Chapter 6 & 7 Flashcards
Define Mutation
Change in base sequence of DNA
What are the 2 ways in which the base sequence of DNA could be changed?
Spontaneously
or
Exposed to Mutagens
Give 2 examples of Mutagens
Radiation
Chemicals
Define Genotypic change
Change in base sequence of DNA
What can Genotypic change cause?
Character changes
Describe these character changes (2 points)
Persistent
Irreversible
Define Phenotypic change
Changes in bacterial character
Describe these bacterial character changes (2 points)
Temporary
Reversible
When are these bacterial character changes become reversible?
Once environmental (external) condition is removed
What is the purpose of Phenotypic change?
To respond to environmental (external) condition
What is not changed in Phenotypic change?
Genetic Constitution
What is an example of a bacteria that posses Phenotypic change?
L-form
Which change is passed to daughter cells? Genotypic change or Phenotypic change?
Genotypic change
What are the 3 ways in which bacterial gene is transferred?
Transformation
Transduction
Conjugation
Between which cells is bacterial gene transferred?
Donor to Recipient
Define Transformation
Uptake of Naked DNA
Describe the occurrence of Transformation
Natural
What is a Naked DNA?
DNA without associated:
Cells
or
Proteins
What are the 2 forms of Naked DNA
Chromosome
Plasmid
Which bacteria are these 2 forms found in?
Lysed
What does Transformation increase?
Virulence
Which Microorganism is used in Transduction?
Bacteriophage
What are the 2 types of Transduction?
Generalized
Specialized
Which bacterial genes are transferred in Generalized Transduction?
Any
What does Generalized Transduction occur during?
Lytic Cycle
What are the 2 forms of bacterial genes in Generalized Transduction
Chromosome
Plasmid
Which bacterial genes are transferred in Specialized Transduction?
Certain
During when does Specialized Transduction occur?
Temperate Cycle
When exactly does Specialized Transduction occur during Temperate Cycle?
When Prophage:
Take adjacent genes
Replicate
Between which cells is bacterial gene transferred in Transduction?
From Male Donor to Female Recipient
Describe the direction in which DNA is transferred in Conjugative Transduction
One way
Through what feature is DNA transferred in Conjugative Transduction?
Sex Pili
What does Conjugative Transduction transfer DNA by?
Cells Physical contact
What is the function of Antimicrobial Agents?
Kill Microorganisms
What do Antimicrobial Agents kill Microorganisms for?
2 points
Therapy
Or
Prophylaxis
What are the 3 Antimicrobial Agents?
Antibiotics
Disinfectants
Antiseptics
Describe the production of Antibiotics
Natural
What produces Antibiotics?
Certain Microorganisms
What are the 2 Antibiotic effects?
Cidal
Static
What is the Cidal effect on the Microorganism?
Killing
What is the Static effect on the Microorganism?
Inhibition
Describe Semisynthetic Antibiotics
Natural
Who modifies Semisynthetic Antibiotics?
Chemist
What synthesize Semisynthetic Antibiotics?
Chemicals
What is the function of Disinfectants and Antiseptics?
Kill microbes
Where do Disinfectants work on?
Non-living surfaces
Give examples of the Non-living surfaces that Disinfectants work on
Table
Floor
Give an example to a Disinfectant
Chlore
Where do Antiseptics work on?
Living tissue
Give examples of the living tissue that Antiseptics work on
Skin
How do Antibiotics contribute to Selective Toxicity?
Antibiotics don’t find microbes targets in human cell
Give an example of an Antibiotic that give rise to Selective Toxicity
Beta Lactam
Give an example of a Beta Lactam that give rise to Selective Toxicity
Penicillin
How does Beta Lactam Antibiotic work?
Inhibit Peptidoglycan cell wall synthesis
What is the effect of Beta Lactam Antibiotic on human cell?
Unaffected
Why isn’t human cell affected by this drug’s action?
Peptidoglycan Cell wall is absent in human cell
Define Action Spectrum
Microorganisms range
What is the Action Spectrum affected by?
Certain antibiotics
What are the 3 types of Antibiotic Spectrum Actions?
Broad
Narrow
Limited
Describe the range of bacteria affected by the Broad Spectrum action of antibiotics
Wide
Which 2 bacteria is Narrow Spectrum Mainly effective against?
