Peracetic Acid Efficacy on Disinfection of Photostimulable Phosphor Plates.

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 aluminum step-wedge were acquired for each plate. Density, noise, uniformity, and contrast were analyzed. Three oral radiologists evaluated the images for the presence of artifacts. One-way Analysis of Variance compared changes on gray values among the disinfections (α = 0.05). Intra- and inter-examiner agreement for the presence of artifacts 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 ≤ 0.05). Small artifacts 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 artifacts.

Effect of Chemical Treatments on the Mechanical Properties of Jute/Polyester Composites.

Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study investigates the impact of chemical treatments on the properties of Brazilian jute woven fabric/polyester resin composites. Sodium hydroxide, hydrogen peroxide, and peracetic acid were utilized to treat the jute fabrics, followed by resin transfer molding (RTM) to form the composites. Evaluation included water absorption, flexural strength, tensile strength, and short-beam strength. The alkaline treatment induced changes in the chemical composition of the fibers' surface. Chemical treatments resulted in increased flexural and short-beam strength of the composites, with no significant alterations in tensile properties. The hydrogen peroxide treatment exhibited lower water absorption, suggesting its potential as a viable option for enhancing the performance of these composites.

Biofilm formation by Listeria monocytogenes from the meat processing industry environment and the use of different combinations of detergents, sanitizers, and UV-A radiation to control this microorganism in planktonic and sessile forms.

This study aimed to evaluate the ability of biofilm formation by L. monocytogenes from the meat processing industry environment, as well as the use of different combinations of detergents, sanitizers, and UV-A radiation in the control of this microorganism in the planktonic and sessile forms. Four L. monocytogenes isolates were evaluated and showed moderate ability to form biofilm, as well as carried genes related to biofilm production (agrB, agrD, prfA, actA, cheA, cheY, flaA, sigB), and genes related to tolerance to sanitizers (lde and qacH). The biofilm-forming isolates of L. monocytogenes were susceptible to quaternary ammonium compound (QAC) and peracetic acid (PA) in planktonic form, with minimum inhibitory concentrations of 125 and 75 ppm, respectively, for contact times of 10 and 5 min. These concentrations are lower than those recommended by the manufacturers, which are at least 200 and 300 ppm for QAC and PA, respectively. Biofilms of L. monocytogenes formed from a pool of isolates on stainless steel and polyurethane coupons were subjected to 14 treatments involving acid and enzymatic detergents, QAC and PA sanitizers, and UV-A radiation at varying concentrations and contact times. All treatments reduced L. monocytogenes counts in the biofilm, indicating that the tested detergents, sanitizers, and UV-A radiation exhibited antimicrobial activity against biofilms on both surface types. Notably, the biofilm formed on polyurethane showed greater tolerance to the evaluated compounds than the biofilm on stainless steel, likely due to the material's surface facilitating faster microbial colonization and the development of a more complex structure, as observed by scanning electron microscopy. Listeria monocytogenes isolates from the meat processing industry carry genes associated with biofilm production and can form biofilms on both stainless steel and polyurethane surfaces, which may contribute to their persistence within meat processing lines. Despite carrying sanitizer tolerance genes, QAC and PA effectively controlled these microorganisms in their planktonic form. However, combinations of detergent (AC and ENZ) with sanitizers (QAC and PA) at minimum concentrations of 125 ppm and 300 ppm, respectively, were the most effective.

Effect of peracetic acid on orthodontic elastics: an in vitro experiment / Efeito do ácido peracético nos elásticos ortodônticos: um estudo in vitro

Objetivo: Este estudo teve como objetivo avaliar a elasticidade de elásticos ortodônticos após desinfecção e esterilização com ácido peracético 0,2%. Materiais e métodos: Neste estudo piloto in vitro, elásticos ortodônticos Morelli® e American Orthodontics™ nas cores cinza e cristal foram divididas em três grupos experimentais: Grupo 1, imerso em água destilada por 72 horas, Grupo 2, imerso em peracético 0,2% por 10 min (para desinfecção) e Grupo 3, imerso em ácido peracético 0,2% por 30 min (para esterilização). Após a imersão, os valores de resistência à tração dos elásticos foram analisados em uma máquina de ensaios universal (EMIC DL-1000) para avaliar a resistência, em Newtons, necessária para a ruptura dos mesmos. A normalidade dos dados foi avaliada pelo teste de Shapiro-Wilk e os dados dos diferentes grupos experimentais foram comparados pelo teste ANOVA. Resultados: Para ambas as marcas, não houve diferença estatisticamente significativa entre os grupos experimentais quanto à resistência à tração. Discussão: O estudo apresentou um método alternativo para a desinfecção e esterilização de materiais termossensíveis. Conclusão: Assim, podemos concluir que a desinfecção e esterilização dos elásticos ortodônticos com ácido peracético 0,2% não alterou seu módulo de elasticidade.

