An in vitro evaluation of endodontic sealers and an antibiotic to assess their antimicrobial effect against Enterococcus faecalis.

Objective: This study aimed to compare the antimicrobial effect of three endodontic sealers (AH Plus, Mineral trioxide aggregate [MTA] Fillapex, and BioRoot RCS) with and without amoxicillin against E. faecalis. Methodology: Amoxicillin, equivalent to 10% of the sealers' total weight, was mixed with the sealers. Another batch was prepared without amoxicillin. The direct contact test (DCT) and the agar diffusion test were used to assess the antibacterial effect. Results were analysed using one-way analysis of variance (ANOVA), the F-test, and the Kruskal-Wallis test. Results: AH Plus significantly suppressed E. faecalis without the addition of amoxicillin in the DCT (p = 0.011), while in the agar diffusion test, BioRoot RCS had a larger inhibition zone than the control (p < 0.001). When amoxicillin was added to the sealers, AH Plus (p = 0.003) and MTA Fillapex (p = 0.042) reduced E. faecalis growth. In contrast, all three sealers showed larger inhibition zones than the control (p = 0.001), with AH Plus displaying a larger inhibition zone than MTA Fillapex (p = 0.042) and BioRoot RCS (p = 0.032). Conclusions: It was thus concluded that the addition of amoxicillin to endodontic sealers enhances their antimicrobial activity against E. faecalis.

Chlamydia trachomatis in the gingival sulcus and pharynx in patients of Northeast Mexico.

BACKGROUND: The oral microenvironment provides the conditions for the establishment of microorganisms not usually considered residents of the normal oral microbiota. Sexually transmitted microorganisms such as Chlamydia trachomatis can adhere to any mucosal surface and ascend to reach appropriate locations to survive and develop symptomatic infections. MATERIALS AND METHODS: To determine the presence of C. trachomatis, direct immunofluorescence of this microorganism was carried out in 76 randomly selected patients attending a periodontal clinic during a period of 1 year. Samples from the gingival sulcus and the pharynx were collected for detection of C. trachomatis. Patients who attended the periodontal clinic were divided into two groups: those without periodontitis and those with periodontitis. For the purpose of performing other statistical analyses, all patients were also divided by gender and age. RESULTS: From the total of 76 patients, in the group without periodontitis, 61% were positive for C. trachomatis in the gingival sulcus and 63.4% in the pharynx; in the periodontitis group, 45.7% were positive in the sulcus and 40% in the pharynx. When we compared patients by gender or age, no statistical difference was found. CONCLUSIONS: The prevalence of C. trachomatis in this group was 53.9% in the gingival sulcus and pharynx of the studied patients.

Electrochemical Behavior of Ti6Al4V Alloy Used in Dental Implants Immersed in Streptococcus gordonii and Fusobacterium nucleatum Solutions.

The titanium alloy, Ti6Al4V, is used in dentistry for dental implants because of its excellent resistance to corrosion and its high biocompatibility. However, periimplantitis is considered the main reason for treatment failure. The Ti6Al4V alloy was used to study the corrosion behavior for dental implant applications, using an experimental arrangement of three electrodes with the bacteria Streptococcus gordonii and Fusobacterium nucleatum, in addition to Ringer's lactate as electrolytes, at 37 °C and a pH of 5.6. Their electrochemical behavior was studied by open circuit potential (OCP) and cyclic potentiodynamic polarization (CPP) according to ASTM G3-14 and ASTM G61-11, respectively. Scanning electron microscopy (SEM) was employed to determine the morphology of the alloy studied. An experimental model, in situ, was established with the bacteria present in an oral environment to understand the electrochemical behavior of the alloy used in dental implants. The greatest corrosion in Ti6Al4V alloy was produced by the medium that contained the bacterium Streptococcus gordonii, which is considered a primary colonizer. In addition, the Ti6Al4V alloy presented uniform corrosion in the three solutions at the different exposure times showing a negative hysteresis in CPP.

