Systemic Microbiology Flashcards
List some of types of microbe.
Viruses Prions Protozoa Fungi Bacteria Helminths
Name some of the common relationships between host and microbiota/
Symbiosis
Commensals
Parasites
Mutualism
Breifly describe the differences between a Eukaryote and a Prokaryote.
Prokaryote has a nucleoid, a capsule a cell wall and a flagellum
Eukaryote has a membran-enclosed nucleus, a nucleolus, and mitochonria
They both have ribosomes and a cell membrane
What is taxonomy?
Classification of organisms
Organisms are identified by two names, indicating what?
The genus and the species
- e.g. Staphylococcus aureus
- Streptococcus pyogenes
- Pseudomonas aerugiosa
Describe gram staining.
Widely used stain Separates bacteria into two groups - gram negative - gram positive Also allows the shape of the bacteria to be identified
Which gram group has a thicker cell wall?
Gram positive (doesn’t have periplasm or an outer membrane)
What colour are gram negative and gram positive bacteria stained?
Positive - purple
Negative - pink
Describe two exceptions on gram stain.
Mycoplasma doesn’t stain as it doesn’t have a cell wall. They are also weakly gram positive but stain best with an acid-fast stain
Spirochetes have a gram negative wall but are too small to be seen with a light microscope
What are the different groupings of cocci bacteria?
Coccus - single round bacteria Diplococci Encapsulated diplococci Staphylococci - pyramid Streptococci - long chain Sarcina - cube Tetrad - group of four
What are the different groupings of bacilli bacteria?
Coccobacillus - oval Bacillus - single bacteria Diplobacilli Paslisades - joined on the long side Streptobacilli - long chain
What are some different groupings of non cocci or bacilli bacteria?
Enlarged rod Vibrio - kidney shape Comma's form Club rod Helical form Corkscrew's form Filamentous Spirochete
Give some examples of gram positive bacilli.
Clostridia
Bacillus
Listeria
Give some examples of gram negative bacilli.
E.Coli Klebsiella Pseudomonas Salmonella Shigella
Give an example of a gram negative cocci.
Neisseriae
List the four classifications of growth atmosphere for bacteria.
Obligate aerobes
Facultative anaerobes
Microaerophilic bacteria
Anaerobes
What are endospores?
Metabolically dormant forms of bacteria that are more resistant to disinfectants, drying or heating
When do bacteria form endospores?
When there is a shortage of needed nutrients - can lie dormant for years
Becomes active again when exposed to favourable environment
Which bacteria genres can form endospores?
Bacillus and Clostridium
What are the 5 types of classification of bacteria?
1) Gram Stain
2) Shape
3) Growth Atmosphere
4) Endospores
5) DNA sequencing
Describe the structure of a basic bacteria?
Cell envelope Cytoplasmic membrane Cell wall (gram negatives have an outer membrane of LPS called endotoxin and a periplasm) Capsule Flagella Pili/Fimbriae
List the four main ways bacteria can be pathological.
Toxins
Adhesions
Enzymes
Capsules
How do bacteria reproduce and adapt?
They reproduce by binary fission - this allows alteration of genetic material which enables adaptation
What are three of the methods of gene transfer?
Transformation
Transduction
Conjugation