A Microbial Biorealm page on the genus Veillonella tobetsuensis
Higher order taxa
Bacteria(Domain); Firmicutes(Phylum); Negativicutes(Class); Vellionellales(Order); Veillonellaceae(family)
Description and significance
V. tobetsuensis is a gram-negative anaerobic coccus. These strains are mostly found in a biofilm of tongue in human adults' mouths ranging in age 22-29 years old. Most of these strains are isolated from the mouths of adults and the intestinal tract of animals and humans. (1) Species of the genus Villonella have caused monomicrobial infections in humans. There are in total 13 species of Villonella; atypica, V. caviae, V. criceti, V. denticariosi, V. dispar, V. magna, V. montpellierensis, V. parvula, V. ratti, V. rodentium, V. rogosae, V. seminalis, and V. tobetsuensis. (2) These species of bacteria have been found in patients with hepatic abscesses, meningitis, osteomyelitis, acute pyelonephritis, secondary bacteremia during pregnancy, opportunistic infections, and prosthetic joint infection. (3)
V. tobetsuensis genome comprises 150-bp read length and over 200-fold genome coverage in lab research tests. There were 2,878,222 and 2,452,016 reads that were found for PAGU 1578 and PAGU 1579 strains of V. tobetsuensis. These draft genome sequences of PAGU 1578 and PAGU 1579 were fixed into 59 (N50 = 96,198) and 129 (N50 = 39,212) contigs.(4) It was discovered that they were 1,935,552 bp and 2,151,918 bp. (4) These draft genomes had G+C contents of 38.4% and 38.5% and 1,789 and 1,869 coding sequences. BLAST results stated the calculations of ANI values between PAGU 1578 and PAGU 1579 strains, and two clinical isolate controls, and V. tobetsuensis species. ANI values state the mean of an identity and similarity values between certain homologous genomic regions from two genomes. It was discovered that these species were closely related by 96.73% and 96.16% to 97.05%.(4)
Cell structure and metabolism
It is a gram-negative coccus that lacks flagella, spores, and capsules. They are non-motile. This was conducted from four unknown strains of gram-negative cocci bacteria that were isolated from the human mouth. The cells were spherical with a convoluted surface and the diplococci shape of the cells. The cells varied in size (0.2–0.7 mm) with a mean size of 0.5 m. (5) Colonies from the strains B16, A16, B4, and Y6 were cultured on a BHI blood agar plate for 5 days at 37 °C under anaerobic conditions appeared to be smooth, circular, grey, and opaque. (6) The four strains of Veillonlla Tubtsuensis had displayed susceptibility to colistin, and metronidazole but they were resistant to vancomycin ( 30mg) and also resistance to kanamycin (30 mg). (6) The strains of Veillonella Tubsuensis; B16T, A16, B4, and Y6 were all negative for catalase examined under aerobic conditions but were weakly positive under anaerobic conditions. (6) Also it was identified that states the bacteria is a 16s RNA bacteria.
Veillonella Tubsusuensis is mostly found in a biofilm of the adult human mouth and in the small intestine. Yet, there are mostly found on the tongue, buccal, mucosa, and saliva. Also found in subgingival biofilm in patients who have periodontal disease because of the lipopolysaccharides that they produce with the oral cavity of the human mouth. (6)
Veillonella tobetsuensis is one of the main oral bacteria that causes periodontal disease from the number of LPS that they produce. They also caused cavities in the mouth. Veillonella facilitates other oral microbes that help the Veillonella species to become established in the oral microbial ecosystem. When high fructose or even glucose is present, the glucose can be converted to lactate, which Veillonella can utilize as a carbon and energy source for growth. (6) Some of the sucrose can be converted to dextran by the extracellular glucosyltransferase, which is used by Veillonella on the teeth and then settles causing the cavities to form. This is common among young children due to their diets that contain a high sugar content. The only way to prevent the growth of Veillonella tubetsuensis is to get regular teeth cleaning and brushing daily. There is no antibiotic released that can prevent the spread of Veillonella tobetsuensis in oral captivity.
The latest research that V. tobestseusis is involved in interactions between oral Streptococcus and the influence of Veillonella species, in particular Veillonella tobetsuensis, in promoting early-stage biofilm formation. Dr. Mashima and Dr. Nakazawa had discovered that there is a clear indication that Streptococcus species and Veillonella species have contributed to the development of biofilm inside the human oral cavity; in a metabolic-dependent situation that create biofilms within the human oral cavities. This happens in the early development of biofilm creation in the human mouth. Yet, Streptococcus gordonii showed biofilm formation with the presence of V. tobetsuensis. These results stated that V. tobetsuensis produces a signaling molecule that promotes the proliferation of S. gordonii in biofilm formation. This molecule is called autoinducer; there were two of them (AI-1 and AI-2) found in V. tobetsuensis species. Which is part of the QS system and acts as signaling responses when biofilms are being developed. It was discovered that V. tobetsusis had the highest activity of A2 which directly correlates with the fact that V. tobesuensis is involved with the formation of biofilms as well as S.gordonii. (7)
1.Delwiche EA, Pestka JJ, Tortorello ML. 1985. The Veillonellae: gram-negative cocci with unique physiology. Annu Rev Microbiol 39:175–19
2. Mays TD, Holdeman LV, Moore WEC, Rogosa M, Johnson JL. 1982. Taxnomy of the genus Veillonella Prèvot. Int J Syst Bacteriol 32:28–36. doi:10.1099/00207713-32-1-28.
3.Yagihashi Y, Arakaki Y. 1 November 2012, posting date. Acute pyelonephritis and secondary bacteremia caused by Veillonella during pregnancy. BMJ Case Rep doi:10.1136/bcr-2012-007364
4.Mashima, Izumi, et al. “Draft Genome Sequences of Two Veillonella Tobetsuensis Clinical Isolates from Intraoperative Bronchial Fluids of Elderly Patients with Pulmonary Carcinoma.” Microbiology Resource Announcements, American Society for Microbiology, 19 Sept. 2019, mra.asm.org/content/8/38/e00397-19.
5. Mashima, Izumi, and Futoshi Nakazawa. “A Review on the Characterization of a Novel Oral Veillonella Species, V. Tobetsuensis, and Its Role in Oral Biofilm Formation.” Journal of Oral Biosciences, Elsevier, 29 Sept. 2013, www.sciencedirect.com/science/article/pii/S1349007913000984.
6. EA Delwiche, JJ Pestka, ML. Tortorello The Veillonellae: gram-negative cocci with unique physiology Annu Rev Microbiol, 39 (1985), pp. 175-193
7.Mashima, I., & Nakazawa, F. (2015). The interaction between Streptococcus spp. and Veillonella tobetsuensis in the early stages of oral biofilm formation. Journal of bacteriology, 197(3), 2104–2111. https://doi.org/10.1128/JB.02512-14
Edited by Angelia Wasi, student of Dr. Charlotte Berkes at Merrimack College