Potential of bacteriophage phT4A as a biocontrol agent against Escherichia coli in food matrices.

Escherichia coli is one of the most prevalent foodborne pathogens, frequently found in meat and dairy products. Current decontamination methods are often associated with changes in organoleptic characteristics, nutrient loss, and potentially harmful side effects. Furthermore, despite the array of available methods, foodborne outbreaks still frequently occur. For this reason, bacteriophages (or simply phages) emerged as a natural alternative for the biocontrol of bacterial contamination in food without altering their organoleptic properties. In this study, the potential of phage phT4A was assessed in the biocontrol of E. coli in liquid (milk) and solid (ham) food matrices. Firstly, as foods have different pH and temperature values, the influence of these parameters on phage phT4A viability was also assessed to develop an effective protocol. Phage phT4A proved to be stable for long storage periods at pH 7-8 (56 days) and temperatures of 4-37 °C (21 days). Before application of phages to inactivate pathogenic bacteria in food, previous assays were carried out in Tryptic Soy Broth (TSB) to study the dynamics of phage-bacteria interaction. Then, the antibacterial potential of phage phT4A was evaluated in the two food matrices at different temperatures (4, 10 and 25 °C). This phage was more efficient at 25 °C in all tested matrices (maximum inactivation of 6.6, 3.9 and 1.8 log CFU/mL in TSB, milk and ham, respectively) than at 10 °C (maximum decrease of 4.7, 2.1 and 1.0 log CFU/mL in TSB, milk and ham, respectively) and 4 °C (maximum reduction of 2.6 and 0.7 log CFU/mL in TSB and milk, respectively). However, the decrease of temperature from 25 °C to 10 and 4 °C prevented bacterial regrowth. The results suggest that during phage treatment, a balance between an incubation temperature that provide effective results in terms of bacterial inactivation by the phages and at the same time prevents or delays bacterial regrowth, is needed. The application of phage phT4A at a temperature of 10 °C can be an effective strategy in terms of bacterial inactivation, delaying bacterial regrowth and also reducing energy costs.

Combined effect of SAR-endolysin LysKpV475 with polymyxin B and Salmonella bacteriophage phSE-5.

Endolysins are bacteriophage (or phage)-encoded enzymes that catalyse the peptidoglycan breakdown in the bacterial cell wall. The exogenous action of recombinant phage endolysins against Gram-positive organisms has been extensively studied. However, the outer membrane acts as a physical barrier when considering the use of recombinant endolysins to combat Gram-negative bacteria. This study aimed to evaluate the antimicrobial activity of the SAR-endolysin LysKpV475 against Gram-negative bacteria as single or combined therapies, using an outer membrane permeabilizer (polymyxin B) and a phage, free or immobilized in a pullulan matrix. In the first step, the endolysin LysKpV475 in solution, alone and combined with polymyxin B, was tested in vitro and in vivo against ten Gram-negative bacteria, including highly virulent strains and multidrug-resistant isolates. In the second step, the lyophilized LysKpV475 endolysin was combined with the phage phSE-5 and investigated, free or immobilized in a pullulan matrix, against Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311. The bacteriostatic action of purified LysKpV475 varied between 8.125 µg ml-1 against Pseudomonas aeruginosa ATCC 27853, 16.25 µg ml-1 against S. enterica Typhimurium ATCC 13311, and 32.50 µg ml-1 against Klebsiella pneumoniae ATCC BAA-2146 and Enterobacter cloacae P2224. LysKpV475 showed bactericidal activity only for P. aeruginosa ATCC 27853 (32.50 µg ml-1) and P. aeruginosa P2307 (65.00 µg ml-1) at the tested concentrations. The effect of the LysKpV475 combined with polymyxin B increased against K. pneumoniae ATCC BAA-2146 [fractional inhibitory concentration index (FICI) 0.34; a value lower than 1.0 indicates an additive/combined effect] and S. enterica Typhimurium ATCC 13311 (FICI 0.93). A synergistic effect against S. enterica Typhimurium was also observed when the lyophilized LysKpV475 at ⅔ MIC was combined with the phage phSE-5 (m.o.i. of 100). The lyophilized LysKpV475 immobilized in a pullulan matrix maintained a significant Salmonella reduction of 2 logs after 6 h of treatment. These results demonstrate the potential of SAR-endolysins, alone or in combination with other treatments, in the free form or immobilized in solid matrices, which paves the way for their application in different areas, such as in biocontrol at the food processing stage, biosanitation of food contact surfaces and biopreservation of processed food in active food packing.

