Haemophilus spp.

Question 1

Grows on Chocolate + Blood agar 5-10% CO2, 37C

Answer 1

Neisseria, Moraxella, Haemophilus

Question 2

Bacteria that do not grow on blood agar

Answer 2

Haemophilus spp.

Question 3

Haemophilus colonies

Answer 3

Chocolate agar 1-2mm convex, grey-white, wet colonies
Pungent odour

Question 4

Presumptive Haemophilus tests

Answer 4

1. X and V Growth factors

Question 5

Haemophilus spp. basic characteristics

Answer 5

Gram negative coccobacilli, KOH positive
Oxidase Positive
Catalase positive (h. influenza) / negative (H. parainfluenza)

Question 6

Oxidase Positive bacteria

Answer 6

Neisseria, Moraxella, Haemophilus, Pseudomonas

Question 7

Catalase negative bacteria

Answer 7

Streptococcus,
haemophilus parainfluenza
Clostridioides

Question 8

Preliminary Haemophilus app test

Answer 8

X and V Growth Factors
1. Prepare heavy inoculum (1-2 colonies in reduced water)
2. Lawn DST agar evenly
3. Allow suspension to dry
4. Use sterile forceps, place X, Y, XY disks in petri plate (3.5cm away)
5. Incubate at 5% CO2 overnight at 35-37C
6. Observe growth of bacteria in vicinity of disks.
Visible colonies around XV only = H. influenza (PC)
Visible colonies around XV + V = H. parainfluenza.

Question 9

Haemophilus biochemical tests

Answer 9

KOH Pos
Catalase pos (H. influenza) or Catalase neg (H. parainfluenza)
Oxidase pos

Question 10

Gram stain

Answer 10

Gram negative coccobacilli

Question 11

Additional confirmatory tests

Answer 11

Vitek
Maldi-tof
ALA-porphyrin test
Send CSF to IMSRL Temple Street for PCR.

Question 12

Haemophilus influenza infection

Answer 12

Respiratory tract infection,
Cellulitis
BSI = meningitis, osteomyelitis

Question 13

H Parainfluenza infections

Answer 13

Rarely pathogenic
Respiratory infections

Question 14

H ducreyi infections

Answer 14

Chancroid (STD) - genital ulcers

Question 15

H. Influenza specimens

Answer 15

CSF, blood, sputum, middle ear aspirate, genital swabs.