Statement of the Problem: There are global efforts for introducing a new herbal antimi-crobial agent with minimal side effects. There are some reports about the antimicrobial properties of Pimpinella anisum and Oregano Vulgare. Purpose: In this study, the antimicrobial properties of Pimpinella anisum and Oregano Vulgare have been assessed. Material and Method: In this experimental in vitro study, the dental plaque samples were collected from children aged 3 to 5 years old who were referred to a private dental office with diagnosis of dental caries. After determination of the bacterial colonies of Streptococ-cus sanguinis, Streptococcus mutans and Streptococcus salivarius, the minimum inhibito-ry concentration (MIC) and minimum bactericidal concentration (MBC) of ethanolic and methanolic extracts of Pimpinella anisum and Oregano vulgare were measured by macrodilution and microdilution methods. Results: The mean MIC and MBC of Pimpinella anisum extract and Oregano vulgare extract and their combination against Streptococcus mutans, Streptococcus sanguinis, and Streptococcus salivarius were statistically different (p< 0. 001). The combination of these extracts showed the lowest MIC and MBC. Conclusion: Hydroalcoholic extracts of the Pimpinella anisum and Oregano Vulgare were effective antibacterial agent against Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguinis so the combination of these two extracts showed the highest antibacterial properties on all the bacteria evaluated.

Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a gram-positive coccus that belongs to group D of the Lancefield grouping. Most SBSEC strains have been characterized as commensal microorganisms, but some can cause severe infections, such as bacteremia and infective endocarditis (IE). Colorectal cancer (CRC) is the third most frequently diagnosed cancer and the third leading cause of cancer-related death. The connection between SBSEC bacteremia, endocarditis, and CRC is well recognized. The presence of CRC is directly linked to the stage of diagnosis, with stage I disease associated with a 5-year survival rate of 90.1%. Epidemiological research has revealed that in CRC patients, the colon is infected with SBSEC, even in the early stages, in ulcer tissues. However, the molecular mechanism of the SBSEC connection in CRC has not yet been identified. According to some reports, there are geographical discrepancies in SBSEC bacteremia, including the occurrence rate and origin of infection. For instance, Streptococcus bovis endocarditis is more prevalent in the European population than in the United States, and within Europe, there is variation between the North and South. In this review, we focus on the major virulence factors, diagnostic methods used to identify SBSEC isolates, and risk factors for CRC.

Leech saliva, containing over 100 biologically active proteins, includes the antimicrobial protein destabilase. Functioning in a manner similar lysozyme, destabilase degrades  bacterial cell walls. Tooth decay, caused by Streptococcus mutans and S. sobrinus, necessitates their elimination for prevention and treatment. The effect of leech saliva from different groups on S. mutans and S. sobrinus was investigated. Saliva samples were collected from three leech groups salivated at one, two and three months after feeding. Additionally, the antibacterial properties of destabilase were investigated through bioinformatics and molecular docking. Our study revealed an increase in salivary protein concentration with the duration of starvation, reaching 769 μg/ml after three months. Among the various samples, the saliva concentration of leeches that had undergone three months of starvation exhibited the most potent antibacterial properties. Specifically, it exhibited an antibacterial percentage of 35.3% against S. mutans and 42.6% against S. sobrinus at a concentration of 2 mg/ml. The concentration of 2 mg/ml in the three-month saliva sample also exhibited the highest anti-biofilm percentage against both bacteria, with values of 31.6% for S. mutans and 44.2% for S. sobrinus. Given the global challenge of tooth decay, leech saliva especially destabilase, shows potential for preventing and treating this common dental condition. A significant concentration of destabilase, an antimicrobial protein present in the saliva of leeches, was identified. Also, a novel strategy was proposed to inhibit the formation of biofilms on S. mutans and S. sobrinus, which are commonly associated with tooth decay.

Background and objectives: The use of antibacterial substances is necessary to reduce pathogens without damaging the normal flora of the oral cavity. Therefore, this study aimed to investigate the antibacterial effect of bitter and sweet almond extracts on Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Streptococcus salivarius and Streptococcus sobrinus. Materials and methods: In this experimental study, laboratory samples were analyzed in three groups as follows: bitter almond extract (Prunus Amygdalus amarus) group, sweet almond extract (Prunus Amygdalus dulcis) group and 0. 2% chlorhexidine. To determine the antibacterial effects of the extracts on the aforementioned bacteria, the disk agar diffusion method was performed according to the CLSI manufacturers. Data were collected and analyzed using SPSS26 software as well as Kruskal-Wallis and Mann-Whitney tests. Results: Findings suggested that Chlorhexidine had the greatest antibacterial effect against the tested bacteria. Bitter and sweet almond extract had no effect on E. faecalis and despite the effect on other bacteria,this effect was not statistically significant (P > 0. 05). A 12. 33 mm and 10. 6 mm inhibition zone diameter of the bitter and sweet almond extracts was observed against S. sobrinus, respectively. Conclusion: The antibacterial effect of chlorhexidine on the tested oral bacteria was much higher than the bitter and sweet almond extracts. Also, the bitter and sweet almond extracts had no effect on E. faecalis. However, the bitter almond was more effective than the sweet almond.