Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Infectious Diseases > Medically Important Microbes > Flashcards

Medically Important Microbes Flashcards

1
Q

What are the ways in which we can categorise bacteria?

A
  1. Gram staining: positive vs. negative
  2. Morphology: cocci vs. bacilli
  3. Growth: anaerobic vs. aerobic
  4. Gram-stainable vs. non gram-stainable
  5. Extracellular vs. intracellular
  6. Culturable vs. non-culturable
  7. Fermenters vs. non-fermenters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is gram staining helpful?

A
  1. It proves there are bacteria present in the sample
  2. It allows us to target certain bacteria groups
  3. It gives us some more clues to help identify which bacteria is causing the infection
  4. Cheap, simple and quick
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which bacteria will stain with counter stain safranin?

A

Gram negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why does a gram negative bacteria stain with safranin, whereas a gram positive bacteria will not?

A

This is due to differences in peptidoglycan thickness difference. Gram +ve bacteria have a thick peptidoglycan layer where as G-ve do not.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What colour does a G+ve bacteria look under the microscope?

A

Purple due to the retention of crystal violet stain due to the thick peptidoglycan content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define the following growth requirement: Obligate aerobe

A

This type of bacteria will only grow in the presence of oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define the following growth requirement: Obligate anaerobes

A

These bacteria will only grow in the absence of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define the following growth requirement: facultative anaerobes and facultative aerobes

A

These bacteria grow well in the presence and absence of oxygen. Most human pathogens have this characteristic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define the following growth requirement: Microaerophilic

A

This type of bacteria prefer lower oxygen concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the following morphology: cocci

A

Round bacteria that can appear in chains, pairs or clusters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define the following morphology: Rods (bacilli)

A

Elongated looking bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define the following morphology: coccobacilli

A

An intermediate shape between rods and cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define the following morphology: Spiral

A

Look like a twirl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do Beta-lactam (penicillin) Abx work?

A

They inhibit peptidoglycan synthesis in bacterial cell walls therefore are bactericidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why do we sometimes have to give beta-lactamase inhibitors with a penicillin (beta-lactam antibiotic)?

A

Some bacteria can neutralise the effect of beta-lactam antibiotics and use beta-lactamase enzymes to break down the beta-lactam ring. The combination of penicillin and a beta-lactamase inhibitor should allow the penicillin to be effective.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Give an example of a beta-lactamase inhibitor

A

Tazobactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What bacteria commonly cause traveller’s diarrhoea?

A
  • Shigella Salmonella
  • Yersinia enterocolitica
  • Campylobacter
  • E.Coli O157:H7
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which parasites can cause traveller’s diarrhoea?

A
  • Entamoeba histolytica

- Isospora belli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When does traveller’s diarrhoea normally present?

A

Within the first few days of travel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the most common route for Traveller’s Diarrhoea?

A

Faecal-oral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the most important piece of advice to give to someone with Traveller’s diarrhoea?

A

Keep hydrated as lots of insensible fluid losses will occur from the diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When would someone with traveller’s diarrhoea need treatment with antibiotics and admission?

A
  • Bacteraemia - bacteria present in the blood culture

- Dysentery - infection of the intestines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What neurological syndrome can be related to infective diarrhoea?

A

Guillan-Barre syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the potential long-term complication of bacterial traveller’s diarrhoea?

A

Reative arthritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the most common cause of bacterial pneumonia?

A

Streptococcus pneumoniae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the morphology of S.Pneumoniae?

A

Gram +ve coccus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the mortality rate in association with candidaemia?

A

40-50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Is candidaemia a medical emergency?

A

YES
This carries a very significant mortality rate and should be treated as quickly as possible.
IV antifungal treatment for 2 weeks will be required

29
Q

What is the most common source for candidaemia?

A

From gut flora - microscopic or macroscopic bowel damage allows the gut flora to pass into the blood stream

30
Q

What are the 3 categories of fungal infection?

A
  • Superficial
  • Subcutaneous
  • Deep
31
Q

List some superficial fungal infections

A
  • Oral and vaginal thrush
  • Tinea
  • Fungal nail infection
  • Pityriasis versicolor
32
Q

Who can get superficial fungal infections?

A

Anyone, they are common. E.g. ringworm, athletes foot etc

33
Q

Who is more at risk of developing superficial fungal infection?

A

Those who are immunocompromised - HIV or diabetic patients

34
Q

Where in the world do subcutaneous fungal infections occur most commonly?

