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For the first time, using a chemical pollutant (an antibiotic) as a photosensitizer to improve the elimination of a microbiological contaminant of emerging concern (antibiotic-resistant bacteria) is presented. The effect of ciprofloxacin (CIP) on the inactivation of three light-promoted antibiotic-resistant bacteria (ARB) was evaluated. Ciprofloxacin-resistant Escherichia coli, ciprofloxacin-resistant Staphylococcus aureus, and carbapenem-resistant Klebsiella pneumoniae. Firstly, the photosensitizing effect of CIP on E. coli inactivation was studied. Irradiated CIP (1 ppm) induced superoxide anion radical formation (confirmed through EPR analyses), and the combination of these reactive oxygen species (ROS) with ongoing solar radiation exposure enhanced bacterial inactivation. CIP enhanced the disinfection of antibiotic-resistant E. coli (by 1.84 log units at 120 min of irradiation) and improved the inactivation of K. pneumoniae (by 3.48 log units at 135 min)-both Gram-negative bacteria. Conversely, the photo-inactivation of the Gram-positive bacteria S. aureus did not significantly change (just a slight reduction of 0.42 log units at 120 min) by the presence of CIP. Showing the bacterial structure influences the disinfection process. Another critical factor was antibiotic concentration. A high CIP concentration (10 ppm) induced an interfering screen effect, while a low concentration promoted bacteria inactivation via photosensitization (in Gram-negative bacteria). Interestingly, no photosensitizing effect was observed when CIP was replaced by levofloxacin (LEV, another fluoroquinolone antibiotic), indicating a strong dependence on antibiotic structure. Additionally, the effect of the light source on photosensitized inactivation was evaluated, substituting sunlight with UVC irradiation. Under UVC light, CIP worsened ARB photo-inactivation, suggesting disinfection was mainly due to direct light action on microorganisms rather than photosensitization. Finally, the influence of water components on sunlight-photosensitized disinfection was examined using simulated urine and freshwater. The ARB inactivation decreased as matrix complexity increased. Thus, the effectiveness order was Milli-Q water > freshwater > urine.

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Despite maintaining a lower mortality rate and greater control of victims infected by COVID-19, the world's population and science are still confronted with this coronavirus. Therefore, the aim was to assess the association between sociodemographic factors and the level of knowledge and attitudes of dental students regarding disinfection as a control measure to reduce the spread of COVID-19. This cross-sectional study evaluated 503 dental students from the capital city and one Peruvian province between February and June 2022. A validated 13-item questionnaire was used. A Poisson regression model with robust variance was used to evaluate the influence of the variables sex, age, year of study, marital status, place of origin, death of a family member due to COVID-19, and history of COVID-19, with the level of knowledge and attitudes of the dental students, considering a significance level of p < 0.05. Of the total participants, 14.3% showed sufficient knowledge, and 89.3% showed positive attitudes regarding disinfection as a control measure to reduce the spread of COVID-19. Furthermore, those from the capital city were 52% less likely to have sufficient knowledge regarding disinfection as a control measure to reduce the spread of COVID-19, compared to those from the province (APR = 0.48; 95% CI: 0.31-0.75). Moreover, none of the variables considered in this study were significantly associated with attitudes toward this topic (p > 0.05). A minority of dental students presented sufficient knowledge, while the majority presented positive attitudes regarding disinfection as a control measure to reduce the spread of COVID-19. In addition, being from the capital city was a limiting factor for sufficient knowledge. The variables sex, age, year of study, marital status, place of origin, death of a family member due to COVID-19, and history of COVID-19 were not influential factors for positive attitudes on this topic.

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The dairy industry faces challenges in controlling spoilage microorganisms, particularly Pseudomonas, known to form resilient biofilms. Conventional disinfection methods have limitations, prompting the exploration of eco-friendly alternatives like ozone. This study focused on Pseudomonas biofilms on polystyrene and polyethylene surfaces, evaluating ozone efficacy when incorporated into different water sources and applied under static and dynamic conditions. Biofilm formation and removal were assessed with conventional microbiological and microscopic techniques. Despite variations in physicochemical properties, ozonized water from different sources showed similar effectiveness in removing Pseudomonas biofilms. Dynamic ozone application was more efficient, achieving a 2.35 log CFU/coupon reduction on polyethylene surfaces, compared to a 1.05 log CFU/coupon reduction under static conditions. These findings highlight the potential of ozonized water for removing Pseudomonas biofilms, especially under dynamic application. This eco-friendly approach could serve as an effective strategy to mitigate biofilm-related challenges in the dairy industry.

