Brainscape's Knowledge GenomeTM

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


See full index

Fundamentals of Pathology > W12 Infectious agents > Flashcards

W12 Infectious agents Flashcards

1
Q

5 Kingdom system

A 
Protista
Plantae
Animalia
Fungi
Monera
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Three Domain System

A

Multiple Kingdoms

Modern DNA analysis

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

Distinctive biological characteristics

A 
All organisms are cells
	not viruses!
Membranes
Cellular and genome organisation
Single cells
Multiple stages –life cycles
Multicellular - parasites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Prokaryotic

A

No nucleus
No mitochondria
Mainly circular DNA
e.g. bacteria

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

Eukaryotic

A

Chromosome

Nucleus

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

Identification essential to understand:

A 
Biology and microbiology 
Evolution and phylogenetics
Pathogenesis of infectious diseases
Life cycles
Accurate diagnosis 
Effective treatment
Public health control of infectious diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Criteria: (Systems of Classification of Pathogenic Organisms)

A

Structural and functional and metabolic observations

Molecular and genetic and genome analysis

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

Sub-species classification:

A

Differentiate pathogenic and non-pathogenic strains

- different disease patterns and clinical outcomes

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

Linnaean Classification - Hierarchical

A

Domain - Eubacteria

Kingdom - Procaryote

Phylum - Gram +ve

Class - Actinobacteridae

Order - Actinomyceteales

Family - Mycobacteriaceae

Genus - Mycobacterium

Species - Mycobacterium tuberculosis

Strain - Beijing W1

Isolate - Mr Bloggs (12/02/2004)

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

Visualisation of Microbes - Viruses

A

Can be seen with
electron microscope
x100,000

20 – 300nm

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

Viruses - size

A

20nm - 300nm

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

Viruses - structure

A

DNA or RNA genome
- linear, segmented, single or double stranded genome size 9Kb- 300Kb

  • protein nucleocapsid - individual capsomeres Helical, cubic or complex arrangement

No cytoplasm

Enveloped or non-enveloped
- may have components derived from host cell

obligate intracellular organism

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

Virus life cycle

A 
Recognition
Attachment
Penetration
Fusion
Uncoating
Transcription
Protein synthesis
Replication
Envelopment
Budding and release
Lysis and release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Common viral infections in the UK - Community

A

Upper respiratory tract infection - rhinovirus, influenza, RSV

Gastroenteritis e.g.
Norovirus (SRSV), adenovirus, rotavirus

Rashes e.g. varicella zoster virus (chickenpox), measles

Meningitis e.g. enterovirus

Hepatitis virus e.g. HepB

Human Papilloma virus (HPV) - genital warts

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

Common viral infections in the UK - Healthcare-associated Infection (Hospital Acquired)

A

Norovirus, flu

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

adenovirus

A

Non-enveloped

DNA virus

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

What virus causes muco-cutaneous lesions ?

A

Human Herpes simplex Type 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Herpes viruses

A

Icosahedral nucleocapsid

Envelope

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

Influenza virus

e.g. H3N2

A

Surface Haemagglutinin

Enveloped
pleomorphic
Segmented RNA genome
Mutation and recombination
Epidemics and pandemics
Vaccine component H and N
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Bacteria - size

A

1/1000th of a mm

0.5 μm to 3 μm

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

Bacteria - structure

A

Prokaryotic

Haploid DNA, circular genome

no nucleus

usually have rigid cell wall outside cytoplasmic membrane

no mitochondria

Binary fission

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

Visualisation of Bacteria

A

Unstained at x400

Motile bacteria with flagella move rapidly
Non-motile bacteria also move “on the spot”
i.e. Brownian motion

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

Gram Staining Bacteria

A

All purple = iodine + crystal violet

G+ purple = alcohol

G- colourless = alcohol

G+ purple = safranin

G- red = safranin

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

Morphology

A

cocci, rod/bacilli, coccobacilli, spirochetes

  • atypicals e.g. mycoplasma (no cell wall), chlamydia (biphasic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Gram stain

A

positive or negative, acid fast, variable

26
Q

Growth requirements

A

aerobic vs anaerobic

27
Q

Biochemical reactions

A

e.g. lactose fermenting or non-fermenting

28
Q

Serotype groups

A

e.g. Streptococcus group A or B; meningococcus B or C

29
Q

Antibiotic resistance

A

e.g. MSSA or MRSA

30
Q

Other classification criteria for bacteria

A

rRNA sequencing
Genome sequencing
MLST or RFLP typing – genetic variation typing methods

