Oral Flora II. Karen Ross 2007. Identification of Oral Microorganisms 16S DNA based detection. Use 2 oligo-nucleotide primers universal to ALL bacteria 16S rDNA, PCR amplification of the total saliva or plaque DNA pool, clone the PCR product and sequence.
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Use 2 oligo-nucleotide primers universal to ALL bacteria 16S rDNA, PCR amplification of the total saliva or plaque DNA pool, clone the PCR product and sequence.
Variation allows similar species to be distinguished. Currently over 125,000 bacterial 16S sequences have been deposited in major public databases (Genbank, Ribosomal Database Project.
Phylogeny -can construct a tree of evolutionary relationships
In the oral cavity more than 700 bacterial species or phylotypes have been detected. At least 50% have not been cultivated yet.
Schachtele et al.,2007 Oral Streptococci: Commenals and opportunistic pathogens (chapter 16) in Molecular Biology of Streptococci.
Mitis salivarius agar levans and dextrans
•Certain dental or medical procedures. Dental procedures that cause bleeding may allow bacteria to enter your bloodstream. Bacteria may also be a concern with procedures done elsewhere in the body, such as in the respiratory tract.
•An infection or other medical condition. Bacteria may spread from an infected area, such as a skin sore. Gum disease, a sexually transmitted disease or an intestinal disorder — such as inflammatory bowel disease — also may give bacteria the opportunity to enter your bloodstream.
•Catheters or needles.
•Common activities. Even everyday activities such as brushing your teeth or chewing food can allow bacteria to enter your bloodstream — especially if your teeth and gums are in poor condition.
Lactobacillus species and a vaginal squaemous epithelial cell. CDC
Invasion of epithelial cells
Colony phase variation -smooth and rough forms, rough colony variants heavily fimbriated
Interference with host defense mechanisms -inhibit PMN chemotaxis, resists phagocyte killing (capsularlike material), causes release of inflammatory mediators by immune cells.
Bone resorption -surface associated material (SAM) containing a heat shock protein acts directly onosteoclasts, LPS and proteolysis-sensitive factor in microvesicles.
Apoptosis -leukotoxin-mediated killing through the activation of caspases, removal of acute inflammatory cells
Fine et al., 1999
Pulpitis, pulp necrosis and infection of the root canal system
Streptococci most commonly identified.
Obligate anaerobes also in high numbers
It is also known as ”Vincent’s stomatitis”, "Vincent's angina”, or "acute necrotizing ulcerative gingivitis” (ANUG).The common name was probably coined during World War I when many soldiers suffered from the condition. There are a number of other theories to the origin of the name. Vincent's angina was named after French physician Jean Hyacinthe Vincent (1862-1950)
Fusobacterium nucleatum and the oral spirochaetes, Treponema spp. Forming a fusospirochaetal complex. If you add Clostridium perfringens you can get an oral gas gangrene equivalent.