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This systematic review aimed to compare postoperative pain in endodontic treatments using PIPS Er: YAG laser-activated irrigation (LAI) versus conventional needle irrigation. An electronic search was conducted to identify randomized clinical trials (RCT) investigating postoperative pain in patients who underwent root canal treatments in permanent teeth using PIPS Er: YAG laser-activated irrigation or conventional needle irrigation. Two reviewers performed study selection, data extraction, risk of bias assessment (RoB 2.0 tool), and the certainty of evidence (GRADE). The meta-analyses were conducted using Review Manager software (p ≤ 0.05). The mean difference (MD) was chosen as the effect measure, and a random-effect model was employed, along with a 95% confidence interval (CI). The search identified 2864 records, and after selecting, three RCTs were included in the quantitative analysis. The meta-analysis showed a difference in postoperative pain according to the evaluation time. The subgroup meta-analysis revealed that the PIPS Er:YAG showed a significant reduction in the postoperative pain in the 48 hours (MD = -0.78; 95% CI [-1.39, -0.17]; p = 0.01; I² = 69%) compared to the control group. However, no statiscally significant results were found when assessing postoperative pain after 1, 3 and 7 days (95% CI; p > 0.05). The PIPS Er: YAG laser-activated irrigation reduced postoperative pain at 2 days following primary endodontic treatment. However, the certainty of the evidence is low and further RCTs are needed to confirm these results and avoid bias and confounding factors. Registration: PROSPERO registration number: CRD42023432499.

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Determinar el nivel de conocimiento de los estudiantes de enfermería de la Universidad Técnica de Ambato sobre la desinfección terminal del área quirúrgica. Metodología: Esta investigación es cuantitativa, con enfoque descriptivo de cohorte transversal ya que el nivel de conocimiento se ha representado mediante tablas y gráficos para describir la problemática del periodo octubre 2023-febrero 2024. Resultados: Se evidencia el alto porcentaje de respuestas incorrectas por cada ítem por parte de los estudiantes. La categoría desinfección fue respondida de manera incorrecta con un porcentaje del 26%, la categoría proceso de desinfección con el 55,6%, la categoría aplicación del DAN con el 45.8%, la categoría desinfectante del DAN con el 36,2% y, por último, la categoría riesgo y prevención del DAN con el 29,2%. Conclusiones: El nivel de conocimiento de los estudiantes sobre desinfección es bajo, porque no están lo suficientemente motivados o interesados en el tema de desinfección[AU]

Determine the level of knowledge of nursing students at the Technical University of Ambato about terminal disinfection of the surgical area.Methodology:This research is quantitative, with a descriptive cross-sectional cohort approach and the level of knowledge has been represented through tables and graphs to describe the problems of the period October 2023-February 2024.Results:A high percentage of incorrect answers for each item by the students is evident. The disinfection category was answered incorrectly with a percentage of 26%, the disinfection process category with 55.6%, the DAN application category with 45.8%, the disinfectant category with 36.2% and, finally, the DAN risk and prevention category. with 29.2%. Conclusions:The level of knowledge of students about disinfection is low, because they are not sufficiently motivated or interested in the topic of disinfection[AU]

Determinar o nível de conhecimento dos estudantes de enfermagem da Universidade Técnica de Ambato sobre desinfecção terminal da área cirúrgica. Metodologia:Esta pesquisa é quantitativa, com abordagem descritiva de coorte transversal e o nível de conhecimento foi representado por meio de tabelas e gráficos para descrever os problemas do período outubro de 2023 a fevereiro de 2024.Resultados: Evidencia-se um alto percentual de respostas incorretas para cada item por parte dos alunos. A categoria desinfecção foi respondida incorretamente com um percentual de 26%, a categoria processo de desinfecção com 55,6%, a categoria aplicação DAN com 45,8%, a categoria desinfetante com 36,2% e, por último, a categoria risco e prevenção DAN. com 29,2%.Conclusões:O nível de conhecimento dos alunos sobre desinfecção é baixo, porque não estão suficientemente motivados ou interessados no tema da desinfecção[AU]

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This work aimed to improve some steps of the existing guidelines of the European Standards to obtain an Aspergillus brasiliensis ATCC 16404 spore suspension with >75% spiny spores without mycelia and a concentration of at least 1.5×108 CFU ml-1. Several manufacturers' combinations "strain/medium" were assessed in terms of yield of spiny spores. Criteria to establish success included 1) the growth over different times of incubation (4, 7 and 10 days); 2) the performance of two different filtration devices (fritted filters and cell strainers) and 3) the fungal spores susceptibility after 4 days of incubation versus 7 days of incubation against a peracetic acid-based disinfectant. The best combination was "Microbiologics strain/Oxoid MEA" with 88.33% of spiny spores already after 4 days, and no statistical differences (p < 0.05) in terms of growth in the three time points were highlighted (from 1.85×108 CFU ml-1 to 2.21×108 CFU ml-1). Cell strainers gave a spore suspension much more concentrated (3.31 times) compared to fritted filters. Furthermore, the 4-day old spore suspension showed the same susceptibility to disinfection when compared to a suspension whose culture was incubated for 7 days.

