Microbiology Lecture 1 Flashcards
Basis of infectious disease Microbiology lecture 1
a harmful organism that produces a pathology, is the definition for
Pathogen
virulence
virulence factors
commensal
opportunistic pathogen
contaminant
Pathogen
the severity or harmfulness of a disease, is the definition for
Pathogen
virulence
virulence factors
commensal
opportunistic pathogen
contaminant
virulence
factors that are produced by a microorganism and evoke disease, such as toxins. is the definition for?
· Pathogen
· virulence
· virulence factors
· commensal
· opportunistic pathogen
· contaminant
virulence factors
an organism that is part of the normal flora (endogenous), with a mutualistic relationship. is the definition for
· Pathogen
· virulence
· virulence factors
· commensal
· opportunistic pathogen
· contaminant
commensal
an organism that causes infection when opportunity/change in natural immunity changes. is the definition for
· Pathogen
· virulence
· virulence factors
· commensal
· opportunistic pathogen
· contaminant
opportunistic pathogen
an organism that is growing in a culture by accident. is the definition for
· Pathogen
· virulence
· virulence factors
· commensal
· opportunistic pathogen
· contaminant
contaminant
what does strain A indicate
![](https://s3.amazonaws.com/brainscape-prod/system/cm/294/799/201/q_image_thumb.jpg?1574883968)
Image shows that strain A is more virulent compared to strain B
Image shows that the lethal dose to kill 50% of host is 30 (strain A)
what does strain B indicate
![](https://s3.amazonaws.com/brainscape-prod/system/cm/294/800/334/q_image_thumb.jpg?1574884085)
Image shows that the lethal dose to kill 50% of hosts in 50 (strain B)
Image shows that strain B is less virulent compared to strain A
an infective material derived from outside the patients body to cause infection is known as?
exogenous infection
where would an endogenous infection occur
infection would occur within host
Bacteria that is commensal has taken advantage due to lower immune response
is an example of exogenous/endogenous
endogenous
bacteria that transfers from a non-sterile location (mouth) to a sterile location (heart) is an example of
exogenous/endogenous infection
endogenous infection
: the microorganisms in a particular environment (including the body or a part of the body).
is called what
microbiome
which type of bacteria dominates the oral cavity
streptococci
the manner of development of a disease. Endogenous bacteria shifting to a parasitic lifecycle requires adaptation. is the definition of
pathogenesis
which branch of biology deals with the relations of organisms to one another and to their physical surroundings.
ecology of bacteria
which relationship best describes - saprophytic (feed on dead organic material)
free living
which relationship best describes - a symbiotic relationship, when host & organism gain mutual value
mutualistic
which relationship best describes - organism gains advantage but host does not gain from association
commensal
which relationship best describes - live on or in living creatures causing harm/damage to host
parasitic
dynamic relationship between host and pathogen, can result in a shift between what for a pathogen
shift between mutalism and paratism
illness or treatment can shift a mutalistic relationship to what
parasitic relationship
what is your carrier state if you are: showing overt clinical presentation
Active • Convalescent • Healthy • Incubator
active
what is your carrier state if you are: recovering but still cariier
Active • Convalescent • Healthy • Incubator
convalescent
what is your carrier state if you are: showing no overt signs of illness
Active • Convalescent • Healthy • Incubator
healthy
what is your carrier state if you are: maintaining large number of pathogens prior to illness
Active • Convalescent • Healthy • Incubator
incubator
pathogens exit hosts through two mechanism
what are they
Natural: through sneezing and, shedding
Artificial: blood, saliva, aerosols (drill)
spread of from a child via breastfeeding is a type of what spread
vetical spread
how does adhesion of a pathogen contribute to its ability to cause disease
- enables binding of the organism to host tissue, helps promote colonisation
how does Invasion of a pathogen contribute to its ability to cause disease
enables the organism to invade a host cell/tissue
where it can replicate its material and spread - virus
destroy the cells and release endotoxins - bacteria
how does Impeding of a pathogen contribute to its ability to cause disease
enables the organism to avoid host defence mechanisms
how does Aggresin of a pathogen contribute to its ability to cause disease
causes damage to the host directly
how does modulin of a pathogen contribute to its ability to cause disease
induces damage to the host indirectly (via immune system)
the study of the occurrence, spread and control of disease (any disease) is the definition of what
epidemiology
the occurence and spread of disease at low levels randomly is classified as
sporadic
the occurence and spread of disease at low levels present all the time is classified as
endemic
the occurence and spread of disease at high levels in geographically one continent is classified as
epidemic
the occurence and spread of disease at high levels in geographically 2 or more continents is classified as
pandemic
surface molecules can have multiple roles such as;
attachment/ colonisation, what is the function of this role?
these pathogens function is to attach to the surface and start colonising the surface, these would be the 1st layer bacteria
surface molecules can have multiple roles such as; rafting/co-aggregation
what is the function of this role?
allows different molecules to attach to the surface molecules
surface molecules can have multiple roles such as;
signal transduction, what is the function of this role?
allows communciation with cells and within cells for a desired outcome.
bacterial mechanisms are used to avoid host defences.
