Haemophilus Influenza Gram Neg

Question 1

1. shape of H. infl
2. Virulent factor ?

Haemophilus Influenza is the smallest bacteria
nearly round (coccobacilli) its most virulent strain is a capsule.

Tiny Gram-Negative coccobacilli

Answer 1

1. cocobacilli
2. polysaccharide capsule

Question 2

1. required cultivating factors for H. infl.
2. which type of bacterial colony does H. inf grow ?

Requires hematin which is found and in enriched blood because of EXOGENOUS hematin and/or nicotinamide adenine NAD which are PRESENT in ERYTHROCYTES

Answer 2

1. Hematin and/or NAD
2. Staph Aureus

Question 3

1. what are the two types of H. Inf
2. What do we call the capsule of Hib ?

Six serotypes of H. influenza are based on CAPSULAR polysaccharide (a-f) the rest have no capsule

Answer 3

1.Hib and NTHi
2.Hib expresses a capsule and NTHi doesnt have a capsule
3.Polyribotol phosphate (PRP)

Question 4

1. what are some adherence factors of H. infl

only capsular H. influenza can be invasive

Answer 4

1. Pili HMW

Question 5

A. What are some diseases that manifest from H. influenza
B. True or False: H. influenza is strictly a human pathogen

Answer 5

A
1. Meningitis 50%
2. Otitis media
3. Sinusitis
4. Bronchitis
4. epiglotitis
5. Arthritis
6. Chancroid

B. TRUE

Question 6

1. Which strains of H. influenza are invasive
2. What percentage of H. Inf is mostly found world wide roughly 80% ?
3. Common places of colonization of H. Inf is where ?

Answer 6

1. Capsular ones
2. H. Influenza Type B
3. Nasopharengeal colonization

Question 7

Describe the features of EPIGLOTTITIS in H. Inf

Answer 7

Inflammed epiglottis
swollen CHERRY RED
obstructed airway
sudden onset muffled cough

Important: affected children have inspiratory stridor with each inspiration (air hunger)

Question 8

Describe Cellulitis and Arthritis manifested by H. Inf

Bacteremia can be prsent in both Cellulitis and Arthritis

Answer 8

Cellulitis is usually facial
redish-blue swelling in the cheek, may follow upper resp and otitis media ear infection

Question 9

1. Gram smear is usually sufficient to make diagnosis of H. Inf. What is the most important thing to remember when making a diagnosis ?
2. Which type of test is useful in systemic H. Inf infection ?

Answer 9

1. The dx must be confirmed by isolation of the organism from the site of infection or from the blood
2. Blood cultures

Bacteriologically, small coccobacillary G neg rods that grow on choc-agar but not blood agar STRONGLY suggest Haemaphilus

Question 10

1. what is the X factor in this topic ?
2. what is the V factor
3. What factors are need by H. Influenza

Answer 10

1.Hematin
2. NAD
3. Factor X and Factor V