respiratory tract infections

Question 1

Nonmotile, nonsporeforming, catalase-negative cocci that occur in pair or chain.

They are widely distributed in nature.

Answer 1

streptococci

Question 2

…… elaborate a variety of extracellular substances and enzymes.

Answer 2

Streptococci

Question 3

The most common infection caused by ……… is streptococcal sore throat or pharyngitis.

Answer 3

β-hemolytic S. pyogenes

Question 4

S. pyogenes adheres to the pharyngeal epithelium by means of ………. surface pili and by means of…….. in encapsulated strains.

Answer 4

lipoteichoic acid-covered

hyaluronic acid

Question 5

Local infection of the superficial layers of skin, especially in children.

Answer 5

Streptococcal pyoderma

Question 6

viruses, mycoplasma, rickettsiae and fungi can all cause ….

Answer 6

lower respiratory
tract infections

Question 7

How microbes gain access to the lower respiratory tract?

Answer 7

• Inhalation
• Aspiration of the normal flora of the upper respiratory tract
• Extension of upper respiratory tract infections
• Blood spread from other infected areas (less common)

Question 8

Involvement of one lobe. The formed exudate clots in the alveoli rendering them solid (consolidation). Infection may spread to adjacent alveoli but limited by anatomic barriers of lung segments/ lobes

Answer 8

Lobar pneumonia:

Question 9

Involve the small airways→ spread throughout the lung → patchy consolidation

Answer 9

Bronchopneumonia

Question 10

Invasion of lung interstitium . Characteristic of viral pneumonia

Answer 10

Interstitial pneumonia

Question 11

necrotizing pneumonia) Cavitation & destruction of lung parenchyma

Answer 11

D. Lung abscess

Question 12

ØStaphylococcus aureus
Ø Pseudomonas aeruginosa
ØKlebsiella pneumoniae
Ø Acinetobacter baumanii

Answer 12

Hospital Acquired Pneumonia
Most common pathogens:

Question 13

Morphology :Gram positive cocci in pairs, capsulated

Culture characteristics:
Alpha hemolysis on blood agar, Optochin sensitive

Answer 13

Streptococcus pneumoniae

Question 14

Morphology:
Gram negative pleomorphic coccbacilli may be capsulated

Culture characteristics:
Grow on chocolate agar
Confirmation by factors X V requirement

Answer 14

Haemophilus influenzae

Question 15

Morphology:
Gram negative bacilli Capsulated

Culture characteristics:
Lactose fermenting pink colonies on MacConkey’s agar

Biochemical reactions
Oxidase negative

Answer 15

Klebsiella pneumoniae

Question 16

caused by Mycobacterium

Answer 16

Tuberculosis

Question 17

Legionella is a genus of pathogenic Gram-negative bacteria that includes the species …..
causing legionellosis

Answer 17

L. pneumophila

Question 18

….. live in water (primarily) and soil, can live inside protozoa

Answer 18

Legionella bacteria

Question 19

• Stagnant water (dead legs in plumbing)
Warmer water (prefers: 77°F-108°F)
• Presence of organic matter
• Absence of residual disinfectant

Answer 19

Legionella Favorable conditions:

Question 20

• A sever atypical pneumonia like infection
• Infection

Answer 20

Legionnaires disease

Question 21

• A mild flu like illness
• Allergic reaction to live/dead Legionella + endotoxins from
non Legionella bacteria

Answer 21

Pontiac Fever

Question 22

Increased Legionella antibodies with no symptoms

Answer 22

Asymptomatic Legionella

Question 23

growth on hot water pipe growth on plastic tubing growth on cooling tower
pipe

Answer 23

Biofilm

Question 24

Legionella detection methods

Answer 24

PCR/qPCR
Fluorescent in situ hybridization (FISH)
Enzyme-Amplified Electrochemical Detection with DNA probe

Question 25

…on BYCE GVPC agar

Answer 25

L. pneumophila