Gram (-) bacilli (Respiratory) - Sketchy Copy Flashcards
Bordetella pertussis
Diagnosis
Board and Care (for vets!!!)
Obligate Aerobe
Bordet-Gengou plate (10% blood, glycerol, potato)- 3-7 days, moist environment (Fastidious, from Nasal Swab)
Serology- antigen detection by latex agglutination and IF
Bordetella pertussis
VF
Board and Care (for vets!!!)
Respiratory droplets are very infective due to their pilus called filamentous hemagglutin
4 toxins; Pertussis toxin, Adenylate cyclase toxin (most virulent), and Tracheal toxin, Dermonecrotic toxin
Bordetella pertussis
Toxins
Board and Care (for vets!!!)
- Pertussis toxin → Ribosylates Gi (G inhibitor protein), disabling it
- Adenylate cyclase toxin (most virulent) → acts like anthracis toxin edema factor → ⬆ cAMP
- Tracheal toxin → damages ciliated cells in the epithelium
- Dermonecrotic toxin - (AB type)- causing SMC contraction, leading to necrosis
Bordetella pertussis
Three stages
(Excluding Prodromal, 7-10 Incubation)
Board and Care (for vets!!!)
- Catarrhal stage → 1-2 weeks. Nonspecific symptoms of URTI such as low-grade fever, nasal congestion. MOST contagious!!!
- Paroxysmal stage → 2-8 weeks. Paroxysms of coughing followed by Inspiratory whoop.
- Convalescent stage → weeks to months. Subsiding cough (100 day cough). MOST susceptible to secondary infections!!! (e.g. Aureus)
Bordetella pertussis
Treatment
Board and Care (for vets!!!)
Macrolides
Very useful for removing from respiratory tract, but not as useful if circulating
Bordetella pertussis
Vaccines
Board and Care (for vets!!!)
DTaP
Acellular vaccine using purified antigens
Haemophilus influenza
lab tests
Phyllis’s Chocolate Covered Cherries
gram (-) Coccobacillary shape
Encapsulated - Quelling Test
grown in chocolate agar due to need for factor 5 (NAD, nicotinamide) and factor 10 (hemodin) *“hemoTEN”
Satelite Phenomena - Blood Agar only with S.Aureus
Haemophilus influenza
VF
Phyllis’s Chocolate Covered Cherries
Polysaccharide Capsule - Type B Strongest
IgA- Protease (“S.Hi.N”)
Haemophilus influenza
signs and symptoms
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
Haemophilus influenza
Vaccines
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 2 Months to 18 Months
Haemophilus influenza
Treatment
Phyllis’s Chocolate Covered Cherries
Ceftriaxone
tx for close contacts is rifampin
Legionella
lab tests
The SS cysteine joins the legion
gram (-) bacilli visualized under silver stain
oxidase (+)
Buffered Charcoal yeast extract agar with cysteine** and **iron added.
Rapid urine antigen test + IF / ELISA
Legionella
signs and symptoms
The SS cysteine joins the legion
- Pontiac Fever: Fever and malaise, usually self limiting.
- Legionnaries Disease: common in smokers and elderly men:
- 1)Atypical pneumonia w/ patchy unilobed infiltrate.
- _2) Hypo_natremia (excess HNO3 ammonia Na. wasteing salt)
- 3) Neurologic symptoms: headache w/ confusion
- 4) Diarrhea
- 5) High fever over 104F
* (high yield: pneumonia w/ diarrhea & hypnonatremia)
Legionella
VF
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
Legionella
Treatment
The SS cysteine joins the legion
macrolides and fluoroquinolones
