Microbiology Flashcards
Spherical shaped bacteria.
Cocci
Rod shaped bacteria.
Bacilli
Comma, S, or Spiral shaped bacteria.
Spirochetes
Shapeless bacteria.
Pleomorphic
What color does Gram + organisms stain?
Blue
What color does Gram - organisms stain?
Red
What does Gram - Rods include?
Prevotella and Porphyromonas gingivalis
What does Gram - Spiral include?
Spirochetes
What does Beta-hemolytic streptococcus, Lancefield Group A (attach to pharyngeal epithelium) cause?
Streptococcal pharyngitis (strep throat)
Tonsillitis
Scarlet and Rheumatic fever
Pyogenic (pus-producing) infections
What does Alpha-hemolytic streptoccocus cause?
Dental caries (strep mutans creates acid and dextran from sucrose)
Endocarditis (strep mitis)
Abscesses (especially due to strep intermedium and strep anginosus)
Cellulitis
Pneumonia
Strep salivarius is associated with the tongue
Early lesion, associated with dextran and acids.
Strep Mutans
Advancing lesion, associated with lexans, advanced caries, and produces lactic acid. This is a Gram + Rod.
Lactobacillus
Associated with root decay. Gram + Rod
Actinomyces
Typically associated with pus and abscess formation.
Staphylococcus
Most drug-resistant disease-causing organism known and treated with Vancomycin and Bactrim.
MRSA, Methicillin Resistant Staphylococcus Aureus
This is a gram - Cocci and the causative organism for meningitis and gonorrhea.
Neisseria
Gram - Rod that is associated with “pregnancy” gingivitis, cellulitis, and NUP/NUG.
Prevotella
Gram - Rod associated with periodontal disease and connective tissue destruction through the production of collegians.
Porphyromonas gingivalis
Gram - spiral shaped, causative organism for syphilis and Lyme disease. Closely associated with NUP and NUG.
Spirochetes
Obligate aerobes
Require oxygen
produce catalase, peroxidase, and superoxide dismutase
Bacteria in this include: neisseria, pseudomonas, and mycobacterium.
Facultative Anaerobes
Aerobic, but can grow in the absence of oxygen via fermentation
BActeria in this include: Staphylococcus, Listeria, and Actinomyces.
Microaerophilic
Can tolerate oxygen, but produce energy via fermentation.
Bacteria in this include: Streptococcus and Spirochetes
Obligate anaerobes
Do not tolerate oxygen.
Bacteria in this include: Prevotella (hormonal gingivitis, facial cellulitis, NUP/NUG), Porphyromonas gingivalis (produces collagenase, destroys collagen).
What’s the ideal non-surgical treatment for periodontal disease?
Tetracycline.
Lag phase
Slow growth with routine metabolic activity.
Growth occurs exponentially, with increased metabolic activity and bacterial organisms most susceptible to antimicrobial agents in this phase.
Logarithmic Phase
Stationary Phase
No growth, as available nutrients have been utilized and waste products accumulate.
Bacterial organisms die off.
Death Phase
A component of normal oral flora, is also present in the digestive, respiratory, and urogenital tracts, and can lead to systemic infection.
Candida Albicans
What can Candidiasis present as?
Pseudomembranous candidiasis ("thrush"), white plaques that wipe off.
Erythematous candidiasis, red ulcerative lesions.A recombinant form of hepatitis B surface antigen, which leads to artificially acquired active immunity without risk of disease.
Hepatitis B vaccine
Non-specific, and does not require exposure to an antigen. It is not strengthened by repeated exposure, nor is it “remembered” by the body. Aided by barriers, natural killer cells, phagocytosis, inflammation, and certain circulating proteins which assist other defensive mechanisms.
Natural Immunity
Occurs after exposure to an antigen, and improves with repeated exposures. Because it is mediated by antibodies and T-cells, it is “remembered”. May be active or passive.
Acquired Immunity
What does naturally acquired active immunity result from?
Infection
What does artificially acquired active immunity typically result from?
Vaccination
Active Immunity
Delayed, but long-lasting
When does naturally acquired passive immunity occur?
During pregnancy
What does artificially acquired passive immunity typically result from?
Injection
Passive Immunity
Immediate, but short-lived.
What are Leukocytes and what do they include?
White blood cells and the cells of the immune system.
Include: Lymphocytes (T-cells, B-cells, and natural killer cells), Monocytes (which differentiate into macrophages), Granulocytes (neutrophils, eosinophils, basophils), and dendritic cells (antigen-presenting cells).
Precursors from bone marrow migrate to, and mature in the thymus. Regulate the production of antibodies, and play a role in the suppression of certain immune responses and involved in tissue graft destruction and delayer hypersensitivity.
T-Cells.
T-helper cell (“CD8-T cell”)
Able to directly attack and destroy diseased cells.
T-helper cell (“CD4-T cell”)
produces cytokines, which stimulate other immune cells-including macrophages, natural killer and dendritic cells-to move to the site of infection, trauma, or inflammation. Stimulates B cells to produce antibodies.
Develop in bone marrow, but do not migrate to the thymus. Differentiate into plasma cells which produce antibodies. Are antigen-presenting cells.
B-Cells
Responsible for phagocytosis, production of cytokines, antigen transportation and presentation to T-cells.
Monocytes (Macrophages)
Most numerous of all white blood cells, represent first line of defense, migrate in response to chemotactic factors, able to squeeze through the epithelial lining of capillaries (diapedesis), and capable of phagocytosis.
Neutrophils.
Help regulate the immune system and act as antigen presenting cells, capable of activating both T and B cells.
Dendritic Cells
Largest antibody, active as the primary responder to the initial encounter of a new antigen.
IgM
Most abundant antibody, the only antibody able to cross the placenta.
IgG
Primary immunoglobulin present in saliva.
IgA
Mediates anaphylactic hypersensitivity by binding to mast cells and basophils.
IgE
Type I-Anaphylactic (Immediate)
Requires previous exposure to the antigen, mediated by IgE, which induces the release of histamine from mast cells and basophils.
Type II-Cytotoxic
Antibody attacks the antigen leading to lysis (complement mediated), IgG and IgM are the principal antibodies involved.
Type III-Immune Complex
Occurs when an accumulation of antibody-antigen complexes have not been cleared, this attracts neutrophils, IgG and IgM are principal antibodies involved.
Type IV-Delayed
Cell mediated (not humoral), Helper T cells are sensitized by an antigen, Cytokines are released upon a subsequent exposure to that antigen, Response is 48-72 hours after exposure to the antigen.
Process by which genetic info is passed from DNA to mRNA
Transcription
Process by which mRNA directs protein synthesis.
Translation
