Infectious Agents: Description Of Pathogenic Microorganisms Flashcards
What are the four types of pathogens?
Virus
Bacteria
Fungi
Parasites
How do you write species’ names?
In italics. The first letter of the first word is capitalised and the first letter of the second word is always lowercase
Name the levels of hierarchy of organisms (10)
Domain Kingdom Phylum Class Order Family Genus Species Strain Isolate
What is the isolate in a hierarchy?
A particular pathogen from a particular person
How can you identify viruses?
By their shape
How do you see viruses?
Through electron microscopes
What size are viruses?
20-300nm
Can viruses have DNA or RNA?
Both
Do viruses have cytoplasm?
No
Are viruses enveloped or non-enveloped?
Can be both depending on the strain
What does an organism being ‘enveloped’ mean?
With an outer membrane
What forms do the genetic material in viruses come in (4)?
Linear, segmented, single or double stranded
What is an ‘obligate intracellular organism’?
An organism that can only replicate inside cells
What is the size range of a bacteria?
0.5-3um
Are bacteria prokaryotic or eukaryotic?
Prokaryotic
What type of DNA does bacteria have?
Haploid
How do bacteria replicate?
Binary fission
What do pili and fimbria do?
Allow bacteria to attach to surfaces
What do flagella do?
Allow the bacteria to be motile
How do you separate out gram positive and gram negative bacteria?
With a stain
+Ve stains dark purple/black
-ve stains pink
Give the four steps in binary fission
- Genome replicates
- genes move to either side of bacteria
- septum forms down the middle of the bacteria
- bacteria splits
What does the outer circle of a gene sequence mean?
Colour coded for the metabolic potential of the gene
What size are fungi?
Over 2 micrometers
Are fungi prokaryotic or eukaryotic?
Eukaryotic
What type of DNA do fungi have?
Haploid or diploid
How many nuclei do fungi have?
Single or multiple
What is the fungi cell wall made up of?
Chitin
What are the two types of fungi?
Yeast or filamenous form/moulds
What is classification of yeast based on (3)?
Morphology, mode of reproduction and disease caused
What does morphology mean?
Growth form
What are the three types of infection caused by fungi?
Superficial mycoses
Cutaneous
Systemic
Give an example of a superficial mycose
Thrush
Give an example of a cutaneous fungal infection
Ringworm
Give an example of a systemic fungal infection
Histoplasmosis
Are parasites eukaryotes or prokaryotes?
Eukaryotes
What are Protozoa?
Single celled organisms
What is the size of a Protozoa?
5-300um
How many nuclei do Protozoa have?
Single or multiple nuclei
What type of DNA do Protozoa have?
Haploid DNA
What are helminths?
Multicellular parasitic worms
What are the three types of helminths?
Cestodes
Trematodes
Nematodes
What are cestodes?
Tapeworms
What are trematodes?
Flatworms or flukes
What are nematodes?
Roundworms