A

In tropical countries

35
Q

Who is at risk of deep fungal infections?

A

Those who are immunocompromised in some way

36
Q

Name some deep fungal infections

A
  • Invasive candida sp. : Central line infection
  • Invasive Aspergillus fumigatus: transplant and chemo patients
  • Pneumocystis jirovecii pneumonia
  • Cryptococcal meningitis
37
Q

What is the clinical term for chickenpox?

A

Primary varicella zoster infection

38
Q

What sort of rash is common in chickenpox?

A

Widespread, itchy, vesicular rash

39
Q

What are some severe complications of chickenpox?

A
  • Pneumonitis
  • Bacterial infection of the skin
  • Encephalitis
  • Hepatitis
  • Myocarditis
40
Q

What treatment should be used in an immunocompromised patient for chickenpox?

A

Aciclovir

41
Q

What is the route of chickenpox infection?

A

Mucosa of the upper respiratory tract or conjunctiva

42
Q

What are the prodromal symptoms of a chickenpox infection?

A
  • Fever

- Lethargy

43
Q

There are dermatological changes in chickenpox. What does it originally present as and develop into?

A

Macules and papules which go on to become vesicles which burst and then crust

44
Q

What are the 4 most important herpes viruses to know?

A
  • Herpes simplex-1 (HSV1)
  • Herpes simplex-2 (HSV2)
  • Epstein-Barr virus (EBV)
  • Cytomegalovirus (CMV)
45
Q

What was the MMR vaccine said to be related to developing in the early 2010s?

A

Autism

46
Q

What are the prodromal features of measles?

A
  • Fever
  • Malaise
  • Conjunctivitis
  • Cough
47
Q

What is a distinguishing feature of measles?

A

Koplik spots in the buccal cavity mucosa - blue/grey/white spots

48
Q

What sort of rash is present in measles?

A

Morbilliform rash (maculopapular) beginning on the face then spreading down the body

49
Q

What are the potential complications of measles?

A
  • Bacterial pneumonitis
  • Otitis media
  • Acute encephalitis
50
Q

What are some of the key features of a HIV infection?

A
  • Generalised rash
  • Pharyngitis
  • Generalised lymphadenopathy
  • Headache
  • Mouth ulcers
  • Flu-like symptoms
51
Q

What does HSV-1 commonly cause?

A

Oral or ocular disease

52
Q

What does HSV-2 commonly cause?

A

Genital lesions

53
Q

What are the symptoms of Glandular fever?

A
  • Fever
  • Sore throat
  • Lymphadenopathy
54
Q

Which drug can precipitate glandular fever?

A

Amoxicillin

55
Q

Define the following; Endoparasites

A

Parasites that live on the skin and hair

56
Q

Define the following; Endoparasites

A

Parasites that live on the mucosal surfaces such as the gut and in tissue

57
Q

What are helminth parasites?

A

Worm-like parasites, mostly visible to the naked eye

58
Q

What are protozoan parasites?

A

Single-celled eukaryotic organisms that are usually motile

59
Q

What is a definitive host?

A

The animal that hosts the adult stage of a parasite

60
Q

What is an intermediate/secondary host?

A

The animal that hosts the developmental stage of the parasites life

61
Q

What is an accidental host?

A

A host that the parasite cannot use to complete its life-cycle. This host is a dead end for the parasite.

62
Q

What is a vector?

A

A parasite that can transmit other diseases such as bacterial infection e.g. some ticks are vectors for Lyme disease

63
Q

What are mosquitos the vector for?

A

Malaria

64
Q

What is the recommended chemoprophylaxis against Malaria?

A

Doxycycline

65
Q

What is the commonest cause of eosinophilia in clinical practice?

A

Atopic disease - asthma, hayfever, eczema

66
Q

What parasite causes pinworm?

A

Enterobius vermicularis

67
Q

How does the lifecycle of the pinworm carry out?

A

An adult worm lives in the gut of the child. During the night the worm ventures out of the anus and lays eggs at the perineum. The child gets an itchy bottom and then transfers the eggs from perineum to mouth or others’ mouths.

68
Q

Where can Diphyllobothrium latum be caught from?

A

Eating undercooked fish or sashimi

69
Q

Which organisms does metronidazole treat?

A 
Obligate anaerobes (G+ve or G-ve)
Giardia

Infectious Diseases (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions