Four-year assessment of masticatory function in mandibular overdenture wearers: A randomised clinical trial comparing two to four implants to retain the prosthesis.

BACKGROUND: Limited data exist on the mid- to long-term masticatory capacity of mandibular overdenture (IOD) wearers, particularly regarding the use of posterior implants to retention. OBJECTIVES: To periodically evaluate mastication of IOD wearers, comparing the effectiveness of two to four implants to retain the prosthesis. METHODS: In a randomised controlled clinical trial, 20 complete edentulous patients (14 women), aged 51-84 years (mean age 69.1 ± 9.6), received new bimaxillary complete dentures (CD). After adaptation, baseline measurements of masticatory performance (X50) and swallowing threshold were conducted using the sieving method. Patients were then randomly assigned to groups: control (two intra-foraminal regular implants) and experimental (two intra-foraminal regular implants and two extra-short posterior implants) (n = 10 each). After 4 months, implants were splinted, and a new mandibular IOD was fabricated with bar/clip retention. Mastication was reassessed after 6, 12, and 48 months, and data analysed with repeated measures ANOVA and Sidak's post hoc (α = 0.05). RESULTS: Despite a loss of two patients per group, masticatory performance significantly improved after mandibular IOD installation (p = .031) in both groups (p = .670). A second improvement was observed after 6 months (p = .027), with no subsequent changes (p > .05). Swallowing threshold improvements were noted with IOD, and no discernible differences between groups were observed (p > .05). CONCLUSION: Masticatory function significantly improved after mandibular IOD installation, with the number of implants demonstrating minimal influence. CLINICAL TRIAL REGISTRATION: The present study was not registered in a public database, as mandated. It is important to note that the recommendation for registration was initiated in 2017 by the Committee of Medical Journal Editors, while patient inclusion in the research took place in 2016. Given that the data presented in this manuscript cover a follow-up period of up to 4 years post-surgical intervention, delayed registration was not feasible.

Ceftazidime and Usnic Acid Encapsulated in Chitosan-Coated Liposomes for Oral Administration against Colorectal Cancer-Inducing Escherichia coli.

Escherichia coli has been associated with the induction of colorectal cancer (CRC). Thus, combined therapy incorporating usnic acid (UA) and antibiotics such as ceftazidime (CAZ), co-encapsulated in liposomes, could be an alternative. Coating the liposomes with chitosan (Chi) could facilitate the oral administration of this nanocarrier. Liposomes were prepared using the lipid film hydration method, followed by sonication and chitosan coating via the drip technique. Characterization included particle size, polydispersity index, zeta potential, pH, encapsulation efficiency, and physicochemical analyses. The minimum inhibitory concentration and minimum bactericidal concentration were determined against E. coli ATCC 25922, NCTC 13846, and H10407 using the microdilution method. Antibiofilm assays were conducted using the crystal violet method. The liposomes exhibited sizes ranging from 116.5 ± 5.3 to 240.3 ± 3.5 nm and zeta potentials between +16.4 ± 0.6 and +28 ± 0.8 mV. The encapsulation efficiencies were 51.5 ± 0.2% for CAZ and 99.94 ± 0.1% for UA. Lipo-CAZ-Chi and Lipo-UA-Chi exhibited antibacterial activity, inhibited biofilm formation, and preformed biofilms of E. coli. The Lipo-CAZ-UA-Chi and Lipo-CAZ-Chi + Lipo-UA-Chi formulations showed enhanced activities, potentially due to co-encapsulation or combination effects. These findings suggest potential for in vivo oral administration in future antibacterial and antibiofilm therapies against CRC-inducing bacteria.

Synthesis of polymeric nanoparticles by double emulsion and pH-driven: encapsulation of antibiotics and natural products for combating Escherichia coli infections.