Aim: This study aimed to evaluate the elasticity of orthodontic elastics after disinfection and sterilization with 0.2% peracetic acid. Materials and methods: In this in vitro pilot study, Morelli® and American Orthodontics™ elastic bands in gray and crystal colors were divided into three experimental groups: Group 1, immersed in distilled water for 72 hours, Group 2, immersed in 0.2% peracetic acid for 10 min (for disinfection) and Group 3, immersed in 0.2% peracetic acid for 30 min (for sterilization). After immersion, the tensile strength values of the elastics were analyzed in a universal test machine (EMIC DL-1000) to evaluate the strength, in Newtons, necessary for their rupture. Normality of the data was assessed using the Shapiro-Wilk test, and data from the different experimental groups were compared using the ANOVA test. Results: For both brands, there was no statistically significant difference between the experimental groups regarding tensile strength. Discussion: This study presented an alternative method for the disinfection and sterilization of thermo-sensitive materials. Conclusion: Thus, it can be concluded that the sterilization of orthodontic elastics with 0.2% peracetic acid did not change their modulus of elasticity.

Peracetic acid application as an antimicrobial and its residual (HEDP): a holistic approach on the technological characteristics of chicken meat.

The most significant occurrence of food-borne diseases is due to Campylobacter and Salmonella contamination from chicken meat, and for this reason, strict regulations about strategies to improve the control of food pathogens are imposed by food safety authorities. Despite the efforts of poultry industry since the beginning of risk analysis and critical control point to reduce the burden of food-borne illness, technological barriers along the way are increasingly necessary to ensure safe food. The aim of this review was to carry out a scientific approach to the influence of peracetic acid (PAA) as an antimicrobial and its toxicological safety, in particular the stabilizer used in the formulation of PAA, 1-hydroxyethylidene 1,1-diphosphonic acid (HEDP), suggesting the possibility of researching the residual HEDP in meat, which would allow the approval of the PAA by the health authorities of several countries that still restrict it. This review also aims to ascertain the effectiveness of PAA, in different cuts and carcasses, by different application methods, comparing the effectiveness of this antimicrobial with other antimicrobials, and its exclusive or combined use, for the decontamination of poultry carcasses and raw parts. The literature results support the popularity of PAA as an effective intervention against pathogenic bacteria during poultry processing.

Effect of irrigation acid solutions on cleaning and bond strength to post-space dentin.

This study evaluated the effects of irrigating solutions containing 5% boric acid + 1% citric acid or 1% peracetic acid + high concentration hydrogen peroxide on root cleaning and bond strength of cementation systems after 24 h and 6 months of glass fiber post cementation. One hundred and twenty roots were endodontically treated. The specimens were randomized into one of four treatments (n = 10): DW (distilled water); NaOCl2.5% + EDTA17% (2.5% sodium hypochlorite solution + 17% EDTA); PA1% + HP (1% peracetic acid solution + high concentration of hydrogen peroxide); BA5% + CA1% (5% boric acid associated with 1% citric acid). The cleaning efficacy in the cervical, middle, and apical thirds of the post-space, and the push-out bond strength at 24 h and 6 months after post cementation were evaluated by Kruskal-Wallis and two-way ANOVA tests, respectively. BA5% + CA1% showed statistically significantly superior cleaning efficacy compared to the other solutions. This irrigation protocol also resulted in higher bond strength at 24 h and 6 months, regardless of the root third considered, and this was statistically significantly higher than those seen for DW and PA1% + HP. For BA5% + CA1% irrigation protocol, type 1 adhesive failure was the most prevalent. Post-space irrigation with BA5% + CA1% provided both higher cleaning efficacy and better bond strength.

Ultrasound, Acetic Acid, and Peracetic Acid as Alternatives Sanitizers to Chlorine Compounds for Fresh-Cut Kale Decontamination.

