NAIP/NLRC4 inflammasome participates in macrophage responses to Trypanosoma cruzi by a mechanism that relies on cathepsin-dependent caspase-1 cleavage.

Inflammasomes are large protein complexes that, once activated, initiate inflammatory responses by activating the caspase-1 protease. They play pivotal roles in host defense against pathogens. The well-established role of NAIP/NLRC4 inflammasome in bacterial infections involves NAIP proteins functioning as sensors for their ligands. However, recent reports have indicated the involvement of NLRC4 in non-bacterial infections and sterile inflammation, even though the role of NAIP proteins and the exact molecular mechanisms underlying inflammasome activation in these contexts remain to be elucidated. In this study, we investigated the activation of the NAIP/NLRC4 inflammasome in response to Trypanosoma cruzi, the protozoan parasite responsible for causing Chagas disease. This parasite has been previously demonstrated to activate NLRP3 inflammasomes. Here we found that NAIP and NLRC4 proteins are also required for IL-1ß and Nitric Oxide (NO) release in response to T. cruzi infection, with their absence rendering macrophages permissive to parasite replication. Moreover, Nlrc4 -/- and Nlrp3 -/- macrophages presented similar impaired responses to T. cruzi, underscoring the non-redundant roles played by these inflammasomes during infection. Notably, it was the live trypomastigotes rather than soluble antigens or extracellular vesicles (EVs) secreted by them, that activated inflammasomes in a cathepsins-dependent manner. The inhibition of cathepsins effectively abrogated caspase-1 cleavage, IL-1ß and NO release, mirroring the phenotype observed in Nlrc4 -/-/Nlrp3 -/- double knockout macrophages. Collectively, our findings shed light on the pivotal role of the NAIP/NLRC4 inflammasome in macrophage responses to T. cruzi infection, providing new insights into its broader functions that extend beyond bacterial infections.

Review: Trends in Processing Prion-Contaminated Surgical Instruments.

This review sought to provide an overview of proposed methods and protocols for processing surgical instruments contaminated with prions. A search of PubMed was conducted to identify studies published between January 1, 2012, and January 2, 2019, with no language restrictions and using varying combinations of the following terms: prions (Medical Subject Heading [MeSH]) OR decontamination (MeSH) OR cleaning OR disinfection OR sterilization. Articles were excluded if they did not involve medical device surfaces or describe the processing protocol. At least two reviewers independently selected articles, extracted data, and assessed data. A total of 627 articles published in peer-reviewed journals were identified. Of the 55 articles assessed for full-text eligibility, eight met the inclusion criteria. Only a few studies investigated protocols and methods for processing prion-contaminated medical devices; therefore, determining the best way to sterilize device surfaces and preserve the integrity of surgical instruments remains challenging. Moreover, the perspective of sterile processing department staff continues to be overlooked when designing studies.

Steam Sterilization Chemical Indicators Are Not Adequate for Monitoring Real Steam Sterilization Cycles.

Chemical indicators are commonly used in hospitals to monitor steam sterilization conditions, indicating that medical devices are safe to be used. The results are stored for future evidence in the event of an infection incident root cause analysis. This type of indicator is also becoming an option for cycle monitoring in pharmaceutical steam sterilizers, improving cycle control. They are constructed and tested according to published standards, but contradictory results between chemical indicators and cycle printouts have a critical impact on process control. We found that Type 6 chemical indicators used in steam sterilizer cycles did not perform according to their intended use, showing an "approved" result in a "failed" cycle (a false positive). This study demonstrated that Type 6 chemical indicator specifications are not adequate for monitoring steam sterilizers. A change in standards is therefore needed.

False positive results of Bowie and Dick type test used for hospital steam sterilizer with slower come-up ramps: A case study.