The design, development, and obtaining of nanostructured materials, such as polymeric nanoparticles, have garnered interest due to loading therapeutic agents and its broad applicability. Polymeric nanoparticle synthesis employs advanced techniques such as the double emulsion approach and the pH-driven method, allowing the efficient incorporation of active compounds into these matrices. These loading methods ensure compound stability within the polymeric structure and enable control of the release of therapeutic agents. The ability of loaded polymeric nanoparticles to transport and release therapeutic agents on target manner represents a significant advancement in the quest for effective therapeutic solutions. Amid escalating concerns regarding antimicrobial resistance, interventions using polymeric nanostructures stand out for the possibility of carrying antimicrobial agents and enhancing antibacterial action against antibiotic-resistant bacteria, making a new therapeutic approach or complement to conventional treatments. In this sense, the capability of these polymeric nanoparticles to act against Escherichia coli underscores their relevance in controlling bacterial infections. This mini-review provides a comprehensive synthesis of promising techniques for loading therapeutic agents into polymeric nanoparticles highlighting methodologies and their implications, addressing prospects of combating bacterial infections caused by E. coli. KEY POINTS: • The double emulsion method provides control over size and release of bioactives. • The pH-driven method improves the solubility, stability, and release of active. • The methods increase the antibacterial action of those encapsulated in PNPs.

Antibacterial and Antibiofilm Potential of Bacterial Cellulose Hydrogel Containing Vancomycin against Multidrug-Resistant Staphylococcus aureus and Staphylococcus epidermidis.

The present study aimed to evaluate the in vitro antibacterial and antibiofilm activity of bacterial cellulose hydrogel produced by Zoogloea sp. (HYDROGEL) containing vancomycin (VAN) against bacterial strains that cause wound infections, such as multidrug-resistant (MDR) Staphylococcus aureus and Staphylococcus epidermidis. Initially, HYDROGEL was obtained from sugar cane molasses, and scanning electron microscopy (SEM) was performed to determine morphological characteristics. Then, VAN was incorporated into HYDROGEL (VAN-HYDROGEL). The antibacterial activity of VAN, HYDROGEL, and VAN-HYDROGEL was assessed using the broth microdilution method to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) against methicillin-sensitive S. aureus (MSSA) ATCC 25923, methicillin-resistant S. aureus (MRSA) ATCC 33591, S. epidermidis INCQS 00016 (ATCC 12228), five clinical isolates of MRSA, and nine clinical isolates of methicillin-resistant S. epidermidis, following the Clinical and Laboratory Standards Institute (CLSI) guidelines. Additionally, the antibacterial activity of VAN, HYDROGEL, and VAN-HYDROGEL was studied using the time-kill assay. Subsequently, the antibiofilm activity of VAN, HYDROGEL, and VAN-HYDROGEL was evaluated using crystal violet and Congo red methods, as well as SEM analysis. VAN and VAN-HYDROGEL showed bacteriostatic and bactericidal activity against MRSA and methicillin-resistant S. epidermidis strains. HYDROGEL did not show any antibacterial activity. Analysis of the time-kill assay indicated that HYDROGEL maintained the antibacterial efficacy of VAN, highlighting its efficiency as a promising carrier. Regarding antibiofilm activity, VAN and HYDROGEL inhibited biofilm formation but did not demonstrate biofilm eradication activity against methicillin-resistant S. aureus and S. epidermidis strains. However, it was observed that the biofilm eradication potential of VAN was enhanced after incorporation into HYDROGEL, a result also proven through images obtained by SEM. From the methods carried out in this study, it was possible to observe that HYDROGEL preserved the antibacterial activity of vancomycin, aside from exhibiting antibiofilm activity and enhancing the antibiofilm effect of VAN. In conclusion, this study demonstrated the potential of HYDROGEL as a candidate and/or vehicle for antibiotics against MDR bacteria that cause wound infections.

Incorporation of essential oils in polymeric films for biomedical applications.