31
Q

The presence of beta-hemolytic colonies indicates

A

indicates the possibility of Streptococcus pyogenes infection

32
Q

Selective Atmosphere - anaerobic culture

A

eg. Clostridium tetani, Clostridium botulinum, Clostridium difficile

GRAM POSITIVE
SPORE FORMING
ANAEROBIC
ROD/BACILLUS SHAPED

Clostridium perfringens on Blood agar
Grown in ANAEROBIC atmosphere

33
Q

Haemophilus influenzae

A

Genome = 1.83Million bases (Mb)

First genome of a free-living organism sequenced was that of HI - 1995

The genome encodes more than 1700 proteins + 70 RNA molecules

Functions of ~ 50% of proteins were determined by comparison w/other species

34
Q

Fungi - Mycoses size

A

over 2 μm

35
Q

Fungi - Mycoses structure

A

Eukaryotic
Haploid or diploid DNA
Single or multiple nuclei
Rigid chitinous cell wall outside cytoplasm Single or multicellular

36
Q

Single or multicellular e.g.

A
  • yeast (spheroid single cells budding and division)
    or
  • Filamentous form/moulds. – hyphae (e.g. Aspergillus spp) multinucleate branching hyphae forming mycelium

Classification is complex and is based on morphology (growth form), mode of reproduction (sexual or asexual) and disease caused: 70,0000species ~300 human pathogens

37
Q

Superficial mycoses

A

Skin, nail hair and mucous membranes (dermatophytes) or thrush (Candida albicans)

38
Q

Cutaneous mycoses

A

e.g. Tanea – aka ringworm

39
Q

Systemic mycoses

A

e.g Histoplasmosis

Histoplasma capsulatum

40
Q

Dimorphic

A

microconidia and hyphae,

yeast like and spores

41
Q

Oral Candidiasis / Candidosis

A

most common oral fungal infection
carriage rates 20% - 75% without any symptoms.
Usually Candida albicans

42
Q

Yeast

A

normal constituent of the digestive and vaginal tracts
Generally no problems in healthy people
Opportunistic pathogens

43
Q

Cryptococcus neoformans

A

Fungal yeast like form – encapsulated – large capsule

44
Q

Pneumocystis carinii (now jiroveci)

A

Previously classified as a protozoan
PCP in AIDS
Single cells (amoeboid)
forms cysts containing spores

45
Q

Athletes foot - Tinea pedis

A

Dermatophytes

multiple septate branching hyphae on microscopy

46
Q

Ringworm (Dermatophytosis)

A

40 types of fungi can cause ringworm.

DO NOT confuse with pinworm, round worm

47
Q

Tinea unguium

A

of the nails is termed onychomycosis

48
Q

Protozoa

A 
Single cells   5 to 300 μm
Single or multiple nuclei
Haploid DNA. 
Morphology varies throughout life cycle`
May have flagella
49
Q

complex life cycles

A

Trophozoites, cysts and other morphotypes

50
Q

Giardia lamblia

A

Trophozoite stage

Cyst stage

51
Q

Protozoa - structures

A

e.g Plasmodium falciparum (malaria)

Uninfected erythrocytes
Schizont
Trophozoites (ring forms)

52
Q

Entamoeba histolytica

A

50 Million people infected
Liver abscess + diarrhoea

Faecal cyst

53
Q

Trichomonas vaginalis

A

Common STI

trophozoite

54
Q

Trypanosoma brucei

A

Trypanosomaa spp – vector tetse fly or reduviid bug
(Chagas disease; Sleeping sickness)

Blood stage

55
Q

Helminths

A

These are multicellular parasitic worms
Different morphology and sizes at different life cycle stages
They can be microscopic or visible to the eye
Multicellular

56
Q

3 Groups of parasites

A

Cestodes are tapeworms e.g. Taenia saginata, the beef tapeworm;

Trematodes are flatworms or flukes and include Schistosoma haematobium the cause of bilharzia or schistosomiasis filarial worm Onchocerca volvulus – River Blindness

Nematodes which are roundworms e.g. Ascaris lumbricoides

57
Q

River Blindness- Oncocerciasis

A

microfilariae migrate to eyes

58
Q

Schistosomiasis

A

microfilariae

59
Q

Helminths- Cestode

A

Tape worm -Taenia saginata

Egg shed in faeces (human)

Cysts in muscle (beef)

Adult tapeworm (human)
2 – 4 metres long
700- 1000 segments
60
Q

Helminths- Trematoda

A

Schistosoma haematobium

Egg shed in urine (human) (via snails)

Metacercaria in water
(burrow into skin)

Adult fluke in human

61
Q

Helminths - nematodes

A

Ascaris lumbricoides

Egg shed in faeces

Adult worm

62
Q

Enterobious virmicularis

A

a nematode – common in UK children
threadworm or pinworm

Asymmetical shape (50 uM)

Sticky tape mount to pinworm eggs

Fundamentals of Pathology (23 decks)

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