Chapter 11: Haemophilus Bordetella, and Legionella Flashcards
Haemophilus influenza, Bordetella, and Legionella
Why are they grouped together?
acquired through respiratory tract
Haemophilus Influenza
Haemophilus means….
Haemophilus =
means “blood loving”
organisms requires a blood containing medium for growth.
hematin found in blood is necessary for bacterium’s cytochome system. Also needs NAD from blood.
Haemophilus influenza
influenza means
bacterium attacks lungs of person debilitated by viral influenza infections
Haemophilus influenza is an
obligate human parasite transmitted via the respiratory route.
What confers haemophilus virulence?
polysaccharide capsule: polyribitol ribose phosphate
6 types: a, b, c, d, e, f
what is the most common capsule type for haemophilus?
capsule B
causes meningitis, epiglotttis and septic arthritis
what three damaging clinical symptoms does HI B cause?
meningitis, epiglottis and septic arthritis
Capsule = B
is bad
what does non-encapsulated Haemoophilus I. do?
colonizes upper respiratory tract of adults and children.
can ONLY cause local infection. frequently cause otitis media and respiratory disease in adults weakened by preexisting lung diease like chronic bronchitis or smoking.
COPD patients get what kind of infections
frequently, nontypeable strains of HI which causes worsening shortness of breath, cough, etc.
Nontypeable HI
Nonencapsulated strains
lack virulent invasiveness or their enapsulated sousins
Antibodies to capsule of HI and age group
infants and children between 6 months-3 yrs of age pick up passively from mother. active for only 6 months, then takes 3-5 yrs to develop their own antibodies, which makes them vulnerable
Haemophilus influenza B
meningitis
worst symptom of HIB
main cause of meningitis of children between 6 months and 3 yrs
inhaled through respiration, then travels in blood and lymph
nonspecific signs: no neck rigidity or nuchal sign. fever, vomiting, altered mental status. potentially fatal.
can leave permanent brain damage.
Three most common causes of meningitis in neonates
1) listeria monocytogenes
2) Escherichia coli
3) Group B strep
Two most common causes of meningitis in children older than 6 months
neisseria meningitides, haemophilus influenzae.
Haemophilus Influenza
Acute epiglottitis
Type B can cause rapid swelling of epiglottis
causes airway obstruction via swelling
child unable to swallow, will be drooling
wheezing (Stridor)
large epiglottis looks like red cherry
HI
septic arthritis
Type B is the most common cause
asymmetric joints afflicted
synovial fluid gram stain: pleomorphic gram neg rods
HI
sepsis: age groups and clinical presentation
children between 6 months- 3 yrs
fever, lethargy, loss of appetite. no evidence of localized disease (otitis media, meningitis, epiglottitis
children missing spleen at highest risk
Haemophilus Ducreyi
clinical presentation and disease
responsible for disease called “chancroid”
presents: painful genital ulcer
painful swollen LNs unilaterally