Natural and synthetic biodegradable polymers are widely used to obtain more sustainable films with biological, physicochemical, and mechanical properties for biomedical purposes. The incorporation of essential oils (EOs) in polymeric films can optimize the biological activities of these EOs, protect them from degradation, and serve as a prototype for new biotechnological products. This article aims to discuss updates over the last 10 years on incorporating EOs into natural and synthetic biodegradable polymer films for biomedical applications. Chitosan, alginates, cellulose, and proteins such as gelatine, silk, and zein are among the natural polymers most commonly used to prepare biodegradable films for release EOs. In addition to these, the most cited synthetic biodegradable polymers are poly(L-lactide) (PLA), poly(vinyl alcohol) (PVA), and poly(ε-caprolactone) (PCL). The EOs of clove, cinnamon, tea tree, eucalyptus, frankincense, lavender, thyme and oregano incorporated into polymeric films have been the most studied EOs in recent years in the biomedical field. Biomedical applications include antimicrobial activity against pathogenic bacteria and fungi, anticancer activity, potential for tissue engineering and regeneration with scaffolds and wound healing as dressings. Thus, this article reports on the importance of incorporating EOs into biodegradable polymer films, making these systems especially attractive for various biomedical applications.

In silico analysis of non-structural protein 12 sequences from SARS-COV-2 found in Manaus, Amazonas, Brazil, reveals mutations linked to higher transmissibility.

The disease coronavirus COVID-19 has been the cause of millions of deaths worldwide. Among the proteins of SARS-CoV-2, non-structural protein 12 (NSP12) plays a key role during COVID infection and is part of the RNA-dependent RNA polymerase complex. The monitoring of NSP12 polymorphisms is extremely important for the design of new antiviral drugs and monitoring of viral evolution. This study analyzed the NSP12 mutations detected in circulating SARS-CoV-2 during the years 2020 to 2022 in the population of the city of Manaus, Amazonas, Brazil. The most frequent mutations found were P323L and G671S. Reports in the literature indicate that these mutations are related to transmissibility efficiency, which may have contributed to the extremely high numbers of cases in this location. In addition, two mutations described here (E796D and R914K) are close and have RMSD that is similar to the mutations M794V and N911K, which have been described in the literature as influential on the performance of the NSP12 enzyme. These data demonstrate the need to monitor the emergence of new mutations in NSP12 in order to better understand their consequences for the treatments currently used and in the design of new drugs.

Development of an antibody against EtpA from enterotoxigenic Escherichia coli and evaluation of its use for bacterial isolation using magnetic beads.

The enterotoxigenic Escherichia coli (ETEC) strain is one of the most frequent causative agents of childhood diarrhea and travelers' diarrhea in low-and middle-income countries. Among the virulence factors secreted by ETEC, the exoprotein EtpA has been described as an important. In the present study, a new detection tool for enterotoxigenic E. coli bacteria using the EtpA protein was developed. Initially, antigenic sequences of the EtpA protein were selected via in silico prediction. A chimeric recombinant protein, corresponding to the selected regions, was expressed in an E. coli host, purified and used for the immunization of mice. The specific recognition of anti-EtpA IgG antibodies generated was evaluated using flow cytometry. The tests demonstrated that the antibodiesdeveloped were able to recognize the native EtpA protein. By coupling these antibodies to magnetic beads for the capture and detection of ETEC isolates, cytometric analyses showed an increase in sensitivity, specificity and the effectiveness of the method of separation and detection of these pathogens. This is the first report of the use of this methodology for ETEC separation. Future trials may indicate their potential use for isolating these and other pathogens in clinical samples, thus accelerating the diagnosis and treatment of diseases.

Ceftazidime/Tobramycin Co-Loaded Chitosan-Coated Zein Nanoparticles against Antibiotic-Resistant and Biofilm-Producing Pseudomonas aeruginosa and Klebsiella pneumoniae.