Chlorinated compounds are usually applied in vegetable sanitization, but there are concerns about their application. Thus, this study aimed to evaluate ultrasound (50 kHz), acetic acid (1000; 2000 mg/L), and peracetic acid (20 mg/L) and their combination as alternative treatments to 200 mg/L sodium dichloroisocyanurate. The overall microbial, physicochemical, and nutritional quality of kale stored at 7 °C were assessed. The impact on Salmonella enterica Typhimurium was verified by plate-counting and scanning electron microscopy. Ultrasound combined with peracetic acid exhibited higher reductions in aerobic mesophiles, molds and yeasts, and coliforms at 35 °C (2.6; 2.4; 2.6 log CFU/g, respectively). Microbial counts remained stable during storage. The highest reduction in Salmonella occurred with the combination of ultrasound and acetic acid at 1000 mg/L and acetic acid at 2000 mg/L (2.8; 3.8 log CFU/g, respectively). No synergistic effect was observed with the combination of treatments. The cellular morphology of the pathogen altered after combinations of ultrasound and acetic acid at 2000 mg/L and peracetic acid. No changes in titratable total acidity, mass loss, vitamin C, or total phenolic compounds occurred. Alternative treatments presented equal to or greater efficacies than chlorinated compounds, so they could potentially be used for the decontamination of kale.

Effect of irrigation protocols on chemical smear layer formation over the post-space dentin.

This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n = 10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p = .05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p < .05), but without difference between them (p > .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p > .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p > .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

Different formulations of peracetic acid: effects on smear layer removal, dentine erosion, cytotoxicity and antibiofilm activity

Abstract Objective: To assess the effects of different peracetic acid (PAA) formulations on smear layer (SL) removal, dentine erosion, cytotoxicity, and antibiofilm activity. Methodology: SL removal and dentine erosion were assessed using 90 premolars, distributed into six groups, according to final irrigation: PAA formulations (1% Sigma, 1% Bacterend OX, 1% Arposept, and 0.09-0.15% Anioxyde), 17% ethylenediaminetetraacetic acid (EDTA), and water (control). Cytotoxicity was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red assays. Antibacterial and antibiofilm effectiveness was evaluated against Enterococcus faecalis. For cytotoxicity and antibiofilm activity assessment, the 2.5% NaOCl was also included. Results: EDTA, Sigma, and Bacterend OX removed more SL than Arposept, Anioxyde, and water (p<0.05). EDTA caused more severe dentine erosion than Sigma and Bacterend OX (p<0.05). Sigma and Bacterend OX had higher cytotoxicity than the other solutions (p<0.05). NaOCl, Bacterend OX, Sigma, and Anioxyde significantly reduced E. faecalis colony-forming units (CFU) (p<0.05). The 2.5% NaOCl solution promoted greater biofilm biomass reduction (p<0.05) than the other solutions. All PAA formulations promoted greater biomass reduction than 17% EDTA (p<0.05). Conclusions: Although Sigma and Bacterend OX had higher cytotoxicity, they had a SL removal capability similar to that of EDTA, were as effective as NaOCl against E. faecalis biofilm, and promoted less dentine erosion than EDTA. Arposept and Anioxyde failed to remove the SL, had lower cytotoxicity, and showed less bacterial activity than NaOCl.

Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28, and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcus spp., Salmonella spp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternative product to chemical sanitizers.(AU)

Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers / Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28, and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcus spp., Salmonella spp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternative product to chemical sanitizers.

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28, and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcus spp., Salmonella spp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternative product to chemical sanitizers.

Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers / Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28, and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcus spp., Salmonella spp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternative product to chemical sanitizers.

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28, and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcus spp., Salmonella spp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternative product to chemical sanitizers.

Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28,and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcusspp., Salmonellaspp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternativeproduct to chemical sanitizers.(AU)

Removal of Mixed-Species Biofilms Developed on Food Contact Surfaces with a Mixture of Enzymes and Chemical Agents.

