Module 8 Flashcards
Control of Microbes and Public Health
strategies for control on inanimate objects (3)
sterilization
disinfection
sanitization
sterilization
elimination of ALL vegetative cells, endospores, and viruses
Disinfection
reduction/destruction of microbial load
Sanitization
reducing microbial loads to a safe public health level
microbial control methods for living tissue (2)
antisepsis
degerming
Antisepsis
reduced microbial loads with antimicrobial chemicals
degerming
reduces microbial load by scrubbing and mild chemicals
physical method classes for control (2)
heat and radiation
heat treatment options (7)
boiling
dry heat
oven
incinerator
flame
pasteurization
autoclave
autoclave
sterilize by cooking at 121C for 15+minutes
radiation
damages DNA causing things to die off
less effective over time
can be ionizing or non ionizing
ionizing radiation
alters melecular structures through x or gamma rays
non ionizing radiation
mutations due to UV light exposure
how do heat and high pressure reduce populations
killing
how do cold, hyperbaric, and desiccation reduce population
by controlling growth
mechanical filtration
done with the use of filters
HEPA filtration
physically remove microbes from the air
pore size 0.3um
membrane filtration
removed microbes from liquid
pore size 0.2um
gas chemical control methods
sterilization
disinfection
liquid chemical control methods
chemotherapy
antisepsis
disinfection
sterilization
-static
stop growth, no kill
-cidal
kills
-lytic
lyses
disc diffusion
assesses susceptibility by looking at how much is killed around the antimicrobial sample
how to calculate kill efficacy
9s = #0s
99.9%=1000 microbes
what does toxicity towards host depend on?
dosage and route
broad spectrum
indiscriminate killing
many different groups
target cell wall
narrow spectrum
kills specific groups
antibiotics
chemicals that kill bacteria or prevent growth
target: penicillin binding proteins, peptidoglycan subunits
Mode: inhibit cell wall biosynthesis
target: 30S + 50S ribosomal subunits
Mode: inhibit biosynthesis of proteins
target: LPPS, inner and outer membrane
mode: disrupt membranes
Target: RNA and DNA
mode: inhibit nucleic acid synthesis
target: folic and mycolic acid synthesis enzyme
mode: antimetabolites
taget: mycobacterial ATP synthesis
mode: Mycobacterial adenosine triphosphate synthase inhibitor
classes of protein synthesis inhibiting antibacterials (5)
chloramphenical
macrolides
lincosamides
aminoglycosides
tetracyclines
linosamides
prevent peptide bond formation, stop synthesis
animogylcosides
impare proofreading, faultry proteins
tetracyclines
block binding to tRNAs, inhibit synthesis
mechanisms of antifungal drugs (4)
inhibiting ergosterol synthesis
bind to ergosterol to create pores disrupting membrane
inhibit cell wall synthesis
inhibit microtubules and cell division
mechanisms of antiviral drugs
nucleoside analogue inhibition
inhibit escape of virus from endosomes
inhibit neuraminidase
inhibit viral uncoating
inhibit protease
inhibit integrase
inhibit membrane fusion
Efficacy
how fast/much it kills
susceptibility
concentration required to kill
ways to become antibiotic resistant (4)
efflux pump
blocked penetration
target modification
inactivate enzymes
ways to overcome resisitance
overproduction of target
production of alternate enzymes
target mimicry
epidemiology
study of occurrence, distribution, and determinants of public health and disease in a population
goal is to identify nature and transmission of disease
public health
health of the population worldwide
public health measures
slow or stop disease to maintain public health
mortality
incidence of death in a population
mobidity
incidence of disease in a population
DALY
disability adjusted life year
disease burden in terms of lost years due to disease, disability, premature death
- effect on morbidity
prevalance
total cases at a given time
incidence
total new cased in a given time
epidemic
large number in a population but localized and narrow (not global)
pandemic
widespread and worldwide disease
endemic
constantly present in a population, reservoir presence
reservoir
(for animal, environmental, and human pathogens)
normal habitat of an infectious microbe
animal = zoonotic
environmental = sapronosis
human = human or orzoanthroponosis
Contact tramsmission
direct: physical contact between host and potential
indirect: via intermediate (vehicle, fomite, vector)
droplet transmission
<1m from source
large droplets on respiratory secretion settle on surface
airborne transmission
> 1m from source
microbes released into air and freely float and attach to dust particles and move with air currents
how to eliminate reservoirs (3 sectors)
animal: immunize or slaughter
environmental: decontaminate or avoid contact
human: identify, isolate, treat
how to limit availability of new hosts
improve living conditions, general health, nutrition
make immune system stronger (vaccinate)
how to block routes of transmission
indirect- clean, prevent contamination, remove vectors
airborne: flow systems to prevent dispersal
droplet/direct: wash hands, barriers
swiss cheese model
multiple layers working to slow transmission
why cant some infections be eliminated(4)
infection cycle variation (asymptomatic, pre-symptomatic)
vaccine compliance
reservoirs
social pressures
purposes of public health measures (3)
decrease morbidity and mortality
decrease prevalence and incidence
increase overall public health
