Natalia Lopes Pontes Iorio

Background: For over 70 years, guidelines have recommended antibiotics for infective endocarditis (IE) prophylaxis before dental procedures, focusing on oral streptococci. Objectives: Our in silico study aimed to evaluate the potential resistance of oral streptococci against prophylactic antibiotics used before invasive dental procedures to prevent IE. Methods: The genomic assemblies and metadata of Streptococcus IE isolates were searched using specific terms in BioSample and RefSeq databases. Their antimicrobial resistance phenotypes for 91 drugs belonging to 22 different classes were predicted with ResFinder and analysed regarding the recommended IE dental prophylactic antibiotics, focusing on the oral streptococci assemblies. Results: Among the 258 Streptococcus isolates dating from 1935 to 2021 from 12 countries, 79.46% were classified as oral streptococci, and 38.37% of the 258 assemblies carried resistance genes to at least one antimicrobial. Seven isolates carried the transposon Tn6331, which can confer resistance to aminoglycosides, macrolides, lincosamides, streptogramins and tetracyclines. Within the oral Streptococcus strains, none carried resistance genes to amoxicillin, but potential resistance to azithromycin (24.88%) and doxycycline (16.59%) was observed. Conclusions: Our in silico study showed that none of the oral Streptococcus assemblies from IE carried resistance genes to the primary regimen recommended for IE prophylaxis following invasive dental procedures. However, several assemblies were potentially resistant to alternative prophylactic regimens for patients allergic to penicillin or ampicillin.

To avoid failure of endodontic treatment, it is important to properly seal the root canals after chemomechanical preparation in order to avoid microleakage. Typically, sealing involves the use of gutta‐percha and sealing cement, the latter of which adheres to the dentin and fills the spaces between the gutta‐percha and the dentin walls. Laboratory studies have been performed to detect microleakage of endodontic sealers based on various criteria, including microbiological ones; however, none guaranteed that the leakage occurred through the root canal space and not through other pathways. This article proposes a new laboratory assay to evaluate bacterial microleakage in endodontic sealers, ensuring visualization of the correct inoculum infiltration pathway. Furthermore, we present the main critical parameters and provide suggestions on how to manage them. These protocols allow the detection of bacterial microleakage in bovine teeth filled with endodontic sealer and inoculated with Enterococcus faecalis . © 2026 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1 : Bovine teeth selection and cleaning Basic Protocol 2 : Bovine teeth inclusion Basic Protocol 3 : Tooth standardization Basic Protocol 4 : Set preparation Basic Protocol 5 : Inoculum preparation Basic Protocol 6 : Canal inoculation Basic Protocol 7 : Set incubation

SignificanceDental caries is a polymicrobial condition derived from microbial biofilm. There is a lack of studies addressing antimicrobial photodynamic therapy (aPDT) activity against a cariogenic multispecies biofilm.AimWe aim to evaluate the activity of aPDT against a cariogenic biofilm composed of a microbial consortium.ApproachEqual parts of Streptococcus mutans, Lactobacillus rhamnosus, and Candida albicans were used to form a microbial inoculum containing ∼107 colony-forming units/mL, which was placed on cellulose acetate membranes to form biofilm. After biofilm formation, the seven groups, each containing four membranes, were treated as follows: laser 1 J (G1); laser 4 J (G2); photosensitizer methylene blue (G3); photosensitizer + laser 1 J (G4); photosensitizer + laser 4 J (G5); chlorhexidine as positive control (G6); and distilled water (G7).ResultsThe number of viable microbial cells per biofilm varied between 1.40×108 (G5) and 7.28×108 (G1), whereas the negative control group (G7) reached 1.38×109. Compared with G7, all groups presented a reduction, with the percentage varying from 47.05% (G1) to 89.85% (G5). However, G5 (photosensitizer + laser 4 J) was the only group to present a statistical reduction (p<0.05).ConclusionaPDT represents an important antibiofilm adjunct therapy, resulting in a significant reduction in microbial cells within a cariogenic biofilm model.

