Step 1: Microbiology Principles

1. coat: keratin like
2. core
-dipicolonic acid: heat resistance
3. peptidoglycan
4. DNA

autoclaving: 121 C for 15 min

H2O2
iodine based agents

gram+ only

-B. anthracis
-B cereus
-C botulinum
-C difficile
-C prefringens
-C tetani

survival: resist dehydration, heat, chemicals

for later reproduction

loose network of polysaccharides that mediates adherence to surfaces; plays role in biofilm formation

1. outer leaflet: endotoxins: LPS, LOS
2. embedded proteins: porins, other outer membrane proteins
3. inner leaflet: phospholipids

space between cytoplasmic membrane and outer membrane

will accumulate components exiting gram- cells, including hydrolytic enzymes

-peptidoglycan is sugar backbone
-peptide side chains that cross-like

network gives rigid support, protects against osmotic pressure damage

cytoplasmic membrane

-phospholipid bilayer
-PPBs and other enzymes
-lipoteichoic acids (g+ only)

spans the peptidoglycan layer and is linked to the plasma membrane

unique to g+: lipotechoic acid

unique to g-: outermembrane, wide periplasmic space w/ beta-lactamases

too thin to visualize
-treponema
-leptospira

not true peptidoglycan wall/too many lipids
-mycoplasma
-urea plasma
-chlamydia (decreased muramic acid)

intracellular organism
-legionella
-rickettsia
-chlamydia
-bartonella
-anaplasma
-ehrlichia

1. chlamydia
2. rickettsia
3. trypanosomes
4. borrelia
5. H. pylori
6. plasmodium

organisms w/ mycolic acid in cell wall
1. acid fast bacteria: Myco
2. Nocardia
3. protozoa: Cryptosporidium

stains glycogen, mucopolysaccharides

diagnose Whipple disease: Tropheryma whiplei

cryptococcus: will highlight against dark stain

1. india ink
2. mucicarmine: stain polysaccharide capsule pink

1. fungi
-coccidioides
-P. jirovecii

2. legionella
3. H pylori

chocolate agar enriched w/ Factors V (NAD+) and X (hematin)

-vanco: gram+
-TMP, colistin: gram- except Neisseria
-nystatin: fungi

Bordet-Gengou agar w/ potato extract

Regan-lower medium w/ charcoal, blood, antibiotics

Tellurite agar
Loffler medium

Eaton agar w/ charcoal

-Brucella
-Francisella
-Legionella
-Pastruella

"the Ella siblings"

1. Clostridium
2. Bacteriodes
3. Fusobacterium
4. Actinomyces israelii

normal flora: gut

pathogenic: everywhere else

aminoglycosides require O2 to enter bacterial cell

1. streptococci
2. staphylocci
3. enteric g- bacteria

obligate: rely on host ATP
-Rickettsia
-Chlamydia
-Coxiella

facultative
-salmonella
-Neisseria
-Brucella
-Myco
-Listeria
-Francisella
-Legionella
-Y. pestis

Please SHiNE my SKiS

Pseudomonas
Strep pneumo
H. influenzae
N. meningitidis
E. coli
Salmonella
Klebsiella
GBS

vaccines targeting polysaccharide capsule are conjugated to proteins to enhance immunogenicity

promote T cell activation and B cell class switching

PCV13: conjugated
PPSV23: nonconjugated

-PCV13
-Hib
-meningococcal vaccine

(coincidentally, these are against their capsule, and therefore are the vaccines needed to give asplenics)

urease hydrolyzes urea to release ammonia and CO2, which can increase pH of urine --> struvite stones

P CHUNKSS

Proteus *
Cryptococcus
H. pylori
Ureaplasma
Nocardia
Klebsiella
S epidermidis
S saprophyticus

Actinomyces israelii: yellow sulfur granules

S. aureus: gold-yellow

P. aeruginosa - blue-green (pyocyanin, pyoverdin)

serratia: red

1. S. epidermidis: prosthetic devices, catheters

2. viridans strep (mutans, sanguinis): dental plaques, infective endocarditis

3. P. aeruginosa: respiratory tree w/ CF, HAP, contact lens keratitis

4. H. influenzae: otitis media

bacteria adhere to tissue --> multiply and communicate w/ each other --> synthesize extracellular polysaccharide matrix

-barrier for antibiotic penetration
-interfere w/ opsonization, neutrophil migration, and T cell activation
-seeds late

1. protein A: binds Fc of IgG to prevent opsonization and phagocytosis

2. IgA proteas: cleaves IgA, allowing bacteria to bind mucus membranes

3. M protein: homologous to human tropomyosin and myosin, prevents phagocytosis

S. aureus

-S. pneumoniae
-H influenzae type B
-Neisseria

*these organisms are also known to transform

GAB (mech of rheumatic fever?)

-S. pneumoniae
-H. influenzae type B
-Neiserria

deoxyribonuclease degrades naked DNA

F+ x F-
-F+ contains genes for sex pilus
-F+ contacts F- bacterium --> single strand of plasmid DNA is replicated and then transferred across conjugal bridge
-NO transfer of chromosomal DNA
-both are F+

Hfr x F-
-Hfr: high frequency recombination cell: cell that can incorporate plasmid into chromosomal DNA
-Hfr can contact F- cell and impart some of its DNA, which is incorporated into F- chromosome
-F- remains F-

generalized
-"packaging" error
-lytic phage infects bacterium, leading to cleavage of bacterial DNA
-parts of bacterial chromosomal DNA can be packaged into phage capsid, which leaves cell and infects another

specialized
-"excision" event
-lysogenic phage infects bacterium, incorporates DNA into bacterial chromosomes
-when phage DNA excised, flanking bacterial DNA can also be excised and incorporated into phage capsid

-GAS: erythrogenic toxin
-C. botulinum: botulinum toxin
-V. cholera: cholera toxin
-C. diphtheriae: diptheria toxin
-Shiga toxin

transposition

exotoxins
-location of gene: plasmid or bacteriophage
-high toxicity
-heat labile

endotoxins
-location of genes: bacterial chromosome
-low toxicity
-heat stable

structure
-O-antigen
-core polysaccharide
-lipid A (toxic component)

released upon cell lysis or as blebs

three effects
-macrophage activation (TLR4/CD14)
-complement activation
-tissue factor activation

macrophage activation
-IL-1, IL-6 --> fever
-TNFalpha --> fever, hypotension
-NO --> hypotension

complement activation
-C3a --> histamine --> hypotension, edema
-C5a --> PMN chemotaxis

tissue factor activation
-coagulation cascade --> DIC


OVERALL
-edema
-hypotension
-fever
-DIC
-PMN invasion