Flashcards in Oral Microbiology Deck (192):
3 features/capacities of Pathogens:
Overcome host immunity
Replicate within the host
Name 5 virulence factors
What are the two types of cells
What is a major virulence factor in Gram negative bacteria?
Bacteria contain no membrane-bound organelles
How is bacterial genetic material packaged?
Bacterial Ribosomes ______
Eukaryotic Ribosomes ______
What do bacteria use for attachment and conjugation?
What is made of carbohydrate polymers and a major virulence factor for bacteria?
Why must bacteria secrete many digestive enzymes?
Only small molecular weight molecules can pass through cell wall and membrane
The ecological biosystem of bacteria are referred to as...
There is often a battle over Fe resources between host and bacteria
Describe the outer layers of a Gram Positive bacteria?
Single inner plasma membrane
*often 50% wall by weight
Describe the outer layers of a Gram Negative bacteria.
Outer membrane (LPS)
Thin cell wall
Cell (inner) membrane
Gram+ bacteria have ___ layers
Gram- bacteria have ____ layers
What often slimy secretion do some bacteria surround themselves with that has strong anti-phagocytic properties?
What is the essential, all enclosing, rigid, porous, protective girdle that surrounds the bacterial cell?
What is its primary function?
Protect from surrounding Osmotic Pressure
What 2 acetylated amine groups make up the glucose dimers that make the polysaccharide of cell wall?
NAG - N-acetylglucosamine
NAM - N-acetylmuramic acid
After the export of 20-ish NAG-NAM from the bacterial cell to the cell wall, what cross links the peptides and affixes the new unit to the cell wall?
What constantly synthesizes and degrades the peptidoglycan making up cell wall?
The toxic LPS found on the outer leaflet of the outer membrane of Gram- bacteria is...
A Gram- can't hold its alcohol:
Crystal violet washes off by alcohol/acetone and accounts for lighter stain
The pattern recognition receptor that binds to LPS is...
TNF-alpha is a...
Large amounts of LPS that activate the clotting system is know as what?
Disseminated intravascular coagulation
What are 2 important pro-inflammatory mediators produced by Macrophage in response to LPS?
(signals NO production, causing pre-capillary sphincters to relax)
If TNF-alpha causes too much of an NO reaction, what could happen?
Blood pressure falls leading to
Hypovolemic Shock (aka septic shock)
What enzyme breaks down starch and glycogen?
What enzyme breaks down peptidoglycan NAG-NAM molecules?
ECF matrix often has glucose polymers that make them up
Bacteria capable or respiration have what?
*no heme proteins = no respiration
Bacteria that must have oxygen:
Bacteria that can respire if Oxygen present, use fermentation if Oxygen absent:
Not killed by Oxygen but only ferment:
Like small amounts of oxygen
Always killed by Oxygen
What process gains energy by partially breaking down substrate to other organic molecules like lactic acid or alcohol?
What 2 enzymes are of utmost importance when dealing with toxic oxygen radicals?
radical to hydrogen peroxide
hydrogen peroxide to water and oxygen
Both Superoxide dismutase and Catalase are found in what type of bacteria?
Aerobes and Facultative aerobes
Strict aerobes have neither Superoxide Dismutase or Catalase.
Supragingival plaque is mostly made up of microaerophilic and facultative bacteria, while sub-gingival plaque is primarily facultative and anaerobic
What inserts into bacterial DNA, can exit, and often carries resistance or toxic coding sequences?
What system acts in a fast, non-specific way that does not require specific recognition of a pathogen?
Innate immunity includes inflammation
*however, inflammation interacts with mechanisms of adaptive
What system of immunity is slow and specific and remembers?
What does it use?
Specific B and T lymphocytes
What kind of cells live below all our epithelial barriers and recognize insults?
What do they release?
*Mast cells or Basophils
The "stop signs" that tell neutrophils to exit circulation in an acute condition are known as...
Tells what to exit during chronic condition?
Cell adhesion molecules
Lymphocytes and Macrophage
S. pneumoniae is Gram...
S. pneumonia can cross BBB and initiate an inflammatory response called...
What blocks phagocytosis by PMN's and Macrophage and is a major virulence factor in S. pneumonia?
The capsule in S. pneumoniae induces what response from the immune systym?
Opsonization with antibodies
What receptors on S. pneumoniae allow for opsonization?
Cell surface receptors are utilized by cytokines (which are activated by T-cells)
Cytokines are required for a full and effective adaptive immune response
What causes the T and B cells to divide into clones?
*stimulated by T cells that received part of bacteria targeted from presenting cells
What causes a Cytokine Storm?
What is the most biologically toxic bacterial product?
What is the most common cold sore treatment?
What increases the potency of vaccines?
Hypersensitivity reactions 1-3 are...
Hypersensitivity 4 is...
Gingival, sulcular, and junctional epithelium are all rapidly dividing, shedding, physical barriers.
