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137 Cards in this Set

  • Front
  • Back
chocolate agar with factors V (NAD) and X (hematin)
H. influenzae
Thayer-Martin media -
vancomycin (gram-positive)
polymyxin (gram-neg)
nystatin (fungi)
N. gonorrhoeae
Bordet-Gengou (potato) agar
B. pertussis
Tellurite plate, Loffler's media
C. diphtheriae
Lowenstein-Jensen agar
m. tuberculosis
Eaton's agar
M. pneumoniae
Pink colonies on MacConkey's agar

eosin-methyline blue (EMB) agar
Lactose-fermenting enterics

E. coli
Charcoal yeast extract agar buffered with cysteine
Sabourad's agar
capsule swells when specific anticapsular antisera are added
positive Quellung reaction

S. pneum, Klebsiella, H. influ, N. meningitidis, Salmonella, group B strep
red pigment
serratia marcescens
binds Fc region of Ig.

prevents opsonization and phagocytosis
Protein A
(S. aureus)
enzyme that cleaves Ig A
IgA protease

helps prevent phagocytosis
inhibits complement activtion
mediates bacterial adherence
target of type-specific humoral immunity to S. pyogenes
M protein

(group A strep)
mode of action for endotoxins
includes TNF and IL-1
bind directly to MHC II and TCR simultaneously, activating large numbers of T cells to stimulate release of IFNy and IL-2
TSST-1 superantigen
food poisoning
S. aureus
scarlet fever
S. pyogenes

erythrogenic toxin >> toxic shock-like syndrome
inactivates elongation factor (EF-2);

>>pharyngitis and "pseudomembrane" in throat
C. diphtheriae
ADP ribosylation of G protein stimulates adenylyl cyclase;
increased pumping of Cl- into gut and decreased Na+ absorption

H2O moves into gut lumen; causes voluminous rice-water diarrhea
V. cholerae
heat-labile toxin stimulates adenylate cyclase.
heat-stable toxin stimulates guanylate cyclase
both cause watery diarrhea
E. coli
increases cAMP by inhibiting Ga1,

whooping cough; inhibits chemokine receptor >> lyphocytosis
Bordetella pertussis
double zone of hemolysis on blood agar

alpha toxin, a lecithinase that acts as a phospholipase to cleave cell membranes >> gas gangrene
Clostridium perfringens
blocks release of GABA and glycine

C. tetani
blocks release of ACh;

>>ACh-ic sxs, CNS paralysis, especially cranial nerves
C. botulinism

spores found in canned food, honey (floppy baby)
edema factor, part of the toxin complex, is an adenylate cyclase
Bacillus anthracis
produced by E. coli O157:H7 cleaves host cell rRNA (inactivates 60S ribosome

enhances cytokine release >> HUS
Streptolysin O is a hemolysis

Ag for ASO Ab (for rheumatic fever Dx)
S. pyogenes
cAMP inducers (4)
V. cholerae
Bordetella pertussis
E coli
Bacillus anthracis
partial hemolysis
S. pneum (optochin sens)
S. viridans (optochin resis)
complete hemolysis (clear)

group A -- S. pyogenes (Bacitracin sens)
group B -- S. agalactiae Bacitracin resis)
catalase positive, coagulase negative
S. epidermidis (novobiocin sens)

S. saprophyticus (novobiocin resis)
degrades H2O2 before it can be converted to microbicidal products by the enzyme myeloperoxidase
Lancet-shaped, encapsulated. IgA protease

rusty sputum
Streptococcus pneumoniae
most common cause of meningitis
strep pneum

(2nd is neisseria meningitidis)
normal flora of oropharynx and cause dental caries; subacute endocarditis
strep vidiridans
subcutaneous plaques, polyarthritis, erythema marginatum, chorea, carditis

carditis is the result of what process?
rheumatic fever (S. pyogenes)

Antigenic mimicry
(both have similar Ag protein sequences; mounted response from immune system >> myocarditis + valvular destruction)
colonizes vagina >> phenumonia, meningitis, sepsis in babies

produces CAMP factor, which enlarges the area of hemolysis formed by S. aureus
Strep agalactiae (group B)
normal colonic flora

cause UTI and subacute endocarditis
Enterococci (group D Lancefield streptococci)
can cause bacteremia and subacute endocarditis in colon cancer

part of normal gut flora
Streptococcus bovis
(gropu D streptococci)
psuedomembranous pharyngitis (grayish-white membrane) with lymphadenopathy

tellurite agar; club-shaped

metachromatic (blue and red) granules
C. diphtheria

stain deeply with aniline dyes
produces 2 toxins
Toxin A, enterotoxin, binds to the brush border of the gut
Toxin B, cytotoxin, destroys the cytoskeletal structure of enterocytes >> pseudomembranous colitis; diarrhea