This study aimed to co-encapsulate ceftazidime and tobramycin in zein nanoparticles coated with chitosan and to characterize and evaluate the antibacterial and antibiofilm activity against antibiotic-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae. Zein nanoparticles, synthesized using the nanoprecipitation method, were characterized by their particle size (Ø), polydispersity index (PDI), zeta potential (ζ), pH, and encapsulation efficiency (%EE). The chitosan coating provided stability, and physicochemical analyses revealed chemical interactions, efficient drug encapsulation, and thermal stability. The release kinetics demonstrated controlled release in simulated gastric and intestinal pH. The antibacterial activity, assessed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), indicated effectiveness against both pathogens. Antibiofilm assays, conducted using the crystal violet method, demonstrated the inhibition and eradication of biofilms. The chitosan-coated zein nanoparticles with CAZ and/or TOB exhibited Ø (315-335 nm), PDI (<0.2), ζ (+40 to +50 mV), pH (5), and %EE (>55%). Notably, the co-encapsulation formulation (CAZ-TOB-ZNP-CH) showed enhanced antibacterial and antibiofilm activities compared to the individual formulations. These findings suggest that the developed nanoparticles present a promising alternative for treating respiratory and intestinal infections caused by antibiotic-resistant and biofilm-producing P. aeruginosa and K. pneumoniae.

Low Cubilin/Myeloperoxidase ratio as a promising biomarker for prognosis of high-grade T1 bladder cancer.

PURPOSE: T1 bladder cancer is known for its high progression and recurrence rates. Identifying aggressive tumours at the non-muscle-invasive stage is crucial to allow early interventions and subsequently increase patient survival. This study aimed to investigate the potential of the cubilin/myeloperoxidase (CUBN/MPO) ratio as a high-grade T1 bladder cancer biomarker. METHODS: Urine samples were collected from 30 patients who underwent transurethral resection of the tumour with high-grade T1 bladder cancer (June 2015 to December 2019) before surgery. The urinary proteome was analysed using high-resolution mass spectrometry and the CUBN/MPO ratio was calculated. The primary outcome was the recurrence during the follow-up (around 31.5 months after resection). Univariate Cox regression and Kaplan-Meier curves were used for data analysis. RESULTS: Patients with a low CUBN/MPO ratio exhibited upregulated MPO and/or downregulated CUBN. This group of patients had a higher incidence of disease recurrence and progression. Low CUBN/MPO ratio was significantly associated with a higher likelihood of recurrence, progression, and death. It is worth noting that this study was exploratory and conducted on a small sample size, so further research is needed to validate these findings in larger cohorts. CONCLUSION: This study highlights the potential of the CUBN/MPO ratio as a prognostic biomarker for high-grade T1 bladder cancer.

Spent coffee grounds as a suitable alternative to standard soil in ecotoxicological tests.

Eisenia andrei is considered in OECD and ISO guidelines to be a suitable replacement for Eisenia fetida in ecotoxicological assays. This suggests that other alternative materials and methods could also be used in standard procedures for toxicity testing. The guidelines also favor using less time-consuming procedures and reducing costs and other limitations to ecotoxicological assessments. In recent years, spent coffee grounds (SCG) have been used to produce vermicompost and biochar and as an additive to organic fertilizers. In addition, the physicochemical characteristics of SCG indicate that the material is a suitable substrate for earthworms, with the organisms performing as well as in natural soil. In the present study, a battery of ecotoxicological tests was established with unwashed and washed SCG and a natural reference soil (LUFA 2.2). The test substrates were spiked with different concentrations of silver nitrate. Survival and reproduction of the earthworm E. andrei were assessed under different conditions, along with substrate basal respiration (SBR) as a proxy for microbial activity. Seedling emergence and the germination index of Lepidium sativum were also determined, following standard guidelines. Exposure to silver nitrate had similar effects on earthworm survival and reproduction, as the estimated effective concentrations (EC10 and EC50) in unwashed SCG and LUFA 2.2 overlapped. A hormetic effect was observed for SBR in LUFA 2.2 spiked with 12.8 mg/kg but not in unwashed SCG. Both SBR and root development were inhibited by similar concentrations of silver nitrate in washed SCG. The findings indicate that unwashed SCG could potentially be used as a substrate in E. andrei toxicity tests and support the eventual inclusion of this material in the standard guidelines.

Olive oil nanoemulsion containing curcumin: antimicrobial agent against multidrug-resistant bacteria.

