
EHEC does NOT invade host cells
Shigella DOES INVADE
whats does 60$ for A #9 HUS burger remind us of?
that shigella and shiga-like toxin remove adenine from the 60S ribosome (rRNA) = inhibit protein synthesis.
burgers = protein
ETEC toxins
heat labile: aL Agua –>increase cAMP = INCREASED Cl secretion
heat stable: San Gabriel–>increase cGMP = DECREASED NaCl and H20 resorption
LAS SG
edema toxin
Bacillus anthracis –> increased cAMP (edematous borders of black eschar)
cholera toxin
increase cAMP = increase Cl secretion = rice water diarrhea
exotoxin that inhibits phagocytic ability
Impairs Gi–>increase cAMP —–>impairs phagocytosis. My nigga Pertussis .Pertussus blocks phagocytosis. (4-5 week hx of cough “100 day cough”)
prevents release inhibitory nt’s (GABA/Glycine)
Tetanospasmin
prevents release of stimulatory signals (ACH) @ NMJ
Botulinum
What bug degrades phospholipids to lyse cell membranes?
C perfrigens. Alpha toxin = lecithinase
double zone of hemolysis on blood agar
alpha toxin c perfringens
Exotoxins that lyse cell membranes
alpha toxin (c perf) and streptolysin O
antibodies against oxin used to dx rheumatic fever
streptolysin o… = ASO
Superantigen releases:
Il-1, Il-2, IFN gamma, TNF alpha. binds MHC II and TCRj
which of the systemic mycoses is not a yeast in the heat (tissue)
Coccioidomycosis is a spherule in the tissue –> filled with endospores
Mississippi and Ohio river valleys and within macrophages
Histoplasmosis hides. bird or bat droppings dont be a peasant and go for crypto
Histo and Cocci and blasto compared to rbc
Histo is much smaller; cocci and paracocci is much bigger. blasto is the same size as rBc
broad base budding
blasto. forms granulomatous nodules granuloma). can disseminate from lung to skin and bone.
pneumonia and meningitis, can disseminate to bone and skin.
Coccidioidomycosis
spherules within endospores
cocci
captains wheel budding yeast
paracocci
severe diarrhea in AIDS
Cryptosporidium–> oocysts on acid-fast stain
tx and triad for toxoplasmosis
Sulfadiazine and Pyrimethamine. Triad = yellow spots on fundus (chorioretinis), hydrocephalus, and intracranial calcifications (ring-enhancing lesions–>abscess)
Ixodes tick
Babesia and Borrelia
Maltese cross + hemolytic anemia (indirect bilirubinemia, increased LDH, decreased haptoglobin, abnormal liver tests)
Babesiosis. Tx with Azithromycin + Atovoquone
Tx for chagas (t cruzi)
Nifurtimox or Benznidazole. I like to Cruz around in a benz or new ferrari (ni fur raari)
Sx of T. cruzi
Chagas disease: DCM + ACHALASIA, megacolon/megaesophagas.
UNILATERAL PERIORBITAL SWELLING = ROMANA SIGN = ACUTE STAGE
Kala-azar: spiking fever, pancytopenia, heaptosplenomegaly
Sandly: Leishmania donovania. Treat with STIBOGLUCONATE, Amphotericin B
rash that starts on face and moves down
Parvovirus (slapped cheek), Rubella, Measles
rash that starts on the trunk and moves up
Rosela (hhv-6)
febrile seizure or just high ass fever, later develops rash
Roseola - HHV-6
hydrops fetalis
Parvo and Syphilis = torch.
alpha thalassemia
nonbacterial thrombotic endocarditis (NBTE)
sterile thrombi attached to mitral valve (noninfectious endocarditis). Associated with: Advanced malignancy, chronic inflam disorders (SLE, antiphospholipid syndrome), and sepsis
Rapidly fatal meningoencephalitis, swimming in freshwater, enters via Cribiform plate
Naegleria Fowleri
Dermatophytes = branching septate hyphae visible on _________
KOH preparation
Microsporum, Trichophyton, Epidermophyton (malessezia is different even though same name)
Malassezia = tinea versicolor = yeast-like fungus. Degradation of lipids produces acids that damage _______ and cause ____ patches. Common in summer. Spaghetti and meatballs on microscopy. Tx:
melanocytes; hypopigmented; selenium sulfide
fungal infection with germ tubes/pseudohyphae/budding
Candida (looks like meth pipe)
causes Bronchiectasis and eosinophilia, associated with asthma and cystic fibrosis
Aspergillus
Acute angled branching septate hyphae vs broad nonseptate hyphae at wide angles
Acute angle = aspergillus
nonseptate hphae = mucor/rhizopus
cryptococcus latex agglutination teset detects _______
polysachharide capsular antigen. MORE SPECIFIC THAN india ink or mucicarmine technically
Cryptococcus (“Budding yeast”) infects:
inhalation so first infects lungs. then hematogenous dissemination to meninges = CNS.
