Micro Haemophilus, Bordetella, And Legionella

Front 1

What three bacteria are acquired through the respiratory tract?

Back 1

Haemophilus influenzae, Bordetella pertussis, and Legionella pneumophila.

Front 2

What is necessary for Haemophilus influenzae cytochrome? And what else is needed?

Back 2

Hemin (factor X) and NAD (factor V) on chocolate agar. There will be also a + Quellung test on diagnosis.

Note: species designated as "para-" (H. parahaemolyticus), require factor V but not factor X for growth.

Front 3

There are six capsules associated with H. influenzae, which one is associated with invasive H. influenzae?

Back 3

Type B

Encapsulated are subdivided into: A, B, C, D, E, and F.

Note: Capsulated are group 1 while unencapsulated strains are group 2.

Front 4

Nonencapsulated strains, AKA nontypeable, are associated with? What do they frequenlty cause?

Back 4

Only local infection since they are non-invasive. Otitis media in children, sinusitis, and COPD exacerbation and pneumonia.

Front 5

PTs with COPD, frequently become infected with?

Haemophilus influenzae type B mainly affects?

Back 5

Nontypeable H. influenzae, S. pneumonia, and Moraxella catarrhalis.

Major cause of lower respiratory tract and CNS infections in infants and children in developing countries where the conjugate vaccine is not used widely.

Front 6

With epiglottis, what should you not do!

Back 6

Do not examine! Laryngeal spasm may result from manipulation, closing the airway. The child will be drooling, and stridor will be present. The child will not be able to swallow.

Front 7

What are the systemic infections caused by H. influenzae type B?

Back 7

Meningitis, septic arthritis, and cellularitis.

Front 8

H. influenzae type B, is the most common cause of what in infants?

Back 8

Septic arthritis.

Front 9

How do you treat H. influenzae type B?

Back 9

3rd generation cephalosporin (cefrtiaxone or cefotaxime).

Macrolides (clarithromycin and azithromycin) can also be used.

Front 10

Bordetella pertussis is AKA?

Back 10

Whooping cough

Front 11

How does Bordetella pertussis attack and what are the four virulence factors?

Back 11

Adheres to cilil in respiratory epithelium via filamentous hemagglutinin and releases: pertussis toxin (decreases phagocytosis); secreted adenylate cyclase (inhibits bactericidal activity); tracheal cytotoxin (kills ciliated epithelial, impairing mucous clearance).

Nath also has: hemolysin, which kills mucosal epithelial cells.

Front 12

What are the three stages of Whooping cough?

Back 12

Catarrhal stage, paroxysmal stage, and recovery stage.

Front 13

Describe the catarrhal stage of whooping cough.

Back 13

Flu-like symptoms, highly contagious.

Front 14

Describe the paroxysmal stage of whooping cough.

Back 14

Fever subsides, and there are intermittent bouts of characteristic burst of non-productive cough of many coughs on a single expiration, followed by a whooping inspiration (due to narrowed glottis). During this stage, PT may be hypoexmic, cyanotic, tongue protrusion, eyes bulging, neck veins engorged, with vomiting often occurring after an attack.

Note: There may be 15 - 25 attacks per day with each attack consisting of 5 - 20 forceful coughs followed by inspiratory gasp through the narrowed glottis.

Front 15

How do you diagnose B. pertussis?

Back 15

They are nutritionally fastidious bacteria, requiring a special growth medium.

Bordet-Gengou medium: swab of calcium alginate (cannot grow on cotton swabs), and wiped on a culture medium with potato, blood, and glycerol agar.

Also with DFA and PCR.

Front 16

How do you treat B. pertussis?

Back 16

Erythromycin before the paroxysmal phase, and supportive care (suctioning to remove the mucus and pressurized oxygen).

Note: erythromycin given later may not alter the course of the illness but may decrease bacterial shedding.

Front 17

How is Legionella pneumophila transmitted?

Back 17

Via aerosols. The bacteria naturally inhabits water reservoirs: AC system, cooling towers, whirlpools, spas, mist machines. They are aerosolized while living in water. Not transmitted P2P.

Note: Legionella can survive in biofilm. It is associated with ameba and other protozoa.

Front 18

Like Mycobacterium tuberculosis, how is Legionella pneumophila related?

What does Legionella pneumophila release?

Back 18

They are both facultative intracellular parasites that settle in the lower respiratory tract and gobbled up by macrophages.

Toxins: phospholipases and metalloproteases that damage host cell. HOWEVER, it is cytokines, PMNs and T cells that inflict damage to the lung tissue, resulting in patchy diffuse infiltrates on chest x-ray.

Front 19

Legionella pneumophilia can cause?

Back 19

Pontiac fever (acute flue like illness with no pneumonic infiltrates) and Legionnaires disease (very high fevers and severe atypical pneumonia).

