Efficacy of the photon-initiated photoacoustic streaming combined with different solutions on Enterococcus faecalis in the root canals.

This study aimed to evaluate the efficacy of different irrigation solutions used in photon-initiated photoacoustic streaming (PIPS) or conventional needle irrigation (CNI) for eradication of Enterococcus faecalis from artificial root canals. Altogether, 240 artificial root canal samples were included. The models were split and incubated for 2 days to allow formation of E. faecalis biofilm. The models were randomly divided into two groups (n = 120): CNI and laser-activated irrigation (LAI). Each group was divided into six subgroups according to different irrigation solutions: distilled water, 1% sodium hypochlorite (NaOCl), 2% NaOCl, 5.25% NaOCl, MTAD, and chlorhexidine, respectively. After irrigation, half of the samples (n = 10) were assessed immediately, and the other half of the samples (n = 10) were incubated for 6 hr. Bacterial suspensions were obtained from all samples before and after irrigation, and after incubation, and were quantified adenosine 5'-triphosphate (ATP) assay kit. The biofilms were examined using fluorescent microscopy and analyzed by Image Pro Plus software. Significant reduction of ATP, average fluorescence density after irrigation, and growth after incubation was obtained in LAI group than in CNI group (p < .05). LAI can improve bacteriostasis effect of 2% NaOCl (p < .05). PIPS improved the antibacterial effect of the 2% NaOCl used in root canal therapy.

Occupational exposure to disinfectants and asthma control in US nurses.

Disinfectant use has been associated with adverse respiratory effects among healthcare workers. However, the specific harmful agents have not been elucidated. We examined the association between occupational exposure to disinfectants and asthma control in the Nurses' Health Study II, a large cohort of female nurses.Nurses with asthma were invited in 2014 to complete two questionnaires on their current occupation and asthma (response rate 80%). Asthma control was defined by the Asthma Control Test (ACT). Exposure to major disinfectants was evaluated by a job-task-exposure matrix (JTEM).Analyses included 4102 nurses with asthma (mean age 58 years). Asthma control was poor (ACT score 16-19) in 12% of nurses and very poor (ACT score ≤15) in 6% of nurses. Use of disinfectants to clean medical instruments (19% exposed) was associated with poorly (OR 1.37; 95% CI 1.05-1.79) and very poorly (OR 1.88, 95% CI 1.38-2.56) controlled asthma (ptrend=0.004, after adjustment for potential confounders). Using JTEM estimates, exposure to formaldehyde, glutaraldehyde, hypochlorite bleach, hydrogen peroxide and enzymatic cleaners was associated with poor asthma control (all ptrend<0.05); exposure to quaternary ammonium compounds and alcohol was not.Use of several disinfectants was associated with poor asthma control. Our findings suggest targets for future efforts to prevent worsening of asthma control in healthcare workers.

Implementation of hospital-wide enhanced terminal cleaning of targeted patient rooms and its impact on endemic Clostridium difficile infection rates.

BACKGROUND: Implementation of a hospital-wide program of terminal cleaning of patient rooms revolving around hydrogen peroxide vapor (HPV) technology and evaluation of its impact on endemic nosocomial Clostridium difficile-associated diarrhea (CDAD) have not been previously reported. METHODS: This was a retrospective quasiexperimental study involving a 900-bed community hospital. During the preintervention period (January 2007-November 2008), rooms vacated by patients with CDAD or on contact precautions for other targeted pathogens underwent 1 or more rounds of cleaning with bleach. During the intervention period (January-December 2009), targeted newly evacuated rooms underwent "enhanced cleaning" consisting of use of bleach followed by HPV decontamination utilizing a priority scale based on the pathogen and room location. Rooms vacated by patients with CDAD but for which HPV decontamination was not possible the same day underwent 4 rounds of cleaning with bleach instead. RESULTS: During the intervention period, 1,123 HPV decontamination rounds were performed involving 96.7% of hospital rooms. Of 334 rooms vacated by patients with CDAD (May-December 2009), 180 (54%) underwent HPV decontamination. The rate of nosocomial CDAD rate dropped significantly from 0.88 cases/1,000 patient-days to 0.55 cases/1,000 patient-days (rate ratio, 0.63; 95% confidence interval: 0.50-0.79, P < .0001). CONCLUSION: A hospital-wide program of enhanced terminal cleaning of targeted patient rooms revolving around HPV technology was practical and was associated with a significant reduction in CDAD rates.

