Degree Type

Creative Component

Semester of Graduation

Spring 2019


Biomedical Sciences

First Major Professor

Steve Carlson


Master of Science (MS)


Biomedical Sciences


The oral cavity offers a wide variety of microenvironments that can support a wide array of microflora. These different environments create a diversity of microflora. In the oral cavity, this microflora produces biofilms that are distinct to the mouth and that can be both beneficial and pathogenic. Practically all bacteria prefer to live in biofilms compared to planktonic solutions. Oxygen availability, nutrient availability, shedding and non-shedding substratum, along with other factors determines which organisms inhabit specific regions of the oral cavity. These organisms attach to surfaces through a succession; primary colonizers initially use the host’s glycoproteins to attach to the substratum, otherwise known as attachment to the acquired pellicle. Streptococcus species are notorious primary colonizers. After the attachment of the bacteria to the pellicle, the bacteria start to secrete chemicals that allow them to stay attached to each other. Microorganisms that come in to further mature the biofilm recognize receptors on primary colonizers and co-aggregate on these bacteria. These biofilms usually contain pores and channels that allow organisms to obtain water and nutrients. These bacteria use synergistic and antagonistic actions to better the situations for themselves and mature the biofilms. Antagonistic actions include the secretion of hydrogen peroxide, quorum sensing, and bacteriocin synthesis. Contrarily, bacteria also use synergistic actions to grow or protect the biofilm, for example bacteria utilize conjugation to transfer plasmids that contain genes beneficial for antibiotic resistance. Bacteria in biofilms are one thousand to fifteen hundred times more resistant to antibiotics compared to planktonic bacteria.

Copyright Owner

Olson, Tyler

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