Microbiology Flashcards
What colour does gram positive bacteria stain?
Purple
What colour does gram negative bacteria stain?
Pinkish red
What shape is cocci bacteria?
Round
What shape is bacilli bacteria?
Rod shaped
Name 1 type of gram positive cocci bacteria.
What type of infection is it present in?
S. Anginosus
Involved in acute dentoalveolar infections
Name 1 type of gram positive bacilli bacteria.
What type of infection is it present in?
Actinomyces israelii
Involved in chronic dentoalveolar infections
Name 1 type of gram negative bacilli bacteria.
What type of infections is it present in?
Prevotella intermedia
Involved in periodontal disease and acute periapical abscesses
What type of bacteria does Metronidazole work on?
Only on strictly anaerobes
What does anaerobic bacteria mean?
Needs oxygen to survive
What does capnophilic bacteria mean?
Needs carbon dioxide to survive
What does facultative bacteria mean?
Can survive with or without oxygen
What does strictly anaerobic bacteria mean?
Species can survive without oxygen
When does antimicrobial resistance occur?
When microorganisms such as bacteria, viruses, fungi and parasites change in ways that render the medications used to cure the infections they cause ineffective
What is intrinsic resistance?
Due to the nature of the bacteria they are resistant due to common structural features
What is acquired resistance?
Mutation in the DNA
-transformation, transduction, conjugation
Acquisition of new DNA
What are the mechanisms of antibiotic resistance?
Altered target site
Enzymatic inactivation
Decreased uptake
What is an altered target site in antibiotic resistance?
The way that the antibiotic gets into the area changes and the antibiotic is no longer effective because it cannot get through and attach the inside of the bacteria
What is enzymatic inactivation in antibiotic resistance?
The bacteria will produce an enzyme that destroys the antibiotic so that it is no longer able to have its effect
What is decreased uptake in antibiotic resistance?
Develop capsules around the bacterial cell wall, nearly as thick as the bacteria itself which stops antibiotics penetrating the cell wall
What is the bacteria that is found in dental sinks, drains and dental unit water lines?
Pseudomonas aeruginosa
What factors affect microbial growth in the mouth?
Temperature
pH
Nutrients
Adherence
Host defences
Anaerobiosis
Antimicrobials
What are the main bacteria in periodontal disease?
P. gingivalis
P. intermedia
B. forsythus
A. actinomycetemcomitans
What is the bacteria found in dental caries?
Streptococcus mutans
What are the bacteria associated with root canal infections?
P. endodontalis
F. Nucleatum
E. Faecalis
What are the stages of tooth development?
Initiation
Morphogenesis
Cyto-differentiation
Matrix secretion
Root formation