Effect of Bacteriophages against Biofilms of Escherichia coli on Food Processing Surfaces.

The bacterial adhesion to food processing surfaces is a threat to human health, as these surfaces can serve as reservoirs of pathogenic bacteria. Escherichia coli is an easily biofilm-forming bacterium involved in surface contamination that can lead to the cross-contamination of food. Despite the application of disinfection protocols, contamination through food processing surfaces continues to occur. Hence, new, effective, and sustainable alternative approaches are needed. Bacteriophages (or simply phages), viruses that only infect bacteria, have proven to be effective in reducing biofilms. Here, phage phT4A was applied to prevent and reduce E. coli biofilm on plastic and stainless steel surfaces at 25 °C. The biofilm formation capacity of phage-resistant and sensitive bacteria, after treatment, was also evaluated. The inactivation effectiveness of phage phT4A was surface-dependent, showing higher inactivation on plastic surfaces. Maximum reductions in E. coli biofilm of 5.5 and 4.0 log colony-forming units (CFU)/cm2 after 6 h of incubation on plastic and stainless steel, respectively, were observed. In the prevention assays, phage prevented biofilm formation in 3.2 log CFU/cm2 after 12 h. Although the emergence of phage-resistant bacteria has been observed during phage treatment, phage-resistant bacteria had a lower biofilm formation capacity compared to phage-sensitive bacteria. Overall, the results suggest that phages may have applicability as surface disinfectants against pathogenic bacteria, but further studies are needed to validate these findings using phT4A under different environmental conditions and on different materials.

Evaluation of UV-C Radiation Efficiency in the Decontamination of Inanimate Surfaces and Personal Protective Equipment Contaminated with Phage ϕ6.

To help halt the global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), appropriate disinfection techniques are required. Over the last years, the interest in Ultraviolet-C (UV-C) radiation as a method to disinfect inanimate surfaces and personal protective equipment (PPE) has increased, mainly to efficiently disinfect and prevent SARS-CoV-2 from spreading and allow for the safe reuse of said equipment. The bacteriophage ϕ6 (or simply phage ϕ6) is an RNA virus with a phospholipid envelope and is commonly used in environmental studies as a surrogate for human RNA-enveloped viruses, including SARS-CoV-2. The present study investigated the use of two new UV irradiation systems ((2)2.4W and (8)5.5W)) constituted by conventional mercury UV-C lamps with a strong emission peak at ~254 nm to potentially inactivate phage ϕ6 on different surfaces (glass, plastic, stainless steel, and wood) and personal protective equipment, PPE, (surgical and filtering facepiece 2, FFP2, masks, a clear acetate visor, and disposable protective clothing). The results showed that both UV-C systems were effective in inactivating phage ϕ6, but the UV-C sterilizing chamber (8)5.5W had the best disinfection performance on the tested surfaces. The inactivation effectiveness is material-dependent on all surfaces, reaching the detection limit of the method at different times (between 60 and 240 s of irradiation). The glass surface needed less time to reduce the virus (30 s) when compared with plastic, stainless, and wood surfaces (60 s). The virus inactivation was more effective in the disposable surgical and FFP2 masks (60 and 120 s, respectively) than in the disposable vest and clear acetate visor (240 s). Overall, this study suggests that UV-C lamps with peak emission at ~254 nm could provide rapid, efficient, and sustainable sanitization procedures to different materials and surfaces. However, dosage and irradiation time are important parameters to be considered during their implementation as a tool in the fight against human coronaviruses, namely against SARS-CoV-2.

Bacteriophages in the Control of Aeromonas sp. in Aquaculture Systems: An Integrative View.

Aeromonas species often cause disease in farmed fish and are responsible for causing significant economic losses worldwide. Although vaccination is the ideal method to prevent infectious diseases, there are still very few vaccines commercially available in the aquaculture field. Currently, aquaculture production relies heavily on antibiotics, contributing to the global issue of the emergence of antimicrobial-resistant bacteria and resistance genes. Therefore, it is essential to develop effective alternatives to antibiotics to reduce their use in aquaculture systems. Bacteriophage (or phage) therapy is a promising approach to control pathogenic bacteria in farmed fish that requires a heavy understanding of certain factors such as the selection of phages, the multiplicity of infection that produces the best bacterial inactivation, bacterial resistance, safety, the host's immune response, administration route, phage stability and influence. This review focuses on the need to advance phage therapy research in aquaculture, its efficiency as an antimicrobial strategy and the critical aspects to successfully apply this therapy to control Aeromonas infection in fish.

