User:S4338763

MIRA SYAHIRA RHYME 43387632 23 SEPTEMBER 2016 MICR3004

Classification

Higher order taxa

Bacteria –Terrabacteria group- Actinobacteria- Actinobacteria- Micrococcales – Micrococcaceae – Rothia [1]

Species

Rothia dentocariosa. The types of strains: ATCC 17931 , ATCC 29070 , BCRC 12926, CCM 3472 , CCM 7007 , CCRC 12926 , CCUG 15599 , CCUG 35437 , CDC X599 , CIP 81.63 , CIP 81.63T , CIP 81.83, CIP 81.83T, CNCTC 5686, DSM 20352, DSM 43762 , DSM 46363 , G.D. Roth XDIA , GTC 267 , HNCMB 110019, IAM 14816 , IFM 1284 , IFO 12531 , IMET 11515 , IMSNU 21309, JCM 3067, K21 , KCC A-0067 , KCTC 3204 , KCTC 3577, Kloos K21 , LMG 21025 , NBRC 12531, NCDC W-858, NCTC 10917 , NCTC 12102 , NRRL B-14758, NRRL B-8017 , PCM 2349 , Roguinsky K21 , Roth XDIA ,W.E. Kloos K 21, XD-1A , XDIA

Description and significance

Rothia dentocariosa (R. dentocariosa) was initially isolated from dental plaque and caries by Onishi in 1949 [7]. It belongs to the genus Rothia and family Micrococcaceae, which was previously thought to belong to the family Actinomycetaceae [1, 2, 5]. This genus Rothia has faced a number of taxonomic changes for the last 15 years [3]. This species of Rothia is commonly found in human oropharynx, upper respiratory tract and mouth [8]. R. dentocariosa is a non-acid fast, non-spore-forming, non-motile and non-pigmented gram positive bacteria [4]. This pleomorphic bacteria can be in either in coccoid to rod-shaped or filamentous form in anaerobic condition. The morphology varies in different culture type such that the filamentous and coccoid forms are more commonly seen in plates and fluid respectively [4].The cells can form single, paired and clustered or chained and colonial structures that are either smooth, convex type or rough form depending on cells maturity [4, 6]. R. dentocariosa prefers aerobic condition such that it would grow faster and does not require carbon dioxide or lipids for growth [4]. This facultative anaerobe bacteria was initially thought to be non-pathogenic until a case involving peri-appendiceal abscess was reported in 1975 [11]. R. dentocariosa was also found to cause other form of abscess, opportunistic pneumonia infection and predominantly endocarditis in which patients are also associated with valvular heart disease, carious teeth and periodontal disease [4, 7, 9]. Other complications resulting from endocarditis include periocoronitis, endophtalmitis, septic arthritis, bacteremia, cornel ulcer, arteriovenous fistula and intracerebral haemorrhage [3, 9]. More recently, R. dentocariosa has been associated with intrauterine foetal death [10].Hence, it is important to study this emerging crucial opportunistic pathogenic bacteria as it is present as normal oral flora that could potentially impact humans’ health.

Genome structure

There are a number of strains that have been associated with R. dentocariosa. Among the strains, strain ATCC 17931 of the bacteria has completed genome assembly and gene annotation (ENSEMBL: ASM16469v2), (GenBank: GCA_000164695.2), (RefSeq: GCF_000164695.2). The total sequence length of the R. dentocariosa genome is 2,506,025 base pair (bp). This particular bacterial strain comprises a total of 1 circular DNA (plasmid) and none assembly gap length [12]. The total number of nucleotides is 2,506,025. The number of protein and RNA genes contained within the genome of this strain are 2,217 and 65 respectively [13]. From the overall gene transcripts which is 2,350, the number of coding genes are 2,217 while the remaining is small non-coding genes [14]. For this specific strain, ATCC 17931, the GC content in terms of moles percentage is 69.7% [15].

Cell structure and metabolism

R. dentocariosa is a gram positive bacteria which results in dark blue-coloured gram staining. Like other gram positive bacteria, this bacteria has thick layer (90% compared to gram negative) of peptidoglycan embedded with teichoic acid and lipoteichoic acid. The peptidoglycan layer surrounding the single lipid membrane of the bacteria consists of alanine, glutamic acid and lysine [17]. Polysaccharides that contributes to the cell wall include glucose, galactose, ribose and fructose through the use of both chromatographic and chemical analysis [19]. R. dentocariosa has no mycolic acid on its cellular structure thus making it non-acid fast [4]. Furthermore, this cocci to rod and sometimes filamentous shaped bacteria has no flagellar and is non motile. Rothia spp. including R. dentocariosa utilise their capability of biofilm formation activity in further infecting their hosts. Gram positive cocci bacteria like R. dentocariosa usually forms the conditioning layer of the biofilm forming on tooth surfaces and gingivae [18]. These biofilms forming on oral surfaces allow them to develop resistance to antibiotics better than planktonic cells. However, multiple reports have shown that nanoparticles (NPs), the alternatives to traditional antimicrobial agents, have the promising antimicrobial and antibiofilm activities against pathogenic bacteria [16].

Current research

.

References

References examples

1. 2.

This page is written by<MIRA SYAHIRA RHYME> for the MICR3004 course, Semester 2, 2016