Microbiology Flashcards
What is microbiology
Study of small forms of life
Who discovered bacteria
(“Plaque”)
Antoni van Leeuwenhoek
Recognized existence of tiny living particles that cause catching diseases
Girolamo Fracastoro
Concept of immunizations
Cowpox / small pox
Edward Jenner
Father of immunology
Louis Pasteur
John Tyndall
Tyndallization
Need for heat to destroy bacteria
Airborne MO’s
Phenols/carbolic acid
Joseph lister
Handwashing importance
Ignaz philipp Semmelweis
Can live and multiply only inside a host
Virus
Barge group of one celled mos
Bacteria
Range from single celled to multi
Seaweed kelp
Most do not produce disease
Algae
Primitive cells, no internal membrane and no nucleus
Prokaryote
Example of prokaryote
Bacteria
Complex cells with internal membrane and have nucleus
Eukaryotes
Examples of eukaryotes
Protozoa fungi algae
MO that is not prokaryote or eukaryote
Virus
Hair like projections with fine short appendages that allow bacteria to adhere
Fimbriae/pili
Mesosomes are mostly present in
Gram positive bacteria
What protects from drying and is a gelatinous covering produced by the cytoplasmic membrane in prokaryotic cells
Capsule
Granules in prokaryotes are considered
Energy reserves
Plasmids in prokaryotes are
Extra chromosomal dna
Resistant to physical and chemical agents
Vacuoles in eukaryotic cell gather
Food
Vesicles in eukaryotic cells surround
Proteins
Gram positive is what colour
Cell walls are?
Blue/ purple
Thick cell walls
Gram negative colour?
Cell walls?
Pink/red
Thin cell walls
Binary fission
Each cell divides into two daughter cells
5 growth requirements of bacteria
Temperature
Acidity
Nutrients
Oxygen metabolism
Water
Bactericidal agents
Kill bacteria
Bacteriostatic agents
Inhibits growth but do not kill
Sequence of viral replication
Attachment/absorption
Penetration
Uncoating
Replication
Assembly
Release
4 transmission routes of viruses
Contaminated water
Insects
Droplet
Direct
Opportunistic pathogens
Cause disease when host defenses are compromised
Endogenous diseases
Caused by mos inside/on the body
Exogenous diseases
Caused by mos not normally found in or on the body
Toxigenic disease describes an exogenous disease without entering and multiplying in body. And example of this
Food poisoning
Bacteriophage
Viruses that infect bacteria
Prion
Poisonous proteins
(Not MOs and are always fatal)
4 modes of disease transmission
Direct
Indirect
Droplet
Airborne
Routes of entry to the body
Inhalation
Ingestion
Mucous membrane
Breaks in skin
Preserving microbes from a substance by removing the water rapidly freezing sample then drying it with a vacuum pump at very low temp
Lyophilization
3 types of sterilization
Gas
Heat
Liquid
Ethylene oxide, long exposure times
(High cost and not common)
Gas sterilization
Factors influencing microbial growth
Temp
Ph
Atmospheric pressure
Salinity
Osmotic pressure
Hydrostatic pressure
Radiation
Thermophiles
Heat loving
Mesophiles
Body temp is ideal
Caries, perio disease
Psychrophiles
Cold loving bacteria
Obligate aerobes
Grown in presence of oxygen (20%)
Obligate anerobes
Grow in absence of oxygen
Acidogenic bacteria
Bacteria produces acid during growth
Aciduric bacteria
Bacteria that survive and grow in acidic environments
Moderate halophile
Marine bacteria (loves salt)
Osmotic pressure
Pressure created by water moving across a selectively permeable membrane due to osmosis
Osmotolerant
Mos can grow at high level salt concentrations
Sacchrophiles
High sugar concentration as osmotic regulator rather than salt
(Yeast/mold)
Hydrostatic pressure
Pressure exerted by a fluid
What is antimicrobial
Term used to designate all categories of drugs used to treat infections
How do antimicrobials work
Inhibit growth and replication of microbes (damage host cell)
CDC
Guidelines for what
Centre for disease control
For infection control in dental settings
Intermediate level disinfectant
Destroys bacteria fungi and most viruses
Low level disinfectant
Destroys some bacteria fungi and viruses
High level disinfectant
Destroys all mos but not spores
Endospores
Most resistant form of life
Another term for virus
Obligate intracellular parasites
Transient flora
Source of disease
Microaerophiles
Can tolerate low level conc of oxygen (4%)
Faculative anerobes
Can live with or without oxygen
Who discovered endospores
Ferdinand Cohn
Discovered penicillin
Sir Alexander Fleming
Outer membrane of gram negative bacteria contains
Endotoxin (transports nutrients)
Sterilant kills
All mos including spores
Resident flora is always
On skin
Mos colonize and become permanent
Transient flora
Contaminates
Can be removed by washing
3 reactions to gloves
Irritant contact
Allergic contact
Latex allergy
Irritant contact dermatitis
Non-immunologic irritation.
Dry itchy hands
Allergic contact dermatitis
Type IV
Delayed hypersensitivity (24-48hrs)
Bacterial flora
Normally resides in on body without causing harm but with disease potential