microbiology

Question 1

Diseases caused by Group A streptococcus (GAS) - particularly Strep Pyogenes

Answer 1

1. Scarlet fever
2. Tonsillitis
3. Erisypelas
4. Cellulitis (image)

Question 2

Gram -ve

Answer 2

1. Neseirra
2. Haemophilis SP (RTI)
3. Spirochaetes (spiral-shaped bacteria)

e.g. Barrelia - too thin to see with gram stain

1. E.coli

Question 3

Cause of lime disease

Answer 3

Barrelia burgdoferi but spread by ticks

Question 4

Staphylococci causing diseases - mainly staph aureus

Answer 4

1. Carbuncle
2. Impetigo (also by strep)

Question 5

Answer 5

Carbuncle

Question 6

Answer 6

Impetigo - caused by strep or staph

Question 7

Target site of penicillins

Answer 7

Cell wall synthesis

Question 8

Erythromycin MOA

Answer 8

protein sythesis - 50S inhibitor

Question 9

Tetracyclin/Streptomycin and gentamycin MOA

Answer 9

Protein synthesis -30 inhibitor

Question 10

Answer 10

Lyme disease

Question 11

Answer 11

Chancre caused by Trepnema Pallidum (spirochaete)

Question 12

Cause of TB

& what staining to use

Answer 12

• Mycobacteria Spp
• Ziehl Neelse stain - Bright red colour
• Unable to take up gram stain (acid fast) due to thick wax-like cell wall -

Question 13

Identification and detection of virus

Answer 13

• Cannot be grown (unlike most pathogenic bacteria) •
• Detected using PCR - polymerase chain reaction: Need a probe for the sequence of interest, if detected can then be amplified and detected.
• Serological testing (early- IgM / late- igG)
• ELISA

Question 14

Definition of parasite

Answer 14

• any living form which is – dependent on other living forms for survival, – causing some damage to the host
• Often used to describe Protozoa and Helminths only

Question 15

How does one get helminths infection?

Answer 15

Contamination of water with human faeces

• has a negative impact on growth and development

Question 16

Protozoa classification is based on their locomotion

Answer 16

Question 17

Plasmodium is a pathogen that causes

Answer 17

Malaria

• it has gliding motility and is a protozoa

Question 18

Diagnosing malaria

Answer 18

Blood film showing RBC infected by malaria parasites

Question 19

country of most global malaria burden

Answer 19

Sub-saharan Africa

• Increased prevention and control measures have led to a 29% reduction in malaria mortality rates globally since 2010.

Question 20

Aspergillosis is caused by a

Answer 20

Fungi

• Resp infection infecting immunocompromised people
• Hyphae may impede lung function and growth into tissues can cause damage and severe pneumonia.
• Reproduce by forming spores which can cause infections and grows as filaments of hyphae

Question 21

Common fungal infections

Answer 21