OBJECTIVE: To determine if the standardized B&D type test for hospital steam sterilizer is correctly indicating cycle failures in slower come-up ramps cycles. METHODS: Two commercially available B&D type test were challenged in a quality control sterilizer. A common failure was simulated in triplicate cycles, using a standardized cycle configuration, and then compared to triplicate cycles of a common cycle configuration. Tests procedures were conducted according to B&D manufacturer test standard and results were compared to standardized endpoint specifications. RESULTS: We found that B&D type tests are only capable of detecting the presence of non-condensable gases if the sterilization equipment is adjusted to meet all the cycle requirements of the test. False positive results were obtained with come-up ramp time of 3 min. Correct results were only obtained with come-up ramp of 1.7-1.9 min. CONCLUSIONS: Until the ISO 17665 and AAMI ST-79 standards are revised, equipment qualification experts should observe come-up time duration criterion for B&D type test cycles according to ISO 11140-4. Sterile Processing Department professionals must add the come-up ramp criterion to cycle evaluation before clearing the equipment for routine use. This will allow B&D correct performance, reducing the infection risk from unsterilized medical device.

Critérios para avaliação de novas tecnologias para esterilização / Criteria for evaluation of new sterilization technologies / Criterios para evaluación de nuevas tecnologías para esterilización

Objetivo: Discorrer sobre critérios e métodos que devem nortear a avaliação de novas tecnologias para esterilização. Método: Estudo de revisão narrativa mediado pela busca e interpretação da legislação nacional relacionada aos processos de esterilização, normas técnicas e documentos que embasam os aspectos construtivos, funcionais e da segurança das tecnologias para esterilização. Resultados: Foram discutidos tópicos relevantes à segurança dos processos de esterilização, como a prova de esterilidade, simulação do ciclo nas piores condições de carga, compatibilidade com sistemas de barreira estéril, testes de biocompatibilidade, controle de processos e avaliação econômica. Conclusão: Os resultados beneficiarão diretamente três segmentos principais; os fabricantes, no desenvolvimento e na solicitação de registro de novas tecnologias para esterilização; a Agência Nacional de Vigilância Sanitária, na adoção oficial de uma lista de exigências junto ao fabricante no momento de petição de registro de novos equipamentos; e os serviços de saúde, no consumo de novas tecnologias para esterilização.

Objective: To discuss criteria and methods that should ideally guide the evaluation of new sterilizing technologies. Method: Narrative review by means of search and interpretation of national legislation related to sterilization processes, as well as technical standards and documents that support constructive, functional, and safety aspects of sterilization technologies. Results: Topics relevant to the safety of sterilization processes, such as sterility testing, simulation of cycle under the worst load conditions, compatibility with sterile barrier systems, biocompatibility tests, process control, and economic evaluation, were discussed. Conclusion: The results will directly benefit three major segments: manufacturers while developing and requesting registration of new technologies; The National Sanitary Surveillance Agency when officially adopting a list of requirements with the manufacturer at the time of new equipment registration request; And health services, which will consume these new sterilization technologies.

Objetivo: Discurrir sobre criterios y métodos que deben guiar la evaluación de nuevas tecnologías para esterilización. Método: Estudio de revisión narrativa mediado por la búsqueda e interpretación de la legislación nacional relacionada a los procesos de esterilización, normas técnicas y documentos que basan los aspectos constructivos, funcionales y de la seguridad de las tecnologías para esterilización. Resultados: Fueron discutidos tópicos relevantes a la seguridad de los procesos de esterilización, como la prueba de esterilidad, simulación del ciclo en las peores condiciones de carga, compatibilidad con sistemas de barrera estéril, pruebas de bio-compatibilidad, control de procesos y evaluación económica. Conclusión: Los resultados beneficiarán directamente tres segmentos principales; los fabricantes, en el desarrollo y en la solicitud de registro de nuevas tecnologías para esterilización; la Agencia Nacional de Vigilancia Sanitaria, en la adopción oficial de una lista de exigencias junto al fabricante al momento de petición de registro de nuevos equipos; y los servicios de salud, en el consumo de nuevas tecnologías para esterilización.

