week 6 micro macules

gram neg diplococci kidney bean shaped

n. meningitidis

n. meningitidis causes

meningitis (petechial and purpuric rash)

meningococcemia (purpuric lesions)

meningitis derm

petechial and purpuric rash macules

meningococcemia derm

purpuric lesions macules

n. meningitidis ferments

glucose and maltose

n. meningitidis is oxidase

pos

n. meningitidis media

chocolate agar plus abx

n. meningitidis transmission

airborne droplets

meningococcal meningitis spread in body

airborne —> nasopharynx —> blood stream —> meninges or joints

abnormal skin coloring w/ meningococcemia indicative of

sepsis

n. meningitidis virulence

capsular polysacc

LOS endotoxin

Type IV pili

opacity proteins (Opa, Opc)

IgA protease

n. meningitidis LOS

endotoxin

induces TNFa and IL1 —> septic shock

n. meningitidis type IV pili

adhere to endothelial cells

breach BBB —> meningitis

Opacity proteins n. meningitidis

outer mem —> binding to nasophar and RBCs

attachment and evasion

serotypes n. meningitidis

B, C, Y in US

A worldwide

rickettsia are _____ bacteria, dependent on

obligate intracellular

dependent on host cell ATP

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia shape and gram

weakly gram neg (giemsa)

coccobacilli

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia stain

weakly gram neg (giemsa)

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia rickettsii reservoir

dog and rodent

rickettsia rickettsii carried by

vector borne- tick, louse, flea

reservoir- dog and rodent

Dermacentor tick needs ____ hrs of feeding to transmit ____

6-10

rickettsia rickettsii

rickettsii targets

endothelial cells

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia exhibits ____ for endothelial cells.

tropism

using rickettsial outer membrane proteins rOMPS

(R. rickettssii, R. typhi, R. prowazekeii)

rOMPS

rickettsial outer membrane proteins rOMPS

endothelial tropism adhesion proteins

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia preferentially infects

vascular endothelial cells

small and medium

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia infecting vascular endothelium causes

systemic sx

disseminated inflammation

altered vasc perm

(R. rickettssii, R. typhi, R. prowazekeii)

rickettsia rickettsii phospholipase D and hemolysin C

lyse host cell phagosomal membranes

rickettsia rickettsii rectruit

actin filaments —> tranverse host cell mem w/o obvious damage

ONLY rickettsia rickettsii CAN DO THIS

what type of bacteria recruits actin —> transverse w little damage

rickettsia rickettsii

type IV secretion system rickettsia

facilitate conjugation, transportation of proteins, transformation of DNA

(R. rickettssii, R. typhi, R. prowazekeii)

rocky mountain spotted fever caused by

rickettsia rickettsii

rickettsia rickettsii sx

fever

myalgias

headaches

confusion

blanching maculopap rash

cardiovasc instability

fever

myalgias

headaches

confusion

blanching maculopap rash

cardiovasc instability

rickettsia rickettsii

rocky mountain spotted fever

(targets vasculature)

RMSF primarily occurs in

southeastern and southcentral US

RMSF mostly seen in what age

children

spring and summer

Encephalitis

coma

seizures

myocarditis

abnormal ECG

pulm edema

cough and dyspnea

Rickettsia complications

R rickettsii and R typhi

R typhi vector and reservoir

vector: rat flea

reservoirs: rats

rickettsia typhi cause

Endemic typhus

murine typhus

rickettsia typhi transmission to humans

infected rat flea bite

food contam w rat urine or rat flea

R rickettsii vs rickettsia typhi

R rickettsii: infect endothel cells w/o damage

rickettsia typhi: stay in endothel cells, multiply, lyse, infect new cells

fever

severe headache

abdom pain

nausea

maculopap rash 4-5 days after fever onset

rickettsia typhi (endemic or murine typhus)

rickettsia typhi rash location

trunk and spreads to extremities

palms and soles spared

Rickettsia prowazekii vector and reservoir

vector: pediculus body louse

reservoir: human

Rickettsia prowazekii unique because

no other members of rickettsia kill vector

Rickettsia prowazekii multiplies

escapes phagosome

mult in cytoplasm until endothel cell bursts —> into EC matrix

Rickettsia prowazekii seen where

developing countries

crowded condition

poor hygiene

Rickettsia prowazekii causes

endemic typhus

high fever

myalgia

headache

dry cough

delirium

rash trunk spreads peripherally

epidemic typhus

complications of Rickettsia prowazekii/epidemic typhus

SEVERE MENINGOENCEPHALITIS

delirium and coma

perivascular collapse or bac pneumonia —> death

SEVERE MENINGOENCEPHALITIS

delirium and coma

perivascular collapse or bac pneumonia —> death

complications of Rickettsia prowazekii/epidemic typhus

treponema pallidum shape

spirochete

microaerophile

treponema pallidum gram

gram neg outer mem

endotoxin like lipids (lacks lipopolysaccharides)

treponema pallidum causes

syphilis

serum tests treponema pallidum

FTA-ABS (antibody)