Front 20

What does Legionnaire's disease cause?

Back 20

Lobar consolidative, fibrinopurulent pneumonia wtih alveolitis and bronchiolitis. Also, fever with pulse-temperature (high fever, low heart rate), non-productive cough, severe headache, confusion, diarrhea, and muscle aches.

Can also infect: lymph nodes, brian, kdiney, liver, spleen, bone marrow, and myocardium.

Hyponatremia and hypophosphatemia are commonly seen.

Front 21

How do you treat L.pneumophila?

How is at risk for catching this microbe?

Back 21

Since this bacteria hides out in macrophages, administer erythromycin, a macrolide. Quinolones or doxycycline can be used as well.

Note: beta-lactams cannot work on intracellular bacteria.

Any process that compromises mucociliary clearance: PTs older than 50, smokers, alcoholics, COPD, immunocompromised PTs.

Front 22

Group 1 Haemophilus influenzae infects?

Group 2 Haemophilus influenzae infects?

Back 22

Group 1 strains cause most disease in children.

Group 2 strains cause most of the disease in adults.

Front 23

How do H. influenzae (nontypable), S. pneumonia, and Moraxella catarrhalis colonize the respiratory mucosa?

How do they cause acute exacerbation of COPD, particularly chronic bronchitis?

Back 23

Via IgA protease.

Excessive tracheobronchial mucus production.

Front 24

How do you prevent H. influenzae?

Back 24

No vaccine against nontypable.

Conjugate HiB vaccine for type B.

Front 25

Other than a polysaccharide capsule, what is the difference between typable and nontypable h. influenzae?

Back 25

Nontypable are not invasive (otitis media, sinusitis, COPD excerbation and pneumonia).

Typable are invasive (meningitis [primary cause of meningitis in infants), acute epiglottis, septic arthritis [in infants], sepsis pneumonia). Typable is group 1, which occurs in infants and children.

Front 26

What is the morphology of Haemophilos, Legionella, and Bordetella?

Back 26

Gram negative, coccobacilli, pleomorphic.

Front 27

What does the virulence factors of Bordetella pertussis allow?

Back 27

Allows the microbe to attach to ciliated epithelial cells of the trachea and bronchi. B. pertussis evades the host's defenses and destroys the ciliated cells, causing whooping cough.

Front 28

What is the MOA of pertussis toxin and what are the observed effects?

Back 28

Exotoxin with AB parts (B for binding; A for action).

ADP-ribosylates inactivates Gi protein complex, resulting in stimulation of adenylate cyclase and rise in cAMP; this results in leukocytosis but impaired phagocytosis.

Observed effects: histamine sensitization; increase in insulin synthesis; promotion of lymphocyte production and inhibition of phagocytosis.

Front 29

What is the MOA of extra cytoplasmic adenylate cyclase from Bordetella pertussis?

Back 29

It is swallowed by host neutrophils, lymphocytes, and monocytes. Once internalized, synthesis of cAMP is increase, resulting of impaired chemotaxis and generation of H2O2 and superoxide.

Front 30

What is the MOA of filamentous hemagglutinin (FHA) from Bordetella pertussis?

ABs directed against B. pertussis does?

Back 30

It attaches to ciliated epithelial cells of the bronchi and releases damaging exotoxins.

ABs directed against FHA prevent binding; therefore, prevents the disease.

Front 31

What is the MOA of tracheal cytotoxin from B. pertussis?

What is the defining characteristic of B. pertussis does this toxin cause?

Back 31

Toxin destroys ciliated epithelial cells, resulting in impaired clearance of the bacteria, mucus, and inflammatory exudate.

Probably responsible for the violent cough (Nath has the mucopurulosanguineous exudate formed in the respiratory tract predisposing to the paroxysmal cough).

Front 32

What is the vaccine for Pertussis?

Back 32

DPT: Diphtheria, Pertrussis, Tetanus.

Front 33

How is Bordetella pertussis spread?

Back 33

Respiratory droplets.

Front 34

Who are at risk from complications from pertussis?

Back 34

Infants born prematurely and PTs with underlying caridac, pulmonary, neuromuscular, or neurologic disease (e.g., pneumonia, seizures, encephalopathy, or death).

Front 35

What is the morphology of Legionellae?

Back 35

Motile, flagellated, pleomorphic rods, with stain faintly with Gram stain--best with silver.

Front 36

How do you culture Legionella pneumophila?

Back 36

On selective buffered charcoal yeast extract, agar medium supplemented with cysteine and iron.

Note: They are nutritionally fastidious, aerobic pathogens that grow slowly. Laboratory must be alerted that Legionella is a diagnostic consideration.

Front 37

Haemophilus influenzae cause?

Back 37

haEMOPhilus causes:

Epiglottits (cherry red in children), Meningitis, Otitis media, and Pneumonia