The present work aimed to develop, characterize, and evaluate the antibacterial and antibiofilm activity of two nanoemulsions (NEs) containing 500 µg/mL of curcumin from Curcuma longa (CUR). These NEs, produced with heating, contain olive oil (5%) and the surfactants tween 80 (5%) and span 80 (2.5%), water q.s. 100 mL, and were stable for 120 days. NE-2-CUR presented Ø of 165.40 ± 2.56 nm, PDI of 0.254, ζ of - 33.20 ± 1.35 mV, pH of 6.49, and Entrapment Drug Efficiency (EE) of 99%. The NE-4-CUR showed a Ø of 105.70 ± 4.13 nm, PDI of 0.459, ζ of - 32.10 ± 1.45 mV, pH of 6.40 and EE of 99.29%. Structural characterization was performed using DRX and FTIR, thermal characterization using DSC and TG, and morphological characterization using SEM, suggesting that there is no significant change in the CUR present in the NEs and that they remain stable. The MIC was performed by the broth microdilution method for nine gram-positive and gram-negative bacteria, as well as Klebsiella pneumoniae clinical isolates resistant to antibiotics and biofilm and efflux pump producers. The NEs mostly showed a bacteriostatic profile. The MIC varied between 125 and 250 µg/mL. The most sensitive bacteria were Staphylococcus aureus and Enterococcus faecalis, for which NE-2-CUR showed a MIC of 125 µg/mL. The NEs and ceftazidime (CAZ) interaction was also evaluated against the K. pneumoniae resistant clinical isolates using the Checkerboard method. NE-2-CUR and NE-4-CUR showed a synergistic or additive profile; there was a reduction in CAZ MICs between 256 times (K26-A2) and 2 times (K29-A2). Furthermore, the NEs inhibited these isolates biofilms formation. The NEs showed a MBIC ranging from 15.625 to 250 µg/mL. Thus, the NEs showed physicochemical characteristics suitable for future clinical trials, enhancing the CAZ antibacterial and antibiofilm activity, thus becoming a promising strategy for the treatment of bacterial infections caused by multidrug-resistant K. pneumoniae. KEY POINTS: • The NEs showed physicochemical characteristics suitable for future clinical trials. • The NEs showed a synergistic/additive profile, when associated with ceftazidime. • The NEs inhibited biofilm formation of clinical isolates.

Prevalence and implications of pKs-positive Escherichia coli in colorectal cancer.

Colorectal cancer (CRC) remains a significant global health concern, necessitating continuous investigation into its etiology and potential risk factors. Recent research has shed light on the potential role of pKs-positive Escherichia coli (pKs + E. coli) and colibactin in the development and progression of CRC. Therefore, this review aimed to provide an updated analysis of the prevalence and implications of pKs + E. coli in colorectal cancer. We conducted a literature review search in major scientific databases to identify relevant studies exploring the association between pKs + E. coli and CRC. The search strategy included studies published up to the present date, and articles were carefully selected based on predefined inclusion criteria. Thus, the present study encompasses scientific evidence from clinical and epidemiological studies supporting the presence of pKs + E. coli in CRC patients, demonstrating a consistent and significant association in multiple studies. Furthermore, we highlighted the potential mechanisms by which colibactin may promote tumorigenesis and cancer progression within the colorectal mucosa, including the production of genotoxic virulence factors. Additionally, we explored current diagnostic methods for detecting pKs + E. coli in clinical settings, emphasizing the importance of accurate identification. Moreover, we discussed future strategies that could utilize the presence of this strain as a biomarker for CRC diagnosis and treatment. In conclusion, this review consolidated existing evidence on the prevalence and implications of pKs + E. coli in colorectal cancer. The findings underscore the importance of further research to elucidate the precise mechanisms linking this strain to CRC pathogenesis and to explore its potential as a therapeutic target or diagnostic marker. Ultimately, a better understanding of the role of pKs + E. coli in CRC may pave the way for innovative strategies in CRC management and patient care.

Establishing a safe anesthesia concentration window for Nile tilapia (Oreochromis niloticus) (Linnaeus 1758) by monitoring cardiac activity in eugenol immersion baths.