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Abstract One of the main aims of a root-canal treatment is to disinfect the root-canal system through mechanical instrumentation and cleaning by endodontic disinfection solutions. The most common endodontic disinfection solution used has been the sodium hypochlorite. However, it has been reported some important biological adverse effects and risks related to it, so it is necessary to propose and evaluate alternatives to be used as an endodontic disinfection solution. Hyperosmotic solution based on sodium chloride and potassium sorbate previously has been shown an adequate antimicrobial effect against endodontic microorganisms in planktonic and biofilm forms. This study evaluated the genotoxicity of a hyperosmotic solution proposed as an endodontic disinfection solution. Human fibroblast cells were seeded and incubated into well-culture plates and exposed to the hyperosmotic solution (30% and 100%) and compared to NaClO 1%, after cells were cultured, an evaluation was performed by Micronucleus, Tunel and Mitotracker assays. Based on results, the hyperosmotic solution is a safe potential endodontic disinfection solution or adjuvant for root canal system disinfection.

Resumen Uno de los principales objetivos del tratamiento de conductos es la adecuada desinfección del sistema de conductos radiculares mediante la instrumentación mecánica en combinación con soluciones desinfectantes para eliminar las bacterias y prevenir la reinfección. La solución irrigante/ desinfectante endodóntica más utilizada es el hipoclorito de sodio, del cual se han reportado efectos adversos biológicos importantes y riesgos relacionados, por lo que es necesario proponer y evaluar alternativas para ser utilizadas como soluciones irrigantes/desinfectantes. La solución hiperosmótica a base de cloruro de sodio y sorbato de potasio ha demostrado tener un efecto antimicrobiano adecuado contra los microorganismos patógenos endodónticos, tanto en forma planctónica y en biopelícula. El presente estudio evaluó la genotoxicidad de una solución hiperosmótica empleada como solución de desinfección endodóntica. Se cultivaron células de fibroblastos humanos en placas de cultivo y se expusieron a la solución hiperosmótica (30% / 100%) y se compararon con NaClO (1%); después de la exposición a las soluciones se realizó una evaluación mediante ensayo Micronucleo, Tunel y Mitotracker. De acuerdo a los resultados, la solución hiperosmótica es una solución de irrigación endodóntica segura o un adyuvante para la desinfección del sistema de conductos radiculares.

RESUMO

Background: The end of the global sanitary emergency derived from the COVID-19 pandemic was declared by WHO in May 2022. In this sanitary emergency, massive campaigns promoting hygiene and social distancing measures were displayed, which may have not only helped to ease the spread of respiratory infections, but also of gastroenteritis of presumably infectious origin (GPIO). Objectives: To estimate the change in prevalence of GPIO in the first level of attention between a pre-pandemic period and during the COVID-19 pandemic. Material and methods: Retrospective, observational, cross-sectional, and comparative study which included all patients who looked for medical attention in a first-level center in 2 periods: pre-pandemic (2018-2019) and during pandemic (2020-2021). Data was retrieved from electronic medical records. It was carried out a descriptive analysis with frequencies and percentages, and Fisher's exact test was used to calculate the prevalence of GPIO. Results: During the pre-pandemic a total of 620,164 consultations occurred and 497,750 in the pandemic period. Prevalence of GPIO in the first period was 1.32% (n = 8207) and 0.42% (n = 2132) in the second period (p < 0.001). No significant changes in symptomatology were observed, except for change in consistency in feces (p = 0.001) and vomiting (p = 0.01). Hand hygiene education was reported in 5.2% of the cases in the first period, and in 19.2% in the second period. Conclusion: There was a significant reduction in the prevalence of GPIO during the pandemic period, probably due to the massive hygienic measures displayed to mitigate the spread of COVID-19.

Introducción: la OMS declaró el fin de la emergencia sanitaria de la pandemia por COVID-19 en mayo de 2022. En ella se desplegaron campañas masivas que promovían medidas de higiene que pueden no solo haber ayudado a frenar la propagación de infecciones respiratorias, sino también de gastroenteritis de origen presuntamente infeccioso (GOPI). Objetivos: estimar el cambio en la prevalencia de GOPI en el primer nivel de atención entre un periodo previo y durante la pandemia de COVID-19. Material y métodos: estudio retrospectivo, observacional, transversal y comparativo que incluyó a todos los pacientes que buscaron atención médica en un centro de primer nivel en 2 periodos: prepandemia (2018-2019) y durante la pandemia (2020-2021). Los datos se obtuvieron de los expedientes médicos electrónicos. Se hizo un análisis descriptivo con frecuencias y porcentajes, y se usó la prueba exacta de Fisher para calcular diferencias en la prevalencia de GOPI. Resultados: durante la prepandemia se realizaron 620,164 consultas y 497,750 en la pandemia. La prevalencia de GOPI en el primer periodo fue 1.32% (n = 8207) y 0.42% (n = 2132) en el segundo (p < 0.001). No hubo cambios significativos en la sintomatología, salvo en el cambio en la consistencia de las heces (p = 0.001) y el vómito (p = 0.01). La educación sobre higiene de manos se informó en el 5.2% de los casos en el primer periodo y 19.2% en el segundo. Conclusión: la prevalencia de GOPI se redujo significativamente en el periodo de pandemia, quizás debido a las medidas de higiene masiva implementadas para mitigar la propagación de la COVID-19.

