Lc 16 Flashcards
What are two types of haemophilus species we are studying
H.influenza and H.ducreyi
Characteristics of hemophillus spp.
Gram negative, coccobacilli or short rods
Facultative anaerobe
Non motile
Non spore
Haemophilus is fastidious. What does fastidious mean?
Growing at specific nutritient agar (selective)
What are some nutrients haemophilus need?
X factor - protoporphyrin IX
V factor- NAD (e transporter)
Doe haemophilus ferment glucose or lactate?
Glucose
How is H.Influenza differentiated?
Encapsulated - type B —> vaccine preventable(Hib)
-key virulence factor: polysaccaharide capsule
-BSI more common
Non- encapsulated - NTHI
—> nasopharyngeal colonizer
—> strain specific immunity
How was using Hib Vaccine?
Very successful
Where in our body get infected from H.influenzae disease?
URT contiguous sites
Blood stream infection (BSI)
- endocarditis, septic arthritis
Pneumonia is a lower respiratory tract infection caused my haemophilus influenzae disease.what are the characteristics ?
Often insidious
Kids and older people get disease
Occur at 15% of disease before we get vaccination
Hib vaccine works for type B H. Influenza. Is this true? If true, explain why.
Yes. Because Hib vaccine is for type H.influenzae type B.
What are the H.influenzae virulence factors and their treatment?
Capsule(esp type B), Adhesins (protein E, type 5 pilus)
Amoxicillin or Amoxicillin-Calvulanate
What is H.ducreyi and its characteristics?
Sexually transmitted diseases
Heterosexual transmission dominant(man higher rate)
Readily treated but no life long immunity
Chancroid characteris and treatment
Multiple lesion
Grey/yellow exudate
Important Bordetella species is
B.pertussis. Describe its characteristics.
Gram negative, coccobacilli
Regan-Lowe medium ( small shiny round colonies)
Strict aerobe
Encapsulated
Non spore former
Describe Bordetella species morphology and cultivation
Fastidious
Oxidase positive
There is an exception to Bordetella species.what is it?
B.bronchispetica is motile
What is the reservoir of Bordetella species
Adults , adolescents, older children.
Disease in unimmunized or 6months old or younger who doesn’t have immune system.
Clinical pertussis symptoms
Prolonged cough
Distinct whooping in infants
Lymphocytosis
Lower respiratory tract , large airway dz
What are the adherence and virulence factors of Bordetella species?
Filamentous hemaglutinin(FHA)
Toxins ( adenylate cyclase toxin, pertussis toxin, tracheal cytotoxin
Explain now pertussis toxin infects
Internalize —> disrupt G-protein coupled receptors—> disrupt cell signals
What are some types of lab detection we can use for bordetella spp?
Culture, PCR, Serology
How do we treat pertussis?
Use macrolides-
Erythromycin for infants. Weight based dosing, fixed dosing for adolescents and adults.
Use respiratory distress-
intubation and ventilation
Minimal utility-
Inhaled corticosteroids, anti-pertussis