Sanicip Bio Control (SBC) is a novel product developed in Mexico for biofilms' removal. The aims of this study were to evaluate (i) the removal of mixed-species biofilms by enzymatic (protease and α-amylase, 180 MWU/g) and chemical treatments (30 mL/L SBC, and 200 mg/L peracetic acid, PAA) and (ii) their effectiveness against planktonic cells. Mixed-species biofilms were developed on stainless steel (SS) and polypropylene B (PP) in whole milk (WM), tryptic soy broth (TSB) with meat extract (TSB+ME), and TSB with chicken egg yolk (TSB+EY) to simulate the food processing environment. On SS, all biofilms were removed after treatments, except the enzymatic treatment that only reduced 1-2 log10 CFU/cm2, whereas on PP, the reductions ranged between 0.59 and 5.21 log10 CFU/cm2, being the biofilms developed in TSB+EY being resistant to the cleaning and disinfecting process. Higher reductions in microbial load on PP were reached using enzymes, SBC, and PAA. The employed planktonic cells were markedly more sensitive to PAA and SBC than were the sessile cells. In conclusion, biofilm removal from SS can be achieved with SBC, enzymes, or PAA. It is important to note that the biofilm removal was strongly affected by the food contact surfaces (FCSs) and surrounding media.

Influence of type, concentration, exposure time, temperature, and presence of organic load on the antifungal efficacy of industrial sanitizers against Aspergillus brasiliensis (ATCC 16404).

Parameters such as type and concentration of the active compound, exposure time, application temperature, and organic load presence influence the antimicrobial action of sanitizers, although there is little data in the literature. Thus, this study aimed to evaluate the antifungal efficacy of different chemical sanitizers under different conditions according to the European Committee for Standardization (CEN). Aspergillus brasiliensis (ATCC 16404) was exposed to four compounds (benzalkonium chloride, iodine, peracetic acid, and sodium hypochlorite) at two different concentrations (minimum and maximum described on the product label), different exposure times (5, 10, and 15 min), temperatures (10, 20, 30, and 40 °C), and the presence or absence of an organic load. All parameters, including the type of sanitizer, influenced the antifungal efficacy of the tested compounds. Peracetic acid and benzalkonium chloride were the best antifungal sanitizers. The efficacy of peracetic acid increased as temperatures rose, although the opposite effect was observed for benzalkonium chloride. Sodium hypochlorite was ineffective under all tested conditions. In general, 5 min of sanitizer exposure is not enough and >10 min are necessary for effective fungal inactivation. The presence of organic load reduced sanitizer efficacy in most of the tested situations, and when comparing the efficacy of each compound in the presence and absence of an organic load, a difference of up to 1.5 log CFU was observed. The lowest concentration recommended on the sanitizer label is ineffective for 99.9% fungal inactivation, even at the highest exposure time (15 min) or under the best conditions of temperature and organic load absence. Knowledge of the influence exerted by these parameters contributes to successful hygiene since the person responsible for the sanitization process in the food facility can select and apply a certain compound in the most favorable conditions for maximum antifungal efficacy.

Salmonella inactivation and sponge/microfiber mediated cross-contamination during papaya wash with chlorine or peracetic acid as sanitizer.

Imported papayas from Mexico have been implicated in multiple salmonellosis outbreaks in the United States in recent years. While postharvest washing is a critical process to remove latex, dirt, and microbes, it also has the potential of causing cross-contamination by foodborne pathogens, with sponge or other fibrous rubbing tools often questioned as potential harboring or transmitting risk. In this study, Salmonella inactivation and cross-contamination via sponges and microfiber wash mitts during simulated papaya washing and cleaning were investigated. Seven washing treatments (wash without sanitizer; wash at free chlorine 25, 50, and 100 mg/L, and at peracetic acid 20, 40, and 80 mg/L), along with unwashed control, were evaluated, using Salmonella strains with unique antibiotic markers differentially inoculated on papaya rind (serovars Typhimurium, Heidelberg, and Derby) and on wash sponge or microfiber (serovars Typhimurium, Newport, and Braenderup). Salmonella survival and transfer on papaya and on sponge/microfiber, and in wash water were detected using selective plating or enrichment. The washing and cleaning process reduced Salmonella on inoculated papayas by 1.69-2.66 and 0.69-1.74 log for sponge and microfiber cleaning, respectively, with the reduction poorly correlated to sanitizer concentration. Salmonella on inoculated sponge or microfiber was under detection limit (1.00 log CFU/cm2) by plate count, but remained recoverable by selective enrichment. Transference of Salmonella from inoculated papaya to sponge/microfiber, and vice versa, could be detected sporadically by selective enrichment. Sponge/microfiber mediated Salmonella cross-contamination from inoculated to uninoculated papayas was frequently detectable by selective enrichment, but rendered undetectable by wetting sponge/microfiber in sanitizing wash water (FC 25-100 mg/L or PAA 20-80 mg/L) between washing different papaya fruits. Therefore, maintaining adequate sanitizer levels and frequently wetting sponge/microfiber in sanitizing wash water can effectively mitigate risks of Salmonella cross-contamination associated with postharvest washing, especially with regard to the use of sponge or microfiber wash mitts.

