Introduction to Medical Microbiology

Question 1

Name the categories of micro-organisms that can cause infection

Answer 1

Bacteria
Fungi
Parasites
Prions
Viruses

Question 2

What are the types of specimen samples collected for culture?

Answer 2

Blood culture
Cerebrospinal fluid
Faeces
Midstream urine
Throat swap
Pus

Question 3

What is the specimen collection for a urinary tract infection?

Answer 3

Midstream urine

Question 4

What is the specimen collection for a chest infection?

Answer 4

Sputum

Question 5

What is the specimen collection for tonsillitis/pharyngitis

Answer 5

Throat swab

Question 6

What is the specimen collection for the site of infection or a wound?

Answer 6

Swab or pus

Question 7

What is the specimen collection for diarrhoea?

Answer 7

Faeces

Question 8

What is the specimen collection for bacteraemia?

Answer 8

Blood culture

Question 9

What is the specimen collection for bacteraemia?

Answer 9

Blood culture

Question 10

What is the specimen collection for meningitis?

Answer 10

CBS

Question 11

How is microscopy used in medical microbiology?

Answer 11

Microscopy is the most common method used both for the detection of microorganisms directly in clinical specimens and for the characterization of organisms grown in culture

Question 12

What does unstained microscopy allow you to see?

Answer 12

Pus cells (urine, CSF)
Parasites (faeces)

Question 13

What does a gram stain allow you to see in microscopy?

Answer 13

Bacteria
Fungi
Yeast

Question 14

What does a ZN stain or an auramine stain allow you to see?

Answer 14

Mycobacteria

Question 15

What is mycobacteria?

Answer 15

A bacterium of a group which includes the causative agents of leprosy and tuberculosis

Question 16

What infecting agent is not visible in light microscope?

Answer 16

Virus

Question 17

What is the difference in the function between gram stain microscopy and culture?

Answer 17

Microscopy is rapid, insensitive, can’t identify a particular species

Culture is slower, more sensitive and the conditions are suitable for the expected species

Question 18

How can a species identified?

Answer 18

Observable characters - Morphological, physiological, biochemical

DNA tests

Typing - determines the strain within the species

Question 19

What are sterile sites of the body?

Answer 19

Areas typically where microorganisms are not found and are often places deeper in the body and more protected from outside infection.

Question 20

What are examples of sterile sites in the body?

Answer 20

Blood
CSF
Pleural fluid
Pericardial fluid
Bone and bone marrow
Joint fluid
Bladder

Question 21

What are non-sterile sites in the body?

Answer 21

Non-sterile sites are areas where microbes are often found and are usually more accessible from the environment.

Question 22

What are examples of non-sterile sites of the body?

Answer 22

Skin
Nose and airways
Stomach and intestines
Mouth and teeth
Genitals

Question 23

Name methods of detecting viruses

Answer 23

Electron microscopy
Cell or tissue culture
Antigen detection
Detection of cytopathic effect
Molecular methods including real time PCR
Serology to determine immunity

Question 24

What is serology?

Answer 24

The investigation of blood serum with regard to the response to an introduced pathogen or introduced substance.

Question 25

What are cytopathic effects?

Answer 25

Structural changes in host cells that are caused by viral invasion

Question 26

What is a parasite?

Answer 26

A parasite is an organism that lives on or in a host and gets its food from or at the expense of its host. Parasites can cause disease in humans.

Question 27

What are the three different types of parasites and give an example of each?

Answer 27

Arthropods - Lice Helminths - Worms Protozoa - Malaria

Question 28

How can parasites be diagnosed?

Answer 28

Microscopy of different stages - parasites, cysts and ova Blood films for malaria Culture rarely possible Sometimes serology is useful

Question 29

What are examples of healthcare acquired infection?

Answer 29

MRSA Clostridium difficile Noroviruses ESBL's - Organisms with extended spectrum beta lactamases

Question 30

What are basic infection control measures?

Answer 30

Hand hygiene. Use of personal protective equipment (e.g., gloves, masks, eyewear). Respiratory hygiene / cough etiquette. Sharps safety (engineering and work practice controls). Safe injection practices (i.e., aseptic technique for parenteral medications). Sterile instruments and devices.

Question 31

What is a microbe?

Answer 31

A living thing that is too small to be seen with the naked eye. Must use a microscope to see it.

Question 32

What are the different microbes?

Answer 32

Viruses - smallest Bacteria Fungi - largest

Question 33

Are all microbes bad?

Answer 33

No - gut bacteria include good microbes, aid in digestion and help us absord all nutirents from our food

Question 34

What is an infection?

Answer 34

When microbes grow in the wrong place

Question 35

What is a pathogen?

Answer 35

A microbe that causes an infection

Question 36

What is an example of a prokaryote organism?

Answer 36

Bacteria

Question 37

What is an example of eukaryote organism?

Answer 37

Fungi

Question 38

What is one big difference between prokaryote and eukaryote cells?

Answer 38

Eukaryotic cells are much bigger

Question 39

Are prokaryotic and eukaryotic cells unicellular or multicellular?

Answer 39

Prokaryotic - unicellular Eukaryotic - uni or multicellular

Question 40

Where can viruses replicate?

Answer 40

Only in the living cell of an organism

Question 41

What can be found in the centre of a virus?

Answer 41

Genetic material - concise but enough of it for the virus to carry out its function - to replicate inside living host

Question 42

What is the role of the caspid?

Answer 42

A protein shell, surrounds the genetic material - providing protection to living material

Question 43

What is the role of the viral envelope?

Answer 43

Protecting the RNA or DNA molecule(s), evading recognition by the immune system, and facilitating virus entry.