16. a. Haemophilus Flashcards
Where does haemophilus influenzae colonise?
Nasopharynx
What haemophilus influenzae strain causes invasive disease?
Encapsulated H. influenza type b
What factors increase the risk for a Hib infection?
Aged under 2
Asplenic
Immune deficient
What infections are caused by non-encapsulated strains of Hi?
Exacerbate chronic bronchitis
Otitis media
Sinusitis
Pneumonia
What are the virulence factors of Hib?
Capsule is anti-phagocytic
Pili, fimbriae and adhesion proteins
LOS endotoxin
Antimicrobial resistance
What is the pathogenesis of non-encapsulated Hi?
Cilia are damaged due to smoking or viral infection
Mucous pools and biofilm formed
What precautions are required for Hib?
Droplet
What are the virulence factors of non-encapsulated Hi?
Fimbriae Opacity associated protein IgA protease LOS Antibiotic resistance
What infections can be caused by Hib?
RTIs in infants (epiglottitis and pneumonia)
Meningitis
Sepsis
Septic arthritis and cellulitis
What does Hi look like under the microscope?
Pleomorphic gram negative bacilli or coccobacilli
What air conditions are best for Hi?
Faculative anaerobes
5% CO2
What agar is needed for Hib and why?
Chocolate agar
Needs both factor X and V for growth
What methods of resistance does Hi have?
Intrinsically resistant to penicillin
Some produce B-lactamase
What treatment should be given to an in patient with an RTI?
IV co-amoxiclav
What treatment should be given to an in patient with meningitis or a BSI?
IV ceftriaxone or cefotaxime
