Studies on the possible association between bacteria and oral squamous cell carcinoma (OSCC) remain inconclusive, largely due to methodological variations/limitations. The objective of this study was to characterize the species composition as well as functional potential of the bacteriome associated with OSCC. DNA obtained from 20 fresh OSCC biopsies (cases) and 20 deep-epithelium swabs (matched control subjects) was sequenced for the V1-V3 region using Illumina’s 2 × 300 bp chemistry. High quality, non-chimeric merged reads were classified to species level using a prioritized BLASTN-algorithm. Downstream analyses were performed using QIIME, PICRUSt, and LEfSe. Fusobacterium nucleatum subsp. polymorphum was the most significantly overrepresented species in the tumors followed by Pseudomonas aeruginosa and Campylobacter sp. Oral taxon 44, while Streptococcus mitis, Rothia mucilaginosa and Haemophilus parainfluenzae were the most significantly abundant in the controls. Functional prediction showed that genes involved in bacterial mobility, flagellar assembly, bacterial chemotaxis and LPS synthesis were enriched in the tumors while those responsible for DNA repair and combination, purine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, ribosome biogenesis and glycolysis/gluconeogenesis were significantly associated with the controls. This is the first epidemiological evidence for association of F. nucleatum and P. aeruginosa with OSCC. Functionally, an “inflammatory bacteriome” is enriched in OSSC.

Salvadora persica L. (Salvadoraceae) is an evergreen shrub growing in the Middle East, Africa, and Southern Asia. It is traditionally known as “miswak” and used as toothbrushes and for the treatment of toothache, gum diseases, boils, chest infection, gonorrhea, headache, spleen troubles, stomachache, and ulcers. To the best of our knowledge, this is the first study aimed at conducting phytochemical, cytotoxic, and antimicrobial investigations of the fruits (berries) of S. persica collected from the Jazan region of Saudi Arabia. Analysis of the ethanol extract of S. persica fruits using GC-MS showed the presence of six esters (20.71%), seven alkanes (15.47%), tetracosamethyl-cyclododecasiloxane (9.91%), eicosamethyl-cyclodecasiloxane (7.27%), and 1-monolinoleoylglycerol (5.17%). The predominant constituents were acetyl dasycarpidan-1-methanol (10.47%), tetracosamethyl-cyclododecasiloxane (9.91%), eicosamethyl-cyclodecasiloxane (7.27%), and 1-monolinoleoylglycerol (5.17%). The petroleum ether extract of the fruits contained mainly eicosamethyl-cyclodecasiloxane (23.81%), 1-monolinoleoylglycerol (11.78%), (Z,Z,Z)-9,12,15-octadecatrienoic acid ethyl ester derivative (10.56%), and tetracosamethyl-cyclododecasiloxane (9.91%). The cytotoxic properties of the ethanol extract were investigated by MTT assay against the breast MCF7, ovary A2780, and colon HT29 cells. The fruit extract of S. persica was selective against the ovarian and colon cancer cells compared to normal fibroblast cells (MRC5) as it showed IC50 values 17.50, 8.35, and 5.12, against MCF7, A2780, and HT29 cells, respectively. Interestingly, the fruit extract was also found to possess selective antimicrobial activity for Streptococcus mutans isolates with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 3.12 and 6.25 mg/mL, respectively. Interestingly, it was found to be ineffective against other Gram-positive as well as Gram-negative microorganisms. This study provides insight into the bioactive components present in the fruits of the plant that can be utilized for its cytotoxic and antimicrobial properties.

Objective:Our goal of the study was to evaluate the antibacterial properties of endodontic sealers against the E. faecalis.Materials and Methods:Six millimeters wells were made for each material in all the preinoculated petri plates. Then, the petri plates were incubated for 24 h. The zones of inhibition appeared were measured, and the measurements were put to statistical analysis.Results:EndoSequence BC Sealer, MM-mineral trioxide aggregate (MTA), and ProRoot MTA showed maximum means of diameter of zones of inhibition, whereas MM-seal and Endoseal did not show any zones of inhibition.Conclusion:EndoSequence BC Sealer was found to be a better endodontic sealer as compared to resin-based and zinc oxide-eugenol-based sealer.

Background: The possibility that smokeless tobacco may contribute to oral carcinogenesis by influencing the oral microbiome has not been explored. This preliminary cross-sectional study sought to assess the effect of using shammah, a form of smokeless tobacco prevalent in Arabia, on the tongue microbiome. Tongue scarping samples were obtained from 29 shammah users (SU; 27.34 ± 6.9 years) and 23 shammah non-users (SNU; 27.7 ± 7.19 years) and analyzed with 16S rRNA gene sequencing (V1-V3). Species-level taxonomy assignment of the high-quality, merged reads was obtained using a previously described BLASTn-based algorithm. Downstream analyses were performed with QIIME, LEfSe, and R. Results: A total of 178 species, belonging to 62 genera and 8 phyla were identified. Genera Streptococcus, Leptotrichia, Actinomyces, Veillonella, Haemophilus, Prevotella and Neisseria accounted for more than 60% of the average microbiome. There were no differences between the two groups in species richness and alpha-diversity, but PCoA showed significant separation (P = 0.015, ANOSIM). LEfSe analysis identified 22 species to be differentially abundant between the SU and SNU. However, only 7 species maintained a false discovery rate of ≤0.2 and could cluster the two groups separately: Rothia mucilaginosa, Streptococcus sp. oral taxon 66, Actinomyces meyeri, Streptococcus vestibularis Streptococcus sanguinis and a potentially novel Veillonella species in association with SU, and Oribacterium asaccharolyticum with SNU. Conclusion: These preliminary results indicate that shammah use induces tongue microbiome changes including enrichment of several species with high acetaldehyde production potential, which warrants further investigation.

Background: The habit of khat (Catha Edulis Forskal) chewing is widely practiced in the southern regions of Saudi Arabia, Yemen, and East Africa. This social habit has tremendous effects on oral and general health of khat chewers. Khat may affect bacterial species in plaque biofilms on oral rehabilitation materials. This preliminary case-controlled study aimed to assess and compare the effect of khat chewing on bacterial biodiversity between nonkhat chewers (NKC) and khat chewers (KC) in oral biofilms on oral rehabilitation materials using polymerase chain reaction (PCR). Material/Methods: Fifty participants were organized into 2 equal groups of NKC and KC, each containing 5 subgroups related to filling material type. Some participants had amalgam (A) or composite (C) restorations, while others had feldspathic porcelain (FP), nickel chromium (NC), and zirconia ceramic (ZC) crowns or bridges. Oral biofilm samples were collected from all participants, DNA was extracted, and samples were subjected to PCR. Bacterial species were then identified and counted. PCR products were sequenced to detect similarity. Partial 16S rRNA gene sequences of the current study samples were compared with 16S rRNA gene sequences from GenBank using BLAST on the National Center for Biotechnology Information website. Results: The Streptococcus sp. was the most common bacterial species among our participants (40; 80%), followed by Lactobacillus and Veillonella spp., accounting for 12% (6) and 8% (4), respectively. Streptococcus sp. was observed equally among NKC and KC, but Lactobacillus and Veillonella spp. were higher in KC and NKC, respectively. Lactobacillus was associated mainly with prosthetic materials, and Streptococcus was found among all examined dental restorative materials. Conclusions: This research concluded that khat chewing significantly affects bacterial biodiversity in oral biofilms in the presence of different restorative and prosthetic dental materials.