Esterilização pelo vapor: aspectos fundamentais e recursos técnicos para redução do consumo de água / Steam sterilization: fundamental aspects and technical resources to reduce water consumption / Esterilización por vapor: fundamentos y recursos técnicos para reduccion del consumo de água

Objetivo: Discorrer sobre os aspectos fundamentais da esterilização pelo vapor e os recursos técnicos que podem ser utilizados para a redução do consumo de água no processo de esterilização. Método: Revisão da literatura e de normas técnicas nacionais e internacionais relacionadas aos aspectos construtivos, funcionais e de operação de equipamentos de esterilização pelo vapor saturado sob pressão. Resultados: A redução do consumo de água pode ser obtida pela aquisição preferencial de equipamentos com bombas water free, desligamento da fonte geradora de vapor quando o equipamento não estiver em uso, utilização de equipamentos com desgasificadores incorporados, montagem da carga de forma a facilitar a penetração do vapor e a diminuição do tempo de secagem, readequação da profundidade do vácuo para reduzir o tempo de uso da bomba de vácuo e manutenção preventiva dos purgadores da linha de vapor. Adicionalmente, a utilização de sistemas de pré-tratamento pode reduzir o rejeito de sistemas de tratamento de água por osmose reversa para geração de vapor. Conclusão: O conhecimento dos aspectos fundamentais da esterilização pelo vapor saturado sob pressão permite a implementação de medidas para a redução do consumo de água no processo de esterilização.

Objective: To discuss the fundamentals of steam sterilization and the technical resources that can be used for a reduction of water consumption in the sterilization process. Method: Review of literature and technical and international standards related to the principles of construction, operation, and use of sterilization equipment by saturated steam under pressure. Results: The reduction in water consumption can be obtained by preferential acquisition of equipment with free water pumps, shutdown of the source of steam-generating power when the equipment is not in use, use of equipment with built-in degassers, assembly of the load in a way to facilitate vapor penetration and reduction of drying time, re-adjustment of the depth of the vacuum to the low time of use of the vacuum pump, and the preventive maintenance of the steam line traps. In addition, a pretreatment system can reduce the waste from reverse osmosis water treatment systems for steam generation. Conclusion: Knowledge of the fundamentals of sterilization by saturated steam under pressure allows an implementation of measures for a reduction of water consumption in the sterilization process.

Objetivo: Discurrir sobre los aspectos fundamentales de la esterilización por el vapor y los recursos técnicos que pueden ser utilizados para la reducción del consumo de agua en el proceso de esterilización. Método: Revisión de la literatura y de normas técnicas nacionales e internacionales relacionadas a los aspectos constructivos, funcionales y de operación de equipos de esterilización por el vapor saturado bajo presión. Resultados: La reducción del consumo de agua puede ser obtenida por la adquisición preferencial de equipos con bombas water free, desconexión de la fuente generadora de vapor cuando el equipo no estuviera en uso, utilización de equipos con desgasificadores incorporados, montaje de la carga de forma de facilitar la penetración del vapor y la disminución del tiempo de secado, readecuación de la profundidad del vacío para reducir el tiempo de uso de la bomba de vacío y manutención preventiva de los purgadores de la línea de vapor. Adicionalmente, la utilización de sistemas de pre-tratamiento pode reducir el rechazo de sistemas de tratamiento de agua por osmosis reversa para generación de vapor. Conclusión: El conocimiento de los aspectos fundamentales de la esterilización por el vapor saturado bajo presión permite la implementación de medidas para la reducción del consumo de agua en el proceso de esterilización.