Detection of Porphyromonas gingivalis and Streptococcus intermedius in chronic periodontitis patients by multiplex PCR.

A Multiplex PCR assay for the detection of Porphyromonas gingivalis and Streptococcus intermedius in chronic periodontitis is presented. A total of 180 samples from 65 adults with untreated periodontitis and 17 healthy volunteers were taken and processed in a simple boiling step. Cell lysates were used as DNA source for multiplex PCR assays. Primers were designed from 16S rRNA gene sequences from the GenBank-EMBL database showing specificity for target pathogens. This multiplex PCR system could detect 8.2 P gingivalis and S. intermedius cells. In untreated periodontitis patients, only 78.5% were positive for one or both bacteria; 37% were positive for P gingivalis only, 17% for S. intermedius and 24.5% for both. P. gingivalis was detected in 23.5% of healthy volunteers, while S. intermedius was not detected in the same patients. The distribution of these bacteria was related to the periodontal probing depth, while 95.23% of patients with pockets wih 6 to 7 mm deep were positive for either or both, only 70.45% of of them with 4 to 5 mm pockets were positive.

Corrigendum to "Subchronic Infection of Porphyromonas gingivalis and Tannerella forsythia Stimulates an Immune Response but Not Arthritis in Experimental Murine Model".

[This corrects the article DOI: 10.1155/2017/2052938.].

Persistence of Toxic Activity of Fermentation Extracts from Bacillus thuringiensis var. israelensis after More Than Three Decades of Storage.

This study was carried out to determine the persistence of toxicity of fermentation extracts of Bacillus thuringiensis var. israelensis after more than three decades of storage. For this purpose, a population of Aedes aegypti was established. The mortality rate of 20 spore-crystal extracts purified using the acetone-lactose coprecipitation method was measured and evaluated by bioassays according to a modified WHO protocol. The extracts with the highest mortality rate were determined in triplicate by their LD50 and LD98. All extracts showed toxicity at the highest tested dose (1000 ppm) and some, such as strains 3260 and 3501, still killed larvae at doses as low as 0.01 ppm. These data are surprising because no study on the activity of B. thuringiensis toxic proteins after such a long storage time has been reported.

Salivary ammonia levels and Tannerella forsythia are associated with rheumatoid arthritis: A cross sectional study.

The aim of this paper is to evaluate the relationship of salivary ammonium levels and the presence of bacteria with rheumatoid arthritis (RA) clinical disease activity in a cross-sectional study of Mexican patients. From a periodontal and disease activity standpoint, 132 consecutive RA patients fulfilling clinical criteria were evaluated. Ammonia levels (including peptidyl arginine deiminase activity) were evaluated by colorimetric assay and the presence of Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia was evaluated by polymerase chain reaction (PCR) technique. After a multivariate analysis, adjusting for clinical and serological parameters, a significant association was only observed between severe periodontitis and probing depth with high RA disease activity. Additionally, in contrast to P. gingivalis, the presence of T. forsythia was significantly associated with high disease RA activity even after multivariable adjustment analysis. There was also a significant increase in ammonium levels in the high RA activity group and a significant correlation between salivary ammonia and RA disease activity but not with autoantibody titers. Similarly, we observed a significant increase in the ammonium levels derived from the cultures of P. gingivalis and T. forsythia, with respect to P. intermedia and S. gordonii cultures, or even healthy donors. These results suggest that RA activity is associated with severe periodontitis, high salivary ammonium levels and the presence of T. forsythia.

Subchronic Infection of Porphyromonas gingivalis and Tannerella forsythia Stimulates an Immune Response but Not Arthritis in Experimental Murine Model.

