Bacteria - Hillard Flashcards
bacteria have what for DNA
plasmids
circular DNA that can be transducted, transformed, or conjugated to other bacteria
Generalized Transduction
Specialized transduction
Generalized : virus of bacteria picks up any part of bacterial genome
Specialized : bacteria or virus is integrated into genome of bacteria and picks specific portion of genome during activation.
Gram + cell wall
thick with peptidoglycans+ Techoic and Lipoteichoic acids
Gram - cell wall
thin with high lipid washed away with alcohol + polysaccharides
**Lipid A ENDOTOXIN
Staining Gram - bacteria cells
- Crystal Violet - nothing
- Iodine - nothing
- Alcohol - removes color
- Safranin (counterstrain or coloring it pink)
Gram + staining
- Crystal Violet - crystal violet (purple)
- Iodine - dye tapping agent (purple)
- Alcohol - nothing
- Safranin - nothing
staining exception in what
- Gram+ Clostridium + Bacillus (mix purple and pink)
2. Acid Fast Bacilli (TB), uses acid decolorizer (red)
unique features of bacillus
some have spores and some are club shaped
coccobacillus shape
rod and sphere shaped
spirochetes
helical shaped
curvilinear
spirilla shaped
spiral or helical shaped stains used
- silver stains
- dark field microscopy
- AB immunohistochemical stains
shape of streptococcous pnemoniae
diplococci
macule
flat area of discoloration < 1cm
Patch
flat circumscribed area > 1cm
Papule
a circumscribed , elevated , solid lesion < 1cm
Plaque
circumscribed elevated solid lesion > 1cm
Nodule
a palpable solid lesion > 1cm
Vesicles
small, superficial, circumscribed blister < 1cm
Ulcer
an open sore or wound (break of skin or mucous membrane)
Cocci catalase +
Staphylococcus
Cocci Catalase -
Streptococcous
Enterococcus
Bacilli , Spore forming
Bacillus (grow in O2)
Clostridium (anaerobic)
Bacilli, Non-spore forming
Corynebacterium (club shape, non mobile)
Listeria (motile at 25 degree C)
Catalase + looks like
function
reduce H2O2 to bubbles
to defend itself against M and N
3 types to staph
- staphylococcus aureus
- Staphylococcus epidermis
- Staphylococcus saprophyticus
coagulase + in Staph
Staphylococcus aureus = activates fibrin clot
coagulase - in Staph
Staphylococcus epidermis
Staphylococcus saprophyticus
Staphylococcus Aureus
proteins
color
gram
Protein A, Penicillinase, Leukocidins, Hemolysins
Staphokinase (clot destroyer), Hemolysins
Golden
Gram +
Hemolysins
destroys RBSCs
Protein A
prevents AB mediated binding and complement activation
4 SX in Staphylococcus aureus
- Pneumonia : after previous viral infection
- Endocarditis
- Superficial skin and underlying soft tissue infections
- Septic Osteomyelitis in < 12yo + elderly
- Gasteroenteritis
Staphylococcus aureus pneomonia
high fever, necrotizing pneumonia, PRODUCTIVE COUGH, LUNG ABSCESSES
Staphylococcus aureus skin stuff
Folliculitis, Impetigo, Cellulitis, Abscesses
pealing of skin = TSS
Staphylococcus aureus osteomyelitis fluid
high N and cloudy
Staphylococcus aureus endocarditis
ACUTE , fever, chills, weakness, IV drug user= tricuspid
rare effect of Staphylococcus aureus
meningitis, brain abscess
Staphylococcus aureus Gasteroenteritis
food contamination ,
ACUTE N, V, D, ABD pain from preformed enterotoxin**
Staphylococcus aureus scaled skin syndrome
usually in children
from EXFOLIATIVE TOXIN A + B
fever, poor feeding
3 SX of toxic shock syndrome and what causes it
TSST-1 toxin
1. Gasteroenteritis
2. Rash on palms and soles (pealing)
3 .Shock, Hypotension, death
2 other then TSS diseases that show sole and palm rash with pealing
- Syphilis
2. rocky mountain spotted fever
what is toxic in tampons
superantigen releasing TNF and IL1
Staphylococcus epidermis virulence factor
