Root canal microbiota as an augmented reservoir of antimicrobial resistance genes in type 2 diabetes mellitus patients.

BACKGROUND: Antimicrobial resistance is a global public health problem. Root canal microbiota associated with apical periodontitis represents a well-known reservoir of antimicrobial resistance genes (ARGs). However, the effect of type 2 diabetes mellitus (T2DM) in this reservoir is unknown. This study aimed to establish if root canal microbiota associated with apical periodontitis in T2DM patients is an augmented reservoir by identifying the prevalence of nine common ARGs and comparing it with the prevalence in nondiabetic patients. METHODOLOGY: This cross-sectional study included two groups: A T2DM group conformed of 20 patients with at least ten years of living with T2DM and a control group of 30 nondiabetic participants. Premolar or molar teeth with pulp necrosis and apical periodontitis were included. A sample was collected from each root canal before endodontic treatment. DNA was extracted, and ARGs were identified by polymerase chain reaction. RESULTS: tetW and tetM genes were the most frequent (93.3 and 91.6%, respectively), while ermA was the least frequent (8.3%) in the total population. The distribution of the ARGs was similar in both groups, but a significant difference (p<0.005) was present in ermB, ermC, cfxA, and tetQ genes, being more frequent in the T2DM group. A total of eighty percent of the T2DM patients presented a minimum of four ARGs, while 76.6% of the control group presented a maximum of three. CONCLUSIONS: Root canal microbiota associated with apical periodontitis in T2DM patients carries more ARGs. Therefore, this pathological niche could be considered an augmented reservoir.

Root canal microbiota as an augmented reservoir of antimicrobial resistance genes in type 2 diabetes mellitus patients

Abstract Antimicrobial resistance is a global public health problem. Root canal microbiota associated with apical periodontitis represents a well-known reservoir of antimicrobial resistance genes (ARGs). However, the effect of type 2 diabetes mellitus (T2DM) in this reservoir is unknown. This study aimed to establish if root canal microbiota associated with apical periodontitis in T2DM patients is an augmented reservoir by identifying the prevalence of nine common ARGs and comparing it with the prevalence in nondiabetic patients. Methodology This cross-sectional study included two groups: A T2DM group conformed of 20 patients with at least ten years of living with T2DM and a control group of 30 nondiabetic participants. Premolar or molar teeth with pulp necrosis and apical periodontitis were included. A sample was collected from each root canal before endodontic treatment. DNA was extracted, and ARGs were identified by polymerase chain reaction. Results tetW and tetM genes were the most frequent (93.3 and 91.6%, respectively), while ermA was the least frequent (8.3%) in the total population. The distribution of the ARGs was similar in both groups, but a significant difference (p<0.005) was present in ermB, ermC, cfxA, and tetQ genes, being more frequent in the T2DM group. A total of eighty percent of the T2DM patients presented a minimum of four ARGs, while 76.6% of the control group presented a maximum of three. Conclusions Root canal microbiota associated with apical periodontitis in T2DM patients carries more ARGs. Therefore, this pathological niche could be considered an augmented reservoir.

Effect of Streptococcus mutans on surface-topography, microhardness, and mechanical properties of contemporary resin composites.

OBJECTIVE: Dental caries is the most prevalent disease globally, and Streptococcus mutans (S. mutans) is a common associated oral bacteria. Additionally, S. mutans possess esterase activity capable of degrading resin composites (RC). However, the effect of degradation on the physical-mechanical properties of the RC has not been extensively studied. We evaluated the flexure strength (FS), the diametral tensile strength (DTS), the modulus of elasticity (ME), and the microhardness of three contemporary RC to establish if S. mutans could affect them. METHODS: One hundred thirty-eight bar-shaped and 276 disc-shaped specimens were fabricated with Enamel Plus HRi, IPS Empress Direct, and Clearfil AP-X, and physical-mechanical testing was done after been incubated during 30 and 60 days in culture media with or without S. mutans. Also, a scanning electron microscope was used to identify surface changes. RESULTS: None of the tested RC were affected in their mechanical properties (FS, ME, and DTS). However, Clearfil AP-X and Enamel Plus HRI showed eroded surfaces and a decreased microhardness after 30 and 60 days S. mutans incubation. IPS Empress Direct presented the lowest values in all the tests, but its physical-mechanical features and surface were not affected by bacteria's exposure. CONCLUSIONS: Exposure to S. mutans could affect some contemporary RC; however, the effect seems superficial since its mechanical features were not affected.

Proangiogenic Effect of Affinin and an Ethanolic Extract from Heliopsis longipes Roots: Ex Vivo and In Vivo Evidence.

Angiogenesis, the formation of new blood vessels, underlies tissue development and repair. Some medicinal plant-derived compounds can modulate the angiogenic response. Heliopsis longipes, a Mexican medicinal plant, is widely used because of its effects on pain and inflammation. The main bioactive phytochemicals from H. longipes roots are alkamides, where affinin is the most abundant. Scientific studies show various medical effects of organic extracts of H. longipes roots and affinin that share some molecular pathways with the angiogenesis process, with the vasodilation mechanism of action being the most recent. This study investigates whether pure affinin and the ethanolic extract from Heliopsis longipes roots (HLEE) promote angiogenesis. Using the aortic ring rat assay (ex vivo method) and the direct in vivo angiogenesis assay, where angioreactors were implanted in CD1 female mice, showed that affinin and the HLEE increased vascular growth in a dose-dependent manner in both bioassays. This is the first study showing the proangiogenic effect of H. longipes. Further studies should focus on the mechanism of action and its possible therapeutic use in diseases characterized by insufficient angiogenesis.

Affinin (Spilanthol), Isolated from Heliopsis longipes, Induces Vasodilation via Activation of Gasotransmitters and Prostacyclin Signaling Pathways.

Heliopsis longipes roots have been widely used in Mexican traditional medicine to relieve pain, mainly, toothaches. Previous studies have shown that affinin, the major alkamide of these roots, induces potent antinociceptive and anti-inflammatory activities. However, the effect of H. longipes root extracts and affinin on the cardiovascular system have not been investigated so far. In the present study, we demonstrated that the dichloromethane and ethanolic extracts of H. longipes roots, and affinin, isolated from these roots, produce a concentration-dependent vasodilation of rat aorta. Affinin-induced vasorelaxation was partly dependent on the presence of endothelium and was significantly blocked in the presence of inhibitors of NO, H2S, and CO synthesis (NG-nitro-l-arginine methyl ester (l-NAME), dl-propargylglycine (PAG), and chromium mesoporphyrin (CrMP), respectively); K⁺ channel blockers (glibenclamide (Gli) and tetraethyl ammonium (TEA)), and guanylate cyclase and cyclooxygenase inhibitors (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and indomethacin (INDO), respectively). Our results demonstrate, for the first time, that affinin induces vasodilation by mechanisms that involve gasotransmitters, and prostacyclin signaling pathways. These findings indicate that this natural alkamide has therapeutic potential in the treatment of cardiovascular diseases.