In vitro comparison of peracetic acid and autoclave sterilization in the corrosion of orthodontic pliers: a pilot study

ABSTRACT Introduction: The most currently recommended method for sterilization of orthodontic pliers is the autoclave, while peracetic acid has also been shown to be effective in the chemical sterilization process. Objective: This study sought to compare the corrosive effects of peracetic acid and autoclave sterilization process of orthodontic pliers. Methods: Four active tungsten carbide (WC) stainless steel tie-cutting pliers from the manufacturers Quinelato (Rio Claro, SP, Brazil) and ICE (Cajamar, SP, Brazil) were selected. The active ends of the pliers were sectioned, and six active tips were obtained and distributed into the following groups: 1) control group (no sterilization); 2) AC group (two active pliers tips submitted to 100 autoclave sterilization cycles); and 3) AP group (two active pliers tips submitted to 100 cycles of sterilization by immersion in 2% peracetic acid solution for 30 minutes). Results: Chemical analysis using X-ray dispersive energy spectroscopy showed that after autoclave sterilization, only the ICE pliers presented oxidation corrosion (Δ[O] = +24.5%; Δ[Fe] = +5.8%; Δ[WC] = -1.9%). In comparison, following peracetic acid sterilization, both manufacturers ICE (Δ[O] = +1.8%; Δ[Fe] = +18.0%; Δ[WC] = -1.1%) and Quinelato (Δ[O] = +5.3%; Δ[Fe] = -10.4%; Δ[WC] = -15.2%) showed corrosion. The morphological analysis revealed that peracetic acid caused a pitting and localized corrosion in both brands, while the autoclave caused uniform surface corrosion on the ICE pliers. Conclusion: Autoclave application was the sterilization method that generated less corrosive damage to the orthodontic cutting pliers, when compared to the immersion in 2% peracetic acid.

RESUMO Introdução: O método mais recomendado para a esterilização dos alicates ortodônticos é a autoclave; porém, o ácido peracético mostrou-se eficaz no processo de esterilização química. Objetivo: O objetivo do presente estudo foi avaliar o efeito corrosivo do ácido peracético e da autoclave no processo de esterilização de alicates ortodônticos. Métodos: Foram selecionados quatro alicates de corte de amarrilho de aço inoxidável, com ponta ativa de carboneto de tungstênio (WC), das marcas Quinelato (Rio Claro/SP, Brasil) e ICE (Cajamar/SP, Brasil), que foram distribuídos em três grupos: 1) Controle (C), o qual não foi submetido à esterilização; 2) Grupo AC, constituído por duas pontas ativas de alicates submetidas a 100 ciclos de esterilização em autoclave; e 3) Grupo AP, formado por duas pontas ativas de alicates submetidas a 100 ciclos de esterilização por imersão em solução de ácido peracético a 2% durante 30 minutos. Resultados: Por meio da análise química (EDS, energia dispersiva de raios X), constatou-se que, após esterilização em autoclave, somente o alicate ICE apresentou corrosão por oxidação (Δ[O] = +24,5%; Δ[Fe] = +5,8% e Δ[WC] = -1,9%), enquanto na esterilização em ácido peracético, ambas as marcas, ICE (Δ[O] = +1,8%; Δ[Fe] = +18,0% e Δ[WC] = -1,1%) e Quinelato (Δ[O] = +5,3%; Δ[Fe] = -10,4% e Δ[WC] = -15,2%), apresentaram corrosão. A análise morfológica demonstrou que o ácido peracético causou uma corrosão localizada em pite em ambas as marcas, enquanto a autoclave ocasionou uma corrosão superficial uniforme no alicate ICE. Conclusão: A autoclave foi o método de esterilização que gerou menor dano corrosivo aos alicates ortodônticos, em comparação à imersão em ácido peracético a 2%.

Comparison of electrolized water and multiple chemical sanitizer action against heat-resistant molds (HRM).