Application of the Resazurin Cell Viability Assay to Monitor Escherichia coli and Salmonella Typhimurium Inactivation Mediated by Phages.

Bacterial inactivation using bacteriophages (or phages) has emerged as an effective solution for bacterial infections, but the screening methods used to evaluate the effectiveness of the phages to inactivate bacteria are not fast, reliable or precise enough. The efficiency of bacterial inactivation by phages has been evaluated by monitoring bacterial concentration either by counting colony-forming units (CFU), a laborious and time-consuming method, or by monitoring the optical density (OD), a less sensitive method. In this study, the resazurin cell viability assay was used to monitor the viability of bacteria from different genera during the inactivation by different phages, and the results were compared with the standard methods used to assess bacterial inactivation. The results showed that the resazurin colorimetric cell viability assay produces similar results to the standard method of colony-counting and giving, and also more sensitive results than the OD method. The resazurin assay can be used to quickly obtain the results of the cell viability effect profile using two different bacterial strains and several different phages at the same time, which is extremely valuable in screening studies. Moreover, this methodology is established as an effective, accurate and rapid method when compared to the ones widely used to monitor bacterial inactivation mediated by phages.

Photodynamic inactivation of methicillin-resistant Staphylococcus aureus on skin using a porphyrinic formulation.

Staphylococcus aureus is responsible for skin and soft tissue infections. Having in mind increased antibiotic resistance, in this study the efficacy of antimicrobial photodynamic therapy (aPDT) with a porphyrinic formulation (FORM) as photosensitizer (PS) to photoinactivate methicillin-resistant Staphylococcus aureus (MRSA) on skin was evaluated. Potassium iodide (KI) and iodopovidone (PVP-I) were also tested in combination with FORM as potentiator agents of FORM efficacy. The aPDT protocol was first developed in Phosphate Buffered Saline (PBS, in vitro). Porcine skin was artificially contaminated with MRSA (ex vivo) and treated with FORM, FORM + KI or FORM + PVP-I under white light. The in vitro results showed that FORM was effective to inactivate MRSA. A substantial reduction in the irradiation time, when compared to FORM alone, was observed for FORM + KI and FORM + PVP-I combinations. On skin, reductions in MRSA survival of 3.1 Log10 colony forming units (CFU) mL-1 were observed with FORM at 50 µM. Although the combined action of FORM + KI and FORM + PVP-I potentiated the aPDT efficacy in vitro, this was not observed ex vivo. Overall, the results showed that aPDT using FORM, even without coadjutants, is a promising approach for MRSA inactivation on skin.

O conhecimento do enfermeiro sobre a prevenção do câncer de colo de útero na atenção básica / The nurse's knowledge nurse cervical cancer prevention in primary care

Objetiva-se identifi car o conhecimento do enfermeiro da Atenção Básica quanto à prevenção do câncer de colo de útero, descrever a percepção do enfermeiro quanto à prevenção deste câncer, e identifi car as atividades de prevenção realizadas pela Atenção Básica de Saúde.Constitui-se uma pesquisa de natureza exploratória com abordagem qualitativa, com 15 enfermeiras atuantes nas unidades de Atenção Primária da cidade de Valença, Rio de Janeiro, durante outubro de 2014, com entrevistas estruturadas com os profi ssionais. Foram discutidas cinco categorias sobre prevenção, educação em saúde, coleta do exame citopatológico, vacina contra HPV e ações do planejamento da prevenção do câncer de colo de útero. Conclui-se que as enfermeiras das unidades de atenção primária possuem certo conhecimento sobre as medidas de prevenção preconizadas pelo Ministério da Saúde, e algumas destas são realizadas nas unidades, porém com determinadas fragilidades do sistema

The aim is to identify nurse's knowledge of basic care regarding the prevention of cervical cancer, to describe the nurses' perception regarding the prevention of this cancer, and to identify the prevention activities performed by Primary Health Care. An exploratory research with a qualitative approach, with 15 working nurses in the Primary Care Unit of the Valença city, Rio de Janeiro, duringoctober 2014, with structured interviews with the professionals. Five categories on prevention, health education, cytopathological examination, HPV vaccine, and cervical cancer prevention planning actions were discussed. It concludes that nurses in the primary care units have some knowledge about the preventive measures recommended by the Ministry of Health, and some of these are carried out in the units, but with certain weaknesses of the system

