Gram (-) bacilli (Respiratory)

Question 1

Bordetella pertussis

lab tests

Answer 1

Board and Care (for vets!!!)

gram (-) bacilli

Aerobic

Lymphocytosis: (ADP disables chemokine receptors for lymphocytes → lymphocytes unable to enter lymphoid tissue → ⬆ WBC in bloodstream )

Question 2

Bordetella pertussis

VF

Answer 2

Board and Care (for vets!!!)

Respiratory droplets are very infective due to their pilus (called filamentous hemagglutin)

3 toxins; Pertussis toxin, Adenylate cyclase toxin (most virulent), and Tracheal toxin

Question 3

Bordetella pertussis

Toxins

Answer 3

Board and Care (for vets!!!)

3 toxins:

1. Pertussis toxin → Ribosylates G_i (G inhibitor protein), disabling it
2. Adenylate cyclase toxin (most virulent) → acts like anthracis toxin edema factor → ⬆ cAMP
3. Tracheal toxin → damages ciliated cells in the epithelium

Question 4

Bordetella pertussis

Three stages

Answer 4

Board and Care (for vets!!!)

1. Catarrhal stage → Last 1-2 weeks. Nonspecific symptoms of URI such as low-grade fever, nasal congestion. MOST contagious!!!
2. Paroxysmal stage → Last 2-8 weeks. Paroxysms of coughing followed by inspiratory whoop.
3. Convalescent stage → Last weeks to months. Subsiding cough (100 day cough). MOST susceptible to secondary infections!!!

Question 5

Bordetella pertussis

Treatment

Answer 5

Board and Care (for vets!!!)

Macrolides

Very useful for removing from respiratory tract, but not as useful if circulating

Question 6

Bordetella pertussis

Vaccines

Answer 6

Board and Care (for vets!!!)

DTaP

Acellular vaccine using purified antigens

Question 7

Haemophilus influenza

lab tests

Answer 7

Phyllis’s Chocolate Covered Cherries

gram (-) Coccobacillary shape

grown in chocolate agar due to need for factor 5 (NAD, nicotinamide) and factor 10 (hemodin) *“hemoTEN”

Question 8

Haemophilus influenza

signs and symptoms

Answer 8

Phyllis’s Chocolate Covered Cherries

epiglottitis: symptoms drooling, inflamed epiglottis, strider (inspiratory strider, high pitched wheezing)

*“Cherry red epiglottis”

Otitis Media

Meningitides (Only caused by type B capsular form!)

Sepsis and Septic arthritis in pt without spleen, hemophilic infections, especially sickle cell disease

Question 9

Haemophilus influenza

Vaccines

Answer 9

Phyllis’s Chocolate Covered Cherries

Conjugated with diphtheria toxoid and haemophilus type B capsule.

(Vaccine for only the B type capsule of H. influenza, vs neisseria vaccine for all but B type!!!)

Vaccinate between 6 weeks to 18 months

Question 10

Haemophilus influenza

Treatment

Answer 10

Phyllis’s Chocolate Covered Cherries

Ceftriaxone

tx for close contacts is rifampin

Question 11

Legionella

lab tests

Answer 11

The SS cysteine joins the legion

gram (-) bacilli visualized under silver stain

oxidase (+)

Charcoal yeast extract agar with cysteine** and **iron added.

Rapid urine antigen test to confirm

Question 12

Legionella

signs and symptoms

Answer 12

The SS cysteine joins the legion

• Pontiac Fever: Fever and malaise, usually self limiting.
• Legionnaries Disease: common in smokers and elderly men.
• Atypical pneumonia w/ patchy unilobed infiltrate.
• Hyponatremia (excess HNO₃ ammonia Na. wasteing salt)
• Neurologic symptoms: headache w/ confusion
• Diarrhea
• High fever over 104F!

* (high yield: pneumonia w/ diarrhea & hypnonatremia)

Question 13

Legionella

VF

Answer 13

The SS cysteine joins the legion

Zinc Melloprotease is the main VF

It’s cytotoxic and inhibits PMN production, inhibits superoxide reduction, deactivates il-1 and CD4 and TNF

Question 14

Legionella

Treatment

Answer 14

The SS cysteine joins the legion

macrolides and fluoroquinolones