An Introduction to Medical Microbiology

Question 1

What are possible infecting agents?

Answer 1

Bacteria

Viruses

Fungi

Parasites

Prions

Question 2

What are the two areas of the body in terms of organisms?

Answer 2

Sterile and non-sterile

Question 3

What is a sterile site?

Answer 3

One which normally does not have infection

Question 4

What is a non-sterile sites?

Answer 4

One which has some degree of harmless infection, usually associated with the outside world

Question 5

What are examples of sterile sites?

Answer 5

Blood

Cerebrospinal fluid (CSF)

Lung

Bladder

Question 6

What are examples of non-sterile sites?

Answer 6

Skin

Nasopharynx

Urethra

Gut

Question 7

Which kind of sites is easier to diagnose a harmful infection?

Answer 7

Sterile sites because you are not expecting to find anything there

Question 8

What are some common speciments collected for bacterial culture?

Answer 8

Mid-stream urine (urinary tract infection)

Sputum (chest infection)

Throat swab (tonsillitis)

Swab or pus (wound or site of infection)

Faeces (diarrhoea)

Blood culture (bacteraemia)

Cerebro-spinal fluid (meningitis)

Question 9

What are different ways of looking for pathogens?

Answer 9

Microscopy

Gram stain and microscopy

Bacterial culture

Question 10

In what site does microscopy work well?

Answer 10

Sterile sites but not non-sterile sites

Question 11

What can microscopes not see?

Answer 11

Viruses, they are too small

Question 12

What can unstained microscopy see?

Answer 12

Pus cells (in urine)

Parasites (in faeces)

Question 13

What is stained microscopy used to see?

Answer 13

Yeasts

Fungi

Question 14

How can flourescent bacteria be seen?

Answer 14

By using flourescent staining such as auramine. such as for mycobacteria

Question 15

What does gram staining identify?

Answer 15

Whether the bacteria is gram negative or gram positive

Question 16

How does gram negative bacteria appear when gram staining?

Answer 16

Pale red

Question 17

How does gram positive appear when gram staining?

Answer 17

Dark purple

Question 18

What is an advantage of microscopy?

Answer 18

It is quick

Question 19

What can gram staining not identify?

Answer 19

The specific speices present

Question 20

What does gram staining not being ‘sensitive’ mean?

Answer 20

There needs to be lots of bacteria present for it to work

Question 21

What are properties of bacterial culture?

Answer 21

It is slow

It is sensitive (do not need lots of bacteria)

Question 22

What can be changed in a bacterial culture?

Answer 22

Culture conditions to promote the growth of certain species

Question 23

What are things that can be controlled in a bacterial culture?

Answer 23

Type of media (selective/non-selective)

Atmosphere

Temperature

Duration of incubation

Question 24

What are observable characteristics that can be used to identify a species?

Answer 24

Morphological

Physiological

Biochemical

Question 25

What distinguishes strains within a species?

Answer 25

Typing

Question 26

How can viral infections be diagnosed?

Answer 26

Molecular methods (such as real time PCR) Antigen detection Serology Electron microscopy Cell or tissue culture

Question 27

What is not really used now for detecting viruses?

Answer 27

Electron microscopy Cell or tissue culture

Question 28

What is serology?

Answer 28

Detecting antibodies that the patient has produced against the virus

Question 29

What are the 3 classes of parasites?

Answer 29

Protozoa Helminths (worms) Arthropods

Question 30

What are examples of protozoa?

Answer 30

Malaria Amoebae Flagellates

Question 31

What are examples of helminths?

Answer 31

Roundwormm Tapeworm Flukes

Question 32

What are examples of arthropods?

Answer 32

Lice Ticks Mites

Question 33

What is normally used to diagnose parasites?

Answer 33

Microscopy

Question 34

What is looked for when diagnosing parasites?

Answer 34

Parasites Cysts Ova

Question 35

What is rarely possible and what is sometimes useful for diagnosing parasites?

Answer 35

Culture is rarely possible and serology is sometimes useful

Question 36

What is a healthcare acquired infeciton?

Answer 36

An infection that is acquired in a hospital or other healthcare facility

Question 37

What are examples of common healthcare acquired infections?

Answer 37

MRSA Clostidium difficile B-lactamases Noroviruses

Question 38

What is antibacterial resistance?

Answer 38

The ability of a microbe to resist the effects of medication that once could successfully treat that microbe

Question 39

What are we currently experiencing in terms of antibiotics?

Answer 39

A discovery void

Question 40

What are examples of basic infection control?

Answer 40

Wash hands before touching the patient Wash hands between patients Swab stethoscope between patients Isolate infectious patients in single rooms