Intraoperative patient skin prep agents: is there a difference?

For health care institutions, intraoperative prep agents are a critical link in combating surgical site infections and the associated economic burden. The question remains, is there an intraoperative prep agent that is truly superior to the others? We conducted a literature review to examine available empirical evidence related to intraoperative prep agents used in our health system for open abdominal, general surgery procedures: povidone-iodine, chlorhexidine gluconate, parachoroxylenol, and iodine povacrylex in 74% isopropyl alcohol. Intraoperative surgical skin prep studies were limited in providing empirical evidence to support one superior prep agent. Each prep agent has a specific mechanism of action along with specific advantages and disadvantages. We concluded that no one perioperative skin prep agent is superior in all clinical situations. Factors to consider when choosing an appropriate intraoperative skin prep agent include contraindications, environmental risks, the patient's allergies and skin condition, the surgical site, the manufacturer recommendations for the prep agent, and surgeon preference.

Análisis de la eficacia de agentes químicos de desinfección en materiales elastoméricos / Analysis of the efficacy of disinfective chemical agents on elastomeric materials

El objetivo de este estudio fue evaluar la eficacia de agentes de desinfección indicados para polisulfuros (mercaptanos), poliéteres y siliconas por condensación y por adición. Fueron confeccionadas noventa muestras de cada material, siendo treinta de ellas contaminadas con Streptococcus mutans o Staphylococcus aureus o Candida albicans. De cada solución microbiana fueron retiradas diez muestras del polisulfeto y de ambas las siliconas, que fueron inmersas por diez minutos en glutaraldehído al 2 por ciento y otras diez inmersas en agua destilada estéril (control negativo). Después de un nuevo lavado en agua destilada, las muestras fueron transferidas a medios de cultivo estériles. Las diez muestras restantes no fueron sometidas al agente de desinfección y fueron transferidas a medios asociados a agentes antimicrobianos específicos (control positivo). La turbidez de los medios de cultivo fue evaluada como indicativo del crecimiento microbiano siguiéndose a la incubación por 24 h a 37O C y se realizó la dilución y sembrado en placas de Petri para contar las colonias. Para el poliéter fue ejecutado el mismo procedimiento, pero el agente de desinfección usado fue el hipoclorito de sodio a 1. No hubo turbidez comprobatoria del crecimiento microbiano en ninguno de los medios de cultivo que contenían los especimenes sometidos a los agentes de desinfección. Se concluyó que el glutaraldehído al 2 por ciento es un agente de desinfección eficaz para el polisulfuro y para las siliconas por adición y por condensación, así como el hipoclorito a 1 por ciento es eficaz para el poliéter, para los microorganismos evaluados

The aim of this in vitro study was to evaluate the disinfection efficacy of elastomeric impression materials such as polysulfides, polyethers, condensation and addition silicones. Ninety samples of each material were made and every thirty samples contaminated with Streptococcus mutans or Staphylococcus aureus or Candida albicans. From each microbial solution there were taken ten samples of polysulfide and of both silicones which were immersed for ten minutes in a 2% glutaraldehyde solution and other ten immersed in sterile distilled water (negative control). After being washed again in distilled water, the samples were transferred to sterile culture medium. The last ten samples were not submitted to any disinfection agent and were transferred to mediums associated with specific anti-microbial agents (positive control). The turbidity of the culture mediums was evaluated as an indication of the microbial growth after a period of 24-hour incubation at 37oC and the dilution and seeding in Petri dishes were done to count the colonies. The same procedure was done for the polyether, but the disinfection agent used was 1% sodium hypoclorite. There was no proved turbidity of the microbial growth in any of the culture mediums which had samples submitted to the disinfection agents tested. It was concluded that the 2% glutaraldehyde is an effective disinfection agent to polysulfides and to both condensation and addition silicones, as well as 1% sodium hypoclorite is effective to polyether, for the tested microorganisms.

