Hemophilus Flashcards
How bacteria are divided?
They are divided on the basis of the capsule and classified from A to F
Which type is the most important one in terms of disease production?
The Hib one
Where can we find them in the body normally?
In the respiratory tract in some people
Where are found the non-capsulated types? What do we call them? Why?
They are part of our normal flora in the respiratory tract or genital tract
They are called non-typable Haemophilus influenzae because they cannot be serotyped
How are H. Influenzae transmitted?
By respiratory secretions
By direct contact
What are virulence factors of the capsulated ones?
Polysaccharide capsule
LPS
Pili
Outer membranes
From what is composed the capsule?
From a polymer of ribosyl-ribitol-phosphate (RRP)
For what is responsible the LPS?
It is responsible for the CSF inflammation, and the sepsis in babies
It is responsible for damage of mucosal cells in respiratory tract, otitis media, sinusitis especially babies who can have 3 to 4 times a year an otitis media due to Haemophilus influenza mostly in addition to other bacteria.
Responsible for acute bronchitis
What is the function of the pili?
For colonization
Which diseases are caused by nontypeable ones?
Otitis media, sinusitis, pneumonia and bronchitis, meningitis
How test is done during otitis media?
It is done by tympanocentesis
Which test is done to detect sinusitis?
Culture of the sinus aspirate
Where bacteria can be detected in the case of pneumonia and bronchitis?
In the sputum. When it doesn’t contain enough specimen the right way is to take an aspirate from the stomach in the morning
In the blood. When it is positive in blood it means that pneumonia followed a bacteremia. It can be hematogenously or lymphogenously
How meningitis is caused?
It is directly spread from the throat not following a bacteremia
What are the diseases caused by the Hib type?
Meningitis, conjunctivitis, cellulitis, epiglottitis, septic arthritis
How meningitis is caused? Where bacteria can be detected in this case?
It is the result of a hematogenous spread
Bacteria can be found in the CSF or the blood if it was a hematogenous spread