Micro 2
Terms
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- Bacteriostatic
- Inhibits growth
- Local infection
- in small area of body
- Diptheria toxin
- Inhibits protein synthesis
- Sepsis vs Asepsis
- Bacterial contamination vs. free pathogens
- Antisepsis
- Destruction of vegetative pathogens on living tissue.
- sterilization
- destruction of all forms of microbial life.
- Lecithinase
-
Destroys lecithin
which causes destruction of cytoplasmic membrane and lysis of cells. - Hyaluronidase
- enzyme that digests hyaluronic acid which is the glue that holds cells together to make tissue in the human body. If this substance is digested, pathogen can spread rapidly through tissue.
- Requirements for infection
-
Adherance
Multiplying
Colonization - Virulence Factors
-
capsules
slime layers
fimbrae
viral spikes
envelopes - Exponential Phase
- If organism reaches this, growth of organism will be so fast that the host will not be able to keep up with the infection.
- Refridgeration
- Has bacteriostatic effect
- Radiation Destruction of DNA
-
Ionizing-gamma rays and high energy elecron beam
Non ionizing-produced by electric currents passing through special lamps - Biguanides
-
used in surgical hand scrubs
binds strongly to skin
low toxicity
vegetative cell and viruses with envelopes. - Halogens
-
Iodine and chloride
Bacteria, spores, fungi, viruses
Chlorine active in water as it forms hypochlorus acid.
10% solution in contact with organisms kill most. - Chemoautotrophs
-
Energy: Inorganic compounds
Source: few bacteria - Lag phase
-
cells increase in size
no cell division
increase in metabolic activity
synthesis of cell components - Tetanus Toxin
- Inhibits release of inhibitory transmitters causin spastic paralysis.
- Syndrome
- specific groups of signs and symptoms that accompany a disease.
- Mutualism
- Both organsims benefit
- Parasitism
- One oranism benefits at the expense of the other.
- Dergerming
- Removing of microbes from a site.
- Sanitation
- Lowers microbial counts on eating utensils to safe public levels.
- Bacteriocidal
- kills bacteria
- M Tuberculosis
- Grows slowly and takes months to treat.
- Microaerophiles
- Oxygen required in low concentrations
- Photohetertrophs
-
Energy source: light
Carbon source: organic - Photoautotroph
-
Energy source: light
Carbon souce: C02 - In absence of C02 certain organisms die:
- Neisseria and Campylobacter
- Faculative anaerobes
- can live in presence or absence of oxygen.
- Organisms that produce SOD
- are capable of living in 02
- The pH that most bacteria grow in
- near neutrality
- Acidic
- Fungi and molds prefer this
- Stationary Phase
-
accumulation of waste producs
Exhaustion of nutrients
decreased growth rate
some cells are dying and some growing - Infectivity
- Ability of an organism to establish a focal point of infection.
- Invasivnes
- Ability of a pathogen to spread to adjacent or other tissues.
-
Lethal Dose 50
Infective Dose 50
ID 50 - How much is needed to kill 50% of the population
- Toxigenicity
- Pathogens ability to produce toxins
- Death Phase
- Numbers of dying exceeds number of new cells formed
- Thermal Death Time
- Amount of time needed for all microbes in a liquid culture to be killed at a given temperature.
- Sign
- A change in the body that can be measured or observed as a result of a disease.
- Symptom
- A change in body function that is felt by a patient as a result of a disease.
- Koch's Postulates
- Used to prove the cause of an infectious disease.
- Microbial antagonism
- Competition between microbes
- Normal microbiota protect host by:
-
occupying niches that pathogens might occupy.
producing acids
producing bacteriocins - Commensulism
- One organism is benefited and the other is unaffected.
- Disease
- An abnormal state in which the body is not functioning normally.
- Stomach
- has a low microbial count due to acid.
- Latent disease
- Disease with a period of no symptoms.
- Opportunistic pathogens
- Microbes that cause disease usually only in immunocompromised individuals.
- Filtration
- Removes organisms
- Obligate Anaerobes
- Die in the presence of oxygen.
- Canophiles
- Organisms that grow better in an environment of higher Co2.
- Generation time
- the time required for a cell to divide and it's population to double.
- Chemotrophs
-
Energy source: Organic compounds
Carbon source: Most bacteria - Pandemic
- Worldwide epidemic
- Epidemic
- Disease acquired by many hosts in a given area in a short time.
- Endemic
- Disease constantly present in a population.
- Sporadic disease
- Disease that occurs occasionally in a population.
- Prevelence
- Fraction of the population having a specific disease at a given time.
- Secondary infection
- Opportunistic infection after a primary infection.
- Primary Infection
- Acute infection that causes the initial illness.
- Viremia
- Viruses in blood.
- Toxcemia
- Toxins in the blood.
- Hypochlorus Acid
-
Very effective against microbial cells including acid fast bacteria & viruses.
Released in water from chlorine gas, sodium or calcium hypochlorite and cyanuric acids.
Used to disinfect swimming pools and drinking water. - Formaldehyde
- gaseous disinfectant ...by heating solution in air
- Transient
- Bacteria may be present for days, weeks, months, sometimes no problems are caused.
- Symbiosis
- Relationship between normal microbiotsa and the host.
- Pathology
- Study of disease.
- Etiology
- Study of the cause of disease.
- Pathogenisis
- Development of a disease.
- Bacteremia
- Bacteria in the blood
- Septicemia
- Growth of bacteria in the blood.
- Subclinical Disease
- No noticable signs or symptoms.
- Focal Infection
- Systemic that begins with local.
- Systemic Infection
- Infection throughout the body.
- Acute disease
- Symptoms are rapid.
- Chronic disease
- Develops slowly.
- Herd immunity
- Most of population immune
- Most bacteria grow at
- 37 degrees
- Thermophiles
- 45-80 C
- Mesophiles
- 20-50 C
- Rapid growth of bacteria
- 20-50 C
- Disinfection
- Destruction of vegetative pathogens
- Osmotic pressure
-
organisms live in aqueous environment
addition of salts & sugars food preservatives by causing loss of water and leads to plasolysis.
Halophiles-tolerate up to 15% salt environment.