RESUMO

Introduction: Oral hygiene education for patients is fundamental in preventive-promotional dentistry. The disinfection of toothbrushes (TBs) must be integrated into this context due to their proximity to contaminant sources that make them vulnerable to cross infection in homes. The objective of this study was to compare the efficacy of domestic techniques for disinfection of TBs. Materials and Methods: We performed an in vitro study of 76 TBs contaminated with Enterococcus faecalis (Ef) ATCC 29212 subjected to different disinfection protocols: G1. Distilled water (DW; negative control; n = 8), G2. Dimethylsulfoxide (DMSO)10% (negative control; n = 8), G3. Chlorhexidine (CHX) 0.12% (positive control; n = 15), G4. 100% white vinegar (WV; n = 15), G5. Microwave (MW) at 700 W (n = 15), and G6. 200 mg/mL of certified alcoholic extract of purple garlic (GARLIC) from Arequipa (Allium sativum L; n = 15). Bacterial count was assessed by colony-forming units (CFU/mL) categorized as contamination: low (<30), medium (30-300), and high (>300). The Kruskal-Wallis test with post hoc pairs was used at a significance level of p < 0.05. Results: Efficacy against Ef showed highly significant differences between groups (p < 0.001) with lower median CFU/mL in G3 and G4 (Me = 0 [IQR (interquartile range) = 0]: low) and G5 (Me = 6000 [IQR = 45,000]: low/medium) versus negative controls (Me = 378,500 and 5,020,000 [IQR = 4,605,000 and 6,760,000]: medium/high; p ≤ 0.019). The counts of the G5 were not statistically different than G3, G4, and G6 (p > 0.06). The G6 (Me = 1,510,000 [IQR = 590,000]: medium) was inferior to G3 and G4 (p < 0.001), but similar to both negative control groups (p > 0.999). Conclusions: Disinfection of TBs with CHX, WV, and MWs produces a significant effective reduction in the count of Ef.

RESUMO

This study aimed to assess the removal of antimicrobial resistance agents (antibiotics, antibiotic-resistant bacteria - ARB, and antimicrobial resistance genes - ARGs) from aerobic and anaerobic sludges treated with quicklime (chemical alkalinization). Different mixing ratios (25%, 35%, and 45%) and contact times (2 h and 72 h) were evaluated. The findings revealed that anaerobic sludge responded more effectively to alkaline treatment, achieving better removal rates of antibiotics, ARB, and ARGs compared to aerobic sludge. The 45% lime treatment yielded the highest antibiotic removal rates, with average reductions of 19% in aerobic sludge and 28% in anaerobic sludge. The 35% lime treatment was the most effective in reducing ARGs across both types of sludge (average removal of 2 logs). The 25% lime treatment proved most efficient for removing ARB, with average reductions of 4 logs (aerobic) and 5 logs (anaerobic). The contact time between the sludge and quicklime also influenced the removal of resistance agents. An increase in the proportion of antibiotics and the absolute concentration of ARB and ARGs was observed after 72 h compared to the samples analyzed after 2 h of contact. This increase was more pronounced in aerobic sludge samples treated with 35% and 45% lime. Despite the overall reduction, none of the monitored resistant genes or bacteria were completely eradicated in both sludge samples, raising concerns about their potential dissemination into the environment.

RESUMO

OBJECTIVES: To evaluate the antimicrobial efficacy of white vinegar, acetic acid, and peracetic acid on photostimulable phosphor (PSP) plates disinfection, and to assess the disinfectant influence on the radiographic quality. METHODS: Eight PSP plates (Express system) were contaminated with Streptococcus mutans and Candida albicans. These plates were wiped with tissues without any substance, with white vinegar, acetic acid, and peracetic acid, followed by an agar imprint. Number of microbial colonies formed was recorded. Afterwards, the quality of radiographs was tested using the more efficient disinfectant. Before disinfection and after every five disinfections, two radiographs of an acrylic-block and two radiographs of an aluminium step-wedge were acquired for each plate. Density, noise, uniformity, and contrast were analysed. Three oral radiologists evaluated the images for the presence of artefacts. One-way analysis of variance compared changes on grey values among the disinfections (α = .05). Intra- and inter-examiner agreement for the presence of artefacts was calculated by weighted Kappa. RESULTS: Peracetic acid was the only one that eliminated both microorganisms. Density and uniformity decreased after 100 disinfections, and contrast changed without a pattern in the course of disinfections (P ≤ .05). Small artefacts were observed after 30 disinfections. Intra- and inter-examiner agreements were almost perfect. CONCLUSIONS: Disinfection with peracetic acid eliminated both microorganisms. However, it also affected density, uniformity, and contrast of radiographs, and led to the formation of small artefacts.