Introduction Intracanal medications must have antimicrobial properties, in addition to reaching the natural complexities of the periapical tissues, to help in their recovery. Considering the need for more studies about associations among these medications, we aimed to analyze the antimicrobial activity of daptomycin, alone and associated with Triple Antibiotic Paste (TAP), through the penetrability of bovine dentin against four Enterococcus faecalis samples: one standard American Type Culture Collection (ATCC) 29212 sample and three clinical samples. Methods Eighty-three bovine freshly extracted teeth were standardized at 15 mm and prepared to file 45, and then sterilized. The roots received, randomly, one of five treatments (n=16/group). Group 1: TAP; Group 2: daptomycin; Group 3: TAP+daptomycin; Group 4: calcium hydroxide; and Group 5: propylene glycol. The treated roots were inserted into a previously prepared orifice in the base of Petri dishes, which were, twice a week, filled with solid medium inoculated with E. faecalis (five fresh inoculated mediums/15 days). After 24 h incubation with each new inoculum, a reading was performed to determine the presence/absence of inhibition zones around the roots. A total of five readings, on days 1, 4, 8, 11, and 15, were performed for each plate. Three untreated roots with culture medium without inoculum represented the sterility control group. Results Group 3 (TAP associated with daptomycin) was the group responsible for the highest number of inhibition zones and the only one capable of inhibiting all E. faecalis strains in at least one of the readings. Comparing TAP (group 1) with daptomycin (group 2) alone, group 1 presented a higher number of inhibition zones than group 2. Groups 4 and 5 (calcium hydroxide and propylene glycol) did not present inhibition halos for any of the evaluated E. faecalis strains. Absence of microbial growth was observed for all roots in the sterility control group. Conclusions This study showed, through the penetrability of bovine dentin, that the association between TAP and daptomycin improved the antimicrobial effectiveness of TAP, demonstrating a possible synergistic activity against E. faecalis (ATCC and clinical samples). TAP associated with daptomycin can be considered as a potential intracanal medication, but only as a last resort.

Concerns over the replicability and reproducibility of published research have grown in many research fields, but empirical data to inform policies are still scarce. Biomedical research in Brazil expanded rapidly over the last three decades, with no systematic assessment of the replicability of its findings. With this in mind, we set up the Brazilian Reproducibility Initiative, a multicenter replication of published experiments from Brazilian science using three common experimental methods: the MTT assay, the reverse transcription polymerase chain reaction (RT-PCR) and the elevated plus maze (EPM). A total of 56 laboratories performed 143 replications of 56 experiments; of these, 90 replications of 45 experiments were considered valid by an independent committee. Replication rates for these experiments varied between 20 and 44% according to five predefined criteria. In median terms, ratios between group means were 58% lower in replications than in original experiments, while coefficients of variation were 82% higher. Effect size decrease was smaller for MTT experiments, original results with less variability and those considered more challenging to replicate, while t values for replications were positively correlated with researcher predictions about replicability, and negatively correlated with the rate of publications by the original article’s last author. Deviations from preregistered protocols were very common in replications, most frequently due to reasons inherent to the experimental model or related to infrastructure and logistics. Our results highlight factors that limit the replicability of results published by researchers in Brazil and suggest ways by which this scenario can be improved.

Introduction: Microorganisms have an important role in the pathogenesis of endodontic disease. Significant advances have been made to increase the sensitivity of microbial detection, identification and enumeration in endodontic samples. The aim of the present study is to compare culture and whole-genome amplification (WGA) followed by PCR assays in the detection of bacteria before and after chemical mechanical preparation (CMP) of root canals.Methods: Ten uniradicular teeth with primary endodontic infections were analyzed. Microbiological samples were collected before and after CMP using paper points, which were separated into two groups: (i) culture assay samples were plated onto Brucella agar with 5% defibrinated sheep's blood, menadione and hemin and incubated anaerobically for 14 days at 36°C; (ii) DNA was extracted from molecular assay samples and subject to WGA by isothermal strand displacement with Phi29 DNA polymerase followed by PCR to determine the presence of bacteria.Results: In both assays, samples before CMP showed the presence of bacteria in all 10 teeth. After CMP, however, bacterial detection differed in the assays performed (p = 0.0198). The presence of bacteria was detected in 70% (7 of 10) of the samples by WGA followed by PCR, where only 10% (1 of 10) had demonstrated bacterial growth in the culture method.Conclusion: The combination of WGA followed by PCR increased the detection of microorganisms from root canal samples after endodontic treatment using NaOCl as a CMP irrigant. So this combination of techniques can represent an important tool to improve the detection of microorganisms in endodontic research.