Gram-Positive
Or
Gram-Negative
What is Limited Spectrum Action effective against? (2 points)
Single:
Organism
Or
Disease
What are the 5 Antimicrobial Agents Action?
Synthesis inhibitor for: Cell Wall Cell Membrane Protein Nucleic Acid
Competitive Antagonists
Describe Cell Wall synthesis inhibitors
Bactericidal
What do Cell Wall synthesis inhibitors target?
Bacterial Peptidoglycan synthesis steps
Which bacterial cells do Cell Wall synthesis inhibitors require?
Actively growing
Why do Cell Wall synthesis inhibitors require actively growing bacterial cells?
To produce toxins
Which bacteria are Cell Wall synthesis inhibitors highly active against?
Gram Positive
What are the 3 Cell Wall synthesis inhibitors?
Beta Lactam
Glycopeptide
Bacitracin
What steps of Cell Wall synthesis does Beta Lactam inhibit?
2 points
Initial
Last
How does Beta Lactam affect the initial steps of Cell Wall synthesis?
Binds to cell receptors
What are the cell receptors that Beta Lactam bind to?
Penicillin-Binding Proteins (PBPs)
How does Beta Lactam affect the last steps of Cell Wall synthesis?
Inhibit Peptidoglycan synthesis
Give examples of Beta Lactam (2 points)
Penicillin
Cephalosporin
What step of Cell Wall synthesis does Glycopeptide inhibit?
Early
How does Glycopeptide affect the early step of Cell Wall synthesis?
Inhibit Peptidoglycan Assembly
Give an example of Glycopeptide
Vancomycin
Describe Bacitracin
Highly Toxic
What is the result of Bacitracin being highly toxic?
Not used systemically
Describe Cell Membrane inhibitors
Microbicidal
What do Cell Membrane synthesis inhibitors target?
Cell Membrane’s functions
What synthesis inhibitors have Selective Toxicity?
Cell Membrane
Protein
What type of Selective Toxicity do Cell Membrane inhibitors have?
Narrow Margin
What causes Cell Membrane inhibitors to have Narrow Margin Selective Toxicity? (2 points)
Phospholipids similarities in membranes of:
Bacteria
Eukaryotes
Give an example of Cell Membrane inhibitor
Polymyxin
What are Protein Synthesis inhibitors highly active against?
Gram Negative Bacilli
What type of ribosomes present in Bacteria?
70s
What characteristics do most Protein Synthesis inhibitors have for the bacterial 70s ribosomes? (2 points)
Affinity
Specificity
What type of ribosomes present in mammals?
80s
What is different between the ribosomes present in bacteria mammals?
Chemical Composition
Functions
Give examples of Protein Synthesis inhibitors (6 points)
Tetracycline Aminoglycoside Chloramphenicol Macrolide Fusidic Acid Clindamycin
State an example of Macrolide that inhibits Protein synthesis
Erythromycin
Describe the activity of Nucleic Acid Synthesis Inhibitors
Selective
What do Bacterial Nucleic Acid synthesis target? (2 points)
DNA
RNA
State the drug that inhibits Bacterial DNA synthesis
Quinolone
State the drug that inhibits Bacterial RNA synthesis
Rifampicin
Describe Competition Antagonism
Bacteriostatic
What is the function of Competition Antagonists?
Inhibit Folic Acid Synthesis
How do Competition Antagonists inhibit Folic Acid Synthesis?
Para-Amino Benzoic Acid (PABA) analogue competes with PABA for enzyme active site
Give examples of Competition Antagonists (2 points)
Sulfonamides
Trimethoprim
What is the purpose of Antibiotic Susceptibility Testing?
Measures in vitro antibiotic activity
Describe the measure of Antibiotic Susceptibility Testing (2 points)
Basic
Quantitative
What are the 2 types of Antibiotic Susceptibility Testing?
Minimum Inhibitory Concentration (MIC)
Minimum Bactericidal Concentration (MBC)
Describe Minimum Inhibitory Concentration (MIC) & Minimum Bactericidal Concentration (MBC)
Antibiotic Lowest Concentration
What is the function of Minimum Inhibitory Concentration (MIC)?