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Reproductive biotechnologies are widely consolidated as a methodology in cattle breeding and have an important impact on the genetic improvement of cattle herds. Semen is an important source of dissemination of pathogenic microorganisms during reproductive procedures. To ensure the sanitary quality of the semen, it is essential to consider the presence of various microorganisms including viruses. One of the main viral agents of reproductive interest is Bovine Alphaherpesvirus 1 (BoHV-1), the etiological agent responsible for bovine rhinotracheitis and vulvovaginitis and frequently associated with reproductive efficiency of matrices and bulls. In artificial insemination centers, semen treatment is generally based only on the use of antibiotics, ignoring the possibility of inactivating other non-bacterial infectious agents. In this context, photodisinfection emerges as a promising alternative to inactivate a wide range of microorganisms, offering a complementary or substitution approach to those conventional semen treatment methods. In this work, we evaluated the use of four halogenated sulfonated porphyrins as potential photosensitizers (PSs) for photodynamic inactivation of Bovine Alphaherpesvirus I (BoHV-1) for bovine semen disinfection. The PSs were synthesized and photophysical parameters, such as UV-Vis absorption spectra and singlet oxygen quantum yield (ΦΔ) were presented. Photoinactivation of BoHV-1 was first shown in cell culture and then confirmed in artificially infected bovine semen and then the phototoxicity of PSs against spermatozoa was evaluated. All PSs were effective in BoHV-1 inactivation; however, the photosensitizer containing two chlorine atoms, showed to be more efficient due to the shorter time required for complete viral inactivation. The slight alterations in sperm kinetics were observed, but remained within those acceptable by regulatory agencies for animal reproduction. Although the methodology used in this work only included bovine semen, we emphasize that the proposed photodisinfection methodology can be adapted and applied to a wide range of biological materials and microorganisms of animal or human interest.

RESUMO

Background and Objectives: The aim of this study is to analyze, through a systematic review and meta-analysis, the identification, resistance and susceptibility of microorganisms present in healthcare workers' hands, identifying the most relevant antimicrobial resistant bacteria and their prevalence. Methods: Several scientific databases were reviewed to summarize contributions of the past 10 years. A meta-analysis was conducted to assess bacteria on healthcare workers' hands and their resistance and susceptibility profiles. Results: healthcare workers were colonized by 35 types of bacteria, highlighting Staphylococcus aureus., Acinetobacter spp., and Escherichia. coli. Although a lower number of bacteria was present on healthcare workers' hands, doctors acquired more bacteria. Specifically, health personnel contracted Enterococcus spp., Staphylococcus. epidermis, Acinetobacter spp., Escherichia. coli, among others. Resistance and susceptibility profiles showed that S. aureus was susceptible to antibiotics; nevertheless, S. aureus was resistant to ceftriaxone, erythromycin and amoxicillin-clavulanic acid. Conclusion: Detected microorganisms trigger pathologies of clinical importance such as skin infections, sepsis, gastroenteritis, among others; in addition, bacteria are the cause of pathologies of greater clinical importance, such as nosocomial pathologies due to work activity in the hospital environment, which require invasive treatment. Even if new drugs are developed, the way of prescribing and using antibiotics needs to be changed to reduce antibiotic resistance.(AU)

Justificación y Objetivos: El objetivo de este estudio es analizar, mediante una revisión sistemática y un metaanálisis, la identificación, resistencia y susceptibilidad de los microorganismos presentes en las manos de los trabajadores de la salud, identificando las bacterias más relevantes y su prevalencia de resistencia a los antibióticos. Métodos: Se revisaron varias bases de datos científicas para resumir las contribuciones de los últimos 10 años. Se realizó un metaanálisis para evaluar las bacterias en las manos de los trabajadores de la salud y sus perfiles de resistencia y susceptibilidad. Resultados: los trabajadores de la salud fueron colonizados por 35 tipos de bacterias, destacando Staphylococcus aureus., Acinetobacter spp. y Escherichia. coli. Aunque las bacterias en las manos de los trabajadores de la salud fueron menores, los médicos adquirieron más bacterias. En concreto, personal sanitario contrajo Enterococcus spp., Staphylococcus. epidermis, Acinetobacter spp., Escherichia. coli, entre otros. Los perfiles de resistencia y susceptibilidad mostraron que S. aureus era susceptible a los antibióticos; sin embargo, el S. aureus fue resistente a ceftriaxona, eritromicina y amoxicilina-ácido clavulánico. Conclusión: Los microorganismos detectados desencadenan patologías de importancia clínica como infecciones de la piel, sepsis, gastroenteritis, entre otras; además, las bacterias son causantes de patologías de mayor importancia clínica, como las patologías nosocomiales debidas a la actividad laboral en el ámbito hospitalario, que requieren un tratamiento invasivo. Es necesario cambiar la forma de prescribir y utilizar los antibióticos, incluso si se desarrollan nuevos medicamentos, para reducir la resistencia a los antibióticos.(AU)

