Bacteria Flashcards
Name the bugs which have capsules.
Some Killers Have Pretty Nice Slimey Capsules
Strep. pneumo Klebseilla pneumo H. influenza Pseudomonas Neisseria meningitidis Salmonella Cryptococcus neoformans
List the catalase positive bugs.
Staph ‘N Enterobacteriaceae Are Listed Catalase Positive
Staph Nocardia Enterobacteriaceae Aspergillus Listeria Candida Pseudomonas
List the urease positive bugs.
K PUNCH
Klebsiella
Proteus Ureaplasma Nocardia Cryptococcus Helicobacter pylori
Name the bacteria which can form spores.
Clostridium and Bacillus
Recall spores are the only place with: Calcium dipicolinate, dipicolinic acid synthetase
Bacteria with gray/black pigment.
C. diphtheriae
Bacteria with yellow-orange pigment.
Mycobacteria
Bacteria with green/blue pigment.
Pseudomonas aeruginosa
Bacteria with red pigment.
Serratia
Bacteria with yellow-gold pigment.
Staph aureus
Name the obligate aerobes.
- Bacillus
- Corynebacterium
- Mycobacterium
- Nocardia
- Pseudomonas
Name the obligate anaerobes.
- Actinomyces
- Bacteroides
- Clostridium
- Fusobacterium
Infections that cross the placenta.
ToRCHHeS
Toxoplamsa gondii Rubella CMV Herpes simplex 2 HIV Syphilis
Zoonotic Anaplamsa infection
Anaplasmosis
Ixodes tick
Zoonotic Bartonella sp
Cat scratch disease
zoonotic Borrelia
Lyme Disease
Ixodes tick
zoonotic Brucella
Brucellosis / undulant fever
unpasturized dairy, veterinarians
zoonotic Campylobacter
bloody diarrhea
puppies, livestock, undercooked meat and poultry
zoonotic Chlamydophila psittaci
Psittacosis
birds, parrots
zoonotic Coxiella burnetti
Q fever
aerosols of cattle/sheep amniotic fluid
zoonotic Ehrlichia chaffeensis
Ehrlichiosis
Lone Star ticks
zoonotic Francisella tularensis
Tularemia
Ticks, rabbits, deer fly
zoonotic Leptospira
Leptospirosis
Animal urine
zoonotic Mycobacterium leprae
Leprosy
humans with leprosy and armadillos
zoonotic Pasteurella multocida
cellulitis, osteomyelitis
after dog and cat bites
zoonotic Rickettsia prowazekii
epidemic typhus (pro-war, war time, trenches) Louse vector
zoonotic Rickettsia rickettsii
Rocky Mountain Spotted Fever
Dermacentor tick
zoonotic Rickettsia typhi
Endemic typhus
Flea vector
zoonotic Yersinia pestis
bubobonic plague
Fleas (from rats and prairie dogs)
Bacteria with sterols in the membrane and no cell wall
Mycoplasma
Bacteria with mycolic acids in the membrane
Mycobacteria
Bugs that don’t gram stain well
These Microbes May Lack Real Color
Treponema (too small, dark field)
Mycobacteria (really thick cell wall, acid fast stain)
Mycoplasma (no cell wall)
Legionella (intracellular; use silver stain)
Chlamydia (intracellular parasite; lacks muramic acid)
Giemsa Stain
Certain Bugs Really Try my Patience
Chlamydia Borrelia Rickettsiae Trypanosomes Plasmodium
PAS (Periodic Acid Schiff)
Stains glycogen and sugars
Use for Tropheryma whipplei
Ziehl-Neelson (carbol fuchsin)
Acid-Fast
Nocardia and mycobacteria
Chocolate agar with Factors V (NAD+) and X (hematin)
H influenzae
Thayer-Martin VPN agar
Neisseria
Bordet-Gengou agar
B pertussis
Tellurite agar, Loffler medium
C diphtheriae
Lowenstein Jensen Agar
M tuberculosis
Eaton agar, requires cholesterol
Mycoplasma pneumoniae
Pink colonies on MacConkey agar
lactose fermenting enterics
Charcoal yeast extract agar with cysteine and iron
Legionella
Obligate intracellular bacteria
Rickettsia, Chlamydia
Both need to steal ATP
Facultative intracellular bacteria
