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Micro exam 3

Terms in this set (107)

Bactericidal
kills bacteria
Bacteriostatic
inhibits bacterial growth
antiseptic
chemicals applied to body surfaces to destroy or inhibit vegetative pathogens
physical agents
heat and radiation
Filtration
Force applied by air or water filter
Sterilization
completely destroys all microbial life, including viruses and endospores
Sterilization is used on
Animate objects, metal
Sterilization happens using
Autoclave or sterilants
Disinfection
Destroys vegetative microbial life; reducing contamination on inanimate objects
disinfectant are used on
inanimate objects
disinfectant do not destroy
Endospores
antiseptic
Applied directly to exposed body surfaces to destroy or inhibit vegetative pathogens
antiseptics are used on
The body
Sepsis
the growth of microorganisms in the blood and other tissues
Asepsis
Prevents the entry of infectious agents into sterile tissue
Decontamination
Decrease the risk of infection or spoilage
Sanitization
Done on inanimate objects using chemicals, hot water, pressure
Degermation
Reduces the numbers of microbes on the human skin
Types of degermation
Alcohol wipes, scrubbing prior to surgery
Factors that affect death rate
Number of microbes
Nature of microbes in the population
Temperature and pH of environment
Concentration or dosage of agent
Mode of action of the agent
Presence of solvents, organic matter, or inhibitors
antimicrobial effects on cell wall
Block its synthesis
Digest it
Break down its surface
The cell becomes fragile and is lysed easily
Antimicrobial effect on cell membrane
All bacteria
Detergents (surfactants) disrupts membrane
Lose selective permeability
Gram - more susceptible
Antimicrobial effect on protein and nucleic acid synthesis
Any level can be affected
Some bind to ribosome stop translation
Bind irreversibly to DNA preventing transcription and translation
Some are Mutagenic agents
Heat agent of microbial control
Moist heat- autoclaving, pasteurization, boiling water
Dry heat- incineration, dry oven
Incineration and dry oven is a
Sterilize
Autoclave is a
Sterilize
Pasteurization and water boiling is a
Disinfectant
Heat resistance microorganisms
Bacterial endospores most resistant
Vegetative cells very sensitive
Viruses high tolerance
The Effects of Cold on Microbes
bacteriostatic preserve food, media, cultures
Freezing will not kill off all microbes
Desiccation
Removal of water, leads to metabolic inhibition
What microorganism can survive in long periods of desiccation?
Viruses and fungal spores
Lyophilization
Freeze drying; used to preserve microorganisms and other cells in a viable state for many years
Radiation
Ionizing and nonionizing
ionizing radiation
Ejects electron, causing ions to form
Breaks DNA
Gamma rays, x rays
Used for food
Sterilization of medical instruments
nonionizing
excites atoms but does not ionize them
Pyrimidine dimers- mutations
UV rays
Disinfectant water, labs, hospitals
Weak penetration
ultraviolet radiation applications
Disinfection
nonionizing radiation destroys
Fungal cells
Bacterial vegetative cells
Protozoa
Viruses
Filtration
Solutions- vaccines
Does not denature vaccine
Removes microorganisms not killing them
Halogens
fluorine, chlorine, bromine, iodine
Interfere or damage proteins
Microbicidal and sporicidal
Iodine
2-2.4% antiseptic
5-10% disinfectant
Phenols
Targets Cytoplasmic and membrane
Cellular poison high concentration
Inactivate enzyme low concentration
Who is Lister
Founder of antiseptic medicine. Found phenols helped people die less in surgery
Chlorhexidine
Targets cell membrane and protein structure
Bactericidal gram+/-
Not active against spores
Chlorhexidine is used for
Prepping for surgery with hand scrubbing
Alcohols
Dissolve membrane proteins and dehydrated cell
Best at 70%
hydrogen peroxide
Forms hydroxyl free radicals
Bactericidal
Virucidal
Fungicidal
High concentration sporicidal
heavy metal compounds
Hg, Ag, Au, Cu, As, Zn
Inactivated proteins
Coat surface to make sterile
Heavy metal compounds can be used to help
Burns to minimize infections