Inhibits growth
Under what conditions does Minimum Inhibitory Concentration (MIC) inhibit the growth?
Standard
Define Antimicrobial Breakpoint
Drug concentration in serum with optimal dose
Describe the organisms with MIC below breakpoint
Sensitive
Describe the organisms with MIC above breakpoint
Resistant
What is the function of Minimum Bactericidal Concentration (MBC)?
(2 points)
Kills 99.9% of original inoculum
In a given time
How is Drug Vitro Activity is not always the same as Vivo Activity?
Host factors can affect Anti-Microbial concentration level at infection site
How many drugs are used in Combination Therapy?
2 or more
When is Combination Therapy used?
In special cases
What are the advantages of using Combination Therapy? (4 points)
Prevents arise of resistant strains Exploit antibiotic synergism Treat: Emergency cases Mixed infections
During what emergency cases does Combination Therapy treat?
Anonymous Etiological Diagnosis
Give examples of Antibiotic Synergism
2 points
Endocarditis
Septicemia
What are the 2 effects of combination therapy?
Antibiotic:
Synergism
Antagonism
What is antibiotic synergism?
2 points
Combination antibiotics effect> Individual antibiotics sum effect
Give examples of antibiotic synergism
2 points
Vancomycin
Gentamycin
These 2 antibiotics are used against which bacteria?
S.aureus
Describe S.aureus (2 points)
Multi-resistant
MRSA
What is antibiotic antagonism?
2 points
Least effect antibiotic+ another antibiotic effects
Give examples of antibiotic antagonists
2 points
Imipenem
Pipracillin
Describe Imipenem
Beta lactamase inducer
How does Imipenem affect Piperacillin?
Destroys it
What is involved in Indifference action?
2 drugs
What is the same for these 2 drugs?
2 points
Action
Target
Which drug obtains the action?
Either of them
Give examples of drugs that trigger Indifference action
2 points
Vancomycin
Cephalosprins
Describe Vancomycin & Cephalosprins
Cel wall synthesis inhibitors
What are the 5 factors that influence antibiotic choice?
Infection
Results
Drug toxicity potential
Duration
What are the 2 features of infection that influence the antibiotic choice?
Site
Nature
What are the 2 results that influence the antibiotic choice?
Culture
Sensitivity
What can the antibiotics determine?
Nature of infection
What are the 3 natures of infection?
Bacterial
Viral
Fungal
Which drugs are not used to treat 2 natures of infection?
Antibacterial drugs
What 2 natures of infections which are not treated by Antibacterial drugs?
Viral
Fungal
What is the advantage derived from Culture and sensitivity results?
Proper antibiotic therapy
Which organ would the concentration of drug toxicity be increased in?
Liver
What condition would the concentration of drug toxicity be increased in?
Kidney failure
What is the range of the usual duration of antibiotics?
5-7 days
Describe the Antibiotic course given
2 points
Full
Uninterrupted
Why is a full uninterrupted antibiotic course given?
To avoid resistant bacterial arise
What are the complications of Chemotherapy?
3 points
Toxicity
Allergy
Resistant bacteria
What are the 2 resistant bacterial complexes that lead to a chemotherapy
complication?
Arise
Superinfection
Or
Overgrowth
What are the 3 drugs that cause toxicity?
Chloramphenicol
Streptomycin
Aminoglycosides
What does Chloramphenicol cause as a result of toxicity?
Bone marrow depression
What does Streptomycin cause as a result of toxicity?
Deafness
Which nerves are affected so that deafness is caused?
8th cranial nerves
What do Aminoglycosides cause as a result of toxicity?
Renal failure
What are the 2 drugs that cause Allergy?
Penicillin
Sulphonamides
What are the 2 types of Penicillin allergies?
Local
Systemic
What does Sulfonamide cause as a result of allergic?
Dermatitis
When is bacterial resistance arise trigged?
3 points
Dose:
Low
Interrupted
Improper antibiotics choice
When is resistant bacterial superinfection/ overgrowth triggered?
After a prolong antibiotic treatment
What are the 2 resistant bacteria that undergo superinfection/overgrowth?
Candida
Clostridium difficilis
What does Candida cause as a result of superinfection/overgrowth?