O objetivo deste estudo in vitro foi avaliar a eficácia de agentes de desinfecção indicados para polissulfetos, poliéteres e siliconas de condensação e adição. Foram confeccionadas noventa amostras de cada material, sendo cada trinta contaminadas com Streptococcus mutans, Staphylococcus aureus ou Candida albicans. De cada solução microbiana foram retiradas dez amostras do polissulfeto e de ambas as siliconas, que foram imersas por dez minutos no glutaraldeído a 2% e outras dez imersas em água destilada estéril (controle negativo). Após nova lavagem em água destilada, as amostras foram transferidas para meios de cultura estéreis. As dez amostras restantes não foram submetidas ao agente de desinfecção e foram transferidas para meios associados a agentes antimicrobianos específicos (controle positivo). A turbidez dos meios de cultura foi avaliada como indicativo de crescimento microbiano após incubação por 24 h a 37O C e realizou-se a diluição e semeadura nas placas de Petri para contagem de colônias. Para o poliéter foi executado o mesmo procedimento, porém o agente de desinfecção empregado foi o hipoclorito de sódio a 1%. Não houve turvação comprobatória de crescimento bacteriano em nenhum dos meios da cultura que continham corpos de prova submetidos aos agentes de desinfecção. Concluiu-se que o glutaraldeído a 2% é um agente de desinfecção eficaz para o polissulfeto e para as siliconas por adição e por condensação, assim como o hipoclorito a 1% é eficaz para o poliéter, para os microorganismos testados.

The effect of Perasafe and sodium dichloroisocyanurate (NaDCC) against spores of Clostridium difficile and Bacillus atrophaeus on stainless steel and polyvinyl chloride surfaces.

Clostridium difficile is an important cause of nosocomial diarrhoea. The aim of this study was to evaluate the potential for Perasafe, a recently introduced biocide, to contribute to control of C. difficile spores in the patient environment, in comparison with the chlorine-releasing agent sodium dichloroisocyanurate (NaDCC). These agents were evaluated against a water control, in a surface test on stainless steel and polyvinyl chloride (PVC) floor covering, materials commonly found in the hospital environment. The organisms studied were a toxigenic clinical isolate of C. difficile, and Bacillus atrophaeus (formerly B. subtilis var niger). The data indicate that in our in vitro system, Perasafe was significantly more active than NaDCC (1000 ppm available chlorine) against C. difficile spores dried on stainless steel surfaces, and against B. atrophaeus on PVC floor covering material, achieving mean log10 reduction factors in viable counts of 6 and 5.5, respectively, at 10 min exposures. Perasafe appeared to be less lethal in 10 min exposures to C. difficile spores fixed on PVC floor covering material. In general, 1000 ppm chlorine generated from NaDCC showed lower log10 reduction factors in viable counts at 10 min, ranging from 0.7 to 1.5, than Perasafe which ranged from 2.7 to 6.0. The potential efficacy of Perasafe in reducing the density of C. difficile spores in the patient environment in hospitals, nursing homes or other long-stay facilities should be evaluated in field studies.

Inactivation of human adenovirus genome by different groups of disinfectants.

Human adenoviruses are model viruses for testing the virucidal efficacy of disinfectants. However, a recent study has shown that the chemical sensitivity of adenovirus serotypes varies significantly, possibly due to the composition of the viral capsid and/or the resistance of nucleic acids. We have investigated the effect of molecular changes in the viral genome of the human adenovirus subgenera C and D. A common oligonucleotide fragment within the hexon gene was amplified by polymerase chain reaction (PCR) after exposure to liposomal povidone-iodine (PVP-I), peracetic acid (PAA), and formaldehyde. The findings were compared with infectivity in cell cultures. PVP-I (0.125%) destroyed the infectivity of most serotypes within 60 min. However, PCR revealed no destruction of the adenoviral genome in most serotypes, even after exposure to higher PVP-I concentrations. PAA (0.5%) failed to inactivate the hexon gene of adenovirus types 22 and 44. Furthermore, the hexon gene of adenovirus type 22 was not altered by 0.7% formaldehyde. In conclusion, the genomes of human adenoviruses show considerably more chemical resistance than the complete viral particle. The molecular resistance of individual serotypes also varies. However, there was no clear correlation between the differences in the effect of disinfectants on infectivity of the complete viral particle and destruction of the viral genome.

Sensitivity of human adenoviruses to different groups of chemical biocides.