Avaliação da técnica de aspiração de paciente em ventilação mecânica realizada pela enfermagem / Evaluation of aspiration technique on the patient with mechanical ventilation performed by nursing / Evaluación de la técnica de aspiración de paciente en ventilación mecánica realizada por la enfermería

Objetivo: identificar o conhecimento dos profissionais de enfermagem sobre a técnica de aspiração depacientes em Ventilação Mecânica (VM) por sistema aberto e discutir a técnica da aspiração endotraqueal.Método: estudo observacional, descritivo, com dados prospectivos e abordagem quantitativa, realizado noHospital Escola Luiz Gioseffi Jannuzzi, com 15 profissionais de enfermagem. Para a coleta de dados, optou-sepela técnica de observação estruturada não participante e um diário de campo. Resultados: foramobservados 50 procedimentos de aspiração, sendo 46% (n= 23) no período diurno e 54% (n=27) no noturno.Todos os procedimentos foram realizados pelos técnicos de enfermagem. Os enfermeiros ficavam apenas naorganização, supervisão e controle do Septor. Conclusão: é premente a elaboração de uma estratégia deeducação continuada, bem como sua aderência pelos profissionais de enfermagem, para nortear sua atuaçãode acordo com os protocolos que regem as práticas de aspiração endotraqueal, contribuindo para menoresíndices de desenvolvimento da Pneumonia Associada à Ventilação Mecânica (PAVM).(AU)

Objective: to identify the knowledge of nursing professionals abOct the technique of aspiration with patients in Mechanical Ventilation (MV) by an open system and to discuss the technique of endotracheal aspiration. Method: this is an observational, descriptive study with prospective data and a quantitative approach, performed at Luiz Gioseffi Jannuzzi School Hospital, with 15 nursing professionals. For the data collection, it opted for the technique of non-participant structured observation and a field diary. Results: 50 aspiration procedures were observed, of which 46% (n=23) in the daytime period and 54% (n=27) at night. All procedures were performed by the nursing technicians. The nurses were only in the organization, supervision, and control of the sector. Conclusion: it is imperative to elaborate a strategy of continuing education, as well as its adherence by the nursing professionals, to guide their performance according to the protocols that govern the practices of endotracheal aspiration, contributing to lower rates of development of Pneumonia Associated to Mechanics Ventilation (PAVM).(AU)

Objetivo: identificar el conocimiento de los profesionales de enfermería sobre la técnica de aspiración de pacientes en Ventilación Mecánica (VM) por sistema abierto y discutir la técnica de la aspiración endotraqueal. Método: estudio observacional, descriptivo, con datos prospectivos y enfoque cuantitativo, realizado en el Hospital Escuela Luiz Gioseffi Jannuzzi, con 15 profesionales de enfermería. Para la recolección de datos, se optó por la técnica de observación estructurada no participante y un diario de campo. Resultados: fueron observados 50 procedimientos de aspiración, siendo 46% (n=23) en el período diurno y 54% (n=27) en el nocturno. Todos los procedimientos fueron realizados por los técnicos de enfermería. Los enfermeros solamente estaban en la organización, supervisión y control del sector. Conclusión: es premente la elaboración de una estratégia de educación continuada, así como su adherencia por los profesionales de enfermería, para guiar su actuación de acuerdo con los protocolos que dirigen las prácticas de aspiración endotraqueal, contribuyendo para menores índices de desarrollo de la Pneumonia Asociada a la Ventilación Mecánica (PAVM).(AU)

Hemoterapia: um desafio no cotidiano da equipe de enfermagem / Hemotherapy: a challenge in the daily team of the nursing team / Hemoterapia: un desafío en el cotidiano del equipo de enfermería

Objetivo: identificar o conhecimento de uma equipe de enfermagem sobre o processo transfusional. Método:estudo descritivo, exploratório e transversal, de abordagem qualiquantitativa, realizado no Hospital EscolaLuiz Gioseffi Jannuzzi, com 57 profissionais da equipe de enfermagem. Os dados foram coletados a partir deum questionário semiestruturado e, posteriormente, analisados de forma descritiva. Resultados: mostram umconhecimento pouco significativo por parte da equipe de enfermagem sobre os cuidados pré e diante de umareação transfusional. Conclusão: destaca-se a necessidade desses profissionais terem educação permanente arespeito do tema, além de treinamento em serviço, para uma conduta mais adequada mediante qualquerintercorrência que possa acontecer, visando a um melhor atendimento e sem riscos maiores para o paciente.(AU)

