User:S4438663
Name Chew Zi Huai (s4438663) Bench ID C Date 23/09/2016 [1]
Classification
Higher order taxa
Bacteria – Firmicutes – Negativicutes – Selenomonadales – Veillonellaceae – Veillonella
Species
Species name and type strain: Veillonella parvula DM2008
Description and significance
Veillonella parvula (V. parvula) first isolated by Veillon and Zuber in 1898 and falls under the 6 species of anaerobic gram-negative cocci under the genus ‘’Veillonella’’. [1]
Veillonella parvula is a small and non-fermentative coccus that forms part of the normal flora of humans in the oropharynx (tongue,dental plaque, and the buccal mucosa, gastrointestinal tract and female genital tract and are harmless in general. Oral V. parvula plays a role in the early development of periodontal disease.[2] V. parvula are rare opportunistic pathogens that are implicated in infections of sinuses, lungs, heart bone and central nervous system.[1] V. parvula can coaggregate with other aerobic and anaerobic bacterias. With the ability of V. parvula to grow in a biofilm with other bacterium could allow the survival of other bacteria in antimicrobial treatment. Caries and periodontitis are polymicrobial disease where multiple bacterium plays a role and that the presence of V. parvulagives other bacteria and itself a survival advantage by being more resistant to antimicrobial treatment.[3] In the dental plague,V. parvula cannot adhere by itself to the surface of the teeth and does so by attaching to Streptococcus mutans" and these two forms a mutualististic relationship with each other.
V. parvula are culture positive organisms can be cultured on lactate agar media forming colonies that are diamond or heartshaped, opaque, smooth, butyrous and grayish white and also culture in blood agar and are non-hemolytic. With incubation time of 48 hours and temperature between 30-37 degree C in an anaerobic environment of pH=6.5-8.0.[4]
Genome structure
Veillonella parvula DSM 2008 has one main circular DNA chromosome with 38.6% GC content. With a total of 2132142 base pair, 1920 predicted genes, 1859 protein genes, 61 RNA genes and 15 pseudogenes.[5]
Cell structure and metabolism
V. parvulacell wall comprises of an outer membrane made up of lipopolysaccharide that has an unusual presence of cadaverine and putrescine. The cell wall is highly endotoxic which might play a role in virulence. Major components of cytoplasmic membrane are plasmalogens which are ether lipids that play an important role in regulation of membrane fluidity.[5] V. parvula DSM 2008 are early colonizers in dental biofilm and resident members in the oral microbial communities and are immobile as they lack flagella for motility. [4]
V. parvula are not able to ferment carbohydrates and uses organic acid by-products of carbohydrate processing microorganisms instead for its own metabolism. Their main source of energy and metabolites comes from the conversion of lactate into propionate and acetate and therefore V. parvula are lactate fermenters.[6]V. parvula has an unusual metabolism that uses methylmalonyl-CoA decarboxylase, converting free energy from decarboxylation reactions into sodium ions electrochemical gradient that comes from the metabolism of succinate in the presence of lactate.[5]
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
- ↑ MICR3004
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This page is written by<Chew Zi Huai> for the MICR3004 course, Semester 2, 2016