What defines gingival junctional epithelium?
not much keratin
not many hydrophobic, granular materials
How do Junctional epithelial cells activate T-helper cells?
with HLA class II
*present extracellular antigenic peptides
Junctional epithelial cells have numerous cytokines and chemokines. What one is found in large amounts?
Cytokines and chemokines are _____ for PMN's
How is junctional epithelium different from sulcular/gingival?
Junctional epithelium allows for easy _____.
Egress of PMN's
What is the exception to epithelia of the mouth being tough, highly keratinized, and mostly impermeable?
What does this allow?
*epithelium that attaches to the tooth
PMN's easy access to the mouth
Outside of the cervicular space, what is a major protective barrier?
2/3 of the WBC's are..
Name two cell surface receptors PMN's use to attach foreign microorganisms.
PMN's either kill pathogens by ingesting them, or ____
*this leads to many side-effects of inflammation
Salivary glands are Ig__ dominant and inflamed gingiva (Crevicular fluid) is Ig__ dominant
What two sources of fluid bathe the oral cavity?
What are the 2 major defense features of Crevicular fluid?
What is a big anti-carie effect of saliva?
Dimeric IgA cells from B cells are cleaved at what site?
When released to mucosa the complex at site is called?
What are 4 unique attributes of sIgA?
Sticks to mucins
Blocks microbe colonization
Name 3 supragingival plaque film Gram+ bacteria associated with Caries.
Name 5 Gram- facultative and anaerobic rods bacteria associated with Periodontal Disease
How many different species of bacteria call the mouth home?
What has been shown to inhabit some perio pockets?
Where do most bacteria live in the mouth
(what 2 places)?
Supragingival plaque biofilm is primarily made of _______ and _______ bacteria.
______ and ______ make up most of the subgingival plaque biofilm
Gingivitis usually has both G+ and G- associated with it.
Describe Streptococcus Viridans
Green on blood agar
What are the 4 subgroups of Streptococcus Viridans?
Which are good/bad?
S. mutans - the bad guys
Name 2 species in the Streptococcus mutans subgroup
*these 2 species most often associated with dental plaque
What Strep. species is a major cause of caries?
Name 3 features of this species
prefers low pH
Lactic Acid producer
What S. Viridans subgroup is found in plaque, mucosa, and respiratory tract and is pus forming?
What S. Viridans subgroup is the pioneer species, making insoluble and soluble polysaccharides, and associated with bacterial endocarditis?
Name 4 species in the S. mitis group
What S. Viridans subgroup colonizes mucosa and not plaque?
(is a good guy)
Name 2 species in the S. salivarius subgroup of S. Viridans.
Peptostreptococcus is Anaerobic
What bacterial species is an opportunist that causes nosocomial problems and can survive harsh environments?
What species of Enterococcus is commonly implicated in endodontic root canal failures and persistent infections
Streptococcus are all Gram___ cocci arranged in ____
Subacute Bacterial Endocarditis is often caused by what?
(also pneumonia and caries)
What type of bacteria is associated with Root caries, ECM production, eats sugars, and tolerates a low pH?
Name a specific species
What species of bacteria is correlated with a high-sugar cariogenic diet, dentin caries, and is the Advancing Front of caries lesions?
(also produces ECM, eats sugar, tolerates low pH)
What 2 bacteria can metabolize lactate (and theoretically reduce caries)?
Name 4 Oral G+ rods.
What G- rod is associated with aggressive Periodontitis in young adults?
What kind of toxin does it produce?
What G- rod associated with Periodontitis has very long thin rod that other bacteria attach to?
Name 4 black pigmenting species of G- rods that (might be) causative agents in Periodontal Disease
What 3 species form the Red Complex associated with aggressive Perio infections?
T. forsythensis (Tannerella)
P. gingivalis (Porphyromonas)
T. denticola (Treponema)
Name an Asachrolytic G- rod.
What species of Prevotella is associated with periodontitis?
What type (G)
*all Prevotella sacharolytic
What very anaerobic species is found in gingivitis and periodontitis?
2 shapes of viral capsid
What are the 2 ways a newly replicated virus leaves the cell
Budding (envelope with spikes)
*enveloped vs. naked
5 cellular outcomes of viral infection
Abortive (no progeny)
Transformation (cell proliferates uncontrollably)
4 binary viral classifications:
helical or icosahedral
enveloped or naked
DNA or RNA
ds or ss
The protein shell of a virus is called a...
What 2 things must a virus do to replicate within the cell?
Replicate their genetic material
Produce +mRNA for protein components
What plant infecting nucleic acids lack capsids?
person to person
mother to fetus/neonate
No symptoms can lead to a large ______
Herpes viruses are enveloped/naked?
dsDNA (large - many targets)
Where do herpes viruses replicate and assemble?
Herpes virus acquires their membrane before/after they reach the cytoplasmic membrane.
