Flávia Morais Gomes Pinto

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.

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

OBJETIVO: avaliar a eficacia desinfetante do alcool 70% (p/v) sob friccao, sem limpeza previa, nas superficies de trabalho, como procedimento de desinfeccao concorrente em Servicos de Saude. METODO: foi desenvolvido estudo experimental laboratorial, randomizado e unicegado. As amostras foram constituidas de superficies esmaltadas, intencionalmente contaminadas com microrganismos Serratia marcescens ATCC 14756 106 Unidades Formadoras de Colonias/mL, acrescidos de 10% de saliva humana, e submetidas ao procedimento de desinfeccao sem limpeza previa. Os resultados foram comparados a desinfeccao precedida da limpeza. RESULTADOS: houve reducao de seis logaritmos da populacao microbiana inicial, igualmente nos grupos com e sem limpeza previa (p=0,440) e uma carga microbiana residual ≤ 102 Unidades Formadoras de Colonias. CONCLUSAO: a pesquisa demonstrou a aceitabilidade da pratica avaliada, trazendo importante resposta para a area da saude, especialmente a enfermagem, que mais executa os procedimentos de limpeza/desinfeccao concorrentes dessas superficies de trabalho.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.

Evaluation of the sterilization efficacy of domestic electric drills used in orthopaedic surgeries

It is estimated that electric drills (ED) have been used in orthopaedic surgeries for bone drilling for more than 50 years in Brazilian hospitals. It is an electric, thermosensitive equipment, not indicated for surgical use, which has not been previously evaluated regarding the sterilization efficacy, being suspect of infection risk. This study evaluated the efficacy of sterilization by ethylene oxide (EtO) of new drills that were intentionally contaminated with Bacillus atrophaeus spores. An experimental, laboratory, randomized applied research was developed, where 16 electric drills were analyzed, in addition to positive and negative controls. All the previously cleaned and sterilized equipment were submitted to contamination by spores. The experimental group was submitted to cleaning and sterilization by EtO and test of sterility by filtration through a 0.45 >m membrane. The membranes were cultivated and Gram and

The practice of disinfection of high-speed handpieces with 70% w/v alcohol: An evaluation.

HighlightsThe high speed handpiece (HSH) are potencial sources of microbial dissemination.The lack of previous cleaning compromise the bactericide action of alcohol.The cleaning and sterilization of the HSH is required by reducing the chance of cross‐infection in dentistry. &NA; A high‐speed handpiece is used in several dental procedures and the official recommendation for safe decontamination consists of rinsing with water, washing with detergent, mechanical friction, and sterilization; however, many professionals only apply 70% w/v alcohol without also cleaning the tool between patients. We performed an analysis of high‐speed handpieces reprocessed only with 70% w/v alcohol and found that the methods used in clinical practice are not safe.

Comparison of hand hygiene antimicrobial efficacy: Melaleuca alternifolia essential oil versus triclosan

OBJETIVOS: este estudio objetivo evaluar la eficacia de la higienizacion de las manos realizada con dos formulas diferentes de jabones: aceite esencial de Melaleuca alternifolia al 0,3% versus triclosan al 0,5%, y compararlas con dos higienizaciones de referencia: procedimiento de la metodologia oficial (soft soap) versus procedimiento de la version draft (soft soap + propan-2-ol). METODO: utilizando la metodologia europea EN 1499, fueron determinados factores de reduccion logaritmica del numero de unidades formadoras de colonia de Escherichia coli K12 antes y despues de la higiene de las manos de 15 sujetos voluntarios y comparados por el test de Wilcoxon de una sola cola. RESULTADOS: Tomando como referencia el soft soap, no hubo diferencia entre el desempeno del jabon con Melaleuca alternifolia al 0,3% o jabon conteniendo triclosan al 0,5%. El soft soap + propan-2-ol se demostro mas eficaz en relacion a los demas procedimientos de higienizacion de las manos. CONCLUSION: estudios que verifiquen la eficacia terapeutica de aceite esencial en la higienizacion de las manos pueden mejorar la adhesion a esa practica.OBJECTIVE this study aimed to evaluate the efficacy of hand hygiene performed with two different soap formulations: 0.3% Melaleuca alternifolia essential oil versus 0.5% triclosan, and to compare them with two reference hygiene procedures: the official methodology procedure (soft soap) versus the draft version of the procedure (soft soap + propan-2-ol). METHOD using the European EN 1499 method, logarithmic reduction factors were determined for the number of colony forming units of Escherichia coli K12 before and after hand hygiene of 15 volunteer subjects, and compared using the one-tailed Wilcoxon test. RESULTS referring to the soft soap, there was no difference between the performance of soap with 0.3% M. alternifolia and soap containing 0.5% triclosan. The soft soap + propan-2-ol proved to be more effective than the other hand hygiene procedures. CONCLUSION studies to verify the therapeutic efficacy of essential oil in hand hygiene can improve adherence to this practice.