The COVID-19 pandemic and its effects on public health have urgently demanded effective health policies to avoid the spread of COVID-19. Thus, public administrators have implemented non-pharmacological and pharmacological interventions to mitigate the pandemic's impacts and strengthen health services. The aim of this ecological study is to describe the scenario of COVID-19 pandemic in a Brazilian city, during 2 years. This ecological study was carried out in Nova Friburgo, a Brazilian city, for 105 weeks (two years), from March 29, 2020 (week 1) to April 02, 2022 (week 105). Data on COVID-19 cases and COVID-19 deaths, occupation of COVID-19 exclusive beds in hospitals, community mobility, vaccination, government regulation on the opening of city establishments and city risk assessment were collected from public datasets. Four waves of COVID-19 cases and deaths were observed during this period. The first case occurred in week 1 and first death in week 3 of this study. The highest peaks of cases and deaths were observed during the third wave with 1,131 cases (week 54) and 47 deaths (week 55) and where the highest occupation of COVID-19 exclusive beds in local hospitals occurred. Interventions from more restrictive to more flexible, were implemented throughout this study, including lockdown and gradual return in economic and social strata levels. Vaccination began on week 43 and at the end of this study 89.91% of the total population was vaccinated with at least one dose, being 83.22% fully vaccinated. A deep description of several interventions used to avoid COVID-19 spread in a Brazilian city during 2 years of this pandemic can help promote better decision-making in the future while it exposes the challenges of conducting public health policies in a pandemic scenario.

The COVID-19 pandemic and its effects on public health have urgently demanded effective health policies to avoid the spread of COVID-19. Thus, public administrators have implemented non-pharmacological and pharmacological interventions to mitigate the pandemic’s impacts and strengthen health services. The aim of this ecological study is to describe the scenario of COVID-19 pandemic in a Brazilian city, during two years. This ecological study was carried out in Nova Friburgo, a Brazilian city, for 105 weeks (two years), from March 29, 2020 (week 1) to April 02, 2022 (week 105). Data on COVID-19 cases and COVID-19 deaths, occupation of COVID-19 exclusive beds in hospitals, community mobility, vaccination, government regulation on the opening of city establishments and city risk assessment were collected from public datasets. Four waves of COVID-19 cases and deaths were observed during this period. The first case occurred in week 1 and first death in week 3 of this study. The highest peaks of cases and deaths were observed during the third wave with 1,131 cases (week 54) and 47 deaths (week 55) and where the highest occupation of COVID-19 exclusive beds in local hospitals occurred. Interventions from more restrictive to more flexible, were implemented throughout this study, including lockdown and gradual return in economic and social strata levels. Vaccination began on week 43 and at the end of this study 89.91% of the total population was vaccinated with at least one dose, being 83.22% fully vaccinated. A deep description of several interventions used to avoid COVID-19 spread in a Brazilian city during two years of this pandemic can help promote better decision-making in the future while it exposes the challenges of conducting public health policies in a pandemic scenario.

Objective: This study aimed to search for Enterococcus faecalis in children’s deep carious dentine and characterize their virulence traits. Material and Methods: Eight isolates from 15 carious molars identified by 16S rDNA species-specific PCR as E. faecalis were included. These eight isolates were subject to identification by MALDI‐TOF and characterized regarding: (i) bacterial aggregation and biofilm formation on polystyrene and glass, with/without saliva, as single or dual-species (associated to Streptococcus mutans); (ii) environmental pH measurement before and after 24 h incubation; (iii) acidogenicity; (iv) gelatinase production; (v) macrophage adherence; and (vi) toxicity towards Caenorhabditis elegans. Statistical analyses were performed using two-way ANOVA/Tukey or Fisher’s exact tests. Results: All isolates initially identified as E. faecalis by PCR were correctly identified as Lactobacillus by MALDI-TOF, being designated as Lactobacillus misidentified as Enterococcus (LME). These isolates produced biofilm in the presence of saliva and in the dual-species assays. Bacterial aggregation was only observed in the dual-species model. After 24 h, environmental pH dropped from 7.5 to 4.5 for seven of eight isolates, and to 4.0 in all dual-species models. LME isolates were acidogenic, none of them produced gelatinase or adhered to macrophages, but all presented toxicity towards C. elegans. Conclusions: No E. faecalis were identified in the children’s caries lesions. All LME isolates presented important virulence traits, including biofilm formation and high acidogenicity, which cause enamel demineralization, that might increase the risk of dental caries in children carrying LME. Thus, the correct identification and in-depth virulence characterization of microorganisms isolated from dental caries are important to understand the dynamics of this disease.