Detection of multidrug-resistant bacteria in the nasal cavities and evaluation of sinus disorders in patients undergoing Le Fort I osteotomy.

INTRODUCTION: Orthognathic surgery can lead to sinus alterations, including sinusitis, attributed to the exposure of maxillary sinuses during Le Fort I osteotomy. Furthermore, being a hospital-based procedure, there is potential risk of complications arising from bacteria prevalent in such environments. This study evaluated maxillary sinusitis occurrence and the presence of multidrug-resistant bacteria in the nasal cavity before and after orthognathic surgery. METHODS: Ten patients with dentofacial deformities underwent Le Fort I osteotomy. Clinical evaluations using SNOT-22 questionnaire were performed, and nasal cavity samples were collected pre-surgery and 3-6 months post-surgery to quantify total mesophilic bacteria and detect Staphylococcus aureus, Acinetobacter baumannii, and Klebsiella pneumoniae. Cone Beam Computed Tomography (CBCT) was performed pre- and post-operatively, and the results were evaluated using the Lund-Mackay system. This study was registered and approved by the Research Ethics Committee of PUCRS (No. 4.683.066). RESULTS: The evaluation of SNOT-22 revealed that five patients showed an improvement in symptoms, while two remained in the same range of interpretation. One patient developed post-operative maxillary sinusitis, which was not detected at the time of evaluation by SNOT-22 or CBCT. CBCT showed a worsening sinus condition in three patients, two of whom had a significant increase in total bacteria count in their nasal cavities. The Brodsky scale was used to assess hypertrophy in palatine tonsils, where 60% of the subjects had grade 1 tonsils, 20% had grade 2 and 20% had grade 3. None of the patients had grade 4 tonsils, which would indicate more than 75% obstruction. Two patients harboured S. aureus and K. pneumoniae in their nasal cavities. Notably, K. pneumoniae, which was multidrug-resistant, was present in the nasal cavity of patients even before surgery, but this did not result in maxillary sinusitis, likely due to the patients' young and healthy condition. CONCLUSION: There was an improvement in signs and symptoms of maxillary sinusitis and quality of life in most patients after orthognathic surgery. However, some patients may still harbour multidrug-resistant bacteria, even if they are asymptomatic. Therefore, a thorough pre-operative assessment is essential to avoid difficult-to-treat post-operative complications.

Nano-scaled surfaces and sustainable-antibiotic-release from polymeric coating for application on intra-osseous implants and trans-mucosal abutments.

Multifunctional surfaces may display the potential to accelerate and promote the healing process around dental implants. However, the initial cellular biocompatibility, molecular activity, and the release of functionalized molecules from these novel surfaces require extensive investigation for clinical use. Aiming to develop and compare innovative surfaces for application in dental implants, the present study utilized titanium disks, which were treated and divided into four groups: machined (Macro); acid-etched (Micro); anodized-hydrophilic surface (TNTs); and anodized surface coated with a rifampicin-loaded polymeric layer (poly(lactide-co-glycolide), PLGA) (TNTsRIMP). The samples were characterized regarding their physicochemical properties and the cumulative release of rifampicin (RIMP), investigated at different pH values. Additionally, differentiated osteoblasts from mesenchymal cells were used for cell viability and qRT-PCR analysis. Antibacterial properties of each surface treatment were investigated against Staphylococcus epidermidis. TNTsRIMP demonstrated controlled drug release for up to 7 days in neutral pH environments. Osteogenic cell cultures indicated that all the evaluated surfaces showed biocompatibility. The TNTs group revealed up-regulated values for bone-related gene quantification in 7 days, followed by the TNTsRIMP group. Furthermore, the antibiotic-functionalized surface revealed effectiveness to inhibit S. epidermidis and stimulate promising conditions for osteogenic cell behavior. Characteristics such as nanomorphology and hydrophilicity were determinants for the up-regulated quantification of osteogenic biomarkers related to early bone maturation, encouraging application in intra-osseous implant surfaces; in addition, antibiotic-functionalized surfaces demonstrated significant higher antibacterial properties compared to the other groups. Our findings suggest that polymeric-antibiotic-loaded coating might be applied for the prevention of early infections, favoring its application in multifunctional surfaces for intra- and/or trans-mucosal components of dental implants, while, hydrophilic nanotextured surfaces promoted optimistic properties to stimulate early bone-related cell responses, favoring its application in bone-anchored surfaces.

Antimicrobial Prophylaxis in Dentistry: Survey among Dental Surgeons in Porto Alegre, Brazil, and the Metropolitan Region.

