User:Peter.kuefler
Rothia dentocariosa Cell Structure Rothia dentocariosa is a common bacteria found in the mouths flora. Rothia dentocariosa is aerobic, gram positive, and can be coccal to rod shaped. The bacteria on agar plates normally tends to be off white, smooth, and creamy but can also be rough and wrinkled (1).
Description and Significance Rothia dentocariosa was first isolated from human mouth flora in 1949.
The bacteria was thought to be part of the groups Actinomyces dentocariosus, Nocardia dentocariosus, and Nocardia salivae until a separate genus of Rothia was created in the family Actinomycetaceae in the early 1960’s (3). A distinguishing feature of Rothia dentocariosa that helped set it apart from Actinomycetes was a study done on the composition of the cell wall. It was found that the cell wall of Rothia dentocariosa contained fructose, glucose, and ribitol components. Fructose had not been found in any other Actinomycetes and is a characteristic sugar of the cell wall of Rothia (5).
Disease and Medicine The bacterium is found in normal mouth flora but also can be the cause of disease. One infection is endocarditis which affects the inner lining of the heart. This occurs when Rothia dentocariosa spreads into the bloodstream and attaches to the damaged areas of the heart. Endocarditis mainly effects people with poor oral dentition (2). Since Rothia dentocariosa is a bacterium penicillin is commonly used during infections. Other antibiotics are also used but penicillin is normally the treatment of choice. Rothia dentocariosa is also very common in individuals with carious lesions, tooth decay or cavities. In one study 95 different taxa were found in the sampled patients but dentocariosa was one of only three found in every patient showing that it is a common bacteria found in dental caries (6). Morphology One uncommon feature of Rothia dentocariosa is the presence of multiple different morphologies. Initially many thought that the different variances in morphology may be due to different DNA compositions. A study was done looking at the GC content, guanine and cytosine, and the melting point of purified DNA extract from coccal and filamentous strains. The study proved that the melting points and GC content were almost identical showing no correlation that multiple species may be present (4).
Annotated Bibliography
1. Barksdale L. 1979. Identifying Rothia dentocariosa. Annals of Internal Medicine. 91(5):786-788. This article explains the general properties that help distinguish Rothia dentocariosa from other similar bacteria. dentocariosa are mostily aerobic, nonmotile, non-spore forming, pleomorphic, gram positive coccal to rod shaped bacteria. It is commonly found in the mouth and is associated with dental caries. The colonies on agar plates are off white, smooth and creamy to rough and wrinkled.
2. Braden DS, Feldman S, Palmer AL. 1999. Rothia Endocarditis in a Child. Southern Medical Journal. 92(8):815-816. This article explains that infective endocarditis, develops in the hearts, can be caused by common oral flora such as Staphylococcus aureus and Rothia dentocariosa. Normally found only in adults, this article talks about the first known case where Rothia caused infective endocarditis in a child. The article also nicely explains some common features of Rothia dentocariosa
3. Brown JM, Georg LK, Waters LC. 1968. Laboratory Identification of Rothia dentocariosa and Its Occurrence in Human Clinical Materials. Applied Microbiology. 17(1):150-156. This article explains how Rothia dentocariosa was found and named at the beginning. The rest of the article explains the tests done to identify the differences between Rothia dentocariosa and other similar bacteria, Actinomyces dentocariosus, Nocardia dentocariosus, and Nocardia salivae. Rothia dentocariosa use to be classified as part of the three organisms listed above.
4. Hammond BF. 1970. Deoxyribonucleic Acid Base Composition of Rothia dentocariosa as Determined by Thermal Denaturation. Journal of Bacteriology. 104(2):1024-1026. This article looks at the different morphologies of the bacteria Rothia dentocariosa and how the DNA relates in the different forms. The idea previously was that the different shapes may be slightly different organisms so they would have different DNA compositions. The researcher looked at the GC content, moles per cent guanine plus cytosine, and melting temperature of the purified DNA extract from a coccal and several filamentous strains. All GC values showed a homogenous relationship and the melting temperatures were within 0.5 degrees celcius of each other (1% change). These two things show a correlation of significant taxonomic significance.
5. Hammond BF. 1970. Isolation and Serological Characterization of Wall Antigen of Rothia dentocariosa. Journal of Bacteriology. 103(3):634-640. This article focuses mainly on the cell wall of Rothia dentocariosa and the antigens that affect it. The researcher was trying to find differences between the cell wall of Rothia dentocariosa and the closely related actinomycetes. The researcher found that an antigen for Rothia dentocariosa contained fructose, glucose, and ribitol components which was different then the study previously done which said glucose was the only monosaccharide. At the time of this study fructose had not been found in the cell walls of any other actinomycete. This study then shows that fructose is a characteristic sugar of the cell wall of Rothia. Similar to how rhamnose is characteristic of the cell wall of streptococci and lactobacilli.
6. Munson MA, Banerjee A, Watson TF, Wade WG. 2004. Molecular Analysis of the Microflora Associated with Dental Caries. Journal of Clinical Microbiology. 42(7):3023-3029. This article identified all taxa found on five teeth with carious lesions involving dentine. The samples were cultured and then identified. Out of the 95 taxa found Streptococcus mutans, Rothia dentocariosa, and Propionibacterium sp. were the only taxa found on all five samples. Besides that this research didn’t have much to do with Rothia dentocariosa except for showing that it is a common bacteria found in dental caries.
