hemophilus 3 Flashcards
What family do Haemophilus species belong to?
Haemophilus species are part of the Pasteurellaceae family.
What is a characteristic feature of Haemophilus species?
They are known for their small size (parvobacteria) and pleomorphism.
What infections are non-typeable H. influenzae strains responsible for?
They are responsible for a substantial proportion of upper respiratory tract infections in adults, especially in smokers and those with chronic lung disease.
What disease does H. ducreyi cause?
H. ducreyi causes chancroid, a sexually transmitted genital ulcer disease common in tropical regions.
What is a unique feature of H. parainfluenzae?
H. parainfluenzae is less pathogenic and occasionally implicated in endocarditis and other systemic infections.
What is the function of IgA protease in Haemophilus species?
IgA protease allows the bacterium to survive on mucosal surfaces by neutralizing a key antibody type.
What role does the lipid A portion of LPS play in Haemophilus infections?
It can stimulate inflammation in the meninges, which is crucial in cases of Hib-induced meningitis.
What was H. influenzae type b (Hib) known for before the Hib vaccine?
Hib was once the leading cause of pediatric bacterial meningitis.
What is a classic emergency associated with Hib?
Epiglottitis, where a swollen epiglottis can block the airway in children.
What conditions can Hib cause in children?
Hib can cause cellulitis, especially around the cheeks or periorbital areas, and septic arthritis in large joints.
What is the satellite phenomenon in laboratory diagnostics?
It helps identify H. influenzae when grown on blood agar alongside Staphylococcus aureus.
What diagnostic tests are essential for rapid diagnosis of Haemophilus infections?
PCR and antigen detection tests like latex agglutination.
What resistance mechanism do some Haemophilus strains have?
Some strains produce beta-lactamase, conferring resistance to ampicillin.
What impact has the Hib vaccine had on infections?
The Hib vaccine has effectively reduced invasive H. influenzae type b infections globally.
Why is vaccination essential for at-risk individuals?
At-risk individuals, such as those with splenic dysfunction, have increased susceptibility to invasive Hib infection.