Nile tilapia, Oreochromis niloticus, is the most cultivated fish species in the world, due to its low cost, high growth rate, environmental adaptability, and resistance to disease and stress. Anesthetics for fish become necessary in management because they minimize mortality during transport and maintenance of ponds, one of the most used anesthetics is clove oil, which has eugenol as the major substance, representing 90-95 % of clove oil. The present study evaluates the effect of eugenol on cardiac activity in Oreochromis niloticus specimens and relates it to behavioral data to determine a concentration window for safe anesthesia. For the comportamental analysis, was used five treatments (50, 75, 100, 125, and 150 µL·L-1) were evaluated and for the eletrocardiographic test was used seven groups (Control, Vehicle, 50, 75, 100, 125, and 150 µL·L-1), n = 9/treatment, totaling 108 animals. Behavioral and electrocardiographic tests were performed on all treatments during induction and recovery. The results of the behavioral tests demonstrated the reversibility of the effects with recovery of the posture reflex, varying according to the concentration. The ECG results showed a slow recovery because, at concentrations above 100 µL·L-1, there was no full reversibility of the cardiac effects in the observed experiment time, which could cause greater changes in the tilapia hemodynamics, which led us to identify a window for safe anesthesia. Eugenol is an effective anesthetic in Nile tilapia juveniles when used in concentrations ranging from 50 to 100 µL·L-1, if there is a need for anesthetic deepening, doses above 100 µL·L-1, however, the animals must be monitored due to hemodynamic changes.

Long-term clinical performance of short 6-mm implants supporting single crowns in the posterior region: A 10-year cohort study.

INTRODUCTION: Long-term clinical success of non-splinted, posterior, and short implants still is unclear. This prospective cohort study reports the 10-year follow-up of 6-mm implants supporting single crowns in the posterior region, and patient-reported outcomes. METHODS: Baseline sample comprised 20 patients treated with 46 screw-retained crowns supported by 6-mm implants with moderately rough implant surface. Participants were recalled for a 10-year clinical follow-up to assess survival rates, biologic and mechanic conditions, quality of life (OHIP-14), and treatment satisfaction. Data were collected with clinical-radiographic exams and analyzed using descriptive and inferential statistics. RESULTS: Fourteen patients with 35 implant-crown units were examined after 127.6 ± 11.8 months. For the entire cohort period, 7/46 implants were lost (survival estimate: 77.7% at 133 months), and mechanic complications occurred in 14/46 units (survival estimate: 66.4% at 116 months). In the Cox models, "maximum occlusal force" had a significant effect for implant loss (p = 0.038) and for prosthetic screw loosening (p = 0.038); "arch" and "bruxism" were not significant. Peri-implant bone loss was 0.4 ± 0.6 mm at 10 years. For peri-implant bone level, "crown-to-implant ratio" (p < 0.001) and "time" (p = 0.001) were significant. Bone levels differed from baseline to 12, 48, and 120 months. Satisfaction VAS was 94.0 ± 7.9 mm and OHIP-14 was 2.3 ± 2.2. CONCLUSION: Single screw-retained crowns supported by 6-mm implants have an acceptable long-term clinical performance, with stable peri-implant bone levels after 10 years of function.

Pogonias courbina sperm characteristcs in its first reproductive season.