Aldehyde as germicides
Used on sensitive equipment that can not be autoclave
Gaseous Sterilants and Disinfectants
Ethylene oxide (ETO)
Block DNA replication
Materials that cannot be autoclaved
Dyes as Antimicrobial Agents
Chemotherapy can alter DNA and the cell cycle
Crystal violet and malachite green active against gram +
Dermatologist use against fungi
Chemicals with Surface Action: Detergents
Actions bind with negatively charged bacterial surface proteins
Weak microbicides
Factors that affect germicidal activity of chemicals
Nature of microorganisms being treated
Nature of the material being treated
Degree of contamination
Time of exposure
Strength and chemical action of the germicide
Choosing a Microbicidal Chemical
-Rapid action even in low concentrations
-Solubility in water or alcohol and long-term stability
-Broad-spectrum microbicidal action without being toxic to human and animal tissues
-Penetration of inanimate surfaces to sustain a cumulative or persistent action
-Resistance to becoming inactivated by organic matter
-Noncorrosive or nonstaining properties
-Sanitizing and deodorizing properties
-Affordability and ready availability
antimicrobial therapy
the use of chemotherapeutic drugs to control infection
ideal antimicrobial drug
Toxic to microbes but not toxic to the host
Microbicidal rather than microbiostatic
Relatively soluble
Remains potent long enough to act
Doesn't lead to antimicrobial resistance
chemotherapeutic drug
any chemical used in the treatment, relief, or prophylaxis of a disease
prophlaxis
Prevent imminent infection of a person at risk
antimicrobial chemotherapy
The use of drugs to control infection
Antimicrobials
all-inclusive term for any antimicrobial drug, regardless of what type of microorganism it targets
antibiotics
substances produced by the natural metabolic processes of some microorganisms that can inhibit or destroy other microorganisms
semisynthetic drugs
drugs that are chemically modified in the laboratory after being isolated from natural sources
synthetic drugs
drugs produced entirely by chemical reactions
narrow spectrum
antimicrobials effective against a limited array of microbial types
broad spectrum
antimicrobials effective against a wide variety of microbial types
Antibiotics were discovered by
Alexander Fleming he found penicillin
Autoclave
Physical
Sterilization
Moist heat high pressure
Kills all bacteria viruses endospores
Denatures proteins
Destroys membranes and DNA
Pasteurization
Physical
Disinfection
Moist heat
Kill potential agents of infection
Not sterile
Disinfectant of liquids
boiling water
Physical
Sterilization
Dry heat
Ignores and reduces microbes to ashes
Bunsen burners
Heat 500 degrees
Dry oven
Physical
Sterilization
Dry heat
Denature proteins and dehydrated cells
Glassware and metallic instruments
refrigerator
Physical
Bacteriostatic
Freezing will not kill microbes
Preserves food, media, cultures
Desiccation/lyophilization
Physical
Bacteriostatic
Dehydration leads to metabolic inhibition
Lyophilization used to preserve microbes
Endospores, viruses, fungal can survive for long periods
Hydrogen to hydroxyl
ionizing radiation
Physical
Bacteriostatic
Disinfectant or sterilization (cold low temp)
Causes mutation in DNA and damages the protein that would fix it
Not affective against endospores unless exposed for long time
Targets atom of the cell
Gamma rays
X rays
Food sterilization or medical equipment
nonionizing radiation
Physical
Disinfection (UV) or sterilization (long exposure)
Pyrimidine dimers
Excited atom
Disinfect water, labs, food prep areas
Causes bubble in DNA
Destroys fungal cells, bacterial vegetative cells, Protozoa, viruses
Filtration
Mechanical
Removes microorganisms but does not kill
Removes form air and liquids
Vaccine development
Halogens
Chemical
Disinfection and antiseptic
Interfere with or damages protein
Iodine
Phenol
Chemical
Disinfection and antiseptic
Disrupts cell wall, membrane, proteins - high
Inactive enzymes - low concentration
Triclosan example
Triclosan
Chemical
Disinfection and antiseptic
Endocrine disruption
