Extracellular Bacteria

Question 1

4 main extracellular bacteria

Answer 1

H flu, bordatella pertussis- G-

strep pneumo- G+

mycoplasma

Question 2

types of hosts and transmission of these 4 bacteria

Answer 2

all obligate human pathogens and person to person transmission

H flu, pertussis, strep pneumo, mycoplasma

Question 3

immune/antibiotic response to extracellular pathogens

Answer 3

phagocytes can clear infection, antibodies can block adeherence or neutralize toxins

antibiotics need to reach infection site but not penetrate cells

Question 4

describe H flu bacteria

Answer 4

G- coccobacillus, some strains have polysaccharide capsule

Question 5

H flu epi

Answer 5

only in human respiratory tract, transmitted by droplets

Question 6

H flu diseases

Answer 6

meningitis (most serious), otitis media (most common)

epiglottitis, penumonia, cellulitis

Question 7

3 virulence factors of Hflu

Answer 7

pili, LPS, capsule

Question 8

immune defense against Hflu

Answer 8

mainly T cell independent antibodies

kids dont have this fully developed, more susceptible to invasive infection- need conjugate vaccines

Question 9

describe conjugate vaccines

Answer 9

polysaccharide antigen conjugated to a antigenic protein (toxoid), polysacc binds B cell and the toxoid stimulates T cell involvement and B cell maturation to plasma cell

plasma cell releases antibodies for the polysaccharide capsule

Question 10

describe bordetella pertussis

Answer 10

G- coccobacillus, obligate aerobe

Question 11

disease/ epi of pertussis

Answer 11

causes Pertussis (whooping cough)

only in human respiratory tract, no other reservoir

transmitted via droplets, very communicable

Question 12

describe the components of DTP vs DTaP

Answer 12

DTP- toxoids of diptheria and tetanus, whole cell of pertussis

DTaP- only antigens of pertussis (acellular)

Question 13

clinical features of pertussis- 4 phases

Answer 13

incubation- 7-14 days
catarrhal- 7 days (cold like sx, increasing cough, organisms found in URT)
paroxysmal- 1-4 weeks (severe coughing w/ whoop, hard to find organism)
Convalescent phase- several weeks (less severe)

Question 14

3 attachment virulence factors for pertussis

Answer 14

pertactin- adhesion, immunogenic

fimbriae- secondary adhesin

filamentous hemagglutinin- large adhesin, multiple affinities, immunogenic

Question 15

toxin secretion by pertussis (3 toxins)

Answer 15

tracheal cytotoxin- fragment of cell wall that kills cilia, helps evade mucociliary clearance

pertussis toxin- early prevention of phagocyte influx

adenylate cyclase toxin- inhibtion of phagocytosis and killing

Question 16

both vaccines for pertussis protect against _____ but not ___

Answer 16

protect against leukocytosis, not colonization ( and thus further transmission)

Question 17

describe strep pneumo

Answer 17

G+ diplocci

Question 18

pneumococcus disease

Answer 18

acute, lobar pneumonia

otitis media, bronchitis, pericarditis, meningitis, sepsis

Question 19

most important strep pneumo virulence factor

Answer 19

capsule- lots of different types

Question 20

rx of strep pneumo

Answer 20

broad spectrum cephalosporin, sometimes vanc

Question 21

strep pneumo vaccines

Answer 21

for over 65- unconjugated pneumovax 23

for under 2- prevnar 13, conjugated to diptheria toxoid

Question 22

mycoplasma pneumonia

Answer 22

chronic w/ long incubation, slow progression of sx- walking pneumonia

Question 23

mycoplasma epi

Answer 23

obligate human pathogen, spread via droplets, prolonged outbreaks

Question 24

structure of mycoplasma

Answer 24

no gram stain used- no cell wall

smallest free living organism

Question 25

mycoplasma require ___ to proliferate and survive

Answer 25

close association w/ eurkaryotic host cells

Question 26

mycoplasma pathogenesis

Answer 26

attachment via specific organelles to respiratory epithelium- these organelles subject to antigenic variation

no cytotoxins, but do secrete H2O2