what is the function of proteases produced by bacteria
proteases target secretory IgA (this is usually in mucosal surfaces, such as tears, respiratory, genital tract and saliva)
what is the function of toxins produced by bacteria
destroy immune cells
what is the function of endotoxins produced by bacteria
interfere with inflammatory response, which can induce inflammation and fever as an immune response
bacterial mechanisms are used to avoid host defences.
what is the function of capsules, mechanisms that inhibit complement, produced by bacteria
evade innate immunity
bacterial mechanisms are used to avoid host defences.
what is the function of antigen varition produced by bacteria
overcome acquired responses
metastasis is an example of what type spread of infection
superficial/systemic spread
lymes disease (tick bite) or malaria is an example of what type of spread of disease
spread of disease via contact or injection
spread of infection from cell to cell is an example of what type of spread
extra or intra cellular spread
migration of pathogens from the mouth to the heart via blood system. can cause which secondary infectious disease in the heart
endocarditis
a bacteria having a thin peptidoglycan layer determines what
that it is a gram -ve bacteria
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/143/401/a_image_thumb.jpg?1578402032)
a bacteria having a thick peptidoglycan layer determines what
the bacteria is a gram +ve
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/143/657/a_image_thumb.jpg?1578402130)
if a bacteria has no outer lipid membrane is it gram -ve or +ve
gram +ve
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/143/764/a_image_thumb.jpg?1578402188)
if a bacteria has an outer lipid membrane is it gram -ve or +ve
gram -ve
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/143/799/a_image_thumb.jpg?1578402248)
what colour would gram -ve bacteria appear under a light microscope
would appear pale reddish colour
This is because the structure of their cell wall is unable to retain the crystal violet stain so are coloured only by the safranin counterstain
what colour would gram +ve bacteria appear under a light microscope
have a distinctive purple appearance
. This is due to retention of the purple crystal violet stain in the thick peptidoglycan layer of the cell wall
the release of cytokines in to the bloodstream, which then make there way to the hypothalamus. resulting in an inflammatory response to the whole body instead of the local site - is known as what
septic shock
the continum od host response to infection - arrange in right order
sepsis
infection
septic shock
severe sepsis
infection
sepsis
severe sepsis
septic shock
what is released , which increases the bodys thermal set point
prostaglandin e
what is the bodys natural response when the bodys thermal set point is increased
the body now percieves that it is cold and starts to shiver to conserve heat.
during the sepsis stage
Small blood vessels become “leaky” and lose fluid into the tissues, what does this do to the blood volume
reduces the blood volume
lower blood volume results in the heart to do what
work harder to maintain oxygenation of tissues thus increasing heart rate
during sepsis stage, poor oxygen perfusion means less essential organs will be shut down
which organs are slowly shut down and which organ is prioritised
prioritised = brain
shurt down = kidneys, skin, liver
during the sepsis stage the blood clotting system is activated.
what are the risk of this
- causes blood clotting in tiny blood vessels, increased risk of haemorrhage.
what are the 4 symptoms of oral abscesses
Pain
Swelling – increase in immune cells in location. Pressed against nerve which causes pain.
Erythema - redness of the skin due to accumulation of vasculature
Suppuration – formation of puss.
what is cellulitis
is a common, potentially serious bacterial skin infection.
Cellulitis usually affects the skin on the lower legs, but it can occur in the face, arms and other areas
caries
gingivitis
periodontitis
pericoronitis
are examples of what
prokaryotic infections of the mouth
if caries of the tooth was not treated and further progressed what type of abscess coul it lead to -
periapical or dentoalveolar abscess
prokarotic infection of the gingiva leads to what
gingivitis
periodontal disease if left to progress
prokaryotic infection of the space between the tooth and the gingiva (periodontal space) leads to development of which dental abscess
periodontal abscess
infection of the gingivae covering partially erupted tooth leads to which pathology
pericoronitis
which type of dental abscess forms - at the apex of the root
periapical abcess
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/146/859/a_image_thumb.jpg?1578405376)
which type of dental abscess forms - in the space between the gum and tooth
gingival abscess
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/146/928/a_image_thumb.jpg?1578405430)
which type of dental abscess forms - in a periodontal pocket
periodontal abscess
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/146/961/a_image_thumb.jpg?1578405465)
which type of dental abscess forms - around impacted or partially erupted tooth
pericoronal abscess
![](https://s3.amazonaws.com/brainscape-prod/system/cm/298/146/986/a_image_thumb.jpg?1578405502)
what would be the treatment options for types of dental abscess
drainage of pus
antibiotics
treatment - root canal
worse case scenario - extraction
what could serious infections of dental abscess lead to
access to soft tissues - development of cellulitis
direct spread - near area of infection
indirect spread - through the vascular system - development of endocarditis
a bacterial complex that involves greater than 4 species of bacteria is known as
polymicrobial
bacteria that don’t grow under laboratory conditions, making it impossible to characterise and understand them. are known as
unculturable microbes
an organism that makes ATP by aerobic respiration if oxygen is present but can switch to fermentation if oxygen is absent. is known as a what
faculative anaerobe
microorganisms killed by normal atmospheric concentrations of oxygen (20.95% O2). And can only survive in environments with lack of oxygen. are known as
obligate anaerobes