Haemophilis and Bordatella

Question 1

H. influenzae

Answer 1

G-
Coccobacilliary
aerosol 
facultative anaerobe
fastidious

Question 2

H. Influenzae Dx

Answer 2

CULTURE:
Chocolate agar: requires factor V-nicotinamide and factor X-hemin

DIRECT MICROSCOPY:
Meningitis: Spinal tap and pt presentation (fev, irritable, headache, stiff neck)

CAPSULE DETECTION:
Type B agglutination test

Question 3

H. Influenzae Sx

Answer 3

epiglottitis, inspiratory stridor, drooling, (URT infxn: sinusitis, pneumonia)
“cherry red epiglottitis”

cellulitis

otitis media

meningitis (capsular– type B strain)

sepsis, septic arthritis & bacteremia (in asplenic patients/sickle cell pts bc spleen required to remove encapsulated organisms)

Question 4

H. influenzae Vaccine

Answer 4

Vaccine for Type B (typeable form)

Polysaccaride capsule conjugated to diptheria protein toxoid

between 2 and 18 month

Question 5

H. influenzae Tx

Answer 5

B-lactam, cephalosporins, macrolides, fluorouquinolones

Meningitis/systemic:
Ceftriaxone, cefotaxmie

Rifampin used for prophylaxis for family members

Question 6

Actinobacillus Actinomycetemcomitans

Answer 6

peridontitis, endocarditis, bite wound infection; heart patients must undergo prophylaxis bc of these

grow slow in blood culture

Question 7

Aggregatibacter aphrophilus

Answer 7

endocarditis; heat pts undergo prophylaxiz bc of these

grow slow in blood culture

Question 8

Pasturella multocida & canis

Answer 8

cat/dog bite wound

sx: cellulitis & lymphadenitis; chronic respiratory disease, systemic infxn for immunocompromised, *meningitis (rare)
dx: chocolate agar, musty odor w/butteryfly colonies, oxidase +
tx: penicillin

Question 9

H. parainfluenzae

Answer 9

bacteremia, endocarditis

Question 10

H. aegyptius

Answer 10

purulent conjunctivitis

Question 11

H. ducreyi

Answer 11

chancroid (STD-rare in US)

Question 12

H. influenzae (typeable)

Answer 12

transient colonizers (create issue and then leave)

polysacc. capsule w/PRP (polyribitol phosphate) – Abs against this effective
Type A-F, B most pathogenic

Question 13

H. influenzae (non-typeable)

Answer 13

URT: sinus and ear issues for children
LRT: pneumonia for COPD pts

throat and mucous membranes (vs transient colonizers)

Question 14

H. influenzae virulence factors

Answer 14

Polysacc capsule: anti-phagocytic (PRP)

LPS lipid A: meningeal inflammation

IgA1 protease: colonization

Question 15

Bordetella pertussis

Answer 15

G-
coccobacilliary
aerosol
obligate aerobes
fastidious

Question 16

B. pertussis virulence factors

Answer 16

Adhesins

• filamentous hemagglutinin (FHA): binds tracheal ciliated cells; primary component of acellular pertussis (aP) vaccine
• Fimbriae (FIM): stimulates humoral immunity; in some vaccines
• Pertactin (PRN): similar to FHA

Toxins
-Pertussis toxin: AB toxin, lymphocytosis, primary component of vaccine; (ribosylation and inhibition of Gi, increase in cAMP and disables chemokines prod by lymphocytes and unable to make into BS = massive aggregation in the bloodstream = lymphocytosis)

• Adenylate cyclase (CyaA): anti-inflamm and anti-phagocytic (like EF in anthrax)
• Tracheal cytotoxin: damages cilia of respiratory tract, induced fever IL-1
• LPS: activates alternate complement pathway

Question 17

Sx/Stages of pertussis

Answer 17

Catarrhal- rhinorrhea, fever, nonspecific cough (greatest communicability)

Paroxysmal- ciliated epithelium must be shed (2wk-2mo)

Convalescent- “100 day cough”; intermittent episodes of cough
(last up to 3 month)

• infant/children disease > adults/adoles
• whoop uncommon in adults
• adults often source of infection

Complications: pneumonia, seizures, encephalopathy, death, hemorrhage

Question 18

B. pertussis Dx

Answer 18

CXR
normal (see some extra white shit)
Elevated WBC

PCR (BEST)
or NAAT- nasopharyngeal secretions

CULTURE (earlier)
Charcoal, BG, RL media

SEROLOGY

Question 19

B. pertussis Tx

Answer 19

Erythro, Clarithro, Azithro

Erythromycin for prophylaxis

Supp

Question 20

B. pertussis Vaccine

Answer 20

DTaP; aP

acellular pertussis; PT, FHA, pertactin, fimbrial protection