activates neutrophils; secondary to antibotics
C. difficile

tx: metronidazole
the only bacterium with a polypeptide capsule (contains D-glutamate)
B. anthracis
black eschar >> bacteremia

inhalation of spores; flulike; pulmonary hemorrhage, mediastinitis, shock, contaminated wool
cutaneous anthrax

pulmonary anthrax; Woolsorters' disease
actin rockets that move cell-to-cell; tumbling motlitiy

amnionitis, septicemia, spontaneous abortion, neonatal meningitis, mild gastroenteritis (healthy PTs)
Listeria monocytogenes

facultative intracellular microbe; unpastereurized milk/cheese and deli meats; vaginal transmission during birth
oral/facial abscesses, drain through sinus tracts in skin.

yellow "sulfur granules"
Actinomyces israelii

tx: Sulfa
pulmonary infection in immunocompromised patients; acid-fast aerobe in soil
Nocardia asteroides

tx: Penicillin
Ghon complex + lobar + perihilar lymph node involvement reflects primary or secondary infection/exposure?
primary infection/exposure
prphlactic treatment of M. avium-intracellulare with what treatment?

all mycobacteria = acid-fast organisms
"serpentine cords" on enriched media is also known as...
cord factor (a mycoside)

establishes virulence via: neutrophil inhibition, mitochondrial destruction, activation TNF release
what is the preferred treatment for mycobacterium leprae (an acid-fast bacillus that infects skin and superficial nn)?
dapsone (long-term, oral)
--toxicity = hemolysis and methemoglobinemia

also, rifampin + clofazimine/dapsone
E. coli produces beta-galactosidase, which breaks down....
lactose >> glucose + galactose
which group of bacteria is resistant to penicillin G but may be susceptible to penicillin derivatives (eg ampilicillin)?
gram-negative bacilli

outer membrane layer inhibits entry of penicillin G and vancomycin
pilus with antigenic variation
army recruit
college student
what is the preferred N. meningococci prophylaxis in close contacts?
cherry red epiglottis in children, meningitis, otitis media, pneumonia

produces IgA protease

what is the preferred treatment?
H. influenzae

tx: ceftriaxone; prophylaxis with close contacts
vaccine for what disease contains type B capsular polysaccharide conjugated to diphtheria toxoid or other protein?
H. influenzae

given between 2 and 18 mo
pneumonia, fever, flulike syndrome, HA, diarrhea, unilateral infiltrate >> consolidation, decreased Na+

grow on charcoal yeast extract culture with iron and cysteine

what is the route of transmission? preferred treatment?
Legionella pneumophila

water source habitat

tx: erythromycin
wound and burn infections
cystic fibrosis/pneumonia,
sepsis, external otitis,
drug use
Diabetic osteomyelitis
hot tub folliculitis

what is the preferred treatment?
pseudomonas aeruginosa

tx: aminoglycoside + extended-spectrum penicillin (piperacillin, ticarcillin)
produces pyocyanin pigment, fruit/grape-like odor

c/o water source

endotxin (fever, shock) and exotoxin A (inactivates EF-2)
psuedomonas aeroginosa

oxidase positive, non-lactose fermenting
fimbriae-- cystitis and pyelonephritis
K capsule -- pneumonia, neonatal meningitis
LPS endotoxin -- septic shock
E. coli virulence factors
invasive diarrhea; dysentery
produces Shiga-like toxin.
microbe invades intestinal mucosa and toxin causes necrosis + inflammation
watery diarrhea during international trip
labile toxins/stable toxin
no inflammation or invasion
diarrhea in 5yo
No toxin produced.
adheres to apical surface, flattens villi, prevents absorption

does not ferment sorbitol

undercooked beef, unclean hands, raw unpasteurized milk
O157:H7 is most common serotype
produces Shiga-like toxin and Hemolytic-uremic syndrome (anemia, thrombocytopenia, acute renal failure)

endothelium swells and narrows lumen >> mechanical hemolysis + reduced RBF; damaged endothelium consumes platelets
lobar pneumonia in alocoholics and diabetics when aspirated

red current jelly sputum

Aspiration pneumonia, abscess in lungs, alcoholics, diabetics
have flagella and can disseminate hematogenously

produce H2S; monocytic response w/ antibiotics
fever, diarrhea, headache, rose spots on abdomen

where in the body can this disease remain?

