M7 Infections if the Upper Respiratory Tract Flashcards
what does pyogenic mean
causes an elevation in temp - heat
what is a pyogenic bac
streptococcus pyogenes
what are the evolutionary groupings of streptococcus
angiosus Oralis Mutans Salivarius Pyogenic Bovis
what are some sp of S. orals
s snaguinis s cristasus s gordonii s mites s oralis s pneumoniae
what is a pyrogen
agent that causes raise in body tissue
what are GAS
Group A Streptococcus
what types of bac are GAS
streptococcus pyrogens
assc with diseases
what are iGAS
invasive GAS
what kind of disease can GAS cause
systemic
major pathogen in skin conditions
what is important to not about a s. pyrogens capsule
hyuloronic acid interfere with complement and Ab
what is important to know of bodies reservoir function
micro biome
commensals
priming immune system
where is a common site fro s progenies
oropharynx
what si percentage of s pyogenes in adult vs children nd why
10% adult
20% children
immune system developing and more susceptible to exposure
where is most comply adhesion occur
oropharynx
nasopharynx
what allows adhesion at sites
non ciliate cells covered in mucus
range of adhesins
what acts as defence to the upper resp tract
mechanical washing cough reponse shedding mucociliary clearance microbiota/flor
what are some infectious organisms in the resp treat
bacteria
viruses
fungi
what is viral pharyngitis
normal cold virus
only need symptomatic therapy 70%
what is a bacterial ppharyngiits
strep throat
GAS 15%
- beta haemolytic S.pyogenes
what complications can occur due to bacterial pharyngitis
acute rheumatic fever
what are some common batter seen in pharyngitis
fusoacterum necrophorum
mycoplasma pneumonia
haemophilia influenza
what can pharngiti lead to
tonsilitis
what represents bacterial pharyngitis
swollen uvula
whitish spots
red swollen tonsils
redness gray furry tongue
what is viral pharyngitis shown by
red swollen tonsils
throat redness
what are some symptoms of viral pharyngtiits
absence of fever
conjuntivitis
coryza
cough
what is coryza
inflammation of nasal mucous membranes
what are the symptoms of strep throat
sudden onset sore throat fever patchy exudates tiny red spots on hard palate tender cervical nodes
what are some other complications that can further from strep throat
tonsillitis
ottis media
sinusitis
if there is bad breath asscw with a sore throat what can this mean
bacterial pharngitits recgo necrotising damage to tissue as being broken down
proteins being broken = odour
What can happen from a more aggressive strain of S. pyogenes
bacteriophage presses haemolytic toxin cause damage to RBC leading to scraeltine appearance
what does a super antigen do
overstimulates system
what is scarlet fever
severe form of strep throat with assc rash
what causes the effects of scalet fever
pyrogenic/erytorogenic exotoxins
what does a scared fever show
typical rash 2 days after illness contagious flushed red face coated tongue swollen tonsils
the does GAS come about
periodic epidemics
possible increasing
when are GAS skin diseases common
in young children
poor hygiene sharing towels
what is ana example of a GAS skin disease
impetigo
what is impetigo
usually face
high contagious
contact with discharge on face
infections immediately beneath surface
what does impetigo show as
sores on stratum core which then goes beneath skin layer invasive GAS
what do GAS skin diseases usually do after colonising skin
disease moves deeper tissue or involves lymphatic system
what does range of spreading subcutaneous skin infections caused by
iGAS
invasive GAS
what is Cellulitis
deeper skin infections in the dermis
develop in lesion
what is erysipelas
localised
fever, rotors, nausea
what is necrotising fasciitis
rapid destroy CT
IGAS penetrate mucous memes and develop in deep lesion
what is mortality rate of necrotising fasciitis
20%
what is acute streptococcal gingivitis
infected gigivae
red swollen
oedematous
follow sore throat
what is TSLS
toxi shock like syndrome
what si the morality of TSLS
30-60%
what causes TSLS
pyrogenic exotoxins
complications of invasive infections
hypooension to organ failure
what dosuperantigens do
activate 1/5 T cells
assc with TSST-1
massive please cytokines and inappropriate immune response
what does a asuperantigen bind to
directly MHCII complex
outside conventional binding groove
what is rheumatic fever
autoimmune disease
what are the symptoms of rheumatic fever
sudden onset
early –> fever, joint pain, nose bleeds, vomit
late –> polyarthritis, inflam of joints and heart
pancarditis
what is pancrditis
peri, tyco and endocardium affected
when is rheumatic fever most likely to occur
young children 5-15
1-4 weeks after are throat
inadequate recoervy from GAS
what is the autoimmune disease PSGN
Post streptococcal Glomerulonephrotis
what happens in PSGN
inflam of glomeruli due to depo of Ag-Abs
what kind of hypersensitivity is PSGN
type 3
what are the key elements involved in adhesion
lipoteichonic aid
M protein
F protein
Hyaluronic acid
what does lipoteichonic acid act as
LTA
fibronectin - FA binding site
what does M protein do
fibronectin
and specific binding site
what is f protein
fibronecting binding protein
fibronetin
what does hyaluronic acid do
capsule
CD44 +ve keratincytes
what is used to identify class Streptococcis
haemolysis
what is an example of biactrin sensitive
GAS
when something is beta haemolytic what does it do on blood agar
clear zones around colony
what is the lance field system
group a terminology
serotyping cell wall carb
what is group A subdivide by
M protein antigens
M1 & M3 - major serotype
M3 & M18 - major invasive
what is M protein involved in
adhesion evading immune system antiphagocytic prevent 3b bind opsonisation via alternate path
what are other ways of evasion of host defences
SpyCEP - protease cleaves IgG
C5a peptidase - cleave C5a
what is Sic and what does it do
strep inhibitor of complement
binds C5b & C7
evasion of host defences
what do pyrogenic exotoxins do as super antigens
evasion of host def
SpeA and SpeC - scarlet fever
SPeG….. assc with rheumatic fever
what causes tissue destruction nd spread
numerous virulence factors
what re some virulence factors able to increase tissue destruction nd spread
haemolysins
DNase A,B, C, D
Streptokinase
what do virulence factors all do
liquefaction of Pus
destroy tissue
dissolution of clot
what is key to iGAS
target immune cells for cel destruction
what are streptolysins (SLS)
pore firing cytolysin
toxic to PMN, organelles, platelets
what is metastasis
tissue penetration
what ar the factors involved in metastasis
m protein
fibronetin binding protein
what si the function of m protein in metastasis
stimulates internalisation
what is fibroncetin binding protein function in metastasis
hide from macrophages
presist in presence of Ab
whats the most affective Ab treat
penicillin V 10 day course
what is amoxicillin
narrow spectrum acceptable to children
when is erythromycin used
patients sensitive to penicillin
