25- H Infleunzae Flashcards
Are they always gram - cocci
No can be filamentous too
Which acute resp infections does it cause
Bronchitis, pneumonia
Which urt major thing can it cause other than sinusitis etc
Epiglottitis
What does it cause mainly in children 3-3 years old
Meningitis/ inflammation of the meninges
Can it be seen in healthy
Yes as an opportunist
What does it need to grow in and why
Blood agar for factor x and v
What is fsctor x
Haemin- it’s required for cytochrome c and fe enzymes of the bacteria
What is factor v
Nad / nad phosphate needed for oxidation reduction processea
Does it need co2
No but there is a 5-10% increase in growth
Why is agar usually heated
To release nadases which increases factor v and then heat also allows rbc to release factor x haemin
How is it diagnosed in rare cases
Microscopy or biochemical tests
What is given without diagnosis
Antibiotics to treat general infection
Give examples of some biochemical tests
Catalase positive and oxidase positive
How many types of capsulated hi are there
6- a to f (b most invasive)
Which polymer capsule does b have
Poly ribosyl ribitol phosphate (in the hib vaccine)
How many biotypes are there based on biochemical tests and which most common
8
1-3 most common
Which type is most invasive
Type 1, b hi
There are 2 types of infection. Invasive and non invasive/respiratory. What causes invasive
90% type b, 10% non capsulated , 1% e and f
What are non invasive most common in
90% occurs in children eg meningitis, pneumonia, sepsis
What causes 90% of non invasive in adults and children eg otitis, sinusitis, epiglottitis
Non capulsated
Which other pathogens can cause invasive infection (demuri)
Viral infections
What sort of vaccine is hib
Conjugated to increase TD responses as polysaccharide don’t produce good responses in children
What after vaccine causes meningitis in children
Non capsulated
When would invasive infections occur in adults whcih is v rare eg pneumonia
If immunocomprised or have chronic infections or malignancy
Since adults have good b ab what can cause these rarely
E and o types
Why are neonates below 2 months not at risk of invasive eg meningitis
IgG transfer from placenta against capsules
When does systemic usually occur/ how
Penetration of submucosa after eg disruption like smoking, viral pathogens. Causes transepithelial migration into blood stream ie bacteraemia
Why is capsule of hib important for virulence
Evades phagocytosis and complement mediated lysis