Microbio-Lange

Front 1

Staph aureus
-toxins
-Tx

Back 1

3 exotoxins:

1. TSST (Toxic Shock Syndrome Toxin):
-superantigen
-stimulates helper T cells to release IL-2==>toxic shock

2. Enterotoxin
-superantigen
-food poisoning via preformed antigen

3. Scalded Skin Syndrome Toxin
-protease cleaves protein in tight jxns of skin
-Protein A binds Fc of IgG==>no complement activation

Tx:
*Penicillin G
-if resistant to Pen G, give B-lactamase-resistant penicillin like ampicillin/nafcillin
-if resistant to those, give Vanc

Front 2

what causes endocarditis on prosthetic heart valves

Back 2

Staph epidermidis

Front 3

Strep pyogenes
-infxns and pathogenesis

Back 3

*M protein inhibits phagocytosis

SUPPURATIVE INFXNS:

1. Cellulitis:
-Hyaluronidase ("spreading factor") mediates subcutaneous spread

2. Scarlet fever
-Erythrogenic toxin (superantigen) causes rash


NON SUPPURATIVE (immunologic) INFXNS:

1. Rheumatic fever
-Anti-M protein Ig cross-reacts w/heart tissue==>damages heart

2. Acute glomerulonephritis
*ImCo (formed by Ag-Ig complexes) deposit in kidney

==>activate complement

Tx: Penicillin G

Front 4

Tx strep

Back 4

Penicillin G

Front 5

Enterococcus faecalis
-what does it cause
-habitat
-Dx
-Tx

Back 5

Causes:
-UTI, biliary tract infxn
-endocarditis (rare)

-habitat: colon, but can infect urethra or female genital tract

-Dx: grows in 6.5% NaCl and hydrolyzes eschulin in the presence of bile

-Tx: Penicillin/Vanc + aminoglycoside like Gentamicin

Front 6

grows in 6.5% NaCl and hydrolyzes eschulin in the presence of bile

Back 6

Enterococcus faecalis

Front 7

Strep pneumo
-causes what dz
-pathogenesis
-Dx
-prevention
-Tx

Back 7

-causes pneumonia & meningitis (adults)
-causes otitis media (kids)

Pathogenesis:
-polysaccharide capsule retards phagocytosis (anti-polysaccharide Ig opsonizes the bug)
-IgA protease secretory IgA on respiratory mucosa==>allows colonization

Dx:
-QueLLUNG rxn ("sweLLUNG" of capsule when administer type-specific antiserum)
-growth inhibited by bile and optochin (vs. Strep viridans)

VAX: There are two VAX:
1. Adults: contains capsular polysaccharide of 23 serotypes that MC cause d
2. Babies <2 y/o: capsular polysaccharide of 7 serotypes
coupled to carrier protein (diptheria toxoid)
Tx: Pen G

Front 8

Quellung rxn

Back 8

mneum: QueLLUNG="sweLLUNG of capsule" when administer type-specific antiserum Ig

Strep pneumo

Front 9

strep viridans
-cause what dz
-habitat and transmission
-how prevent

Back 9

-cause endocarditis
-habitat: oropharynx; transmitted to blood stream during dental procedures
-prevent: give Pen G before dental procedures to ppl w/damaged heart valves

Front 10

what Rx give to ppl with damaged heart valves before dental procedures?

Back 10

Pen G

Front 11

Neisseria meningitidis
-habitat & transmission
-pathogenesis
-Dx

Back 11

Habitat: URT, transmitted via respiratory droplets

Pathogenesis:
-Endotoxin==>septic shock
-no known exotoxin
-IgA protease (degrades secretory IgA==>allows colonization)
-Capsule=antiphagocytic

-Dx: ferments maltose ("M"eningitidis ferments "M"altose)--vs Neisseria gonorrohoea

Front 12

Neisseria gonorrhoea
-Dx
-Tx

Back 12

-Dx: oxidase+ on Thayer Martin medium
-do not ferment maltose (vs. N meningitidis)

Tx:
-ceftriaxone for uncomplicated cases
-add Tetracycline for urethritis caused by Chlamydia trachomatis
-Tx newborns' eyes w/erythromycin ointment or silver nitrate to prevent conjunctivitis

Front 13

oxidase+ on Thayer Martin medium

Back 13

Neisseria gonorrhoea