Lesson 1: Bacterial Colonization, Tissue Invasion and Clinical Disease Flashcards
(29 cards)
A number of bacterial species can reside in animal hosts, either as what?
COMMENSALS OR POTENTIAL PATHOGENS
are hosts to an enormous number
of resident microbes
MAMMALS
a healthy adult human can harbour up to
how many
bacteria?
10¹⁴ bacteria
The vast majority of resident bacteria are _______ that have a
history of co-evolution and harmonious co-existence with the host
COMMENSALS
It can interact with host tissues in ways that result in disease.
PATHOGENIC BACTERIA
What are commensals?
Commensal organisms, acquired soon after birth, are able to adhere to body
surfaces. They form stable polymicrobial communities that are present throughout
life as ‘normal microflora’ on the skin and in the hollow organs whose surfaces and
cavities are open to the environment.
acquired soon after birth, are able to adhere to body
surfaces
COMMENSAL ORGANISMS
Commensal organisms form ___________ that are present throughout
life as ‘normal microflora’ on the skin and in the hollow organs
STABLE POLYMICROBIAL COMMUNITIES
Commensal organisms form stable polymicrobial communities that are present throughout
life as what?
NORMAL MICROFLORA
Commensal organisms form stable polymicrobial communities that are present throughout
life as ‘normal microflora’ on these organs whose surfaces and
cavities are open to the environment.
SKIN AND IN THE HOLLOW ORGANS
What is the composition of the microbial communities?
HOST-SPECIFIC & ORGAN-SPECIFIC (within hosts)
is beneficial to the host in many ways
STABLE MICROFLORA
the digestive relies on this to degrade ingested material in the rumen of
cattle and sheep, in the caecum and colon of horses, and in the colon of pigs
normal microflora
What is the purpose of the normal microflora in the digestive system?
To degrade ingested material in the rumen of cattle and sheep, in the caecum and colon of horses, and in the colon of pigs.
The
microflora of the rumen synthesizes what? as
does the microflora of the intestine in non-ruminants
vitamin K and some of the vitamin B group
The normal microflora primes
_________, facilitating a more efficient host response to challenge by
bacterial pathogens.
IMMUNE SYSTEM
What happened when the community of commensals occupying a particular niche is in
ecological balance?
bacteria utilize the resources they require from the host without causing any obvious adverse effects
when that equilibrium is
disturbed or when the host is under severe stress, an indigenous member may
escape from the restraining influences of the bacterial community and act as an
opportunistic pathogen. This can occur in what organ?
gastrointestinal tract (following the
administration of oral antibiotics)
Bacteria that are harmless in their usual ecological niche can cause disease in another site. Give an example of a bacteria.
Fusobacterium necrophorum
can exist as a commensal in the rumen but when it
transfers to the liver of feedlot cattle it can act as a pathogen that causes hepatic
abscesses
Fusobacterium necrophorum
Fusobacterium necrophorum can exist as a _________ in the rumen but when it
transfers to the liver of feedlot cattle it can act as a __________ that causes hepatic
abscesses.
COMMENSAL
PATHOGEN
Fusobacterium necrophorum can exist as a commensal in the rumen but when it
transfers to the liver of feedlot cattle it can act as a pathogen that causes what?
HEPATIC
ABSCESSES
The ability of a microbe to damage a host is
pathogenicity
The ability of a microbe to damage a host is
pathogenicity