The irrational use of antimicrobial drugs has become a serious epidemiological problem due to the development of bacterial resistance, causing consequences for global health. In dentistry, antibiotics are the second most common pharmacological class prescribed. Thus, we evaluated the use of antimicrobial prophylaxis by dentists in Porto Alegre, Brazil, and the metropolitan region using an online questionnaire. Dentists were asked to complete an anonymous questionnaire concerning antimicrobial prescription. The questionnaire was prepared on the Microsoft Forms platform and shared with dentists through social media and was available for a period of 40 days. The questionnaire was answered by 82 dentists, and 85.3% of them reported prescribing antibiotic prophylaxis (AP). Many different protocols were observed, but the majority of dentists prescribe amoxicillin (2 g) 1 hour before a procedure. The greatest diversity was found in the prescriptions for post-procedure prophylaxis, but most professionals prescribe 500 mg of antibiotics every 8 hours for 7 days. An overwhelming 91.5% of participants think that guidelines for prescribing antibiotics in dentistry are necessary, and 62.2% believe that the use of AP can have some impact on bacterial resistance. There is a wide range of different prescriptions for antimicrobials, suggesting a need for better aligned guidelines and education of professionals on the proper use of antimicrobials and its consequences on bacterial resistance to antibiotics.

Antimicrobial and bone repair effects of boric acid in a rat model of dry socket (alveolar osteitis) following dental extraction.

BACKGROUND: Alveolitis occurs after dental extraction without blood clot formation, leading to an inflammatory process and bacterial contamination. Boric acid (BA) demonstrates anti-inflammatory, antimicrobial, and osteogenic properties. This study aims to evaluate the possible antimicrobial effects and bone repair of BA in a rat model of alveolitis (dry socket). METHODS: 33 male Wistar rats were submitted to the extraction of the upper right incisor and dry socket induction. They were first divided into two groups: dry socket (n = 17) and dry socket + 0.75 % BA (n = 16). Samples for the microbiological analysis were collected immediately after dental extraction, at the detection of clinical alveolitis, 7, and 14 days after BA application. For microCT and histological analysis, samples from euthanized rats were used in 14 and 28 days after alveolitis detection. RESULTS: Higher bacterial counts were found in 4-5 days after alveolitis induction, compared to the baseline in both experimental groups, decreasing significantly after 7 and 14 days of treatment with BA (P < 0.05). The microCT evaluation displayed increased bone volume, bone volume fraction, trabecular thickness, and bone mineral density in a time-dependent manner, regardless of BA treatment. On the other hand, the number of trabeculae and total bone porosity decreased over the 28 days of the experiment in the dry-socket group and both groups, respectively (P < 0.05). Histological analysis did not differ on bone repair in both experimental groups. CONCLUSION: This was the first report investigating the effects of BA in a rat model of alveolitis regarding microbiological and bone repair aspects. The BA local application decreased the total aerobic and facultative bacteria counts and does not seem to benefit the bone repair after alveolitis development. This study paves the way for more studies involving alveolitis and different BA applications.

Comparative Genome Analysis of Bacillus sporothermodurans with Its Closest Phylogenetic Neighbor, Bacillus oleronius, and Bacillus cereus and Bacillus subtilis Groups.

Bacillus sporothermodurans currently possesses one of the most highly heat-resistant spores (HRS), which can withstand ultra-high temperature (UHT) processing. Determination of multiple whole genome sequences of B. sporothermodurans provided an opportunity to perform the first comparative genome analysis between strains and with B. oleronius, B. cereus, and B. subtilis groups. In this study, five whole genome sequences of B. sporothermodurans strains, including those belonging to the HRS clone (SAD and BR12) normally isolated from UHT milk, were compared with the aforementioned Bacillus species for gene clusters responsible for heat resistance. In the phylogenomic analysis, B. sporothermodurans, with its closest phylogenetic neighbor, B. oleronius, clustered with B. thermoamylovorans and B. thermotolerans. Heat shock proteins GrpE, GroES, GroEL, and DnaK presented identical sequences for all B. sporothermodurans strains, indicating that differences in functional efficiency are not involved in the thermal resistance variations. However, comparing all species evaluated, B. sporothermodurans exhibited a different gene configuration in the chromosomal region of the heat shock protein GrpE. Furthermore, only B. sporothermodurans strains presented the stage II sporulation protein P gene located in this region. Multisequence alignment and phylogenetic analysis of the ClpB protein showed differences for HRS and non-HRS strains. The study identified ClpC, ClpE, and ClpX as the three ATPases putatively involved in protein disaggregation in B. sporothermodurans. Bacillussporothermodurans exhibits high homology with other Bacillus species in the DnaK, DnaJ, GroEL, and GroES cluster of genes involved in heat resistance. The data presented here pave the way to select and evaluate the phenotypic effects of genes putatively involved in heat resistance.