Biofilms = extracellular polysaccharide matrix adhering to foreign device + barrier against immune system
Staphylococcus epidermis infects how
Nosocomial infection (epidermidis) = prosthetic components like heart valves, hardware, catheters, shunts **** endocarditis it gets into blood
Staphylococcus epidermis epidermidis
endocarditis, high fever, redness of skin
Staphylococcus saprophyticus causes what
UTI most common community acquired one
“honeymoon cystitis”
Streptococcus is classified by growth pattern
B-hemolysis (complete)
a- hemolysis (partial)
y- hemolysis (no)
B-hemolysis (complete)
complete breakdown of of blood = clear ring around circular colony
a- hemolysis (partial)
makes green ring around colony
Streptococcus is classified by Lancefield classification
*based on C carbohydrate group
= Group A and Group B
= Lancefield classification
Streptococcus Pyrogenes
classification
virulence factor
EX: most common
B-hemolytic + Group A
M-protein —–I complement
Streptococcal pharyngitis (exudate on tonsils, fever, lymphadenopathy)
what can streptococcus pyrogenes lead to if untreated
- rheumatic fever
2. post-strep glomerulonephritis
Streptococcus pyrogenes
Streptococcal pharyngitis sx
(exudate on tonsils, fever, lymphadenopathy)
Streptococcus pyrogenes
Scarlet fever SX
fever, red rough rash on trunk and neck = “sandpaper” NOT ON FACE, SOLE, PALM
red strawberry tongue
+ pharyngitis
scarlet fever caused by what and in what age
pyrogenic endotoxin
school children
Streptococcus pyrogenes
Erysipelas SX
sunburn looking rash on FACE
warm to touch
60-80yo
Streptococcus pyrogenes
Nectrotizing faciitis
ACUTE infection of fascia (CT)
= purple color + PAINFUL
= need surgery
Streptococcus pyrogenes
cellulitis and impetigo
Impetigo : golden crusty rash (children)
Cellulitis : infection on skin , swollen, warm, red, blotchy
Streptococcus pyrogenes
Rheumatic Fever SX
AB and T-cell reaction against M protein Ag
- fever HIGH
- migratory polyarthritis (joints)
- pancarditis (mitral valve regurg, pericarditis)
- Subcutaneous nodules (large bumps)
- Red ring shaped rash (erythema marginatum)
- Syndenham chorea (happing, halting gait, jerking, grimacing)
Rheumatic fever SX happen
1-5 weeks after initial acute infection (streptococcal pharyngitis)
Streptococcus pyrogenes
Post- Streptococcal Glomerulonephritis SX
AB-Ag complex deposited on glomerular BM
- edema
- HTN
- hematuria
- proteinuria
how to test for RF or Post-strep GN
detection of AB to streptolysin O and DNase B
Streptococcus agalactiae
classification
can cause
colonizes the
B- hemolytic + Group B
neonatal meningitis, pneumonia, sepsis
vagina
3 organisms that can cause neonatal meningitis
- streptococcus agalactiae
- Listeria monocytogenes
- E coli
Streptococcus pneumoniae classification shape colonizes virulence factor sensitive to
a-hemolytic diplococci with CAPSULE nasopharynx IgA protease * Optochin sensitive
Streptococcus pneumoniae
how to test for capsule
anti-capsular AB (QUELLING TEST) = swollen capsule
optochin
kills streptococcus pneumoniae
Streptococcus pneumoniae
pneumococcal pneumonia SX
(common community acquired pneumonia) 1. lobar consolidation in lungs 2. high fever, chills 3. cough, SOB, CP older then 65yo common
pneumococcal pneumonia after autopsy
CDC recommendation
heavy and diffuse consolidation
over 65yo get vaccine
Streptococcus pneumoniae
Meningitis
- high fever
- nuchal rigidity
- abnormal mental status changes
(you can also see headaches)
bacterial meningitis CSF
turbid looking
high N (normal is high monocytes)
low glucose
high protein
viral meningitis CSF
clear looking
high lymphocytes
some elevated protein
normal glucose