(Salmonella typhi--typhoid fever)
1. enters via M cells in Peyer's patches
2. lyse its containment vacuole + enter cytosol
3. induce apoptosis of neutrophils

AB exotoxin inhibits 60s ribosome
no flagella but can propel itself within a cell by actin polymerization
bloody diarrhea in 5yo

comma/s-chaped, oxidase positive, grows at 42 C

this disease is a common precursor to what condition?
Campylorbacter jejuni

Guillain-Barre syndrome
rice-water diarrhea via toxin that permanently activates Gs, increases cAMP

what is the preferred treatment?
Vibrio cholerae

tx: prompt oral rehydration

stool = mucus + epithelial cells
diarrhea in preschooler
Yersinia enterocolitica
causes mesenteric adenitis that can mimic Crohn's or appendicitis
creates alkaline environment

>> gastritis and up to 90% of duodenal ulcers

what is the triple therapy designated for this disease?
1. metronidazole, bismuth
2. tetracycline, amoxicillin
3. metronidazole, omeprazole, clarithromycin
spirochete that can be visualized using aniline dyes (Wright's or Giemsa stain) on LM
flulike symptoms, fever, HA, abdominal pain, jaundice, photophobia + conjunctivitis

question-mark shaped bacteria

what is the severe form?
Leptospira interrogans

found in water contaminated with animal urine

Wei's disease --- + jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage, anemia
erythema chronicum migrans, red rash w/ central clearing

arthritis, cardiac block, Bell's palsy

what is the preferred treatment?
Lyme disease (Borrelia burgdorferi, by Ixodes tick)

tx: doxycycline, cetriaxone
condylomata lata, maculopapular rash, constitutional symptoms
secondary syphilis (systemic)
gummas, aorititis, tabes dorsalis, constricted pupils, stroke without HTN
teritary syphilis
Saber shins, saddle nose, CN VIII deafness, Hutchinson's teeth mulberry molars
congenital syphilis
screen for syphilis with...
confirm with...
visurses (mono, hepatitis)
rheumatic fever
lupus and leprosy
prolonged PTT and false-positive VDRL

APAs + venous/arterial thromboembolism; increased miscarriages
SLE --> APLA syndrome
cat scratch + culture-negative endocarditis/bacillary angiomatosis
Bartonella spp.
undulant fever; from dairy products, contact with animals
Brucella spp.
flea bite; rodents, prairie dogs

(Yersinia pestis)
gray vaginal discharge w/ fishy smell
clue cells or epithelial cells covered with bacteria
Gardnerella vaginalis
need CoA and NAD+
transmitted bia arthropod vector

headache, fever, rash

what is the preferred treatment?
(obligate intracellular organism)

tx: doxycycline
rash starts on hands and feet

rash starts on the trunk
1. ricketssial

2. typhus
when patient serum is mixed with Proteus antigens, antirickettsial antibodies cross-react to Proteus O antigens and agglutinate
Weil-Felix reaction

(negative in Coxiella)
palm and sole rash >> trunk, headache, fever, East Coast
Rocky Mountain spotted fever
(Rickettsia rickettsii)
Labs = cytoplasmic inclusions seen on Giemsa or fluorescent antibody-stained smear

what are the 2 forms of this organism? how is its structure unique?

what is the preferred treatment?
1. elementary body -- infectious + enters cell via endocytosis

2. reticulate body --- replicates in cell by fission, seen on tissue culture

cell wall lacks muramic acid

tx: azithromycin or doxycycline
chronic infection, blindness due to follicular conjunctivitis in Africa
Types A, B, C
Chlamydia trachomatis
urethritis/PID, ectopic pregnancy, neonatal pneumonia, neonatal conjunctivitis
Types D-K
Chlamydia trachomatis
lymphogranuloma venerum; can be acquired during passage throught infected birth canal

what is the preferred teratment?
Types L1, L2, L3
Chlamydia trachomatis

tx: azithromycin
headache, nonproductive cough, diffuse interstitial infiltrate; military recruits, prisons, <30 yo

high titer of cold agglutinins (IgM)

grown on Eaton's agar

What is the preferred treatment?
Mycoplasma pneumoniae
("walking pneumonia")

tx: tetracycline or erythromycin
this organism has no cell wall and not seen on gram stain

the only bacterial membrane containing cholesterol
mycoplasma pneumoniae

penicillin resistant because they have no cell wall
preferred treatment for mycoses? (local v. systemic)
local-- fluconazole or ketoconazole

systemic -- amphotericin B
bird or bat caves

Mississippi and Ohio river valleys

hiding in macrophages
inflammatory lung disease >> skin and bone
granulomatous nodules

East Coast and Central America

broad-base budding (same size as RBC)
pneumonia + meningitis >>bone + skin

Southwestern US, California

spherules filled with endospores (larger than RBC)
Latin America

budding yeast with "captain's wheel" formation (larger than RBC)
degradation of lipids produces acids that damage melanocytes >> hipopigmented/hyperpigmented patches

"spaghetti and meatball" appearance on KOH prep

what is the cause?