Avaliação da segurança do processamento de fresas intramedulares flexíveis para cirurgia ortopédica / Safety assessment of reprocessing of flexible intramedullary bone reamers for orthopedic surgery / Evaluación de la seguridad del procesamiento de fresas intramedulares flexibles para cirugía ortopédica

Objetivos: Avaliar a eficácia de um procedimento operacional padrão para limpeza de fresas intramedulares flexíveis, bem como o alcance da esterilidade, e evi-denciar a citotoxicidade da sujidade residual de uma fresa flexível utilizada na prática assistencial. Métodos: Fresas intramedulares flexíveis foram pesadas antes do processamento, após contaminação desafio e depois da limpeza. Elas foram contaminadas com Soil Test™, suspensão de Geobacillus stearothermophilus, na concentração de 106 UFC/mL, e farinha de osso bovino. Após processamento, as amostras foram incubadas em meio de cultura por 21 dias. A sujidade residual de uma fresa utilizada na prática foi submetida ao teste de citotoxicidade in vitro. Resultados: As amostras, embora esterilizadas, apontaram acúmulo de sujidade e o processamento foi ineficaz. A sujidade residual apresentou efeito citotóxico. Conclusão: Recomenda-se que o design flexível das fresas seja descontinuado pela insegurança no processamento.

Objectives: To assess the efficacy of a standard operational procedure to clean flexible intramedullary bone reamers, as well as the sterilization level, and to show the cytotoxicity of the residual dirtiness of a flexible reamer used in care practice. Methods: Flexible intramedullary bone reamers were weighed before processing, after challenge contamination and after cleaning. They were contaminated with the Soil Test™, Geobacillus stearothermo-philus suspension, in the concentration of 106 cfu/ml, and bovine bone flour. After processing, the samples were inoculated into a culture medium and incubated for 21 days. Residual dirtiness of a flexible intramedullary bone reamer used in practice was submitted to in vitro cytotoxicity test. Results: Despite being sterilized, the samples indicate to accumulated dirtiness and the processing was inefficient. Residual dirtiness presented a cytotoxic effect. Conclusion: It is recommended that the flexible design of reamers is discontinued by the lack of safety of reprocessing.

Objetivos: Evaluar la eficacia de un procedimiento operacional estándar para limpieza de fresas intramedulares flexibles, así como el alcance de la esterilidad, y evidenciar la citotoxicidad de la suciedad residual de una fresa flexible utilizada en la práctica asistencial. Métodos: Fresas intramedulares flexibles fueron pesadas antes del procesamiento, tras contaminación desafío y después de la limpieza. Fueron contaminadas con Soil Test™, suspensión de Geobacillus stearothermophilus, en la concentración de 106 UFC/mL, y harina de hueso bovino. Tras el procesamiento, las muestras fueron incuba-das en medio de cultura por 21 días. La suciedad residual de una fresa utilizada en la práctica fue sometida al test de citotoxicidad in vitro. Resultados: Las muestras, aunque esterilizadas, apuntaron acumulación de suciedad y el procesamiento fue ineficaz. La suciedad residual presentó efecto citotóxico. Conclusión: Se recomienda que el design flexible de las fresas sea descontinuado por la inseguridad en el procesamiento.

Fundamentos para uso seguro de lavadoras termodesinfetadoras com ênfase na liberação para uso após intervenção técnica / Bases for safe use of thermal washer disinfectors emphasizing the release for use after technical intervention / Bases para el uso seguro de las lavadoras termodesinfectantes colocando énfasis en la liberación para el uso después de la intervención técnica

No cotidiano dos Centros de Material e Esterilização (CMEs), observa-se que as lavadoras termodesinfetadoras submetidas a intervenções técnicas para correção de falhas são liberadas para uso sem evidência de operação conforme os parâmetros requeridos para realizar limpeza e termodesinfecção eficientes. Considerando a importância da prevenção das infecções relacionadas à assistência à saúde, este estudo apresenta como inovação a sistematização dos ensaios requeridos para a liberação de termolavadoras após intervenções técnicas, assim como as informações necessárias para a conservação desses equipamentos em condições ótimas de operação. A liberação segura do equipamento deve incluir a avaliação dos parâmetros de temperatura e tempo em comparação aos dados obtidos na qualificação, a conferência do volume de detergente admitido durante a limpeza, a avaliação da eficácia da limpeza com monitores comercialmente disponíveis, o estabelecimento de um controle de mudanças e um protocolo para direcionar a requalificação, atendendo à legislação nacional e Às recomendações internacionais.