TPPA (agglutination)

EIAs

treponema pallidum reservoir

humans

treponema pallidum transmission

sexual contact

direct vaginal oral anal contact w mucocutaneous lesions

vertical (preg, birth)

treponema pallidum difficult to fight bc

outer mem lacks lipopolysaccharides —> few surface proteins

difficult for immune system to recog and fight

treponema pallidum infects what in body

endothelium of small vessels

inflammation of inner lining of arteries

where does treponema pallidum cause inflamm

inner lining of arteries

Stages of syphilis

Primary and secondary (1/3 recover)

Latent (1/3, no lesions but sero pos)

Tertiary (1/3, gummas, cardiovasc and CNS)

treponema pallidum

Primary syphilis

treponema pallidum

bac multiply at site of inf —> chancre

Bacteria spread widely via bloodstream

chancre

treponema pallidum

primary syph

nontender ulcer

secondary syph

treponema pallidum

maculopapular rash on palms and soles

large lesions in moist areas rich w/ bacteria

maculopapular rash on palms and soles

large lesions in moist areas rich w/ bacteria

treponema pallidum

secondary syph

Latent syph

treponema pallidum

pos sero tests w/o lesions

tertiary syph

treponema pallidum

GUMMAS: granulomas on skin and bones

CNS and cardiovasc involvement

GUMMAS

treponema pallidum

tertiary syph

granulomas on skin and bones

Borrelia burgdorferi shape

spirochete

axial filament

Borrelia burgdorferi vector and reservoir

vector: ixodes tick

reservoir: small mammals, white footed mouse

Borrelia burgdorferi transmission

bite from vector: ixodes tick

Borrelia burgdorferi visualization

dark field microscopy

giemsa and silver

Borrelia burgdorferi spread in body

skin bite

dissemination in blood

bacteremia

organs: heart, joints, CNS

How does Borrelia burgdorferi adapt to two different hosts (tick and mammal)

change outer surface proteins (OSP)

Borrelia burgdorferi causes

lyme disease

Lyme stage 1

early localized

3-30 days

erythema chronicum migrans

lyme stage 2

early disseminated

weeks-months after inf

cardiac and neuro ie bells palsy

lyme stage 3

late disseminated

autoimmune arthritis in large joints

viral capsid vs virus envelope

viral capsid: viral origin, protects viral genome

virus envelope: host derived, improves host interactions

enveloped virus sensitive to

extreme pH (does not enter GI)

heat, dryness, simple disinfectants

cell lysis is ____ for enveloped

not requried

naked virus sensitivity

less sens than eveloped to pH (can enter GI)

less sens heat, dryness, simple disinfectants

naked virus cell lysis

required

measles (rubeola) virus

paramyxoviridae

paramyxoviridae (measles) genome

-ssRNA

paramyxoviridae (measles) outer

spherical, enveloped virus

(-ssRNA)

paramyxoviridae (measles) transmission

resp droplets during prodrome and secretions

paramyxoviridae (measles) integral mem proteins

VIRAL SPIKES

hemagglutinin

F fusion protein

Hemagglutinin

antigenic glycoprotein binds virus to host cell

paramyxoviridae (measles)

F protein

fuses viral and target cell mem —> viral pen and coating

paramyxoviridae (measles)

explain how paramyxoviridae (measles) is lymphotrophic

airborne transmission

reach local lymph nodes

replicates

lymphopenia and weakened immunity

CD46

cellular receptor for paramyxoviridae (measles)

primary viremia paramyxoviridae (measles)

epithelial cells lining upper resp tract

enters blood

secondary viremia paramyxoviridae (measles)

after entering blood in primary

infects retinaculoendothelial cells

replicates

enters blood

skin rash

paramyxoviridae (measles) rash

cytotoxic T cells attacking virus infected cells in vasc endothelial cells

Ab mediated vasculitis

paramyxoviridae (measles) is considered

one of the most contagious viruses

Rubella virus (german measles) genome and outer

enveloped, icosahedral, +ssRNA

Rubella virus capsid protein

encloses viral RNA —> nucleocapsid

surrounded by lipid membrane

Rubella virus envelope

surrounds nucleocapsid

lipid membrane, glycosylated membrane proteins E1 and E2

Rubella virus transmission

resp droplets

transplacental

Rubella virus spread in body

multiplies in cells of resp system

rep in lymph nodes

viremic spread to organs