Haemophilus and Bordetella

Question 1

Very tiny GNRs, very fastidious, capnophilic

Answer 1

Haemophilus

Question 2

Hemin/hematin, derived from RBCs, heat stable

Answer 2

X factor

Question 3

NAD; Present in yeast extract (CHOC), RBCs contain this w/ an enzyme inactivator, produced by S. aureus, Neisseria, and S. pneumoniae

Answer 3

V factor

Question 4

Why is a suspension first made in broth before testing for X and V factor?

Answer 4

To dilute any X factor carried over from the plate

Question 5

These two medias do not contain any X or V factor

Answer 5

T. soy or Mueller Hinton agar

Question 6

SBA contains which factors?

Answer 6

X only

Question 7

Chocolate agar contains which factors?

Answer 7

X and V

Question 8

Rabbit blood agar contains which factors?

Answer 8

X and V

Question 9

Fildes enrichment contains which factors?

Answer 9

X and V

Question 10

Rabbit or horse blood hemolysis looks for the presence of ____ hemolysis

Answer 10

Beta

Question 11

Which two species are beta hemolytic?

Answer 11

H. haemolyticus and H. parahemolytics

Question 12

Alternative test for determining X factor; eliminates problem of hemin carryover; fluorescence positive

Answer 12

Porphyrin test

Question 13

Meningitis was the leading cause in young children before Hib vaccine and was caused by ____ ____

Answer 13

H. influenzae

Question 14

This is a secondary invader after H. influenzae

Answer 14

Pneumonia

Question 15

Infection from H. influenzae in the respiratory tract area

Answer 15

Otitis media, epiglottitis

Question 16

Primary virulence factor of H. influenzae

Answer 16

Capsule

Question 17

Serotypes of H. influenzae are based on the ____

Answer 17

Capsule

Question 18

Encapsulated strains of H. influenzae are more likely to be ____, whereas nonencapsulated strains are ____ and often part of the normal respiratory flora

Answer 18

Invasive; noninvasive

Question 19

Vaccination against invasive Type b strains of H. influenzae

Answer 19

Hib (“Haemophilus influenzae type b”) vaccine

Question 20

Blood cultures are positive in vasive infections, smooth colonies on chocolate agar, requires both X and V factors, non-hemolytic on Rabbit blood agar

Answer 20

H. influenzae

Question 21

Requires only V factor, hemolytic on rabbit blood agar

Answer 21

H. parahemolyticus

Question 22

Requires only V factor, non-hemolytic on rabbit blood agar

Answer 22

H. parainfluenzae

Question 23

Requires X and V facctors, hemolytic on rabbit blood agar

Answer 23

H. hemolyticus

Question 24

Former strain of and identified as H. influenzae, causative agent of contagious conjunctivitis (“pinkeye”)

Answer 24

H. aegyptius

Question 25

Biogroup of H. influenzae primarily in South America; agent of Brazilian purpuric fever (BPF) an ddpurulent conjuctivitis; high mortality rate

Answer 25

H. aegyptius

Question 26

Not prt of normal flora; agent of "soft chancre" or "genital ulcer disease"; STD; painful ulcerative genital lesion; enlarged lymph nodes; very fastidious; slow grower (5-7 days) on chocolate agar

Answer 26

H. ducryei

Question 27

HACEK group; indigenous to upper respiratory tract; fastidious; endocarditis, septicemia in immunocompromised patients

Answer 27

Aggregatibacter (Haemophilus) aphrophilus

Question 28

Gram variable pleomorphic rods; common cause of bacterial vaginosis; can be sexually transmitted

Answer 28

Gardnerella vaginallis

Question 29

↑ in pH of vaginal fluid (> 4.5), ↓ Lactobacillus (normal flora), overgrowth of seeral normal flora organisms, not an infection

Answer 29

Bacterial vaginosis

Question 30

How can you diagnose bacterial vaginosis?

Answer 30

Culture is NOT useful; direct exam for "clue cells" (wet prep or gram stained); foul odor of clear, watery exudate; amine test in 10% KOH or vaginal pH > 4.5

Question 31

Describe clue cells

Answer 31

Squamous epithelial cells plastered w/ variable rods

Question 32

Does not require X or V factors; inhibition by SPS (sodium polyanethol sulfonate) disk, S. pneumoniae inhibition

Answer 32

G. vaginalis

Question 33

Stain poorly, small GN coccobacilli,, noninvasive, does not require X or V factors

Answer 33

Bordetella

Question 34

Agent of pertussis or "whooping cough", spread by respiratory route

Answer 34

Bordetella pertussis

Question 35

Toxin produced by organism in B. pertussis ____ ____, and causes accumulation of thick mucous

Answer 35

Paralyzes cilia

Question 36

What are the 3 stages of pertussis?

Answer 36

1. Catarrhal 2. Paroxysmal 3. Convalescent

Question 37

Symptoms of a cold, duration of 1-2 weeks, the IDEAL time to culture, rhinorrhea, malaise, fever, sneezing, anorexia

Answer 37

Catarrhal stage

Question 38

Characteristic cough/whoop, duration of 2-4 weeks, vomiting, leukocytosis

Answer 38

Paroxysmal stage

Question 39

Duraction for (3-4 weeks) or longer; diminished paroxysmal cough, development of secondary complications such as pneumona, seizures, and encephalopathy

Answer 39

Convalescent stage

Question 40

Describe pertussis in infants

Answer 40

Life-threatening, choking, apena, may not be a cough

Question 41

Describe pertussis in adults

Answer 41

Hernia, broken ribs from coughing, often undiagnosed or misdiagnosed, high risk for transmitting disease to infants

Question 42

Lab identification of B. pertussis by 4 methods

Answer 42

- Culture - PCR - Nasopharyngeal culture - Cough plates

Question 43

Recommended method for culture for B. pertussis

Answer 43

Nasopharyngeal culture using flexible calcium alginate or Dacron swabs

Question 44

B. pertussis secretes ____ ____ which builds up and inhibits growth; how do we prevent this?

Answer 44

Fatty acids; charcoal or increased blood in medium to neutralize fatty acids

Question 45

Which types of media are used to isolate colonies of B. pertussis?

Answer 45

- Bordet-Gengou (potato-glycerol w/ increased blood) - Charcoal cephalexin blood agar - Regan-Lowe agar (incubate 7 days) - Amies (w/ charcoal) or Regan-Lowe transport media

Question 46

Vaccines for infants vs. adults

Answer 46

DTaP for infants, TdaP booster for adults (aP = acellular pertussis, D = Diphtheria, T = tetanus)

Question 47

Increased incidence of B. pertussis due to...

Answer 47

Non-immunized children, vaccines are serotype specific or short-lived, adults not receiving boosters

Question 48

Small percentage of "whooping cough" cases, milder disease, brown pigment, may grow on SBA, MAC agar

Answer 48

B. parapertussis

Question 49

Present in dogs (kennel cough) and other animals, mild respiratory infection, RAPID UREASE, cross reacts w/ B. pertussis and B. parapertussis on fluorescent Ab, may grow on SBA or MAC agar

Answer 49

B. bronchiseptica

Question 50

If you don't have any X factor, what can you use?

Answer 50

SBA

Question 51

If you don't have any V factor what can you do?

Answer 51

Add yeast to T. soy (Staph streak)

Question 52

If you don't have any XV factor, what can you do?

Answer 52

SBA w/ Staph streak (satellitism)