Influence of titanium and zirconia modified surfaces for rapid healing on adhesion and biofilm formation of Staphylococcus epidermidis.

OBJECTIVE: Surface alterations have been employed to enhance the osseointegration process in biomedical implants. However, these modifications may influence bacterial adhesion in different ways. Therefore, this study developed five different surfaces and evaluated the Staphylococcus epidermidis growth in early (1 h) and late (24 h) contact. DESIGN: The Titanium (Ti) and Zirconia (Zr) surfaces were divided in five groups and characterized concerning your morphology, roughness, wettability and chemical surface composition. Then, were evaluated regarding bacterial adhesion and biofilm formation/thickness, viability and morphology. RESULTS: Different topographies were manufactured resulting in a variety of combinations of surface properties. High roughness showed significantly higher bacterial adhesion in 1 h, while high hydrophilicity revealed greater bacterial proliferation in 24 h. Morphological changes were not found visually, however the viability test showed some cell membrane damage in the Ti micro and nano groups. CONCLUSIONS: Finally, surface distinct properties influence the growth of S. epidermidis independent of the based-material. Furthermore, some surface properties require precautions for use in contaminated sites according to the increased adhesion of S. epidermidis presented when in contact.

Genome Sequences of Bacillus sporothermodurans Strains Isolated from Ultra-High-Temperature Milk.

Here, we report the draft genome sequences of 3 Bacillus sporothermodurans strains isolated from ultra-high-temperature milk products in South Africa and Brazil and the type strain MB 581 (DSM 10599). The genomes will provide valuable information on the molecular dynamics of heat resistance in B sporothermodurans.

Respiratory Syncytial Virus induces the classical ROS-dependent NETosis through PAD-4 and necroptosis pathways activation.

Respiratory syncytial virus (RSV) is a major cause of diseases of the respiratory tract in young children and babies, being mainly associated with bronchiolitis. RSV infection occurs primarily in pulmonary epithelial cells and, once infection is established, an immune response is triggered and neutrophils are recruited. In this study, we investigated the mechanisms underlying NET production induced by RSV. We show that RSV induced the classical ROS-dependent NETosis in human neutrophils and that RSV was trapped in DNA lattices coated with NE and MPO. NETosis induction by RSV was dependent on signaling by PI3K/AKT, ERK and p38 MAPK and required histone citrullination by PAD-4. In addition, RIPK1, RIPK3 and MLKL were essential to RSV-induced NETosis. MLKL was also necessary to neutrophil necrosis triggered by the virus, likely promoting membrane-disrupting pores, leading to neutrophil lysis and NET extrusion. Finally, we found that RSV infection of alveolar epithelial cells or lung fibroblasts triggers NET-DNA release by neutrophils, indicating that neutrophils can identify RSV-infected cells and respond to them by releasing NETs. The identification of the mechanisms responsible to mediate RSV-induced NETosis may prove valuable to the design of new therapeutic approaches to treat the inflammatory consequences of RSV bronchiolitis in young children.

Isolation and Characterization of Stenotrophomonas maltophilia Isolates from a Brazilian Hospital.

Stenotrophomonas maltophilia is an emerging nosocomial pathogen responsible for several infections in immunocompromised patients. To characterize the antimicrobial resistance and virulence potential of this microorganism in a Brazilian hospital, a total of 936 samples were collected from a nosocomial environment and medical devices, and 100 isolates from clinical specimens were obtained in the same hospital. S. maltophilia was found in 3% of the samples collected, especially in bed rails from hospital rooms. The smf-1 gene was detected in 23% and 42% of the clinical and hospital environment isolates, respectively, and almost all (96.8%) isolates that harbored smf-1 were able to form biofilm. All isolates were susceptible to minocycline and chloramphenicol, and the majority of isolates were susceptible to levofloxacin. High resistance to ceftazidime was detected in both groups of isolates. Resistance to trimethoprim-sulfamethoxazole (TMP/SMX) was found in 14.8% of the isolates. All TMP/SMX-resistant isolates presented class 1 integron and sul1 gene, and 47.4% of them also harbored the sul2 gene, which was inserted into a 7.3 kb plasmid. Genetic relatedness among the isolates was evaluated by enterobacterial repetitive intergenic consensus-PCR, and eight genetic patterns were identified. One pattern comprised 54.7% of isolates and was spread among clinical and environmental (furniture and medical devices) sources. The presence of S. maltophilia in the hospital environment indicates that it can act as a reservoir of this microorganism. In addition, hospital isolates resistant to TMP/SMX showed that the genetic determinants were present in mobile elements, which can constitute great concern, as it may indicate a tendency to spread.