Evaluation of microbial growth on single-use vitrectomy probes reprocessed in healthcare practice

O objetivo deste estudo foi avaliar o crescimento microbiano em sondas para vitrectomia de uso unico, reprocessadas na pratica assistencial. Foram investigadas nove sondas reusadas e reprocessadas por diferentes metodos. As sondas foram segmentadas, individualmente, em porcoes de 3,5 cm, totalizando em 979 unidades amostrais (extensoes, conectores e ponteiras) inoculadas em meio de cultura e incubadas a 37oC, por 14 dias. Os resultados mostraram crescimento microbiano em 57 (5,8%) unidades amostrais, das quais, 25 foram esterilizadas por Oxido de Etileno, 16 por Plasma de Peroxido de Hidrogenio e 16 por Vapor a Baixa Temperatura e Formaldeido. Foram identificadas 17 especies microbianas, sendo as mais prevalentes o Micrococcus spp., Staphylococcus coagulase negativa, Pseudomonas spp. e Bacillus subtilis. O reuso de sondas de uso unico para vitrectomia nao se mostrou seguro, portanto tal pratica nao e recomendada.The aim of this study was to evaluate the microbial growth on single-use vitrectomy probes reprocessed in healthcare practice. We investigated nine vitrectomy probes that had been reused and reprocessed using different methods. The samples were sectioned, individually, in portions of 3.5 cm, totaling 979 sampling units (extensions, connectors and vitrectomy cutters), which were inoculated in culture medium and incubated at 37º C for 14 days. The results showed microbial growth on 57 (5.8%) sample units, 25 of which had been sterilized using ethylene oxide, 16 by hydrogen peroxide plasma, and 16 by low-temperature steam and formaldehyde. Seventeen microbial species were identified. The most prevalent were: Micrococcus spp., coagulase-negative Staphylococcus, Pseudomonas spp., and Bacillus subtilis. The reuse of single-use vitrectomy probes was shown to be unsafe, therefore this practice is not recommended.

Eficácia da desinfecção com álcool 70% (p/v) de superfícies contaminadas sem limpeza prévia

OBJETIVO: avaliar a eficacia desinfetante do alcool 70% (p/v) sob friccao, sem limpeza previa, nas superficies de trabalho, como procedimento de desinfeccao concorrente em Servicos de Saude. METODO: foi desenvolvido estudo experimental laboratorial, randomizado e unicegado. As amostras foram constituidas de superficies esmaltadas, intencionalmente contaminadas com microrganismos Serratia marcescens ATCC 14756 106 Unidades Formadoras de Colonias/mL, acrescidos de 10% de saliva humana, e submetidas ao procedimento de desinfeccao sem limpeza previa. Os resultados foram comparados a desinfeccao precedida da limpeza. RESULTADOS: houve reducao de seis logaritmos da populacao microbiana inicial, igualmente nos grupos com e sem limpeza previa (p=0,440) e uma carga microbiana residual ≤ 102 Unidades Formadoras de Colonias. CONCLUSAO: a pesquisa demonstrou a aceitabilidade da pratica avaliada, trazendo importante resposta para a area da saude, especialmente a enfermagem, que mais executa os procedimentos de limpeza/desinfeccao concorrentes dessas superficies de trabalho.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.

Manual and Automated Cleaning Are Equally Effective for the Removal of Organic Contaminants From Laparoscopic Instruments

OBJECTIVE To compare the effectiveness of manual and automated methods for cleaning laparoscopic instruments. DESIGN Experimental laboratory study. METHODS We evaluated 4 methods of cleaning laparoscopic instruments: (1) manual-only cleaning and rinsing with potable tap water; (2) manual cleaning and rinsing with potable tap water, followed by ultrasonic cleaning without rinsing; (3) manual cleaning and rinsing with potable tap water followed by ultrasonic cleaning and rinsing with potable tap water; and (4) manual cleaning and rinsing with potable tap water, followed by ultrasonic cleaning and rinsing: first with potable tap water and then with sterile distilled water. Organic residues of protein, hemoglobin, and carbohydrates were evaluated using spectrophotometry. RESULTS The various cleaning methods tested did not result in statistically significant differences (P>.05) in the levels of investigated organic residues. CONCLUSIONS All cleaning and rinsing methods tested were found to be effective in reducing the levels of organic residues on laparoscopic instruments. Thus, there is no advantage gained by supplementing manual-only cleaning with automated ultrasonic cleaning, nor was there a difference between rinsing with potable tap versus sterile distilled water. Infect Control Hosp Epidemiol 2018;39:58-63.

