M3 Koch's Postulates Flashcards
what are the different ‘ages’ moved through time
age of disaster
age of disease
now = ape of decay
what does age of decay mean
treating disease efficiently but body wearing out
cancer, ageing and obesity
what dd koch hypothesise and when
germ theory of disease 1880’s
what is koch postulates about
microorganisms is present in every case of disease but absent in health
how can koch’s postulates be confirmed
suspected organisms isolated and grown in pure culture then inoculate healthy see if become diseased
what should be seen form the pt’s innoculum of infectious agent
Ab in pt’s serum
what are the major groups of infectious agents
protozoa
fungi
bacteria
viruses
what are protozoa
single celled animals
eukaryote
e.g. malaria
what are fungi
higher plant like organism
eukaryotes
e.g. candida albicans - thrush
what are bacteria
generally small, single celled
prokaryotes
what are viruses
very small obligate parasites
non living
resp and blod bourne
the human body is know as a what
eosytem
micro- biome
how many mammalian cells in human bod
10^13
how many microorganisms in human bod
10^14
what are the two types of micro organisms assc with body
endogenous - majority
exogenous - not normla flora
what is a free living bacteria
saprophytic
feed on dead org mat
one genus sp
what is commensal bacteria
organisms gains advantage but host doesn’t gain from ass
what is a mutualistic bacteria
or symbiotic
relationship
host and org mutual benefit
what is a parasitic bacteria
live on or in living creature causing harm/damage to host
can organisms change lifestyle
yes
can e.g. free liv - parasite
what is the mutualism and parasitism described as
dynamic relationship
large num bacteria in body the ability to shift and adapt
what is mutualistic symbiotic relationship
organism can prod nutrients or vitamins
can degrade harmful chemicals
colonisation resistance
hat si colonisation resistance
can exclude access/colonisation by pathogen
what are some sites where there is common ‘microflora’
body surfaces - epi oral cavity resp tract GI tract urinary tract
is there microflora in stomach
not usually
s cocci and lactobacilli
h pylori
stomach cancer
does the colon have microflora
has a lot micro orgs
complex micro flora
obligately anaerobic sp
is the duodenum densely populated
more complex
prelim s.cocci, lactobacilli, bactericides
what si the ileum population like
more densely populated than jejunum
complex microflora
what is usually sterile
bronchi alveoli trachea
where can oral microbial flora found
mucosa lips, cheek and palate tongue tooth surfaces- approximate and sbginigval saliva tonsils area dentures
what bac is found in gingiva
s. cocci
actinomyces
what bac is found in palate
s.cocci
actinomyces
what bac is found on tooth surface
s.cocci
actinomyces
fusobacterium
what bac is found on tongue
s.cocci
what bac is found in cheek
s.cocci
actinomyces
what bac is found on gingival crevice
v.complex
s.cocci
actinomyces
gram -ve anaerobic cocci and rods
gram +ve anaerobic cocci nd rods
how is sampling done of microflora
difficult to do
stimulated/non stim saliva
mucosal surfaces
plaque
where is s mutant found
saliva & approximal plaque
where is s sanguinias found
tongue, saliva, approximate nd sub gingival
where is s oralis found
tongue, saliva, approximal, sub gingival
where is s salvarius found
tongue
saliva
approximal
sub gingival
where is actinomyces found
saliva
approxiaml
subgigival
where is lactobacillus found
saliva
approximal
where fusobacterium found
tongue
saliva
approximal
subigiinigval
where ar spirochetes found
sub gingival
where are candida found
tongue
saliva
what are some key points
normal flora varies
imp prevent disease
microflora potential pathogens
change in state
what is a pahogen
microbe capable of causing host damage
includes classical pathogens and opportunistic pathogens and damage prod direct or via host immune response
what is virulence
measure capacity of pathogen to cause disease
microbe cause damage to host
what is a virulence factor
making more or less capable of disease
component pathogen damages host not needed for survival
what is an adhesin
enables binding of organism to host tissue
what is an invasin cell
enables organism to avoid host defence mechanisms
what is aggressin
causes damage to host directly
what is modulin
induces damage to host directly
what is the molecular level of koch postulates
virulence trait strongly assc with pathogenic strain
inactivation dec pathogenicity
gene expressed at some point
what are produced to protect host
antibodies directed ag geen product to protect host
what are limitations of koch postulates
organism cannot be cultured/isolated - obligate intracellular organism
organism is a human pathogen
what is a obligate pathogen
must cause disease for transmission
human disease
what is an opportunistic pathogen
do not have to cause disease for transmission
animal pathogen
what is an ‘accidental’ pathogen
disease hinders or prevents transmission
notmal flora –> disease
what are some examples of obligate pathogen
TB
csyphilus
what are examples of opportunistic pathogens
vibrio cholera
what are some examples of accidental pathogens
meningitis
what is epidemiology
study of occurnace, spread and control of disease
what do u consider for any organism in epidemiology
infection dose virulence of organism host status (resistance)
what is sporadic
not consistent
small peaks
what is endemic
present whole time at low level
what is epidemic
sudden spike to high level location of significant land area
what is pandemic
travels the whole world
2 or more continents
whats prevalence
proportion of pop affected
what is retrospective
clinical effect studied
what is prospective
pop expo to presumed cause studied
what is microflora
endogenous pop of microbes
simply what is koch postulates
basis for demo cause of disease
what is pahogeniciyt
capacity to cause disease/damge
what is virulence
relative ability to cause disease
