NSG 511: Exam 3 Questions and Correct Answers
elective toxicity
The ability of the antimicrobial to kill or suppress the pathogen without injuring the host
Unique features of bacterial cell (3)
-rigid cell wall
-must synthesize folic acid
-unique ribosome for protein synthesis
bacteriocidal
agent that kills bacteria (targets cell wall or nucleic acid synthesis)
bacteriostatic
inhibits bacterial growth (usually by impairing protein synthesis)
Narrow spectrum antibiotics
Effective against specific bacteria
broad spectrum antibiotics
affect a wide range of gram-positive or gram-negative bacteria
Why we do not like using broad spectrum antibiotics (3)
-likely to cause secondary infection
-disruption of GI biome
-can promote acquired resistance
bacterial acquired resistance
bacteria become resistant to effects of drug through evolutionary selection pressure
,Ways bacteria develop resistance (5)
-develop new cell processes to avoid using antibiotic's target
-change or destroy antibiotics with enzymes
-restrict access by changing entryways
-change antibiotic's target
-use pumps to get rid of antibiotics
Transduction
resistance genes transferred between bacteria via phages
Conjugation
resistance genes transferred between bacteria via physical connection
Transformation
resistance genes released from live or dead bacteria and picked up by neighboring bacteria
Order of operations to select antibiotics
1. Identify organism (gram +/- or polymerase testing)
2. sensitivity testing (if sensitive, antibiotic is effective; if resistant, antibiotic is not effective)
3. culture and sensitivity report (including degree of inhibition and sensitivity/resistance to
antibiotic)
Sensitivity testing
Testing to determine the antibiotic that will most effectively inhibit the pathogen (with Kirby
Bauer test - discs on inoculated agar plate)
source of culture
wherever infection is presumed to be
, minimal inhibitory concentration (MIC)
if large, resistant
if small, sensitive
empiric therapy
treatment of an infection before specific culture information has been reported or obtained
(due to having a really sick patient)
usually guessed based on location of infection and common infecting organisms of that area
Misuse of antibiotics (5)
-using broad spectrum vs. narrow spectrum
-using them for non-bacterial infections
-fever of unknown origin
-in animal feed
-incorrectly (not completing full course)
antibiotic course
most sensitive bacteria killed off early
slightly less sensitive/more resistant linger after symptoms end, but drug needs to be
completed to kill these too
superinfection
an infection caused by the treatment of another infection, usually due to broad spectrum
antibiotic treatment
MRSA (methicillin-resistant Staphylococcus aureus)
elective toxicity
The ability of the antimicrobial to kill or suppress the pathogen without injuring the host
Unique features of bacterial cell (3)
-rigid cell wall
-must synthesize folic acid
-unique ribosome for protein synthesis
bacteriocidal
agent that kills bacteria (targets cell wall or nucleic acid synthesis)
bacteriostatic
inhibits bacterial growth (usually by impairing protein synthesis)
Narrow spectrum antibiotics
Effective against specific bacteria
broad spectrum antibiotics
affect a wide range of gram-positive or gram-negative bacteria
Why we do not like using broad spectrum antibiotics (3)
-likely to cause secondary infection
-disruption of GI biome
-can promote acquired resistance
bacterial acquired resistance
bacteria become resistant to effects of drug through evolutionary selection pressure
,Ways bacteria develop resistance (5)
-develop new cell processes to avoid using antibiotic's target
-change or destroy antibiotics with enzymes
-restrict access by changing entryways
-change antibiotic's target
-use pumps to get rid of antibiotics
Transduction
resistance genes transferred between bacteria via phages
Conjugation
resistance genes transferred between bacteria via physical connection
Transformation
resistance genes released from live or dead bacteria and picked up by neighboring bacteria
Order of operations to select antibiotics
1. Identify organism (gram +/- or polymerase testing)
2. sensitivity testing (if sensitive, antibiotic is effective; if resistant, antibiotic is not effective)
3. culture and sensitivity report (including degree of inhibition and sensitivity/resistance to
antibiotic)
Sensitivity testing
Testing to determine the antibiotic that will most effectively inhibit the pathogen (with Kirby
Bauer test - discs on inoculated agar plate)
source of culture
wherever infection is presumed to be
, minimal inhibitory concentration (MIC)
if large, resistant
if small, sensitive
empiric therapy
treatment of an infection before specific culture information has been reported or obtained
(due to having a really sick patient)
usually guessed based on location of infection and common infecting organisms of that area
Misuse of antibiotics (5)
-using broad spectrum vs. narrow spectrum
-using them for non-bacterial infections
-fever of unknown origin
-in animal feed
-incorrectly (not completing full course)
antibiotic course
most sensitive bacteria killed off early
slightly less sensitive/more resistant linger after symptoms end, but drug needs to be
completed to kill these too
superinfection
an infection caused by the treatment of another infection, usually due to broad spectrum
antibiotic treatment
MRSA (methicillin-resistant Staphylococcus aureus)
