Haemophilus Exam 2

Question 1

What organism is small, non-motile, pleomorphic gnb, capnophilic, and mousy odor.

Answer 1

Haemophilus spp.

Question 2

What factors does Haemophilus spp. require?

Answer 2

X factor (protoporphyrin IX) and V factor (nicotinamide adenine dinucleotide-NAD)

Question 3

True/false? Haemophilus spp. are prone to drying and sensitive to temperature, thus need to be inoculated to chocolate immediately or use T-1 medium (which supports N. meningitidis, H. influenzae, and S. pneumoniae.

Answer 3

True.

Question 4

How does H. ducreyi (STI) need to be handled?

Answer 4

Ulcer needs to be cleaned. Cotton swab with saline is used to collect bacteria from ulcer.

Question 5

Why does Haemophilus spp. not grow well on SBAP?

Answer 5

SBAP only contains X factor

Question 6

What agar should be used for children with CF?

Answer 6

Chocolate agar with bacitracin. It isolates H. influenzae and prevents overgrowth of many G+ and G- cocci.

Question 7

What organism can Haemophilus spp. can grow near on SBAP? What is this phenomenon called?

Answer 7

Staph aureus; releases X factor and produces V factor.

Satellite phenomenon

Question 8

Which Haemophilus specie is not normal flora?

Answer 8

H. ducreyi

Question 9

What is the most common type infection?

Answer 9

Type B; can cause meningitis, bacteremia, epiglottis

Question 10

Why are most infections of H. influenzae caused by non-typeable strains?

Answer 10

Because of vaccines

Question 11

ID for Haemophilus spp?

Answer 11

Large, round, colorless to gray colonies on chocolate. 
Oxidase positive (purple)

Question 12

When are the 4 does for H. influenzae vaccine given?

Answer 12

1st dose-2 months of age
2nd dose-4 months of age
3rd dose- 6 months
4th dose- 12-15 months of age

Question 13

What does H. ducreyi look like what on gram stain?

Answer 13

A school of fish (arrows)

Question 14

What is H. ducreyi usually confused with?

Answer 14

Syphilis

Question 15

Why is it important to differentiate H. ducreyi from syphilis?

Answer 15

They have different treatments. Syphilis is treated with penicillin and H. ducreyi is treated with macrolides.

Question 16

Describe Legionella pneumophila

Answer 16

Obligate aerobe
Gram neg bacilli
Motile

Question 17

What does Legionella pneumophila utilize?

Answer 17

Utilizes protein not carbs for growth

Question 18

True/false? Legionella pneumophila is transmitted from person to person.

Answer 18

False. Is not

Question 19

How is Legionella pneumophila transmitted?

Answer 19

Inhalation of mist containing microbes.

Question 20

What can Legionellosis cause?

Answer 20

Legionnaires disease- causes pneumonia.

Pontiac fever-flu-like symptoms; less severe and doesn’t present with respiratory involvement.

Question 21

How does Legionella pneumophila evade host defenses?

Answer 21

Is taken up by macrophages but NOT killed. Microbe replicates and kills macrophage and infects new cells. They evade destruction by studded with host factors. They also release chemicals that degrade host lipases and proteinases.

Question 22

What is Legionella pneumophila treated with?

Answer 22

Fluoroquinolones and macrolides

Penicillin, cephalosporins, and aminoglycosides are ineffective.

Question 23

What is the media of choice for Legionella pneumophila?

Answer 23

Buffered Charcoal Yeast Extract; one with cysteine and one without. Sent to reference labs.

Question 24

What is the presumptive ID for Legionella pneumophila? Definitive ID?

Answer 24

Fluoresce a yellow-green on BCYE under UV light source. Definitive ID comes via serotyping.

Question 25

What is the Bordetella spp. vaccine called? What is the booster called?

Answer 25

DTaP-infants and toddlers (5 doses)

Tdap- preteens and teens

Question 26

What Bordetella species is also known as whooping cough?

Answer 26

Bordetella pertussis

Question 27

Bordetella pertussis/parapertussis ID?

Answer 27

Both motile, gram - coccobacilli to short rods.
Infect only humans, pathogens.
Cause upper respiratory tract infections.
Spread from person to person via respiratory droplet.

Question 28

Cause of kennel cough in dogs

Answer 28

Bordetella bronchiseptica

Question 29

What are the virulence factors of Bordetella pertussis?

Answer 29

Fimbriae-connect to the epithelium URT
Toxins- pertussis toxin that impairs function of macrophages and neutrophils.
Outer bacterial membrane- help protect against lysoenzymes.

Question 30

True/false? If antibiotics are given late (paroxysms have started) they are unlikely to alter the disease progression.

Answer 30

True.

Question 31

List and describe the stages of Whooping Cough.

Answer 31

Catarrhal- mild cough and cold; usually lasts 7-10 days, up to 21 days.
Paroxysmal- Increase in severe coughing up to 25x/day. May last 1-6 weeks; up to 10 weeks.
Convalescent- usually 7-10 days, recovery, less persistent cough which disappears in 2-3 weeks.

Question 32

When are people infectious with Whooping Cough?

Answer 32

Catarrhal stage through the 3rd week of Paroxysms.

Question 33

What are acceptable specimens for Bordetella spp? Unacceptable?

Answer 33

Acceptable: Nasopharyngeal aspirate, Nasopharyngeal swab (Dacron or calcium alginate swabs preferred).
Unacceptable: Sputum, throat, or nares swab (These areas lack ciliated epithelium which is where the bacteria bind to via fimbriae.

Question 34

What is the selective media for Bordetella spp?

Answer 34

Bordet-Gengou, Modified Jones-Kendrick charcoal agar, Regan-Lowe (gold standard-ID)- Confirm with PCR and serology

Question 35

What do the colonies of Bordetella pertussis and parapertussis?

Answer 35

Small, shiny colonies resemble MERCURY DROPLETS

Question 36

What is the treatment for B. pertussis?

Answer 36

Susceptible to macrolides: erythromycin, azithromycin, and clarithromycin. **In infants less than a month old azithromycin is preferred as erythromycin as been linked to infantile hypertrophic pyloric stenosis.