Pathogens of Resp Tract 2 Flashcards
give some examples of upper resp tract infections
s. pyogenes
corynebacterium
bordetella pertussis
haemophilia influenza
give some examples of lower resp tract infections
haemophilia influenza
s. pneomoniae
legionella
mycobacterium TB
what are the range diseases haemophilia influenza causes
epiglottis bacteremia sinusitis tracheobronchitis pneumonia meningitis cellulitis
what are some characteristics of haemophilia influenza
exclusive human parasite small non motile pleomorphic gram -ve
what are some sp growth requirements
chocolate
cooked blood agar
supplemented with factor X or V
aerobic
what doe factor X and V distinguish
diff types of influenza
what si the non invasive pathogenesis
h influenza non encapsulated strains
opportunistic infection
secondary invaders of damaged issue
what is the invasive pathogenesis
capsulate strain causes acute primary infections
sore throat and fever
pneumonia, bacteriamia
how does infection arise
from resp droplet or direct contact with pt
how does the infection precede after entry
attach to epi cells
organism penetrates to submucosa
causes local inflammation
spread from initial site to infect bones, joints
what is types meningitis
winter disease
children 2 month - 2 years
what is the significance of the capsule
encapsulated and non encapsulated forms - polysac capsule - serotype * Hib non uncap = commensal
what si the virulence assc with the capsule fomration
PRP capsule
protect bac from phagocytosis
reduces susceptibility to antibacterial role of serum
what si the action of P2
(and other mem proteins)
silica acid oligosaccharides in mucin
what si the action of fimbriae
mucosal cells of nasopharynx
what is the action of non plus adhesins
mucosal cells of nasophaynx
how can h influenza be isolated from sub epithelial layers without damaging epi
passes between cell junctions (paracytosis)
adhere and enters non ciliated epi cells
viable bac detceted in macrophage cells
what Ab is used in bronchitis
amoxycillin or erythromycin
what is Ab used in pneumonia
flucloxacillin and amoxycillin
what is the Ab used in meningitis
cephtriaxone
what is the immunisation used for resp infections
Hib (capsule type B) vaccine
what is pneumonia
an acute inflammation of the lungs caused by inhaled pneumococci of s pneumoniae
what happens in pneumonia
alveoli and bronchioles of the lung become plugged with a fibrous exudate
what are some causes of community acquired pneumonia
s. pneumonia
h influenza
legionella
moraxella cattarhalis
what are some hospital acquired pneumonia
s. aureus
gm -ve baclli
e. coli
what is the structure of s pneumonia
encapsulated gm +ve cocci oval arranged in pairs alpha haemolytic fastidious
what is fastiduos
grows on media enriched with blood products
catalase -ve
needs catalase to prevent build up of h2o2
how is s pneumonia identified
optochin sensitivity
deoxycholate sensitivity
gm +ve stain
alpha haemolytic
what diseases does s pneumonia cause
pneumonia
ottis media
menigitis
how is s pneumonia transmitted
horizontal transfer from resistant to susceptible
how does s pneumonia bind to carb surfaces
n acetyl glucosamine
neuraminidase A
what is the infection of pneumococcal pneumonia
invasion of lower resp tract by aerosol
bypass ciliated epi
what does pneumococcal pneumonia progress to
alveolus and cells wall promotes binding to cells expressing platelet activating factor receptor
techioci acids are expo on cel surface and present in cell wall
how does pneumococcal pneumonia overcome IgA
through the secretion of proteases
how does pneumoccoccla pneumonia overcome the mucociliary escalator
prod cytotoxin that kills ciliated epi cells and phagocytes using PNEUMOLYSIN
whee does the bac of pneumococcal pneumonia multiply
in nutrient rich edema fluid
what causes pururlet fluid
build up of erythrocytes, neutrophils and macrophages
what are some virulence factors of pneumococcal pneumonia
cell wall = inflam (techie acid)
pneumolysin pore form toxin
h2o2
phophorycholine
what is phosphorycholine
present on cell wall
binds to PAF receptor
induces creeper mediated exostosis
what are 2 main mean of phagocytic survival
capsule - smooth
- key to virulence
- complex serotypes
- inhibit complement
penumolysin
- disrupt mem
- inhibit oxidative burst
what are some symptoms of pneumococcal pneumonia e
abrupt onset fever an shake chill productive cough tinged red chest pain lobar pneumonia bacteriamenia if untreated
how treat pneumococcal pneumonia
amoxycillin or erythromycin - resistance
what is used ag meningitis
cephtriaxol
what is the vaccination processes used ag pneumococcal pneumoni
PCV7
pneumococcal vaccine
anti capsular vaccine
what is legionnaires disease
atypical, acute lobar pneumonia with multi system symptoms
when does legionnaires occur
sporadic cases or outbreaks
who does legionnaire mostly effect
immune or pulmonary compromised
how does one get infected with legionnaires disease
inhalation of water drop
no person to person spread
what cause common outbreaks of legionnaires
circ water drops
whirlpool spas
fountains
cooling towers
what are the symptoms of legionaries
incubation 2-10 days
cough, fever, loss appetite, headache, sputum, breathless, confusion, complications with heart/brian/kidneys
what are the sp symptoms of legionnaires
non - pneumonic legionellosis
dry cough, malaise, headache
acute inlllnes resolve in 2-5 days
what are the non resp infection symptoms assc with legionnaires
wound infection after immersion in contam water
hematogenous spread o extra pulmonary sites
what is pathogenesis
fail to clear inhaled organism
contact alveolar macrophages multiply in phagocyte
lyse and re infect
spread through blood and lymph
what is legionella pneumophila
facultative intracellular parasite unencapsulated gm -ve aerobe bye green algae tim growth fastidious
how is the diagnosis of legion pneumo done
culturing
direct Ab test
rRNA ID
what i the treatment of legion pneumo
erythromycin
azithromycin for pneumonia
what is the control of legion pneumo
clean water systems
hot water monitored
