EX2 Leys Flashcards
This is a mixture of microbes and a matrix made up of extracellular polymers
biofilm
What do you find in complex structures within a biofilm
bacteria
True or False
Most biofilms are mixtures of different species of bacteria
True
True or False
Biofilms can include other micro-organisms than bacteria
True
Biofilms have complex structures that do what
give accessibility to nutrients and removal of waste products
True or False
Bacteria in a biofilm are more resistant to antibiotics and host attacks
True
Most bacteria form biofilms in an environment where there is what
liquid flowing
Wild bacteria have extracellular polymers attached to their surface that allow what
binding to surfaces or other bacteria
Biofilms are associated with what dental diseases
periodontal disease
caries
Many bacterial diseases involve what type of species
polymicrobial
What is the type of communication between bacteria
quorum sensing
What are the two general mechanisms for quorum sensing
recognizes similar bacteria (same species)
recognizes all bacteria
True or False
Essentially all bacteria have mechanisms for quorum sensing
True
When do quorum sensing mechanism produce a response
when a certain threshold concentration of secreted molecules is reached
This is an essential process in biofilm formation
quorum sensing
This type of bacteria must have oxygen to grow
strict aerobes
This type of bacteria cannot tolerate oxygen
obligate anaerobes
This type of bacteria can grow with or without oxygen
facultative anaerobes
DNA that enters a bacterial cell can undergo what three things
be degraded
integrated into the host chromosome
integrated into plasmid
These are used by bacteria to degrade foreign DNA
restriction endonucleases (restriction enzymes)
This is the uptake of naked DNA by “competent cells”
transformation
This is the transfer of DNA between bacteria through a virus
transduction
This is the transfer of DNA through cell to cell contact using a sex pilus
Conjugation
Mutations in DNA can cause this
antibiotic resistance
This type of mutation is less likely to cause antibiotic resistance
deletion
Bacteria remove oxygen radicals from cells how?
by converting them to hydrogen peroxide with superoxide dismutase
Hydrogen peroxide is converted to what
converted to water and oxygen with a catalyst
Bacteria that do not have superoxide dismutase and catalase are what
anaerobic
they do not tolerate oxygen
These are the most numerous members of the normal flora of the human colon
bacteroides
This disease is a result of spillage of intestinal material into the peritoneal cavity
biphasic disease
acute inflammation followed by localized abscesses
This is the most common isolate from intra-abdominal abscesses
bacteriodes fragilis
This on the surface of B. fragilis is not toxic, unlike other gram negative bacteria
LPS
Of the hundreds of different species of bacteria that may spill into the peritoneal cavity, this will help the bacteria evade phagocytosis of the host
a polysaccharide capsule
Intra-abdominal abscesses caused by B. fragilis or other bacteria can lead to this
bacteremia
septic shock
This is the presence of bacteria in the blood, with out without the presence of an illness
bacteremia
This is a severe systemic illness marked by hemodynamic derangement and organ malfunction
sepsis
The treatment of sepsis with antibiotics is important but can be difficult because of this
the dead bacteria can release toxins that initially cause more damage
These are widespread in nature, but few cause disease
spirochetes
The corkscrew-like movement of spirochetes is facilitated by what
a periplasmic flagella
This is the causative agent of syphilis, and is difficult to study because it cannot be grown in the lab
treponema pallidum
When T. palladium enters the body, it becomes systemic almost immediately, how?
by traveling via the lymphatic system to system circulation
The primary chancre (painless ulcer) formed by T. palladium heals (spontaneously/with treatment), and the infection (is/is not) systemic
spontaneously
is
What percentage of patients who do not receive treatment for primary syphilis enter the secondary stage of syphilis
50%
True or False
The rash produced by secondary syphilis is often mistaken for other problems
True
Tertiary syphilis, if left untreated, can progress where and cause what
to the CNS
causing ataxic gait, paresis, blindness, dementia, and death
True or False
Syphilis is one of the hardest STDs to control
False; it is one of the easiest to control; there are good diagnostic tests and treatment is available and inexpensive
This is the causative agent of Lyme’s disease
Borrelia burgdorferi
Lyme’s disease progresses in stages to from what to what
from an acute and local skin infection to a chronic disease of the CNS and joints
B. burgdorferi is transmitted by what
ticks
There are how many different bacterial species found in the oral cavity, from many different phyla
500-1000
True or False
You can find all the different types of bacteria everywhere in the mouth
False; different bacteria occupy different environmental niches
Subgingival bacteria are generally what
Supragingival bacteria are generally what
subgingival = proteolitic supragingival = saccrolitic
These factors promote colonization in the oral cavity
adherence properties
synergistic bacteria
nutritional substrates
temperature/moisture content
These factors inhibit colonization in the oral cavity
antimicrobial properties of saliva
mechanical shearing
temperature/moisture content
True or False
There are many bacteria associated with periodontitis, while there are fewer species associated with periodontal heath
True
Shifts in microbial composition occur in periodontitis, however no bacterium is what
found on all patients with periodontitis and never found in healthy subjects
The tissue destruction that occurs during periodontitis is a result of what
host response
There is a small shift of what bacteria during periodontitis
from gram positive to gram negative
The complexity of the microbial community (increases or decreases) during periodontal disease
increases
There is a slight shift to more what bacteria in periodontal disease
uncultivated
True or False
Microbial diversity declines in caries
True
True or False
There is progression of dominant species as caries progresses
True
Each location in the oral cavity has its own associated microbial composition, and there (is/is not) any overlap of species
is overlap of species
