Streptococcal pneumonia part 2

Question 1

what is the class cause of bacterial pneumonia

Answer 1

streptococcal pneumonia

Question 2

what does the sputum of a person with bacterial pneumonia shows

Answer 2

pus cells and positive gram cocci.

Question 3

what does pneumococcus do?

Answer 3

colonize the upper resp tract. it may be asymptomatic and lead to local surface diseases like pneumonia, otitis media and enter the bloodstream to the brain.

Question 4

what normally protect the mucosal surface by biding to bacteria?

Answer 4

IgA

Question 5

What produces IgA protease that inactivates slgA?

Answer 5

Pneumococcus

Question 6

what does excess inflammation leads to ?

Answer 6

• Excess inflammation leads to accumululation of exudate in alveoli and thus to classical
  lobar consolidation or lobar pneumonia
• Does also secrete toxins, e.g. pneumolysin, that damage host cells

Question 7

what usually phagocytize Bacteria?

Answer 7

Macrophages and neutrophils

Question 8

what causes th bacteria ( pneumonia to be not cleared or easly treated.

Answer 8

• S. pneumoniae capsule is key virulence factor because it prevents opsonisation thereby preventing
  clearance of bacteria in spleen
• ‘Smooth ‘ strains with

Question 9

explain how the pneumococci can escape any bodies defence ?

Answer 9

have ability to take up foreign DNA (called ‘competence’) so they can switch
capsule genes and thereby escape type specific protection

Question 10

what are the Predisposing factors for infection?

Answer 10

Mechanisms:
* Previous viral respiratory infection
* Previous damage to lungs by smoking or pollution
* Decreased antibody production
* Decreased numbers or function of neutrophils
* Decreased clearance by spleen

Some multifactorial
* Aging- decreased immunity
* Young children: immune resp
alcohol
diabetes
hospitalisation or immortality

Question 11

S. pneumoniae can cause infection at many other sites- local spread through respiratory tract?

Answer 11

• Otitis media
  *sinusitis

Question 12

S. pneumonia can distant spread via bloodstream.

Answer 12

arthritis
meningitis
peritonitis

Question 13

what is the fisrt line treatment for pneumococcal infection

Answer 13

Penicillin.

the first line of the beta-lactam group of antibiotics.

Question 14

how antibiotics kill bacteria.

Answer 14

All beta-lactams kill bacteria by inhibiting the enzymes responsible for synthesis of
peptidoglycan in bacterial cell wall.

Question 15

drug used for meningitis ?

Answer 15

ceftriaxone- is a cephalosporin.
also bata lactam

Question 16

2 types of vaccination use to prevent strept. pneumonia.

Answer 16

1.Polysaccharide vaccine (covers 23 serotypes) ‘older
vaccine’ problem is that polysaccharide vaccines don’t provide
long lasting protection, AND don’t work in young children

2. conjugate vaccine – capsule conjuugated or linked to protein
   (covers 13+ serotypes) ‘new vaccine’
   Much more effective, including in infants

Vaccination with pneumococcal conjugate vaccine part of EPI
in children, and recommended for older adults or those with
underlying predisposing condition