Studies have proposed that Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf) promote a nonspecific inflammatory response that could produce systemic disease. Oral inoculation of Pg and Tf on the immune and arthritis response was evaluated in BALB/C mice divided into four groups: (1) sham; (2) food contaminated with Pg/Tf; (3) complete Freund's adjuvant (CFA) + Pg/Tf; and (4) CFA alone. CFA was administered subcutaneously on days 1 and 14. The arthritis response was monitored for 21 days after day 14 of CFA administration. IL-1ß and IL-6 were determined in serum. T cell activation was evaluated by CD25 in salivary lymph nodes or mouse spleen. Pad inflammation appeared by day 19 in the CFA group, but animals with bacteria inoculation presented a delay. A significant increase in IL-6 was found in Groups 3 and 4, but not with respect to IL-1ß. We observed an increase in CD25 in cells derived from cervical nodes and in animals with bacteria inoculation and CFA. A local immune response was observed in mice inoculated with Pg and Tf (T cell activation); a systemic response was observed with CFA. Since pad inflammation was delayed by bacterial inoculation this suggests that local T cell activation could decrease pad inflammation.

Nivel de higiene y prevalencia de Porphyromona gingivalis y Fusobacterium nucleatum en pacientes recuperados de SARS-CoV-2 / Hygiene level and prevalence of Porphyromona gingivalis and Fusobacterium nucleatum in recovered SARS-CoV-2 patients

Introducción: El SARS-CoV-2 afecta el sistema respiratorio en diferentes grados. La cavidad oral es el lugar más colonizado por bacterias, por lo tanto, al no tener una adecuada higiene pueden presentarse diferentes enfermedades secundarias, lo que ha causado alerta en el gremio odontológico, ya que puede contribuir a complicaciones posteriores en los pacientes. Material y métodos: El estudio fue conformado por 47 pacientes voluntarios recuperados de SARS-CoV-2, residentes de Montemorelos, Nuevo León, México, donde fueron atendidos en Bucalia Dent, consultorio dental. Después del consentimiento informado de cada paciente, se realizó una historia clínica para conocer los síntomas, enfermedades sistémicas, ausencia de dientes y nivel de inflamación gingival de acuerdo al índice de Loe y Silness. A continuación, se tomó una muestra de biofilm microbiano (placa dentobacteriana), la cual se suspendió en una solución buffer de fosfato, posteriormente fue llevada al Centro de Investigación y Desarrollo en Ciencias de la Salud (CIDICS), Monterrey, N.L, México. Se extrajo DNA y se purificó, después se realizó PCR para detectar los patógenos orales; la PCR se visualizó en gel de agarosa (1.5%) por tinción de bromuro de etidio. Resultados: Se detectó 80.85% Porphyromona gingivalis y 68.09% Fusobacterium nucleatum en pacientes recuperados de SARS-CoV-2; 23.4% presentaron inflamación leve de acuerdo al índice de Loe y Silness, 54.5% fueron masculinos y 45.5% femeninos. Por otro lado, 36.4% de los pacientes con inflamación leve tenían de cuatro a seis dientes ausentes. En estos pacientes se detectó 18.18% únicamente con Fusobacterium nucleatum y 27.27% sólo con Porphyromona gingivalis; el sexo masculino tuvo predisposición en 66.6% y el femenino en 33.33%. Se observó infección con los dos patógenos presentes en 45.45%; y 60% de estos pacientes fueron masculinos. Conclusiones: Los pacientes recuperados de SARSCoV- 2 analizados en esta investigación mostraron mala higiene oral y alta prevalencia de los patógenos mencionados altamente relacionados a inflamación gingival o enfermedad periodontal, lo que nos indica que es indispensable la intervención del odontólogo al finalizar el periodo de infección de cada paciente (AU)