It is seen, in the daily routine of Material and Sterilization Centers (CMEs, acronym in Portuguese), that thermal washer disinfectors submitted to technical interventions for correcting failures are released for use without evidence of operation following the required parameters for the effective performance of cleaning and thermal disinfection. Given the importance of preventing healthcare-related infections, this study presents innovated systematization of assays required for the release of thermal washers after technical interventions, as well as the necessary information to preserve such equipment in optimal operation conditions. Safe release of the equipment should include the evaluation of temperature and time parameters compared to data obtained during qualification, the conference of admitted detergent volume during cleaning, the evaluation of cleaning effectiveness with commercially available monitors, the establishment of a change control, and a protocol for directing the requalification, following the Brazilian regulations and international recommendations.

En lo cotidiano de los Centros de Material y Esterilización (CMEs), se observa que las lavadoras termodesinfectantes sometidas a intervenciones técnicas para corrección de fallas son liberadas para uso sin evidencia de operación según los parámetros requeridos para realizar limpieza y termodesinfección eficientes. Considerando la importancia de la prevención de las infecciones relacionadas a la asistencia a la salud, este estudio presenta como innovación la sistematización de los ensayos requeridos para la liberación de termolavadoras tras intervenciones técnicas, así como las informaciones necesarias para la conservación de esos equipos en condiciones excelentes de operación. La liberación segura del equipo debe incluir la evaluación de los parámetros de temperatura y tiempo en comparación a los datos obtenidos en la calificación, la conferencia del volumen de detergente admitido durante la limpieza, la evaluación de la eficacia de la limpieza con monitores comercialmente disponibles, el establecimiento de un control de cambios y un protocolo para direccionar la recalificación, atendiendo la legislación nacional y las recomendaciones internacionales.

Effectiveness of disinfection with alcohol 70% (w/v) of contaminated surfaces not previously cleaned.

OBJECTIVE: To evaluate the disinfectant effectiveness of alcohol 70% (w/v) using friction, without previous cleaning, on work surfaces, as a concurrent disinfecting procedure in Health Services. METHOD: An experimental, randomized and single-blinded laboratory study was undertaken. The samples were enamelled surfaces, intentionally contaminated with Serratia marcescens microorganisms ATCC 14756 106 CFU/mL with 10% of human saliva added, and were submitted to the procedure of disinfection WITHOUT previous cleaning. The results were compared to disinfection preceded by cleaning. RESULTS: There was a reduction of six logarithms of the initial microbial population, equal in the groups WITH and WITHOUT previous cleaning (p=0.440) and a residual microbial load ≤ 102 CFU. CONCLUSION: The research demonstrated the acceptability of the practice evaluated, bringing an important response to the area of health, in particular to Nursing, which most undertakes procedures of concurrent cleaning /disinfecting of these work surfaces.

[Cytotoxicity of PVC tubes sterilized in ethylene oxide after gamma radiation exposure]. / Citotoxicidade de tubos de PVC esterilizados em óxido de etileno após exposição à radiação gama.

Do materials sterilized using gamma rays become toxic when re-sterilized in ethylene oxide? This question guided the objective of this study, which was to investigate the potential cytotoxic effect of PVC sterilized by gamma radiation and re-sterilized with EO by the agar diffusion method in cell cultures. Nine PVC tubes were subjected to gamma radiation sterilization and were re-sterilized in EO. The tubes were divided into a total of 81 units of analysis that were tested so as to represent the internal and external surfaces and mass of each tube. It was concluded that the PVC materials sterilized in gamma radiation and re-sterilized in EO are not cytotoxic.