Bacterial resistance
Hormonal effects not used anymore
Soaps and cat liter examples
Broad spectrum
Chlorhexidine
Chemical
Disinfectant
Bactericidal from gram +/-
Target cell membrane and protein structure
Prepares skin for surgery - hand scrubbing
Alcohols
Chemical
Antiseptic
Germicidal
70% best
Dissolve membrane proteins and dehydrated cell
Surfactant agents
hydrogen peroxide
Chemical
Disinfectant
Bactericide
Antiseptic but not very affective
Vircucide
Fungicide
Cells cannot produce catalase to neutralize excessive hydrogen peroxide
heavy metals
Chemical
Disinfectant can be used as a sterilization if used to coat surfaces - doesn't kill endospores
Binding to protein and inactivating them
Kills all except endospores
Cofactors
Silver nitrate example used for burns
Zone of inhibition
Aldehydes
Chemical
Disinfectant
Germicide
Disrupts enzymes within cell
ethylene oxide
Chemical
Sterilization
Used on material that can't be autoclaved
Blocks DNA replication
crystal violet
Chemical
Antimicrobial disinfectant
Active against gram + and fungi
Dermatologist use
Alter DNA and cell cycle
Acids/bases
Chemical
Disinfectant
Low or high pH can destroy or inhibit microbial cell
Detergents (surfactants)
Chemical
Weak antimicrobial disinfectant
Disrupts membrane creating abnormal channels
Lipidphillic
Not normally affective on their own
natural antibiotics
Penicillin
Cephalosporins
Bacitracin
Vancomycin
Streptomycin
Gentamicin
Erythromycin
Chloramphenicol
Tetracycline (also synthetic)
semisynthetic drugs
Ampicillin
Amoxicillin
Methicillin
Augmentin
Azithromycin
Rifampin
synthetic drugs
Tetracycline (also natural)
Ciprofloxacin
Levofloxacin
Sulfasoxazole
Penicillin
Beta-lactam
Natural
Narrow spectrum (G+ cocci )
Cell wall synthesis inhibitor
Intravenously
Strep throat, staph infection, some pneumonia
Ampicillin
Beta-lactam
Semisynthetic
Broad
Cell wall synthesis inhibitor
Bladder infections, pneumonia, gonorrhea, meningitis, infections of stomach or intestines
Amoxicillin
Beta-lactam
Semisynthetic
Broad
Cell wall synthetic inhibitor
Tonsillitis, bronchitis, pneumonia, gonorrhea, infections of the ear, nose, throat, skin, urinary tract
Methicillin
Beta-lactam
Semisynthetic
Narrow (G+)
Cell wall synthesis inhibitor
Staph infection
Cephalosporins
Beta-lactam
Natural
Broad
Cell wall synthesis inhibitor
Causes fewer allergic reactions than penicillin
Resistant to beta-lactamases
Should be given parenterally
Augmentin
Beta-lactam and clavulanic acid
Semisynthetic
Broad
Cell wall synthesis inhibitor
Beta-lactamase inhibitor
Combination of amoxicillin and clav. Acid
Sinusitis, pneumonia, ear infection, bronchitis, uti
Bactiracin
Non beta-lactam
Natural
Narrow (staphs/streps)
Cell wall synthesis inhibitor
Staphs and strep skin infection
Component of Neosporin
Streptomycin
Aminoglycoside
Natural
Broad (especially G-)
Protein synthesis inhibitor binds to 30s
Endocarditis, TB, mycobacterium
Gentamicin
Aminoglycoside
Natural
Broad (especially to G-)
Protein synthesis inhibitor binds to 30s
UTIs
Tetracycline
Tetracyclines
Natural/synthetic
Broad
Protein synthesis inhibitor blocks A site
Kills Protozoa
Microbiastatic against Lyme disease and ance
Teeth staining
Erythromycin
Macrolides
Natural
Broad
Protein synthesis inhibitor
Given to those allergic to penicillin
Low toxicity
Upper respiratory infection
Microbacteria
Azithromycin
Macrolides
Semisynthetic
Broad
Protein synthesis inhibitor binds to 50s
Z-pack
Ear throat and URI
Derived from erythromycin
Chloramphenicol
Other
Natural
Broad
Protein synthesis inhibitor
Typhoid fever
Restricted in US
Bone marrow suppression
Ciprofloxacin
Fluoroquinolone
Synthetic
Broad
DNA synthesis inhibitor
Kidney infections
Pneumonia
Levofloxacin
Fluoroquinolone
Synthetic
Broad
DNA synthesis inhibitor
Used when there is resistance
Rifampin
Anti-mycobacteria
Semisynthetic
Broad (mycobacteria)
RNA synthesis inhibitor
TB
mycobacterial infections
MRSA
Sulfasoxazole
Sulfonamides
Synthetic
Broad
Folic acid synthesis inhibitor
UTI (e.coli)
Can cause brain damage if used for long time
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