Oral thrush
What does Clostridium difficilis cause as a result of superinfection/overgrowth?
Pseudomembrane colitis
What causes the appearance of Antimicrobial resistance?
Antibiotics misuse
Where could antibiotics be misused in?
3 points
Human
Veterinary medicine
Agriculture
What are the 2 types of bacterial antibiotic resistance?
Inherent/Intrinsic/Natural
Acquired
What does an organism’s antibiotic lack when its inherently resistant?
Transport system
Molecule target
Give an example of an antibiotic molecule target
L form
What causes Acquired resistance?
Bacterial genome changes
What is acquired resistance triggered by?
Bacterial genetic processes
What are the 2 bacterial genetic processes that trigger acquired resistance?
Mutation & Selection
Gene exchange
What are the 2 evolutionary ways of gene transfer?
Vertical
Horizontal
What happens when a drug is introduced?
Resistance appears
What is the evolutionary way in which gene is transferred in selective pressure?
Vertical
Which strains does the antibiotic select in selective pressure?
Resistant strains
Between what does gene exchange occur?
Strains
Species
What is the evolutionary way in which gene is transferred in gene exchange?
Horizontal
What are the 4 ways in which resistant genes can be obtained by from another organism?
Plasmid
Phage
Transposon
Integron
What do the genes obtained by the 4 ways code for?
Enzyme production
What is the function of these enzymes?
Destroy Antibacterial drugs
What are the 2 factors involved in the mechanism of resistance?
Antimicrobial agent
Pathway
How is the antimicrobial agent affected during bacterial resistance?
Inactivated
What are the 2 main features of an antimicrobial agent that are altered?
Permeability
Target site
How is the antimicrobial agent inactivated?
By enzyme production
What are the 2 enzymes that inactivate the antimicrobial agent?
Beta lactamase
Acetyl transferase
What is the effect of these 2 enzymes on the antibiotics?
Destruction
What are the 2 antibiotics which are destroyed by Beta lactamase?
Penicillin
Cephalosporin
What is the antibiotic which is destroyed by Acetyl transferase?
Chloramphenicol
What is the effect of the permeability alteration on the antimicrobial agent?
Unable to enter bacterial cell
What is the antimicrobial agent which is unable to enter bacterial cell after the alteration of its permeability?
Imipenem
What is the name of the bacteria which Imipenem is unable to enter into after the alteration of the its permeability?
Pseudomonas
What are the 2 altered target sites in an antimicrobial agent?
Receptors
Ribosomal units
What is an example of a receptor which is modified due to the alteration of the target site of antimicrobial agent?
Penicillin binding protein (PBP)
What are the 2 modifications of Penicillin binding protein (PBP) receptors?
MRSA
Resistant S. pneumonia.
What are the 2 antibiotics affected by ribosomal units alteration?
Erythromycin
Aminoglycoside
How is the sensitive pathway replaced?
New enzyme obtained
Give an example of Sensitive pathway replacement
Folic acid
What is the antibiotic involved in Sensitive pathway replacement
Trimethoprim
What feature is new for the synthesis of folic acid?
Metabolic pathway
What is the result of having a new metabolic pathway for folic acid synthesis?
Trimethoprim resistance
Define Cross Resistance
The possibility of a microorganism to be resistant to another drug after bein resistant to the first drug
What could both drugs have making them ineffective against a resistant bacteria?
Same action
Similar chemical structure
But what is different in both drug?
Types of aminoglycosides
Define Chemoprophylaxis
Antimicrobial prevent disease occurrence
Where does Chemoprophylaxis occur in?
Surgery time
Immuno-compromised patient
People with normal immunity exposed to certain pathogens
Give an example of Chemoprophylaxis at surgery time
Anaesthesia
Describe the time when antimicrobial is given in Anaesthesia
Pre-operative
Give an example of an inflammation prevented in a surgery of immuno-compromised patient
Endocarditis
What is the type of this surgery?
Dental
Which case requires antimicrobial to be used to prevent Endocarditis?
Damaged valves
Give 2 examples of damaged valves
Heart
Prosthetic
Give an example of an antimicrobial used in people with normal immunity who have been exposed to certain pathogens
Rifampicin
What do patients suffer from in order to be given Rifampicin?
Meiningo-coccal meningitis