Detection and quantification of viable Bacillus cereus group species in milk by propidium monoazide quantitative real-time PCR.

The Bacillus cereus group includes important spore-forming bacteria that present spoilage capability and may cause foodborne diseases. These microorganisms are traditionally evaluated in food using culturing methods, which can be laborious and time-consuming, and may also fail to detect bacteria in a viable but nonculturable state. The purpose of this study was to develop a quantitative real-time PCR (qPCR) combined with a propidium monoazide (PMA) treatment to analyze the contamination of UHT milk by B. cereus group species viable cells. Thirty micrograms per milliliter of PMA was shown to be the most effective concentration for reducing the PCR amplification of extracellular DNA and DNA from dead cells. The quantification limit of the PMA-qPCR assay was 7.5 × 10(2) cfu/mL of milk. One hundred thirty-five UHT milk samples were analyzed to evaluate the association of PMA to qPCR to selectively detect viable cells. The PMA-qPCR was able to detect B. cereus group species in 44 samples (32.6%), whereas qPCR without PMA detected 78 positive samples (57.8%). Therefore, the PMA probably inhibited the amplification of DNA from cells that were killed during UHT processing, which avoided an overestimation of bacterial cells when using qPCR and, thus, did not overvalue potential health risks. A culture-based method was also used to detect and quantify B. cereus sensu stricto in the same samples and showed positive results in 15 (11.1%) samples. The culture method and PMA-qPCR allowed the detection of B. cereus sensu stricto in quantities compatible with the infective dose required to cause foodborne disease in 3 samples, indicating that, depending on the storage conditions, even after UHT treatment, infective doses may be reached in ready-to-consume products.

Characterization of antimicrobial resistance in Salmonella enterica strains isolated from Brazilian poultry production.

Antimicrobial resistance profiles and presence of resistance determinants and integrons were evaluated in Salmonella enterica strains from Brazilian poultry. The analysis of 203 isolates showed that those from the poultry environment (88 isolates) were significantly more resistant to antimicrobials than isolates from other sources, particularly those isolated from poultry by-product meal (106 isolates). Thirty-seven isolates were resistant to at least three antimicrobial classes. Class 1 integrons were detected in 26 isolates, and the analysis of the variable region between the 5' conserved segment (CS) and 3' CS of each class 1 integron-positive isolate showed that 13 contained a typical 3' CS and 14 contained an atypical 3' CS. One Salmonella Senftenberg isolate harbored two class 1 integrons, showing both typical and atypical 3' CSs. The highest percentage of resistance was found to sulfonamides, and sul genes were detected in the majority of the resistant isolates. Aminoglycoside resistance was detected in 50 isolates, and aadA and aadB were present in 28 and 32 isolates, respectively. In addition, strA and strB were detected in 78.1 and 65.6% isolates resistant to streptomycin, respectively. Twenty-one isolates presented reduced susceptibility to ß-lactams and harbored bla(TEM), bla(CMY), and/or bla(CTX-M). Forty isolates showed reduced susceptibility to tetracycline, and most presented tet genes. These results highlight the importance of the environment as a reservoir of resistant Salmonella, which may enable the persistence of resistance determinants in the poultry production chain, contributing, therefore, to the debate regarding the impacts that antimicrobial use in animal production may exert in human health.

Sodium chloride affects propidium monoazide action to distinguish viable cells.

Propidium monoazide (PMA) is a DNA-intercalating agent used to selectively detect DNA from viable cells by polymerase chain reaction (PCR). Here, we report that high concentrations (>5%) of sodium chloride (NaCl) prevents PMA from inhibiting DNA amplification from dead cells. Moreover, Halobacterium salinarum was unable to maintain cell integrity in solutions containing less than 15% NaCl, indicating that extreme halophilic microorganisms may not resist the concentration range in which PMA fully acts. We conclude that NaCl, but not pH, directly affects the efficiency of PMA treatment, limiting its use for cell viability assessment of halophiles and in hypersaline samples.

Can we add chlorhexidine into glass ionomer cements for band cementation?