Objective: to identify the knowledge of a nursing team about the transfusion process. Method: this is a descriptive, exploratory, and transversal study, with a qualitative approach, performed at the Luiz Gioseffi Jannuzzi School Hospital, with 57 professionals from the nursing team. The data were collected from a semistructured questionnaire and, subsequently, analyzed in a descriptive way. Results: a little knowledge by the nursing team is shown the care before and in the transfusion reaction. Conclusion: the need for these professionals to have permanent education on the subject, in addition to in-service training, for an adequate conduct through any intercurrence that may happen, aiming at a better care and without greater risks for the patient.(AU)

Objetivo: identificar el conocimiento de un equipo de enfermería sobre el proceso transfusional. Método: estudio descriptivo, exploratório y transversal, de enfoque cualitativo y cuantitativo, realizado en el Hospital Escuela Luiz Gioseffi Jannuzzi, con 57 profesionales del equipo de enfermería. Los datos fueron recogidos a partir de un cuestionario semi-estructurado y, posteriormente analizados de forma descriptiva. Resultados: muestran un conocimiento poco significativo por parte del equipo de enfermería sobre los cuidados pre y frente una reacción transfusional. Conclusión: se destaca la necesidad de esos profesionales tener educación permanente al respecto del tema, además de entrenamiento en servicio, para una conducta más adecuada mediante cualquer intercurrencia que pueda acontecer, visando a un mejor atendimiento y sin riesgos mayores para el paciente.(AU)

Desmame ventilatório no pós-operatório imediato de cirurgia cardíaca: implantação de um protocolo por enfermeiros / Ventilation waning on the cardiac surgery immediate postoperative: a protocol implemented by the nurse

O desmame de pacientes sob ventilação mecânica é uma das etapas críticas da assistência ventilatória em Terapia Intensiva. Existem vários critérios para a retirada de pacientes da prótese respiratória. O objetivo deste estudo foi comparar o tempo de desmame ventilatório entre dois métodos distintos - ventilação mandatória intermitente sincronizada (SIMV) e tubo T - e avaliar a implantação de protocolos de desmame ventilatório no pós-operatório imediato de cirurgia cardíaca. Trata-se de um ensaio clínico pragmático, quantitativo, prospectivo, comparativo, randomizado e de grupo controle, realizado no Centro de TerapiaIntensiva Cardíaca (CTIC) do Hospital Universitário Pedro Ernesto (HUPE). No grupo controle foi empregada como modalidade de desmame a SIMV, e no grupo experimental foi utilizado o tubo-T. Foram considerados dois desfechos como critérios de avaliação: extubação do paciente (sucesso) ou retorno àprótese ventilatória após três tentativas de desmame em cada protocolo (insucesso). A maioria dos pacientesfoi extubada no período de desmame ventilatório em até duas horas. Ressalta-se, entretanto, que 72% dos pacientes do grupo experimental apresentaram menor tempo de desmame (menor que uma hora) em comparação com o grupo controle, que teve apenas 8% dos pacientes desmamados neste mesmo período de tempo. A implantação de condutas padronizadas para o desmame da ventilação mecânica, rotinas parasedação e analgesia, assim como protocolos guiados por profissionais de enfermagem, são medidas efetivaspara abreviar o tempo de ventilação mecânica.

Condutas de enfermagem no desmame ventilatório: uma contribuição para o cuidado de enfermagem no pós-operatório imediato de cirurgia cardíaca

Este estudo, realizado no Centro de Tratamento Intensivo Cardíaco (CTIC) do Hospital Universitário Pedro Ernesto (HUPE), teve como objeto o procedimento do desmame ventilatório realizado por enfermeiras no pós-operatório imediato de cirurgia cardíaca. O objetivo que orienta a pesquisa é descrever e analisar, o atendimento ao cliente do CTIC em processo de desmame ventilatório. A fundam entação teórica vincula-se à literatura pertinente ao cuidado de enfermagem em Unidade de Terapia Intensiva. A metodologia se estruturou no estudo de caso, com abordagem qualitativa, utilizando para a coleta de dados a entrevista semi-estruturada. A análise dos dados deu origem a duas categorias denominadas: Saber/Fazer: o cuidado durante o desmame ventilatório; e Condutas técnicas no processo de cuidar. Os resultados apontam para as condutas de enfermagem baseadas em um conhecimento preexistent e, adquirido ao longo de um a prática e realizado com competência e habilidade, necessitando-se de um instrumento (protocolo) que subsidie legalmente a enfermeira para prestar um a assistência autônoma e embasada em conhecimento científico.