Microbiology-Cases:9, 22, 23

Front 1

67 year old presents iwth ABRUPT onset of shaking, chills, high fever, and right sided chest pain. his cough produces rust colored sputum. and he is a diabetic who smoked 2 packs of cigs a day and has not received any vaccinations. what is causing his lung infection?

Back 1

strep pneumoniae

Front 2

which two organisms are commonly seen in pneumonia infections in people with COPD?

Back 2

H influenzae and M catarrhalis

Front 3

K pneumoniae infections are seen in this group of people?

Back 3

alcoholics

Front 4

describe S. pneumo?

Back 4

gram positive lancet shaped diplococci, alpha hemolytic, catalase negative, optochin sensitive, thick capsular polysaccharide outer layer.

Front 5

S pneumoniae is the most common cause of this?

Back 5

community acquired pneumonia (CAP) afflicting all ages

Front 6

what are some conditions that predispose a person to pneumococcal (strep pneumo) pneumonia and poor prognosis?

Back 6

AIDS, asplenia, influenza, sickle cell, multiple myeloma, alcoholism, smoking, diabetes, hypogammaglobulinemia, and nephrotic syndrome

Front 7

what does strep pneumo use to evade IgA?

Back 7

IgA protease

Front 8

what are the 4 stages of lobar pneumonia as caused by S pneumo?

Back 8

congestions, red hepatization, gray hepatization and reoslution

Front 9

what is the red hepatizaiton phase?

Back 9

reflects teh liver like appearance of the consolidated lung, airspaces are filled with PMNs vascualr congestions occurs and extravasation of RBCs causes a reddish discoloration on gross examination.

Front 10

what is grey hepatization?

Back 10

results form an accumulation of fibrin associated with inflammatory WBCs and RBCs in various stages of disintegration; alveolar spaces are packed with inflammatory exudates

Front 11

step pneumonia is a classic airspace infection with intra-alveolar exudates spreading rapidly within a lobe through these things?

Back 11

pores of khon- until entire lobe is consolidated

Front 12

treatmetn of choice for strep pneumo?

Back 12

remains penicillins

Front 13

what is teh empirical therapy of community acquired pneumonia before the culture results are known?

Back 13

3rd generation cephalosporin (cefotaxime or ceftraxone) plus a macrolide or newe quinolone (levofloxacin or gatifloxacin)- these regimens reasonably cover both resistant pneumococci and atypical organisms

Front 14

for highly resistant strains of pneumococci what would you use?

Back 14

vancomycin

Front 15

a 23 yo man admitted for fever, nonproductive cough, progressive shortness of breath for 2 weeks, he is HIV positive and he has stopped taking all his meds and now he has progressed to AIDS. what is causing his infection?

Back 15

pneumocystis jiroveci (pneumocystic pneumonia)- most common pneumonia in AIDS patients??

Front 16

what is Pneumocystis jiroveci classified as?

Back 16

fungi

Front 17

what are the life stages of P. jiroveci?

Back 17

cyst which has athick cell wall and contains up to eight intracystic sporozoites (used to be classified as protozoa until nucleic acid testing)

Front 18

P jiroveci adheres via ___ and glycoproteins to type I pneumocytes?

Back 18

fibronectin

Front 19

does P jirovecci invade the lung tissue?

Back 19

no remians extracellular

Front 20

a series of complex events int eh lungs lead to these things following a P jirovecci infection?

Back 20

increased phospholipase activity and a deficiency of surfactant secretion by type II cells (as seen in ARDS), explaining the pneumocystis pneumonia. a foamy exudate develops int eh alveoli and iintersitial pathology occurs (radiology reveals a bilatera GROUND GLASS APPEARANCE)

Front 21

what is the treatment for P jirovecci?

Back 21

TMP-SMX for 21 days

Front 22

an 18 yo presents with worsening of her chronic cough for the past week. she has productive cough with greenish sputum that was thick and tenacious. she was diagnosed with CF at age 4 and has had multiple hospitalizations for resp infections. what is causing this woman's symptoms?

Back 22

pseudomonas aeruginosa

Front 23

describe pseudomonas aeruginosa?

Back 23

gram neg rod, motile, stric AEROBIC, nonfermentative and oxidase positive. water soluble pigment pyocyanin (blue pus), charteristic fruity odor, mucoid appearance in CF pt isolates attibutable to its produciton of alignate capsule

Front 24

what is the characteristic fruity odor of Pseudomonas aeruginosa?

Back 24

grape like (tie in to CE !!)

Front 25

pseudomonas is a common inhabitant of ___

Back 25

soil and water and is ubiquitous in nature

Front 26

early in the life of a CF patient P. aeruginosa colonize the trachea via these things/

Back 26

flagella dn pili aas well as surface bound exoenzyme S

Front 27

sometime after colonization Pseudomonas moves down to teh bronchi and undergo a phenotypic shift, becoming ____

Back 27

mucoid- owing to de novo alginate capsule

Front 28

when low int he bronchi pseudomonas loses its ability to ____

Back 28

move- by shutting down the producitonfo polar flagellum, establishing a permanent and localized chronic infection

Front 29

what products secreted by pseudomonas contribute to lung tissue damage?

Back 29

elastase, exotoxin A and phospholipases

Front 30

what does the exotoxin A of pseudomonas do?

Back 30

causes ADP ribosylation of EF-2, resulitng in inhibition of protein synthesis and ultimate cell death

Front 31

what is teh treatment for pseudomonas infection?

Back 31

extended spectrum penicillins such as piperacillin, cephalosporin (ceftazidime), or carbapenem (imipenem) AND an antipseudomonal aminoglycoside (eg tobramycin)