Jessekah Butterworth Bench B Date 
Higher order taxa
Bacteria – Proteobacteria – Betaproteobacteria – Neisseriales – Neisseriaceae – Kingella
Strain: strain UB-38 = ATCC 51147 = CCUG 30450 = CIP 103803.
Description and significance
Kingella oralis is a gram-negative, bacilli bacteria that was first observed by Chen et al in 1989, who were investigating the presence of Eikenella corrodens in the human oral cavity. This isolate was further investigated by Dewhirst et al in 1993, who identified several characteristics that distinguished the two species from each other including colony morphology on agar and acid production from sugars.
In early identification and research into K. oralis, the bacteria was successfully grown on Trypticase soy agar plates that contain 5% sheep blood, 5mg of hemin per litre and 0.5mg of menadione per litre at 37°C in a humidified anaerobic chamber containing 5% CO2. However the specific growth requirements of K. oralis are still unknown.
K. oralis is found in both supragingival and subgingival plaque, as well as in mucosa and saliva. There is a high association between K. oralis presence and periodontitis. Therefore research into K. oralis can potentially aid in periodontitis prevention or treatment.
The representative K. oralis strain ATCC 51147, has a total genome size of 2.41Mb consisting of 2435 genes which encode approximately 2315 proteins and 6 rRNAs.  It has a GC% content of 54.3%.
The genome assembly consists of 5 scaffolds that contain no gaps in between and 12 contigs, with a contig N50 of 792,850. K. oralis does not form chromosomes and contains no plasmids either.
Cell structure and metabolism
K. oralis is a gram negative, bacilli(rod)- shaped bacteria that consists of the usual cell was structure of plasma membrane, periplasmic space, thin peptidoglycan layer and an outer membrane containing lipopolysaccharide and proteins. Cells can reach sizes of approximately 0.6 to 0.7µm in diameter by 1 to 3µm in length and will either grow in pairs or chains within the colony.
K. oralis do not have flagella and therefore do not move around very much. However the cells can form spreading colonies allowing the bacteria to have 'twitching motility'.
K. oralis is oxidase positive, but catalase negative. The bacteria has a weak ability to produce acid from glucose but is unable to utilize other sugar compounds, such as lactose, maltose, mannitol, sucrose and xylose, for the same purpose. In addition to this, K. oralis does not reduce nitrate or nitrite, nor produce lysine, ornithine decarboxylase, indole and urease, nor hydrolyze esculin.
To date, there have been no observations or reports of K. oralis in any other environment. However, due to the lack of knowledge of required growth conditions, it is still possible that K. oralis utilizes alternative habitats to the oral microbiome.
Aerobe/anaerobe, habitat (location in the oral cavity, potential other environments) and microbe/host interactions.
K. oralis was initially isolated and identified from the supragingival and subgingival plaque formation in both adult and juvenile cases of periodontitisis. Therefore was thought that the bacteria is associated with periodontitis, an inflammatory disease of the gums that left untreated can lead to degradation of the oral bone and connective tissue surrounding the teeth. However, the bacteria was also isolated from both plaque formation sites in healthy candidates.
In addition to this, research into the involvement of K. oralis in other oral diseases, found that the bacteria was found most abundant in healthy patients rather than those with oral diseases such as root carries. Therefore the pathology of K. oralis remains unclear.
Application to biotechnology
Bioengineering, biotechnologically relevant enzyme/compound production, drug targets,…
Summarise some of the most recent discoveries regarding this species.
3. Dewhirst, FE., Chen, C., Paster, BJ., Zambon, JJ. (1993) Phylogeny of Species in the Family Neisseriaceae Isolated from Human Dental Plaque and Description of Kingella orale sp.nov. Internation Journal of Systematic Bacteriology 43:490-499.
This page is written by Jessekah Butterworth for the MICR3004 course, Semester 2, 2016