This study aimed to evaluate the sensitivity of heat-resistant molds isolated from spoiled thermally processed foods to antimicrobial compounds used for food industry sanitation. An ortho-phenylphenol-based smoke generator sanitizer, liquid chemical sanitizers (benzalkonium chloride, biguanide, iodine, peracetic acid, and sodium hypochlorite), and acidic and alkaline electrolyzed water were used against Aspergillus australensis (MB 2579; NFF 02), Aspergillus aureoluteus (NFC1), Paecilomyces fulvus (PFF 01), Paecilomyces niveus (PNT 01; PNDC 01; PNB1 01), and Paecilomyces variotii (PV 01; PV 01; PVCH 03). The fungal strains were exposed separately to liquid sanitizers and electrolyzed water in stainless steel discs for 15 min following the European Committee for Standardization (CEN) recommendations. Moreover, the fungal strains were exposed to the smoke generator sanitizer for 7 h following French protocol NF-T-72281. The best results of fungal inactivation were achieved when the highest concentration specified in the label of these sanitizers was tested. On the opposite, the lowest concentration specified in the label should be avoided since it was ineffective in most cases (94%). The ortho-phenyphenol-based smoke generator sanitizer and peracetic acid (1%) showed the best results of spore inactivation, while iodine and benzalkonium chloride achieved satisfactory results against the strains evaluated. Sodium hypochlorite and biguanide were ineffective against most of the fungi studied at all concentrations tested. Acidic and basic electrolyzed water was also ineffective to achieve the 3-log CFU reduction required in the concentrations tested. In general, Paecilomyces spp. was more sensitive than Aspergillus spp. against all sanitizers evaluated, whereas A. aureoluteus NFC1 was resistant to all agents and concentrations tested. The heat-resistant fungal strains showed varied sensitivity against the different agents. Notably, the two most effective commercial sanitizers against the heat-resistant strains were ineffective against the filamentous fungi recommended for sanitizer testing (A. brasiliensis ATCC 16404), which demonstrates the relevance of testing fungal isolates that cause spoilage to choose the most effective compound and obtain the best results of fungal control.

Peracetic acid: Structural elucidation for applications in wastewater treatment.

Peracetic acid (PAA) is an oxidizer widely used for the sterilization of equipment in hospitals, pharmaceutical, cosmetic and food industries and also for water and wastewater disinfection. Even with its increasing applications, there have been no previous theoretical studies that explain the experimental results based on its molecular behavior. In this context, this work used calculations based on the density functional theory (DFT) combined with experimental results to elucidate the decomposition mechanisms of PAA for predicting its stability and the possible products generated from its decomposition. The results obtained showed that the protonation of PAA promoted its spontaneous decomposition in acetic acid and molecular oxygen. The hydrolysis mechanism of PAA in acidic medium indicated that the low energy difference involved in the mechanism's stages is responsible for the equilibrium between PAA and H2O2. The structural and electronic comparison of PAA with H2O2 showed that the O-O bond length of PAA is longer than that of H2O2 and is also weaker, therefore may demonstrate greater efficiency in advanced oxidative processes by photocatalysis.

Effects of wastewater disinfectants on the soil: Implications for soil microbial and chemical attributes.

In most cases, chlorination is used for effluent disinfection. However, this process can lead to the formation of byproducts hazardous to the environment and public health. Therefore, new disinfectants, such as calcium hypochlorite (CH) and peracetic acid (PAA), were investigated as alternatives. This study aimed at determining doses of the disinfectants PAA and CH to be applied to the soil and analyzing the possible changes in the major chemical and microbiological attributes of the soil, thus encouraging the practice of reusing wastewater in agriculture. Initially, toxicity bioassays were conducted with lettuce (Lactuca sativa L.) seeds in order to determine which concentrations affected germination and also which would be analyzed. From these trials, three concentrations of each disinfectant were chosen to be subjected to basal respiration, microbial biomass carbon and metabolic quotient analyses. Doses of 3, 5 and 10 mg L-1 were used for PAA, and concentrations of 25, 32 and 64 mg L-1 for CH. Thus, it was observed that the greater concentration of each disinfectant provided a significant increase in the metabolic potential of microorganisms. However, it was observed that PAA increased ecotoxicity besides promoting changes in the chemical attributes of the soil, compared to CH. On the other hand, concentrations of 3 mg L-1 and 25 mg L-1 of PAA and CH, respectively, did not cause large impacts and could be an alternative in effluent disinfection with the aim of recycling it in agriculture.