As it is no longer readily permissible to propagate polioviruses, adenoviruses will probably become more frequently used for virucidal testing of broad-spectrum disinfectants. We tested prototype strains of different adenovirus serotypes belonging to the subgenera C and D for sensitivity to liposomal povidone-iodine (PVP-I), peracetic acid (PAA) and formaldehyde. Virucidal assays were performed as suspension tests in accordance with the German guidelines for testing the effectiveness of chemical disinfectants against viruses. The sensitivity of the adenovirus serotypes to test disinfectants varied greatly. Prototype strains of adenovirus 5 and 44 statistically selected as 'little sensitive' to PVP-I, PAA and formaldehyde were found to be the most resistant. These might be suitable as model viruses for testing the broad-spectrum virucidal activity of disinfectants and might even replace the resistant poliovirus type 1. The main reason for the different chemical sensitivity of adenovirus serotypes may be the composition of the viral capsid proteins. Alternatively a different chemical inactivation of the viral genome could be involved.

Cleaning and disinfection practice in the meat industries of Europe.

The application and efficacy of cleaning and disinfection methods are reviewed, together with the relevant European and French legislation. European Commission Hygiene Directive 93/43/EEC of 14 June 1993 proposes the adoption of hazard analysis and critical control points (HACCP) for the meat industry, and this includes cleaning and disinfection. It is necessary to organise a team for washing, cleaning, rinsing, disinfection and final rinsing; three different types of organisation are compared. Application of HACCP and its contribution to the shelf life of products and their contamination with Listeria monocytogenes is discussed in the light of practical experience with poultry meat and cured pork products. Various means of verifying the efficacy of cleaning and disinfection (turbidimetry, adenosine triphosphate assay and macroscopic observation) are compared with the techniques of conventional microbiology. The authors conclude that cleaning and disinfection are essential for application of HACCP to the meat industry.

Acido acético: su capacidad desinfectante / Acetic acid: desifectant capacity

El objetivo de este trabajo es demostrar la desinfección de elementos críticos y semicríticos, mediante la aplicación durante un tiempo que resulte práctico, de una solución de ácido acético, en una concentración que no sea tóxica para el humano. Para ello, en primer lugar se determina la concentración inhibitoria mínima (CIM) y la concentración bacteriana mínima (CBM) del ácido acético (AA) frente a cepas de Escherichia coli, Staphylococcus aureus y Pseudomonas aeruginosa. También para un germen esporulado. Luego se busca el tiempo de contacto práctico para una concentración no tóxica frente a distintos inóculos de Escherichia coli. Y, por último se prueba la acción desinfectante del AA frente a tetinas de goma y pinzas metálicas. Se comprueba que el ácido acético a una concentración de 0,5 por ciento durante 2 horas y a temperatura ambiente, es capaz de eliminar el 100 por ciento de un inóculo de 10 a la quinta ufc/ml (unidades formadores de colonias por mililitro) de E.coli presentes en pinzas y el 99,9 por ciento del mismo inóculo que contaminan tetinas. Se concluye que es posible utilizar soluciones de ácido acético al 0,5 por ciento durante un tiempo de contacto de dos horas, cuando se desea desinfectar elementos semicríticos. Con este estudio, los autores tratan de rescatar la capacidad del AA como agente químico desinfectante

Propuestas de normas de bioseguridad en la práctica neurofisiológica / A proposal for safety normams in neurophysiological practice

El SIDA y la hepatitis B son enfermedades producidas por agentes etiológicos virales que comparten las mismas vías de transmisión, a saber: el contacto sexual, el uso compartido de jeringas (drogadicción), las transfusiones y la vía transplacentaria. La probabilidad de transmisión a través de las prácticas neurofisiológicas, por el uso de electrodos de aguja o de superficie colocados sobre piel dañada, es mínima o inexistente. No obstante, dada la posibilidad potencial de la misma, el equipo de salud debe ceñirse al empleo de recomendaciones o normas de seguridad adecuadas a los fines de evitar la transmisión de paciente a paciente, así como de paciente al personal médico o técnico. Las normas propuestas contemplan la utilización de métodos de limpieza, decontaminación y esterilización de los materiales empleados, así como la forma de proceder ante casos de accidentes imprevistos. Las mismas están basadas en las Normas de Bioseguridad del Ministerio de Salud y Acción Social de la República Argentina, las guías para la prevención de la transmisión del virus de la inmunodeficiencia humana y de la hepatitis B del Centro para el Control de Enfermedades de los EE.UU. y las recomendaciones de la Academia Americana de Neurología