[Microorganisms of the Coccidia subclass: resistance and implications for the aseptic processing of healthcare products]. / Micro-organismos da subclasse Coccidia: resistência e implicações para o processamento de materiais de assistência à saúde.

This theoretical study proposes a reflection on the intrinsic resistance of the subclass Coccidia, particularly the genus Cryptosporidium, considered to be potential pathogens for immunocompromised patients, and the implications for nursing practice. Currently, the international and national guidelines support the chemical disinfection of digestive system endoscopes after their cleansing as a safe and effective procedure. However, studies show that microorganisms of the subclass Coccidia, namely Cryptosporidium, responsible for enteric infection, are more resistant than mycobacteria and are not inactivated by high-level disinfectants, except for hydrogen peroxide 6% and 7.5%, which are not currently available in Brazil. We conclude that the legislation should include this agent among test microorganisms for approving high-level disinfectants. Health authorities should make efforts to ensure that healthcare institutions have access to effective disinfectants against Cryptosporidium.

[Compatibilities and incompatibilities between gamma rays and ethylene oxide as consecutive sterilization methods]. / Compatibilidades e incompatibilidades entre radiação gama e óxido de etileno como métodos sucessivos de esteriliza.

The doubt regarding the re-sterilization of articles made of polyvinyl chloride (PVC) sterilized with gamma radiation (GR) and subsequently with ethylene oxide (EO) persists to date. Through a systematic literature review, this article analyzed studies that demonstrated compatibilities and incompatibilities between the sterilization processes with GR and EO, when used as consecutive sterilization methods. Seven studies were analyzed. It was verified that there is a multifactor influence regarding the safety of the procedure and that the chromatography analytical method employed by most studies yielded controversial results. This fact indicates the need for further studies on the issue, using more sensitive analytical methods than gas chromatography, such as the biological reactivity test in cell cultures, in an attempt to clarify the chronic doubt regarding the adequacy or inadequacy of sterilizing previously gamma-irradiated materials with EtO.

Analysis of the microbial load in instruments used in orthopedic surgeries.

BACKGROUND: Because of advances in technology, the number of orthopedic surgeries, mainly hip and knee replacement surgeries, has increased, with a total of 150,000 prosthetic surgeries estimated per year in the United States and 400,000 worldwide. METHODS: We used an exploratory cross-sectional study, with a quantitative approach to determine the microbial load in instruments used in orthopedic surgeries, quantifying and identifying the microbial growth genus and species, according to the surgical potential of contamination that characterizes the challenge faced by the Material and Sterilization Center at the Institute of Orthopedics and Traumatology of Hospital das Clinicas of the School of Medicine of the University of Sao Paulo, Brazil.The orthopedic surgical instruments were immersed, after their use, in sterilized distilled water, sonicated in an ultrasonic washer, and posteriorly agitated. Subsequently, the wash was filtrated through a 0.45-mum membrane and incubated in aerobic and anaerobic mediums and in medium for fungi and yeasts. RESULTS: In clean surgeries, 47% of the instruments were contaminated; in contaminated surgeries, 70%; and, in infected surgeries, 80%. Regardless of the contamination potential of the surgeries, the highest quantitative incidence of microorganism recovery was located in the 1 to 100 colony-forming unit range, and 13 samples presented a microbial growth potential >300 colony-forming units. Regardless of the contamination potential of the surgeries, there was a convergence in the incidence of negative-coagulase Staphylococcus growth (28%, clean surgeries; 32%, contaminated surgeries; and 29%, infected surgeries) and Staphylococcus aureus (28%, contaminated surgeries; and 43%, infected surgeries). CONCLUSION: Most of the microorganisms recovered from the analyzed instruments (78%) were vegetative bacteria that presented their death curve at around 80 degrees C, characterizing a low challenge considering the processes of cleaning and sterilization currently employed by the Material and Sterilization Center. Fewer microorganisms were recovered from instruments used in clean surgeries in comparison with those used in contaminated and infected surgeries.