OBJECTIVE: To test if the addition of chlorhexidine digluconate (CHD) might influence the mechanical properties and antibacterial properties of two different conventional glass ionomer cements (GICs) used for band cementation. MATERIALS AND METHODS: Two commercial brands of conventional GICs were used: Ketac Cem Easymix (3M/ESPE, St Paul, Minn) and Meron (Voco, Cuxhaven, Germany). The cements were manipulated in their original composition and also with 10% and 18% CHD in the liquid to create a total of six groups. Diametral tensile strength, compressive strength, microhardness, shear bond strength, and antibacterial effects in 5, 45, and 65 days against Streptococcus mutans were tested in all groups, and the data were submitted to statistical analyses. RESULTS: There were no significant differences between the groups of the same material in diametral tensile, compressive strength, and shear bond strength (P > .05). There was significant improvement in the microhardness to the Ketac Cem Easymix (P < .001). GICs with the addition of CHD showed significant inhibition of S. mutans growth in comparison with the control groups at the three time points evaluated (P < .001). The addition of 18% CHD resulted in higher bacterial inhibition (P < .001). CONCLUSIONS: The addition of chlorhexidine digluconate to conventional GICs does not negatively modify the mechanical properties and may increase the antibacterial effects around the GICs even for relatively long periods of time.

Comparação entre a medida contínua do débito cardíaco e por termodiluição em bolus durante a revascularização miocárdica sem circulação extracorpórea / Continuous and bolus thermodilution cardiac output measurement during off-pump coronary artery bypass surgery

JUSTIFICATIVA E OBJETIVOS: A cirurgia de revascularização miocárdica sem o uso de circulação extracorpórea (CEC) relaciona-se a importantes alterações hemodinâmicas bruscas, que podem não ser prontamente detectadas pela medida contínua de débito cardíaco. Este estudo compara resultados obtidos pela medida do índice cardíaco com o cateter de artéria pulmonar com filamento térmico (Baxter Edwards Critical Care, Irvine, CA) com o método padrão por termodiluição com solução, durante a anastomose coronariana distal. MÉTODO: Dez pacientes submetidos à cirurgia de revascularização miocárdica sem CEC foram monitorizados com o cateter de artéria pulmonar com filamento térmico. As medidas de índice cardíaco foram obtidas em quatro momentos: no início da anestesia, enquanto o tórax ainda estava fechado (M1), após a esternotomia (M2), após a estabilização do coração com o aparelho octopus (M3) e ao final da anastomose coronariana distal (M4). RESULTADOS: Houve diminuição significativa (p < 0,05) do índice cardíaco durante a anastomose coronariana, detectada pela medida com termodiluição com bolus de solução. O índice cardíaco variou de 2,8 ± 0,7 para 2,3 ± 0,8 l.min.m-2 no início da anastomose e 2,5 ± 0,8 l.min.m-2 ao final da mesma. Essa variação não foi detectada pela medida contínua (de 3 ± 0,6 para 3,2 ± 0,5 e 3,1 ± 0,6 l.min.m-2 durante a anastomose coronariana). CONCLUSÕES: A medida de débito cardíaco contínuo utilizando o cateter de artéria pulmonar com filamento térmico apresentou atraso na detecção das alterações hemodinâmicas agudas relacionadas à mudança do posicionamento do coração na cirurgia de revascularização miocárdica sem CEC.

[Continuous and bolus thermodilution cardiac output measurement during off-pump coronary artery bypass surgery.]. / Comparação entre a medida contínua do débito cardíaco e por termodiluição em bolus durante a revascularização miocárdica sem circulação extracorpórea.

BACKGROUND AND OBJECTIVES: Off-pump CABG surgery is related to major and abrupt hemodynamic changes that may not be immediately detected by continuous cardiac output measurement (CCO). This study aimed at comparing results of cardiac index measurement with pulmonary artery catheter (PAC) with thermal filament (Baxter Edwards Critical Care, Irvine, CA) versus standard bolus thermodilution method during distal coronary anastomosis. METHODS: Participated in this study 10 patients undergoing off-pump CABG who were monitored with PAC with thermal filament. Measurements of cardiac index were obtained in four moments: at anesthetic induction with the chest still closed (M1), after sternotomy (M2), after heart stabilization with the octopus device (M3) and at distal anastomosis completion (M4). RESULTS: There has been significant cardiac index decrease (p < 0.05) during coronary anastomosis, detected when measurements were taken with bolus thermodilution method. Cardiac index has varied 2.8 +/- 0.7 to 2.3 +/- 0.8 L.min.m-2 in the beginning and 2.5 +/- 0.8 L.min.m-2 at the end of anastomosis. This variation was not detected by the continuous method (from 3 +/- 0.6 to 3.2 +/- 0.5 to 3.1 +/- 0.6 L.min.m-2 during anastomosis). CONCLUSIONS: CCO measurement with PAC was late in detecting acute hemodynamic changes due to changes in heart position during off-pump CABG.