Introduction: SARS-CoV-2 affects the respiratory system to different degrees. The oral cavity is a colonized place by bacterias, therefore, by not having good hygiene, different secondary diseases can occur; this has caused an alert in the dental industry, since it can contribute to later complications in patients. Material and methods: The study was conducted in 47 SARS-CoV-2 recovered volunteers from the Montemorelos city of the Nuevo León state, Mexico, who were attended at the Bucalia Dent dental clinic. An informed consent was obtained from each of the patients, then their clinical history was documented in order to know the symptoms, previous systemic diseases, absence of teeth and degree of gingival inflammation, as suggested by Loe and Silness. Subsequently, a dental plaque sample was taken from all patients, which was suspended in a phosphate buffered solution and shipped to The Center for Research and Development in Health Sciences (CIDICS), Monterrey, NL, Mexico for storage. DNA extraction and purification was performed and PCR was carried out for the oral pathogens detection. All PCR products were visualized on 1.5% agarose gel by ethidium bromide staining. Results: Porphyromona gingivalis and Fusobacterium nucleatum were detected in 80.85% and 68.09% of SARS-CoV-2 recovered patients, respectively. 23.4% showed mild inflammation based on the Loe and Silness criteria, 54.5% were male and 45.5% female. On the other hand, 36.4% of patients with mild inflammation had between 4 to 6 missing teeth. A single infection by Fusobacterium nucleatum was detected in 18.18% and by Porphyromona gingivalis in 27.27%; the male sex had a predisposition with 66.66% and 33.33% female; coinfection of both pathogens was observed in 45.45% where 60% were male. Conclusions: SARS-CoV-2 recovered patients show poor oral hygiene and a high prevalence of oral pathogens related to the development of inflammatory gingival or periodontal disease, this suggests the need for an odontological clinical intervention at the end of the course of infection or disease caused by SARS-CoV-2 (AU)

Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm.

BACKGROUND AND METHODS: Despite continuous efforts, the increasing prevalence of resistance among pathogenic bacteria to common antibiotics has become one of the most significant concerns in modern medicine. Nanostructured materials are used in many fields, including biological sciences and medicine. While some bismuth derivatives has been used in medicine to treat vomiting, nausea, diarrhea, and stomach pain, the biocidal activity of zerovalent bismuth nanoparticles has not yet been studied. The objective of this investigation was to analyze the antimicrobial activity of bismuth nanoparticles against oral bacteria and their antibiofilm capabilities. RESULTS: Our results showed that stable colloidal bismuth nanoparticles had 69% antimicrobial activity against Streptococcus mutans growth and achieved complete inhibition of biofilm formation. These results are similar to those obtained with chlorhexidine, the most commonly used oral antiseptic agent. The minimal inhibitory concentration of bismuth nanoparticles that interfered with S. mutans growth was 0.5 mM. CONCLUSION: These results suggest that zerovalent bismuth nanoparticles could be an interesting antimicrobial agent to be incorporated into an oral antiseptic preparation.

Detection of Porphyromonas gingivalis and Streptococcus intermedius in chronic periodontitis patients by multiplex PCR

Se muestra la utilización del ensayo de polimerasa en cadena (PCR) múltiplex para la detección de Porphyromonas gingivalis y Streptococcus intermedius en pacientes con periodontitis crónica. Se analizaron un total de 180 muestrasde 65 adultos con periodontitis no tratada y 17 voluntarios sanos, las células se procesaron inicialmente colocándolas a baño María durante 10 min. El lisado celular fue usado comofuente de ADN para los ensayos del PCR múltiplex. Los primers fueron diseñados a partir de secuencias génicas defracciones 16 rRNA obtenidas de la base de datos GenBank-EMBL y que mostraron especificidad para los patógenos mencionados. El sistema PCR múltiplex fue diseñado para identificar 8.2 células de P. gingivalis y S. intermedius. De los pacientes con periodontitis, sólo el 78.5 por ciento fueron positivos para una o ambas bacterias. En el 37 por ciento se identificó únicamente P. gingivalis, en el 17 por ciento S. intermedius y en un 24.5 por ciento ambos. P. gingivalis fue detectada en el 23.5 por ciento de los voluntarios sanos, mientras que, S. intermedius no se detectó en esegrupo de pacientes. La distribución de la identificación de estas bacterias está relacionada con la profundidad de las bolsas periodontales. Mientras que el 95.23 por ciento de los pacientes con bolsas de 6 a 7 mm fueron positivas para ambas bacterias, mientras que sólo el 70.45 por ciento de ellos fue positivo cuando las bolsas tenían de 4 a 5 mm de profundidad