Microbiology of Lower Respiratory Infections

Question 1

Bronchiolitis

Answer 1

RSV - ssRNA neg…paramyxovirus

Outbrekas in winter

Low grade fever with prodrom URI

Wheezes, HYPOxia, hyperinflation…detect serologically

Question 2

Intierstitial vs. typical in appearance

Answer 2

Typical - toxic, productive cough…fever…neutrophils

Atypical - mononuclears…nonproducitve cough…seems pretty well…gradual onset

Question 3

Strep penumo

Answer 3

Lancet shaped diploccoci

Polysach capsule (important virulence factor…antigenic and antiphagocytic

PIli - enable attachment

IgA protease

Penumolysin - binds cholesterol and forms transmembrane pores sleading to cell death…inhibts cells of immune system

Question 4

S. aureus

Answer 4

Coag positive beta hemolytic

Hematogenous spread in IVDU and IE

Acute lobae with abscess

Question 5

Kleb and Hib

Answer 5

Gram neg rods

Think alcoholics or hospitalized (aspiration)

Question 6

Legionella

Answer 6

Diarrhea and abdominal pain

Very high fever

Can lead to resp failure and shock

Fastidious gram neg rosd

Urine antigen

Question 7

Myco pneumo

Answer 7

Earache with gradual headache, feve,r chills, dry cough

P1 protein binds sialic acid receptors…grow closely attached and inhibit ciliary action…desquamate…lack of cilia means decrease mucous clearance

Question 8

Pesudo aeruginosa

Answer 8

LPS, pili, alginate and a flagellum help to attach

Exotoxin A inhibits elongation factor

CF, neutropenia, hospital

Question 9

Coccidio

Answer 9

Enter throgh arthroconidia…germinate into spherules

Question 10

Histo

Answer 10

YEast in macrophages

Question 11

Blasto

Answer 11

Borad based buds…can have purulent sputum,

Question 12

Aspergillus

Answer 12

Gliotoxin inhibits phagocytic killing

Question 13

Pneumocystic jiroveci

Answer 13

HIV patients

CANNOT be cultured

Alveoli filled with desquamated alveolar cells, monocytes, etc, which produce foamy, honecycombed appearance