Southern black drum (Pogonias courbina) is a species distributed along the western Atlantic Ocean, and it is the largest Sciaenidae observed in the coast of Rio Grande do Sul state, Brazil. However, it is listed as a vulnerable species at The IUCN Red List of Threatened Species™, and their fishing is prohibited. The objective of this study was to determine the sperm characteristics of P. courbina. Sperm samples of five young males (two-year-old fish) were collected through abdominal pressure. The sperm kinetics parameters were sperm motility (MOT) 10.7 ± 5.6%, curvilinear velocity (VCL) 120.07 ± 16.16 mm s ± 1, average path velocity (VAP) 75.64 ± 23.78 mm s ± 1, straight-line velocity (VSL) 62.49 ± 15.83 mm s ± 1, straightness (STR) 83.9 ± 5.3%, wobble (WOB) 61.9 ± 12.7%, beat cross frequency (BCF) 42.981 ± 4.627 Hz and progression (PRG) 1,805.4 ± 564.5 µm. The proportion of normal spermatozoa was 35.6 ± 6.1%. About the abnormalities observed, 22.7% occurred in the tail (short tail = 0.6 ± 0.5%, distally curled tail = 2.4 ± 1.6%, strongly curled tail = 1.9 ± 1.3%, broken tail = 7.9 ± 5.1%, folded tail = 5.5 ± 0.8%, loose tail = 4.4 ± 1.9%); 14.2% occurred in the head (degenerate head = 4.2 ± 1.6%, microcephaly = 1.8 ± 2.5%, loose head = 8.2 ± 2.1%) and 27.5% of the spermatozoa showed cytoplasmatic gouts (proximal gout = 20.0 ± 8.4%, distal gout = 7.5 ± 2.8%). Besides that, a correlation analysis was performed between sperm morphology and kinetics parameters, and the spermatozoa were measured for the morphometric parameters. There was a positive correlation between BCF and normal spermatozoa (r =  0.9269). A negative correlation occurred between BCF and loose head (r =  -0.9047); WOB and strongly curled tail (r =  -0.8911); and PROG and strongly curled tail (r =  -0.9191). The morphometric measures found for the head were length of 2.50 ± 0.21 µm and width of 2.12 ± 0.22 µm, and for the tail it was length of 37.97 ± 2.01 µm. It was possible to verify that the animals have sperm characteristics that indicate reproductive aptitude, but an abnormal behavior on sperm activation and high presence of the cytoplasmic gout abnormality indicates that the animals are not fully mature in their first reproductive season. This work contributes to a better understanding of the P. courbina spermatic parameters, what can be allies to recovery this species population in nature and promote its production in fish farms.

Improvement of Bacillus subtilis Spore Enumeration and Label Analysis in Flow Cytometry.

The spores of Bacillus subtilis have already been proposed for different biotechnological and immunological applications; however, there is an increasing need for the development of methodologies that improve the detection of antigens immobilized on the surface of spores together with their quantification. Flow cytometry-based analyses have been previously proposed as fast, reliable, and specific approaches for detecting labeled cells of B. subtilis. Herein, we propose the use of flow cytometry to evaluate the display efficiency of a fluorescent antibody (FA) on the surface of the spore and quantify the number of spores using counting beads. For this, we used ethidium bromide as a DNA marker and an allophycocyanin (APC)-labeled antibody, which was coupled to the spores, as a surface marker. The quantification of spores was performed using counting beads since this technique demonstrates high accuracy in the detection of cells. The labeled spores were analyzed using a flow cytometer, which confirmed the coupling. As a result, it was demonstrated that DNA labeling improved the accuracy of quantification by flow cytometry, for the detection of germinated spores. It was observed that ethidium bromide was not able to label dormant spores; however, this technique provides a more precise determination of the number of spores with fluorescent protein coupled to their surface, thus helping in the development of studies that focus on the use of spores as a biotechnological platform in different applications.

Behavioral, electrocorticographic and electrocardiologic changes in Colossoma macropomum (Tambaqui) in the effect of cunaniol.

The Clibadium spp. is a shrub of occurrence in the Amazon, popularly known as Cunambi. The compounds in the leaves demonstrate ichthyotoxic properties, and its major substance, cunaniol, is a powerful central nervous system stimulant with proconvulsant activity. Few current studies relate behavioral changes to the electrophysiological profile of fish poisoning. This study aimed to describe the behavioral, electromyographic, electroencephalographic, electrocardiographic, and seizure control characteristics of anticonvulsant drugs in Colossoma macropomum submitted to cunaniol intoxication during bathing containing 0.3 µg/L cunaniol. The behavioral test showed rapid evolution presenting excitability and spasms, which were confirmed by the analysis of Electroencephalogram (EEG), Electromyogram (EMG), and changes in cardiac function detected in the ECG. Cunaniol-induced excitability control was evaluated using three anticonvulsant agents: Phenytoin, Phenobarbital, and Diazepam. While phenytoin was not effective in seizure control, diazepam proved to be the most efficient. These results demonstrate the susceptibility of Colossoma macropomum to cunaniol poisoning, given that the central nervous system and electrocardiographic changes were considered severe.

