Flashcards in Bugs in the system Deck (15)
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What is the bacterial reproduction mechanism in broth?
-Binary fission
1
Define infection
The establishment of an organism on/in a host associated with multiplication and destruction/dysfunction of the host
2
What can cause infection?
Bacteria, archea, protozoa, fungi, prions, viruses
3
What are the possible mechanisms of infection transmission
-Air borne droplets (coughing/sneezing)
-Direct contact (exchange of bodily fluids)
-Animal transmission
-Contaminated products
-Maternal->foetal
4
Describe the concept of gram staining
-Stain cells with crystal violet
-Add iodine which forms complexes with crystal violet
-Add acetone to decolourise cells by removing complexes. Those cells which thick peptidoglycan wall (i.e. gram positive bacteria) will retain crystal violet-iodine complexes as they will be too large to pass through
-Counterstain with safranin
-View under microscope to see staining colour
5
Why are acid fast stains useful and what type of bacteria do they stain?
-Stain bacteria which do not have thick peptidoglycan wall content and also have an extra cell membrane
-Mycobacterium Tb and Leprosy
6
Define pathogen
-Any micro/organism which parasitises a host and causes disease
7
Why are bacterial cell walls of interest and significance?
-Used in detection and diagnosis
-Can be a target for antibiotics
-Gram -ve have LPS with endotoxin effects
8
Name the most common gram +ve cocci
-Streptococcus
-Staphlococcus
9
Name the most common gram -ve cocci
-Neisseria
10
Name the most common gram +ve bacilli
-Clostridium
11
Name the mose common gram -ve bacilli
-Escherchia Coli
-Pseudomonas
-Helicobacter
-Salmonella
12
Which microorganisms are prokaryotic and which are eukaryotic?
-Bacteria and Archea are prokaryotic
-Protozoa and Fungi are Eukaryotic
13
List the main differences between prokaryotes and eukaryotes
Prokaryotes
-No membrane bound organelles
-1 Chromosome
-Coupled biochemical reactions
-V.labile mRNA
-30s and 50s ribosomal subunits
Eukaryotes
-Membrane bound organelles
-Many chromosomes
-Compartmentalised reactions
-mRNA stable
-40s and 60s ribosomal subunits
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