lec 3 h.influenza Flashcards
which type of bacteria is hemophilus influenza?
Gram negative coccobacili capnophillic
can be either encapsulated or non capsualated
H.Influenza is cultured under:
-Enriched chocolate agar = hematin and NAD
-bloood agar in prescence of staph aureus
Epidemiology of H.influenza:
nasopharyngeal, meningitis most common from in children
H.influenza type B and what it infects:
most virulent encapsulated type
can infect CNS,epiglottis and soft tissues
-Disease begins with fever and lethargy.
H.influenza type B pathogenisis:
-Normal flora invades deeper tissues
-attachment by pilli
-capsule role is to defect C3b deposition
-Endotoxin- septecemia
-Has no exotoxin.
True about the immunity of H.Influenza:
-PRP antibodies
-peak is between 6-18 months
-similar to meningococci
Clinical manifestations of H.influenza
Meningitis
acute epiglottis
cellulitis and arthritis
otitis media
pneumonia
acute and chronic bronchitis
Diagnosis of h.influenza:
clinical findings
gram stain
serotyping
treatment of h.influenza:
DOC: ampicillin or amoxicillin
if resistant, 3rd gen of cepahlosporin
Bordetella pertussis type:
slow growing Gram negative small coccobacilli
require NAD and charcoal
Attachment proteins of B.pertussis:
-(filamentous hemoagglutinin) FHA
-pilli
-pertacin in outer membrane
Extracellular products of B.pertussis:
ADP ribolysation
Adenalate cyclase toxin, cAMP increase
interferes with cellular signalling
Whooping cough of B.pertussis
Transmission: airborne
Fatal in infants <1 year
pathogenisis of whooping cough:
‘-humans affected only
-cilliated columnar epithelium, attached by pilli, FHA,OMP
-cillia damage by tracheal cytotoxin
-adenylate cyclase and PMN’s
Gene regulation of whooping cough:
-Incubation period, 7-10 days
-catrrhal, paroxysmal, convalescent
-lymphocytosis
