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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). These microorganisms are motile, travelling in a gliding motion as they lack the presence of flagella or flagellates. Microscopy has revealed that C. gingivalis are straight rod-shaped bacteria with a fusiform morphology, having a granulated outer surface.

 This purple stained, gram negative bacteria (kagermeier, newman) has fermentative physiology, with a preference for growing in environments with high levels of carbon dioxide. This being said, it is able to aerobically respire in the presence of glucose (London), and can be cultured in a lab. This oral microorganism can become pathogenic in the right conditions, causing numerous ailments including: periodontal infections, tooth loss, decay of supporting tissues and alveolar bone loss in the mouth. In some cases, C. gingivalis can spread into the eyes, brain, lungs, digestive tract, heart or muscular skeletal system. 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): Cultured?: Yes (kagermeier) Functional role: Importance:

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

Cell wall: Being a gram negative bacteria, the cell wall of C. gingivalis is composed of an outer membrane containing a thin peptidoglycan layer within.

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 is a motile organism that lacks both flagella and flagellates. It creates 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