anti-microbials

Question 1

what is included in infection control?

Answer 1

disinfection of non-sterilisable surfaces and equipment
heat sterilisation of all compatible equipment
handwashing techniques + appropriate antiseptics
combined with barrier techniques: masks, gloves and eye protection

Question 2

what are disinfectants?

Answer 2

strong chemical agents that inhibit or kill microorganisms

Question 3

what are antiseptics?

Answer 3

disinfecting agents with sufficiently low toxicity for host cells
-can be used directly on skin, mucous membranes, or wounds

Question 4

what are sterilants?

Answer 4

kill both vegetative cells and spores when applied to materials for appropriate times and temperatures

Question 5

what is antisepsis?

Answer 5

use of chemicals to destroy most pathogenic organisms on animate surfaces

Question 6

what properties are important for antiseptics and disinfectants?

Answer 6

toxicity to microorganisms but not to human cells

degree of selectivity depending on contacted tissues

Question 7

what are uses of antiseptics?

Answer 7

treatment of skin conditions
prevention of infections in cuts and wounds
cleaning the skin area of surgery from microorganisms
prophylaxis and treatment of infections in mucosal areas such as mouth, nose, vagina that are open to environment
as a scrub for surgeons and the medical personnel

Question 8

what are the classifications of antiseptics?

Answer 8

those that denature proteins (cidal)
those that cause osmotic disruption of the cell (cidal)
those that interfere with specific metabolic processes (growth arrest/static)

Question 9

what is the mechanism of action of phenols, iodine, alcohols, aldehydes and metallic compounds?

Answer 9

denature proteins and DNA bases

Question 10

what is the mechanism of action of cationic detergents?

Answer 10

interfere w/ plasma membrane permeability and cause leakage of enzyme, coenzyme and metabolites

Question 11

what is the mechanism of action of oxidizing compounds?

Answer 11

oxidize functional molecules in the microorganisms

Question 12

what are iodophores?

Answer 12

oxidize -SH groups of proteins and enzymes to produce S-S bonds and disrupt structure and function of these
either antiseptic/disinfectant
kill vegetative bacteria, mycobacteria, fungi, lipid containing viruses

Question 13

what are alcohols?

Answer 13

ethyl alcohol (70%) and isopropyl alcohol
antiseptic/disinfectant
reduce bacterial numbers 90% on skin
rapidly kill vegetative bacteria, fungi and inactive lipophilic viruses
denature proteins and disturb the membrane permeability of bacteria
limited antibacterial spectrum

Question 14

what is chlorhexidine?

Answer 14

antiseptic
most effective agains gram+ cocci
less gram- and + rods
spore germination inhibited
strongly adsorbs to bacterial membranes and causes leakage of small molecules and precipitation of cytoplasmic proteins
resistant to inhibition by blood/organic material

Question 15

what are oxidising agents?

Answer 15

H2O2 antiseptic
concentrations potentially useful for antisepsis are against vegetative bacteria, higher conc. sporicidal
disinfection of respirators, acrylic resin implants, plastic eating utensils, soft contacts, cartons for milk/juice
10-25%

Question 16

what is the danger of antiseptic, disinfectant and sterilant to users

Answer 16

short term/long term toxicity
general biocidal activity
accumulate in environment/body

Question 17

what are antibiotics?

Answer 17

a chemical substance produced by one organism that is destructive to another
naturally occurring antimicrobials
-metabolic products of bacteria and fungi
-reduce competition for nutrients and space

Question 18

what are the types of antibiotic?

Answer 18

bacteriostatic

bacteriocidal

Question 19

what are the cellular targets of antibiotics?

Answer 19

cell wall
cell membrane
nucleic acid
protein synthesis

Question 20

what properties does the ideal antimicrobial agent have?

Answer 20

selective toxicity against microbial target
minimal toxicity to host
cidal activity
long plasma half-life
good tissue distribution
low binding to plasma proteins
oral and parenteral preparations
no adverse interactions with other drugs

Question 21

what is the mechanism of action for antibiotics?

Answer 21

cross linking of cell wall prevented

Question 22

what contributes to antibiotic resistance?

Answer 22

misuse

Question 23

what is included in misuse of antibiotics?

Answer 23

using outdated or weakened antibiotics
using antibiotics for the common cold & other inappropriate conditions
using antibiotics in animal feed
failing to complete the prescribed regimen
using someone else’s leftover prescription

Question 24

what are the resistance mechanisms for antibiotics?

Answer 24

blocking entry
inactivating enzymes
alteration of target molecule
efflux of antibiotic