Some Nasty Bugs May Live FacultativeLY
Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersina pestis
Protein A
expressed by staph aureus
binds the Fc region of IgG, preventing opsinization and phagocytosis
IgA protease
Strep pneumo, H flu B, Neisseria
enzyme that cleaves IgA
Notice it’s the same list as the bad capsular bacteria. That has nothing to do with the IgA protease, but one less list to memorize
M protein
Group A Strep
prevents phagocytosis
Diphthera toxin
ADP ribosylates EF-2, preventing translocation and stopping protein synthesis
Exotoxin A (not the exotoxin)
Pseudomonas
ADP ribosylates EF-2 preventing translocation and stopping protein synthesis
Shiga toxin / Shiga-like toxin
Shigella / EHEC
inactivates 60S ribosome by removing adenosine for the rRNA
Heat labile toxin (LT)
ETEC
overactivates adenylate cyclase (ADP ribosylation) increasing cAMP causing Cl secretion and water loss
Heat stable toxin (ST)
ETEC
overactivates guanylate cyclase, increasing cGMP causing decreased absorption of NaCl and water
Edema factor
Bacillus anthracis
mimics adenylate cyclase, increasing cAMP
Cholera toxin
Vibrio cholera
activates adenylate cyclase, increasing cAMP by permanently activating Gs (ADP ribosylation): secretes Cl and massive water efflux
Pertussis toxin
Bordetella pertussis
increases cAMP by disabling the Gi unit (ADP ribosylation)
inhibits phagocyte function
Tetanospasmin
C tetani
cleaves SNARE proteins required for inhibitory NT release -> rigid paralysis
Botulinum toxin
c botulinum
cleaves SNARE proteins required for stimulatory (ACh) NT release -> flaccid paralysis
Alpha toxin
C perfringens
lecithinase that degrades membranes and tissues
leads to gas gangrene and ‘zone of double hemolysis’ on blood agar
Streptolysin O
Strep pyogenes
degrades the cell membrane; lyses RBCs -> beta hemolytic
antibodies are the basis of rheumatic fever
Name the two important superantigens and their sources and mechanism
Toxic Shock Syndrome Toxin (TSST1) - Staph aureus
Exotoxin A - strep pyogenes
bring MHCII and TCR close enough to activate each other without actually binding the receptors -> no specificity, all macrophages are activated leading to a massive cytokine storm
Cytokines released in toxic shock syndrome
Th releases IL-2 (stimulates more T cells) and IFN-gamma (activates macrophage)
Macrophage releases IL1, IL6 and TNF-alpha
Endotoxin
LPS found on the outer membrane of gram negatives
Lipid A is the active part
Activates macrophages to release IL-1, TNF-alpha and NO
Activates complement - hypotension, edema and neutrophil chemotaxis
Activates tissue factor (Hageman factor) -> coagulation and DIC
Toxins carried by lysogenic phages
LOVED CBS
Labile of ETEC O antigen of Salmonella Verotoxin of EHEC Erythrogenic factor of strep A Diphtheria toxin Cholera toxin Botulinum toxin Shiga toxin
gram positive, branching, aerobe, acid fast
Nocardia
gram positive, branching, anaerobe, not acid fast
actinomyces
gram positive cocci, catalase positive
staph spp.
gram positive cocci, catalase negative
strep spp.
coagulase positive staph
S aureus
coagulase negative, novobiocin sensitive staph
S epidermidis
coagulase negative, novobiocin resistant staph
S saprophyticus
alpha hemolytic, optochin sensitive strep
Strep pneumo
alpha hemolytic, optochin resistant strep
Viridans strep
beta hemolytic, bacitracin sensitive strep
group A strep
beta hemolytic, bacitracin resistant strep
group B strep