User:S4352142

Rochelle Overton

Bench E

31082016

Capnocytophaga gingivalis

Classification

Higher order taxa

Kingdom	Bacteria
Domain	Bacteroidetes
Phylum	Bacteriodetes
Class	Flavobacteriia
Order	Flavobacteriales
Family	Flavobacteriaceae
Genus	Capnocytophaga

Species

Capnocytophaga gingivalis ATCC 33624

Description and significance

Capnocytophaga gingivalis are a class of Flavobacteriia that inhabit the oral cavity of the mouth (kagermeier), making up a large component of subgingival plaque (spratt). Microscopy has revealed that C. gingivalis are straight rod-shaped bacteria with a fusiform morphology, having a granulated outer surface. Capnocytophaga gingivalis are a motile facultative anaerobe, meaning that it can create ATP through aerobic respiration if oxygen is present(London), but is also also to use fermentation in instances where oxygen is poor/absent (kagermeier, newman). Gram staining produced a purple, gram negative cell, which was is also able to be successfully cultured in laboratories with a preference from environments with high carbon dioxide levels (London).

Whilst present in natural microbiome of the mouth, C. gingivalis can become pathogenic under certain conditions. Dental ailments such as periodontal infections, loss of teeth and supporting tissues as well as alveolar bone loss can occur. In severe cases, C. gingivalis has also spread to the eyes, brain, lungs, digestive tract, heart or muscular skeletal system and causing disease. Although these diseases are treatable with antibiotics, there have been reports of resistant strains occurring since the mid 1980's, making it an important bacteria to study.

Discovered (when/where): Examples of citations ^[1], ^[2]

Genome structure

This microaerophilic organism

Select a strain for which genome information (e.g. size, plasmids, distinct genes, etc.) is available.

Cell structure and metabolism

Being a gram negative bacteria, the crystal violet stain used in gram staining does not stick to C. gingivalis as its cell wall contains a very small amount of peptidoglycan. The cell walls of gram negative bacteria are composed of a nuclear envelope, a thin layer of peptidoglycan and an outer membrane. Due to the presence of peptidoglycan in their cell walls, gram negative bacteria are still susceptible to lysozyme which catalyses hydrolysis of the cell by weakening the glycosidic bonds, although often used in conjunction with ethylenediaminetetraacetic acid (Ianco)(Voss).

A biofilm is the clustered formation of a thin layer of microorganisms which cling together to adhere to a hard surface, such as the tooth. It begins with the pellicle (saliva) containing large quantities of absorbed macromolecules directly to the teeth (sakaguchi). Free-floating bacteria will then attach themselves to the saliva-coated tooth in order to feed, being the primary colonizers. Then the secondary colonizers, Capnocytophaga gingivalis, bind to the primary colonizers creating a second layer, proving increased strength and structure to the biofilm. When left over long periods of time, this can create instances of plaque which if left unchecked can result in periodontal infections. Throughout this microcolony, each microorganism is exposed to different environmental conditions such as; physical proximity, oxygen and glucose requirements . This is why each C. gingivitis will exhibit different phenotype throughout the oral cavity (hosohama-saito).

motility: Capnocytophaga gingivalis are motile organisms, despite lacking botth flagella and flagellates. They create longitudinal movement in a gliding motion with the mechanisms involved in this process being unknown (Mcbride).

metabolic functions: Glucose is a necessary source of energy required for Capnocytophaga gingivalis to aerobically respire. Despite its

Ecology

Aerobe/anaerobe, habitat (location in the oral cavity, potential other environments) and microbe/host interactions.

Pathology

Do these microorganisms cause disease in the oral cavity or elsewhere?

Application to biotechnology

Bioengineering, biotechnologically relevant enzyme/compound production, drug targets,…

Current research

Summarise some of the most recent discoveries regarding this species.

References

References examples

1. Sahm, K., MacGregor, B.J., Jørgensen, B.B., and Stahl, D.A. (1999) Sulphate reduction and vertical distribution of sulphate-reducing bacteria quantified by rRNA slotblot hybridization in a coastal marine sediment. Environ Microbiol 1: 65-74.

2. Human Oral Microbiome

This page is written by Rochelle Overton for the MICR3004 course, Semester 2, 2016