***this is unique
Herpes initially infects the _______ and lasts _____
Example of an antiviral therapy for Herpes:
Herpes is serious if fetus infected, mild if child, and moderate to serious in adults
1: cold sores
3: Varicella Zoster (chickenpox, shingles)
What HHV strains are latent in the neuron?
What HHV is an important congenital infection?
What Herpes virus is Kaposi's sarcoma?
DNA viruses can cause...
What HHV isn't spread through mucosal contact?
Varicella zoster (3)
Viremic (first) infections can be dangerous to...
What is the name for the manifestation of HSV-1?
What is the most common cause of viral encephalitis in the USA?
Describe Herpetic Stomatitis
rupture and leave small painful ulcer
What is the leading infectious cause of blindness in the USA?
HIV transmission is increased 2-4 fold with the presence of what?
In the 1st 5 years of life HSV-1 primarily presents with a lip lesion, but is ____ asymptomatic
Lesions of HSV-1 present in what 2 places?
(area called what)
What ganglia are typically infected in HSV-1?
Primary HSV-1 and HSV-2 infections can pass to fetus
Secondary recurrences of HSV-2 can pass to fetus during delivery
The only HHV spread by respiratory droplets is
(infects lung mucosal lining initially)
*zoster is the shingles bit
What are the 2 major diseases caused by EBV?
Burkitt's B Cell Lymphoma
Burkitt's lymphoma, aside from having an association with EBV, is associated with...
Hairy Leukoplakia is caused by what virus?
*benign, which lesion, hyperkeratosis
2 cancers associated with EBV
T-cell leukemia is associated with what virus?
What percentage of young adults infected with EBV develop Mono?
What is the number 1 cause of retardation?
Cytomegalovirus primary infection when pregnant
Acyclovir works on Cytomegalovirus
There is no vaccine for the multiple strains of Cytomegalovirus
Worldwide ____% seropositive for cytomegalovirus
US ____ %
Of the 1% pregnant that develop primary Cyto infections, ___% develop neural sequelae in fetus
CMV is the most common cause of intrauterine infections and congenital abnormalities in the US
Primary or reactivation of latent CMV is very serious in what population?
Describe the Coxsackie virus
common and mild diseases in young
What is the non-specific flu-like illness caused by the Coxsackie virus?
What 2 diseases does the Coxsackie virus cause?
Hand, foot and mouth disease
*both mostly young children
What is the most communicable disease worldwide (no iceberg effect)?
Describe the measles virus (capsid, genome)
Describe the Mumps virus (capsid, genome)
The characteristic symptom for mumps is...
Inflammation associated with this does what?
blocks salivary fluids
HPV - describe (capsid, genome)
*warts - hyperplastic epithelial lesions
HPV is associated with what type of cancer?
What is the most common fungal infection relevant to dentistry?
Candidiasis is an _________.
What is an organism that lives on dead/decaying matter?
What is different about a fungal cell membrane?
(compared with human cell mem)
Ergostal instead of cholesterol
What inhibits ergostol synthesis?
What drug binds to and forms holes in ergostol-containing membranes?
What makes up the cell wall of fungi?
Compared to antibiotics, there are relatively few anti-fungals.
*Because non-toxic anti-eukaryotic drugs hard to find
2 basic morphologies of fungus:
The collective term for a mass of hyphae is...
Some yeast are ______ , and can exist in both yeast and filamentous forms
What fungus of oral concern can assume a pseudohyphae form and is dimorphic/polymorphic
Fungi has a huge cell wall, up to 90% of dry weight
Why is humoral immunity no good in combating fungi?
Proteases/enzymes of fungi
Fatty acids, pH, epithelial cell turnover, and normal bactera all help resist against fungal invasions
Mycotoxicoses are _____
Hay fever and asthma is a Type ____ hypersensitivity
Contact Dermatitis to a fungal product is a Type ____ hypersensitivity
Superficial mycoses typically don't cause pathology
______, think cutaneous mycoses
What 3 Dermatophytes cause Tinea (cutaneous mycoses)?
Subcutaneous mycoses are common
Systemic fungal infections tend to enter via what?
List 4 opportunistic mycoses from common to rare:
Candida albicans, along with being an opportunist, is part of the normal flora
What should a clinician think in an otherwise healthy adult in case of oral thrush?
The yeast or hyphae form of Candida depends on what?
*acidic favors yeast, alkaline favors hyphae
**remember it's pseudohyphae for Candida
A pH switch to alkaline promotes what kind of Candida?
Why doesn't humoral immunity do much against fungi?
Antibodies are degraded quickly by enzymes / proteases
What type of cells typically respond to fungal antigens?
(which initiates inflammation, cell turnover, etc)
An immune dysfunction will almost always have thrush
PMN's attacking Candida can sometimes form what?
Loosely adherent pseudomembranes
*easily wiped off
**diptheria firmly adhere
Primary Candidiasis is found where?
Secondary Candidiasis is found where?
Which is seen in immunosuppression and HIV?
Orally (and surrounding)
Other mucosal/cutaneous sites