Justificativa e Objetivos: O objetivo deste estudo é analisar, por meio de uma revisão sistemática e metanálise, a identificação, resistência e suscetibilidade de microrganismos presentes nas mãos de profissionais de saúde, identificando as bactérias mais relevantes e sua prevalência à resistência aos antibióticos. Métodos: Diversas bases de dados científicas foram revisadas para resumir as contribuições dos últimos 10 anos. Foi realizada uma meta-análise para avaliar bactérias nas mãos dos profissionais de saúde e os seus perfis de resistência e suscetibilidade. Resultados: os profissionais de saúde foram colonizados por 35 tipos de bactérias, destacando-se Staphylococcus aureus., Acinetobacter spp. e Escherichia. coli. Embora o número de bactérias nas mãos dos profissionais de saúde fosse menor, os médicos adquiriram mais bactérias. Especificamente, o pessoal de saúde contraiu Enterococcus spp., Staphylococcus. epiderme, Acinetobacter spp., Escherichia. coli, entre outras. Os perfis de resistência e suscetibilidade mostraram que S. aureus era suscetível a antibióticos; no entanto, S. aureus foi resistente à Ceftriaxona, Eritromicina e Amoxicilina-Ácido Clavulânico. Conclusão: Os microrganismos detectados desencadeiam patologias de importância clínica como infecções de pele, sepse, gastroenterites, entre outras; além disso, as bactérias são causadoras de patologias de maior importância clínica, como as patologias nosocomiais decorrentes da atividade laboral no ambiente hospitalar, que requerem tratamento invasivo. A forma de prescrever e usar antibióticos precisa ser alterada, mesmo que novos medicamentos sejam desenvolvidos, para reduzir a resistência aos antibióticos.(AU)

RESUMO

Background and Objectives: Hand hygiene should be encouraged among the nursing team of the materials and sterilization center, as various processes can be sources of microorganism transmission. The objective is to assess the quality of hand hygiene technique and adherence in the materials and sterilization center, according to the recommendations of the World Health Organization. Methods: This is an observational, descriptive, and prospective study, in which weekly visits were conducted from February to May 2023. On-site direct observation was used, followed by notes on an adapted form. Results: Out of 364 observations made, only 91 (25%) performed hand hygiene, and only 7 (1.9%) executed the correct technique. Moments with the highest adherence were upon arrival at the unit (35.1%), upon leaving the unit (12.1%), and before handling packaging and health products. Among the supplies used, liquid soap had the highest frequency (51.6%). Males showed higher adherence compared to females (p<0.01). Conclusion: Adherence to hand hygiene was low among the nursing staff, and few executed the correct technique according to the steps recommended by the World Health Organization. The results underscore the need for awareness-raising and training actions regarding this preventive measure in the materials and sterilization center.(AU)

Justificativa e Objetivos: A higienização das mãos deve ser incentivada entre a equipe de enfermagem do centro de materiais e esterilização, uma vez que diversos processos podem ser fontes de transmissão de microrganismos. O objetivo é avaliar a qualidade da técnica e adesão à higiene de mãos no centro de materiais e esterilização de acordo com as recomendações da Organização Mundial da Saúde. Métodos: Este é um estudo observacional, descritivo e prospectivo, no qual foram realizadas visitas semanais durante o período de fevereiro a maio de 2023. Utilizou-se observação direta no local e, posteriormente, foram feitas anotações em um formulário adaptado. Resultados: No total de 364 observações realizadas, apenas 91 (25%) realizaram a higienização das mãos, e somente 7 (1,9%) executaram a técnica correta. Os momentos com maior adesão foram ao chegar à unidade (35,1%), ao sair da unidade (12,1%) e antes de manusear embalagens e produtos para a saúde. Entre os insumos utilizados, o sabonete líquido obteve maior frequência (51,6%). O sexo masculino apresentou maior adesão quando comparado ao feminino (p<0,01). Conclusão: A adesão à higiene de mãos foi baixa entre a equipe de enfermagem e poucos realizaram a técnica correta de acordo com os passos recomendados pela Organização Mundial da Saúde. Os resultados reforçam a necessidade de ações de sensibilização e treinamento em relação a esta medida preventiva no centro de materiais e esterilização.(AU)

Justificación y Objetivos: La higiene de manos debe ser fomentada entre el personal del centro de materiales y esterilización, ya que varios procesos pueden ser fuentes de transmisión de microorganismos. El objetivo de este estudio es evaluar la calidad de la técnica y la adherencia a la higiene de manos en el centro de materiales y esterilización según lo recomendado por la Organización Mundial de la Salud. Métodos: Este es un estudio observacional, descriptivo y prospectivo, en el cual se realizaron visitas semanales durante el período de febrero a mayo de 2023. Se utilizó la observación directa en el lugar y, posteriormente, se realizaron notas en un formulario adaptado. Resultados: De un total de 364 observaciones realizadas, solo 91 (25%) realizaron la higiene de manos, y solo 7 (1,9%) ejecutaron la técnica correcta. Los momentos con mayor adherencia fueron al llegar a la unidad (35,1%), al salir de la unidad (12,1%) y antes e manipular envases y productos de salud. Entre los suministros utilizados, el jabón líquido tuvo la mayor frecuencia (51,6%). Los hombres mostraron una mayor adherencia en comparación con las mujeres (p<0,01). Conclusión: La adherencia a la higiene de manos fue baja entre el personal de enfermería y pocos ejecutaron la técnica correcta según lo recomendado por la Organización Mundial de la Salud. Los resultados refuerzan la necesidad de acciones de sensibilización y capacitación con respecto a esta medida preventiva en el centro de materiales y esterilización.(AU)