what is the preferred treatment?
Tinea versicolor
(Malassezia furfur)

tx: topical miconazole, selenium sulfide (Selsun)
pruritic lesions with central clearing (ring-like) caused by dermaphytes

See mold hyphae in KOH prep, not dimorphic

what is the reservoir?

what is the preferred treatment?

tinea pedis, cruris, corporis, capitis ( c/o Microsporum, Trichophyton, Epidermophyton)

tx: topical azoles
dimorphic yeast with pseudohyphae

stacked budding yeasts + germ tubes

what is the preferred treatment?
candida albicans

tx: nystatin for superficial
amphotericin B for systemic
mold with septate hyphae that branch at acute angles, not dimorphic

type I hypersensitivity
Aspergillus fumigatus
encapsulated yeast, not dimorphic
narrow-based budding

Sabourad's agar; muscarmine circles

latex agglutination test detects polysaccharide capsular Ag and is more specific. "soap bubble" lesions in brain
Cryptococcus neoformans
diffuse interstitial pneumonia

bdiffuse bilateral CXR

methenamine silver stain of lung tissue for ID

saucer-shaped yeast forms

what is the preferred treatment?
Pneumocystis jiroveci

tx: TMP-SMX, pentamidine, dapsone

start prophylaxis when CD4 drops <200 cells/mL in HIV patients
dimorphic fungus (cigar-shaped yeast forms with unequal budding)

caused by thorn >> local pustule or ulcer with nodules along draining lymphatics

dimorphic fungus

what is the preferred treatment?
Sporothrix schenckii

tx: itraconazole or potassium iodide
ring-enhancing brain lesions on CT/MRI

chorioretinitis, hydrocephalus, intracranial calcifications

what is the preferred treatment?
Toxoplasma gondii

tx: sulfadiazine + pyrimethamine
enlarged lymph nodes, refurring fever (d/t antigenic variation), somnolence, coma

Trypanosoma brucei, gambiense, rhodesiense (tsetse fly)

tx: Suramin (blood)
Melarsoprol (CNS)
dilated cardiomyopathy, megacolon, megaesophagus

S. America
(Reduviid bug)

Trypanosoma cruzi
(Chagas disease)

tx: Nifurtimox
spiking fevers, hepatoslenomegaly, pancytopenia


macrophages w/ amastigotes (lack flagella)
Leisnmania donovani

tx: Sodium stibogluconate
cyclic fever, HA, anemia, splenomegaly

mosquito (Anopheles)
Plasmodium vivax/ovale, falciparum, malariae

tx: 1. chloroquine
2. mefloquine

vivax/ovale -- add primaquine for dormant forms in liver (hypnozoite)
vaginitis, foul-smelling greenish discharge, itching, burning

trophozoites on wet mount
Trichomonas vaginalis

tx: Metronidazole
preferred treatment of nematodes?

(ivermectin -- strongyloides stercoralis)
(pyrantel pamoate -- ancylostoma duodenale, necator americanus)
ingestion of larvae encysted in undercooked pork >> intestinal tapeworms.

cysticerosis and neurocysticercosis, swiss cheese appearance in brain

preferred treatment?
Taenia solium

tx: praziquantel
(use -bendazoles for neurocysticercosis
enterobius, ascaris, trichinella
nematodes infect via INGESTION
strongyloides, ancylostoma, necator
nematodes infect via CUTANEOUS route
brain cysts, seizures
Taenia solium
liver cysts
Echinococcus granulosus

(eggs in dog feces >> anaphylaxis; surgeons inject ethanol before removal to kill daughter cells)

tx: -bendazoles
B12 deficiency
Diphyllobothrium latum
Biliary tract disease,
Clonorchis sinesis

(undercooked fish)

tx: praziquantel
Paragonimus westermani

(undercooked crab meat >> lung infection)

tx: praziquantel
portal hypertension
Schistosoma mansoni

hematuria, bladder cancer
Schistosoma haematobium

microcytic anemia
Ancylostoma, Necator
perianal pruritus

inflammation of muscle (larvae encyst in muscle)
periorbital edema

undercooked pork
Trichinella spiralis

tx: -bendazoles
block cell wall synthesis by inhibition of peptidoglycan cross-linking (drugs)
ampicillin, ticarcillin, piperacillin imipenem, aztreonam, cephalosporins
block peptidoglycan synthesis
bacitracin, vancomycin
disrupt bacterial cell membranes
block nucleotide synthesis
sulfanomides, trimethoprim
block DNA topoisomerases
block mRNA synthesis
block protein synthesis at 50S ribosomal subunit
chloramphenicol, macrolides, clindamycin, streptomgramins (quinupristin, dalfopristin),
block protein synthesis at 30S ribosomal subunit