Standardization of a Cytometric Bead Assay Based on Egg-Yolk Antibodies.

Immunoassays are important tests for the detection of numerous molecular targets. Among the methods currently available, the cytometric bead assay has gained prominence in recent decades. Each microsphere that is read by the equipment represents an analysis event of the interaction capacity between the molecules under test. Thousands of these events are read in a single assay, thus ensuring high assay accuracy and reproducibility. This methodology can also be used in the validation of new inputs, such as IgY antibodies, for the diagnosis of diseases. These antibodies are obtained through immunizing chickens with the antigen of interest and then extracting the immunoglobulin from the yolk of the animals' eggs; therefore, this is a painless and highly productive method for obtaining the antibodies. In addition to a methodology for the high-precision validation of the antibody recognition capacity of this assay, this paper also presents a method for extracting these antibodies, determining the best coupling conditions for the antibodies and latex beads, and determining the sensitivity of the test.

Antibiotic resistance profiles on pathogenic bacteria in the Brazilian environments.

The present study aimed to elaborate a review of multidrug-resistant (MDR) bacteria in soil, food, aquatic environments, cattle, poultry, and swine farms in Brazil. Initially, the literature database for published papers from 2012 to 2023 was Scientific Electronic Library Online (SciELO), U.S. National Library of Medicine (PubMed), and Google Scholar, through the descriptors: antimicrobial resistance, resistance profile, multidrug resistance, environmental bacteria, and pathogenic bacteria. The studies demonstrated the prevalence of pathogenic and resistant bacteria in environments that favor their rapid dissemination. Bacteria of medical importance, such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Salmonella spp., Shigella spp., Vibrio spp., were present in samples from animal farms and foods, including cheese and milk, urban aquatic environments, hospital effluents, and shrimp farms. Studies suggested that important bacteria have been disseminated through different niches with easy contact with humans, animals, and food, demonstrating the danger of the emergence of increasingly difficult conditions for treating and controlling these infections. Thus, better understanding and characterizing the resistance profiles of bacteria in these regions, mainly referring to MDR bacteria, can help develop solutions to prevent the progression of this public health problem.

Using an Aluminum Hydroxide-Chitosan Matrix Increased the Vaccine Potential and Immune Response of Mice against Multi-Drug-Resistant Acinetobacter baumannii.

Acinetobacter baumannii is a Gram-negative, immobile, aerobic nosocomial opportunistic coccobacillus that causes pneumonia, septicemia, and urinary tract infections in immunosuppressed patients. There are no commercially available alternative antimicrobials, and multi-drug resistance is an urgent concern that requires emergency measures and new therapeutic strategies. This study evaluated a multi-drug-resistant A. baumannii whole-cell vaccine, inactivated and adsorbed on an aluminum hydroxide-chitosan (mAhC) matrix, in an A. baumannii sepsis model in immunosuppressed mice by cyclophosphamide (CY). CY-treated mice were divided into immunized, non-immunized, and adjuvant-inoculated groups. Three vaccine doses were given at 0D, 14D, and 28D, followed by a lethal dose of 4.0 × 108 CFU/mL of A. baumannii. Immunized CY-treated mice underwent a significant humoral response, with the highest IgG levels and a higher survival rate (85%); this differed from the non-immunized CY-treated mice, none of whom survived (p < 0.001), and from the adjuvant group, with 45% survival (p < 0.05). Histological data revealed the evident expansion of white spleen pulp from immunized CY-treated mice, whereas, in non-immunized and adjuvanted CY-treated mice, there was more significant organ tissue damage. Our results confirmed the proof-of-concept of the immune response and vaccine protection in a sepsis model in CY-treated mice, contributing to the advancement of new alternatives for protection against A. baumannii infections.