RESUMO

Ultraviolet light-emitting diodes (UV-LEDs) have demonstrated the ability to inactivate microorganisms in water, offering an environmentally safer alternative to the conventional mercury lamp, in UV applications. While several studies have explored the microbiological effect of UVC-LEDs (200nm-280nm), limited information exists regarding their effects on waters with critical qualities. These critical qualities encompass bacteria, viruses, and protozoa - drinking water quality indicators defined by the World Health Organization for small water systems. For the first time, this work reports on the Escherichia coli, PhiX-174, MS2, and Cryptosporidium oocysts inactivation using a bench-scale UVC-LED (280 nm) water disinfection system. UV doses at a wavelength of 280 nm (UV280) of up to 143.4 mJ/cm2 were delivered under two quality-critical water conditions: filtered water (UV transmittance at 280 nm - UVT280 90.2 %) and WHO challenge water (UVT 15.7 %). Results revealed microbiological reductions dependent on exposure time and UVT. For UV280 dose of 16.1 mJ/cm2, 2.93-3.70 log E. coli reductions were observed in UVT 90.2 % and 15.7 %, 3.49-4.21 log for PhiX-174, 0.63-0.78 log for MS2, and 0.02-0.04 log for Cryptosporidium oocysts. Significantly higher UV280 doses of 143.4 mJ/cm2 led to reductions of 3.94-5.35 log for MS2 and 0.42-0.46 log for Cryptosporidium oocysts. Statistical analysis revealed that the sensitivity among the organisms to UV280 exposure was E. coli = PhiX-174 > MS2 >> Cryptosporidium oocysts. Although experiments with WHO challenge water posed greater challenges for achieving 1 log reduction compared to filtered water, this difference only proved statistically significant for PhiX-174 and MS2 reductions. Overall, UVC-LED technology demonstrated notable efficacy in microbiological inactivation, achieving significant reductions based on WHO scheme of evaluation for POU technologies in both bacteria and viruses even in critical-quality waters. The findings emphasize the potential for extending the application of UVC-LED as a viable solution for household water treatment.

RESUMO

Carbon nitrides can form coordination compounds or metallic oxides in the presence of transition metals, depending on the reaction conditions. By adjusting the pH to basic levels for mild synthesis with metals, composites like g-C3N4-M(OH)x (where M represents metals) were obtained for nickel (II) and manganese (II), while copper (II) yielded coordination compounds such as Cu-g-C3N4. These materials underwent spectroscopic and electrochemical characterization, revealing their photocatalytic potential to generate superoxide anion radicals-a feature consistent across all metals. Notably, the copper coordination compound also produced significant hydroxyl radicals. Leveraging this catalytic advantage, with band gap energy in the visible region, all compounds were activated to disinfect E. coli bacteria, achieving total disinfection with Cu-g-C3N4. The textural properties influence the catalytic performance, with copper's stabilization as a coordination compound enabling more efficient activity compared to the other metals. Additionally, the determination of radicals generated under light in the presence of dicloxacillin supported the proposed mechanism and highlighted the potential for degrading organic molecules with this new material, alongside its disinfectant properties.

RESUMO

Reclaimed water poses environmental and human health risks due to residual organic micropollutants and pathogens. Ozonation of reclaimed water to control pathogens and trace organics is an important step in advanced water treatment systems for potable reuse of reclaimed water. Ensuring efficient pathogen reduction while controlling disinfection byproducts remains a significant challenge to implementing ozonation in reclaimed water reuse applications. This study aimed to investigate ozonation conditions using a plug flow reactor (PFR) to achieve effective pathogen removal/inactivation while minimizing bromate and N-Nitrosodimethylamine (NDMA) formation. The pilot scale study was conducted using three doses of ozone (0.7, 1.0 and 1.4 ozone/total organic carbon (O3/TOC) ratio) to determine the disinfection performance using actual reclaimed water. The disinfection efficiency was assessed by measuring total coliforms, Escherichia coli (E. coli), Pepper Mild Mottle Virus (PMMoV), Tomato Brown Rugose Fruit Virus (ToBRFV) and Norovirus (HNoV). The ozone CT values ranged from 1.60 to 13.62 mg min L-1, resulting in significant reductions in pathogens and indicators. Specifically, ozone treatment led to concentration reductions of 2.46-2.89, 2.03-2.18, 0.46-1.63, 2.23-2.64 and > 4 log for total coliforms, E. coli, PMMoV, ToBRFV, and HNoV, respectively. After ozonation, concentrations of bromate and NDMA increased, reaching levels between 2.8 and 12.0 µg L-1, and 28-40.0 ng L-1, respectively, for average feed water bromide levels of 86.7 ± 1.8 µg L-1 and TOC levels of 7.2 ± 0.1 mg L-1. The increases in DBP formation were pronounced with higher ozone dosages, possibly requiring removal/control in subsequent treatment steps in some potable reuse applications.