Bactrim
Pentamidine
Dapsone (also for leprosy)
Atovaquone
PCP
budding yeast is traumatically introduced, causes a local pustule/ulcer, and spreads along lymphatics
Sporothrix schenkii: ascending lymphangitis
Major defense against Giardia infection
Its a GI infection so secretory IgA impairs its adherence (so don’t be a peasant and pick eosinophils because its a protozoa)
bloody diarrhea, liver abcess, RUQ pain. Flask-shaped ulcer seen on histology
Entamoeba histolytica (amebiasais). Tx with Iodoquinol or metronidazole
Toxoplasma: tell me the triad and treatment
Yellow/white retinal spots (chorioretinitis), hydrocephalus, intracranial lesions.
Reactivated in AIDS = ring-enhancing lesions = abscess
Tx= sulfadiazine + pyrimethamine. PS: ring-enhancing lesions in AIDS reactivation
Name the protozoa in which you see a recurring fever due to antigenic variation
Trypanosoma brucia –> TseTse fly.
Tx = Suramin and Melarsoprol
what are you dx with scotch tape test?
Enterobius vermicularis –> Pinworm
Nematodal infection at ileocecal valve
Ascaris lumbricoides
Diethylcarbamazine used for
Loa loa and Wucheria bancrofti(elephantiasis)
Ingestion of larvae from freshwater causes megaloblastic anemia
Diphyllobothrium: vit b12 deficiency (tape worm competes for b12 in the intestine)
Biliary tract inflammation (pigmented gallstones) and cholangiocarcinoma
Clonorchis sinensis: Liver fluke
HDV is an example of ____________ because this is when 1 of 2 viruses infecting the cell has a mutation that results in a ___________ protein
Complementation; nonfunctional.
–>the nonmutated virus “complements” the mutated one by making a functional protein that serves both viruses
Live vaccines (dangerous to give to immunocompromised or their contacts. Can give MMR to HIV+ pt with no signs of immunodef)
MMR Smallpox Yellow fever Chickenpox (VZV) Sabin polio Influenza (intranasal)
Sabin the small yellow chicken FLUE IN (influenza) my nose
Killed Vaccines
RIP Always: Rabies, Influenza, Polio (salk), HAV
dsRNA and ssDNA
dsRNA: Reo
ssDNA: Parvo
Naked nucleic acids of __________ are not infectious and require _____
- strand ssRNA and dsRNA; require polymerases in virion
Viral replication rules (nucleus/cytoplasm)
DNA: all in nucleus (except Pox)
RNA: all in cytoplasm (except Influenza and Retro)
enveloped viruses acquire their envelopes from ________, except for ___________
Plasma membranes as the exit the cell
exception = Herpesviruses, acquire from nuclear mem
what does Pox carry so that it can replicate in cytoplasm
DNA-dep RNA polymerase
non-retro virus that has a reverse transcriptase
HBV
Sx of Adenovirus
Febrile pharyngitis (sore throat)
Hemorrhagic cystitis (acute)
Pneumonia
Conjunctivitis (close quarters)
Molluscum contagiosum
flesh-colored papule with central umbilication –> Poxvirus
Intranuclear acidophilic inclusions:
Intranuclear basophilic inclusions:
acidophilic = HSV basophilic = CMV
Latent in trigeminal ganglion
VZV, HSV 1
which LN does EBV attack
Posterior Cervical
Pharyngitis +
- —Tenosynovitis
- —Glomerulonephritis
- —Endocarditis
P and T: Neisseria Gonnorhea
P and G: Strep Pyo
P and E: Corynebacterium Diptheria
G- Lactose Fermenter: Indole + vs Indole -
Indole+: E coli
Indole-: Enterobacter
both = common cause UTI
Treatment for bacterial (Gardnerella) vaginalis
Metronidazole or CLINDAMYCIN
cat scratch vs dog bite
Cats: Pasteurella (more common); Bartonella henslae (self-limiting lymphadeno)
Dogs: Pasteurella , Strep, Staph
Facial pain, headache, black necrotic eschar
Mucormycosis (not anthrax fool). Seen in DKA pt
Need to do histology aka Mucosal BIOPSY –>will show broad non-septate hypae with R-angle branching