Microbiological evaluation of the steam sterilization of assembled laparoscopic instruments

ABSTRACT Objective: assess the safety of steam sterilization of assembled laparoscopic instruments with challenge contamination. Method: a laboratory experimental study, using as test samples trocars and laparoscopic graspers. Geobacillus stearothermophillus ATCC-7953 was used, with a microbial population of 106UFC/Filter paper substrate, removed from the biological indicator. Three of them were introduced into each instrument at the time of assembly, and sterilized at pressurized saturated steam, 134oC for 5 minutes. After sterilization, the instrument was disassembled and each filter paper substrate was inoculated in soybean casein culture and incubated at 56oC for 21 days. In case of absence of growth, they were subjected to heat shock of 80oC, for 20 minutes and re-incubated for 72 hours. Sample size: 185 graspers and 185 trocars, with 95% power. We paired the experiments with comparative negative control groups (5 graspers and 5 trocars with challenge contamination, sterilized disassembled) and positive control (30 filter paper supports, unsterilized), subject to the same incubation procedures. Results: there was no microbial growth in experimental and negative control. The results of the positive control were satisfactory. Conclusion: this study provided strong scientific evidence to support the safety of steam sterilizing of the assembled laparoscopic instrument.Objetivo: avaliar a seguranca da esterilizacao a vapor, do instrumental laparoscopico montado com desafio da contaminacao. Metodo: estudo experimental laboratorial, cujo corpo de prova foram trocarte e pinca laparoscopica. Utilizou-se esporos Geobacillus stearothermophillus ATCC-7953, com populacao microbiana de 106UFC/suporte de papel filtro, removidos do indicador biologico. Tres deles foram introduzidos no interior de cada instrumento, no momento da montagem, sendo esterilizados a vapor saturado sob pressao, 134oC por 5 minutos. Depois da esterilizacao, o instrumental foi desmontado, e cada suporte de papel filtro foi inoculado em meio de cultura de caseina soja, incubado a 56oC por 21 dias. Nao havendo crescimento, foram submetidos a um choque termico de 80oC, por 20 minutos e reincubados por 72 horas. Tamanho da amostra, 185 pincas e 185 trocartes, com poder de 95%. Os experimentos foram acompanhados dos grupos controle negativo comparativo (5 pincas e 5 trocartes com contaminacao desafio, esterilizados desmontados) e positivo (30 suportes de papel filtro, nao esterilizados), submetidos aos mesmos procedimentos de incubacao. Resultados: nao houve nenhum crescimento microbiano nos grupos experimental e controle negativo. Os resultados do controle positivo foram satisfatorios. Conclusao: este estudo forneceu fortes evidencias cientificas para sustentar a seguranca da pratica de esterilizacao a vapor do instrumental laparoscopico montado.

Evaluación microbiológica de la esterilización a vapor de instrumental laparoscópico montado

ABSTRACT Objective: assess the safety of steam sterilization of assembled laparoscopic instruments with challenge contamination. Method: a laboratory experimental study, using as test samples trocars and laparoscopic graspers. Geobacillus stearothermophillus ATCC-7953 was used, with a microbial population of 106UFC/Filter paper substrate, removed from the biological indicator. Three of them were introduced into each instrument at the time of assembly, and sterilized at pressurized saturated steam, 134oC for 5 minutes. After sterilization, the instrument was disassembled and each filter paper substrate was inoculated in soybean casein culture and incubated at 56oC for 21 days. In case of absence of growth, they were subjected to heat shock of 80oC, for 20 minutes and re-incubated for 72 hours. Sample size: 185 graspers and 185 trocars, with 95% power. We paired the experiments with comparative negative control groups (5 graspers and 5 trocars with challenge contamination, sterilized disassembled) and positive control (30 filter paper supports, unsterilized), subject to the same incubation procedures. Results: there was no microbial growth in experimental and negative control. The results of the positive control were satisfactory. Conclusion: this study provided strong scientific evidence to support the safety of steam sterilizing of the assembled laparoscopic instrument.Objetivo: avaliar a seguranca da esterilizacao a vapor, do instrumental laparoscopico montado com desafio da contaminacao. Metodo: estudo experimental laboratorial, cujo corpo de prova foram trocarte e pinca laparoscopica. Utilizou-se esporos Geobacillus stearothermophillus ATCC-7953, com populacao microbiana de 106UFC/suporte de papel filtro, removidos do indicador biologico. Tres deles foram introduzidos no interior de cada instrumento, no momento da montagem, sendo esterilizados a vapor saturado sob pressao, 134oC por 5 minutos. Depois da esterilizacao, o instrumental foi desmontado, e cada suporte de papel filtro foi inoculado em meio de cultura de caseina soja, incubado a 56oC por 21 dias. Nao havendo crescimento, foram submetidos a um choque termico de 80oC, por 20 minutos e reincubados por 72 horas. Tamanho da amostra, 185 pincas e 185 trocartes, com poder de 95%. Os experimentos foram acompanhados dos grupos controle negativo comparativo (5 pincas e 5 trocartes com contaminacao desafio, esterilizados desmontados) e positivo (30 suportes de papel filtro, nao esterilizados), submetidos aos mesmos procedimentos de incubacao. Resultados: nao houve nenhum crescimento microbiano nos grupos experimental e controle negativo. Os resultados do controle positivo foram satisfatorios. Conclusao: este estudo forneceu fortes evidencias cientificas para sustentar a seguranca da pratica de esterilizacao a vapor do instrumental laparoscopico montado.