RESUMO

Pathogenic bacteria, introduced in water sources through faecal contamination, have traditionally been investigated as individual species, leading to the establishment of microbial, sanitary, and environmental quality indicators. Recent advancements in our understanding of the microbiome and its intricate interactions within the human-microbiome-environment network advocate for a broader evaluation of the impact of disinfection on the entire microbial community. In this study, we conducted a comprehensive screening experiment involving four disinfection processes; ozone, ultraviolet radiation with wavelengths between 200 - 280 nm (UV-C), photo-Fenton, and chlorination, applied to two distinct water sources; surface (SW) and groundwater (GW). The cells that remained viable after treatment were recovered using Brain Heart Infusion (BHI) broth, and 16S rRNA gene sequencing was used for their identification. Our findings confirmed the presence of faecal contamination in the water sources and revealed distinct effects of each treatment on the recovered bacterial populations. The chlorination of groundwater samples likely had a greater impact on bacteria in a vegetative state than on spores. Consequently, this led to a higher abundance in the BHI cultures of sporulating bacteria such as Bacillus (increasing from 0.36 to 93.62 %), while ozonation led to an elevated recovery of Pseudomonas (increasing from 45.2 to 69.9 %). Conversely, in surface water, calcium hypochlorite and ozone treatments favored the selection of Staphylococcus and Bacillus, whose relative abundance in the cultures increased from 0 to 39.22 % and from 0.35 to 96.6 %, respectively. In groundwater, Pseudomonas was resistant to UV-C radiation and their relative abundance increased from 45.2 % to 93.56 %, while photo-Fenton was effective against this bacterial group decreasing its relative abundance to 0.46 %. However, other genera such as Bacteroides, Aeromonas, and Citrobacter seemed to be less injured by this disinfection process. BHI broth was successful in recovering various bacterial groups that exhibited resistance to sublethal water disinfection.

RESUMO

Chlorine is a common disinfectant used in water treatment. However, its reaction with organic matter can lead to the formation of harmful byproducts, such as trihalomethanes (THMs), which are potentially carcinogenic. To address this issue, the aim of this work was to enhance a colorimetric method capable of quantifying THMs in drinking water through UV/Vis Spectrophotometry, using cost-effective equipment, and validate this methodology for the first time according to established validation protocols. The method's innovation involved replacing the solvent pentane with the more common hexane, along with adjusting the heating ramp, elucidating the mechanisms involved in the process. This method involves the reaction between THMs, pyridine, and NaOH to produce a colored compound, which is then monitored through molecular absorption spectroscopy in the visible region. The method was thoroughly validated, achieving a limit of detection of 13.41 µg L-1 and a limit of quantification of 40.65 µg L-1. Recovery assays ranged from 86.1 % to 90.7 %, demonstrating high accuracy. The quality of the linear fit for the analytical curve exceeded R2 > 0.98. The method was applied to real samples, revealing concentrations ranging from 13.58 to 55.46 µg L-1, all way below the legal limit in Brazil (Maximum Contaminant Levels (MCL) = 100 µg L-1). This cost-effective and straightforward method is suitable for integration into water treatment plant laboratories.

RESUMO

Advanced Oxidation Processes (AOPs) offer promising methods for disinfection by generating radical species like hydroxyl radicals, superoxide anion radicals, and hydroxy peroxyl, which can induce oxidative stress and deactivate bacterial cells. Photocatalysis, a subset of AOPs, activates a semiconductor using specific electromagnetic wavelengths. A novel material, Cu/Cu2O/CuO nanoparticles (NPs), was synthesized via a laser ablation protocol (using a 1064 nm wavelength laser with water as a solvent, with energy ranges of 25, 50, and 80 mJ for 10 min). The target was sintered from 100 °C to 800 °C at rates of 1.6, 1.1, and 1 °C/min. The composite phases of Cu, CuO, and Cu2O showed enhanced photocatalytic activity under visible-light excitation at 368 nm. The size of Cu/Cu2O/CuO NPs facilitates penetration into microorganisms, thereby improving the disinfection effect. This study contributes to synthesizing mixed copper oxides and exploring their activation as photocatalysts for cleaner surfaces. The electronic and electrochemical properties have potential applications in other fields, such as capacitor materials. The laser ablation method allowed for modification of the band gap absorption and enhancement of the catalytic properties in Cu/Cu2O/CuO NPs compared to precursors. The disinfection of E. coli with Cu/Cu2O/CuO systems serves as a case study demonstrating the methodology's versatility for various applications, including disinfection against different microorganisms, both Gram-positive and Gram-negative.