Bactericidal Effects and Quality Impact of Peroxyacetic Acid and Sodium Hypochlorite on Chicken Carcasses.

With the increase in consumer interest in food safety, in this study, we aimed to investigate the antibacterial effect of peraceic acid (A, B, and Daesung; 50-200 ppm) and sodium hypochlorite disinfectants on chicken carcasses and contaminated water, respectively, and changes in the appearance of chicken carcasses. Considering the antibacterial effect of each disinfectant concentration, the most significant antibacterial efficacy was observed for general bacteria and Escherichia coli at 200 ppm regardless of disinfectant type. Considering the disinfectant type at 200 ppm, sodium hypochlorite was the least effective, and peracetic acid A showed the highest antibacterial efficacy at all concentrations. In chicken carcasses, 200 ppm of peracetic acid A exhibited the highest bacterial reduction rates of 92.7% and 89.3% for general bacteria and E. coli, respectively; in contaminated water, 200 ppm of peracetic acid A exhibited a significantly higher reduction rate (p<0.05). Salmonella was negative throughout the experiment, and discoloration of the neck and tip was observed for peracetic acid A and peracetic acid (Daesung) at 100 ppm and peracetic acid B at 150 ppm. Sodium hypochlorite did not cause discoloration at any concentration. Flavor analysis indicated that 100 ppm of peracetic acid A exhibited olfactory characteristics similar to those of 100 or 150 ppm of sodium hypochlorite. In conclusion, 50 ppm of peracetic acid A was adequate for use in poultry processing plants.

Comparison of sanitization efficacy of sodium hypochlorite and peroxyacetic acid used as disinfectants in poultry food processing plants

Comparison of sodium hypochlorite and peracetic acid as sanitising agents for stainless steel food processing surfaces using epifluorescence microscopy

Hospital Infections (HI) are a serious problem for public health services and one of the most significant microorganisms is methicillin-resistant Staphylococcus aureus (MRSA). Among the processes of HI control, we can outline procedures of disinfection using chemical agents. Among the most-used chemical agents currently utilized in hospitals sodium hypochlorite and peracetic acid are considered to be the ones that best meet the demands of efficacy and safety. The aim of this study was to compare the germicide activity of sodium hypochlorite and peracetic acid on MRSA. For this evaluation, 1% sodium hypochlorite and 0.1% peracetic acid solutions were used, and analyzed against one sample of MRSA isolated from one case of hospital infection at Maringa University Hospital. The results showed that the contact of either solution with a suspension of MRSA, 108 ufc/mL initial inoculum, for 5 minutes was enough to cause a bactericide effect. An increase in time to 10 minutes intensified the action, allowing the bacterial death in concentrations 10 times lower of each one of two disinfectants. It was concluded that sodium hypochlorite and peracetic acid feature equivalent germicide activity for MRSA.

Inhibition of regrowth of planktonic and biofilm bacteria after peracetic acid disinfection

La disinfezione con acido peracetico (PAA) rappresenta un’alternativa all’utilizzo di composti cloro-derivati che sta recentemente riscuotendo successo crescente. Questo articolo è la sintesi di un lavoro di ricerca svolto nel corso di diversi anni e finalizzato ad una valutazione complessiva delle prestazioni del PAA per la disinfezione di effluenti secondari, condotto a scala di laboratorio e pilota utilizzando l’effluente di un impianto di depurazione. Nella fattispecie, nell’ottica del rispetto di standard per lo scarico in corpo idrico superficiale e per il riuso agricolo, il processo di disinfezione è stato studiato rispetto a due organismi target (Escherichia coli e coliformi fecali) con diverse finalità: (1) determinare il decadimento del PAA e le cinetiche di decadimento in funzione delle condizioni operative; (2) valutare l’applicabilità del PAA come disinfettante; (3) studiare l’efficienza di disinfezione sul lungo periodo; (4) investigare l’ecotossicità dell’effluente disinfettato su alcuni organismi indicatori (Vibrio fischeri, Daphnia magna, Selenastrum capricornutum); (5) comparare l’acido peracetico con alcuni disinfettanti convenzionali (ipoclorito di sodio, radiazione UV). Nel corso della sperimentazione condotta, la disinfezione con PAA ha permesso il rispetto della normativa italiana sul riuso agricolo (10 UFC/ 100 mL per E. coli) e si è rivelato competitivo con gli altri disinfettanti. Inoltre, non si sono osservati fenomeni di ricrescita batterica in seguito alla disinfezione con PAA per i tempi necessari al riuso agricolo della risorsa idrica, ovverosia fino a 29 h dopo il trattamento, anche a concentrazioni trascurabili di disinfettante residuo. Infine, si è osservato che l’ecotossicità del PAA sull’ambiente acquatico è determinata dal disinfettante residuo in acqua, piuttosto che dall’alterazione chimica della matrice acquosa e dalla generazione di sottoprodotti.

Listeria monocytogenes continues to be a problem in ready-to-eat foods. Tolerance and adaptation to biocides have been proposed to contribute to the persistence of L. monocytogenes in the food processing industry. This study aimed to determine if the sensitivity to common biocides varies among 240 L. monocytogenes isolates. The impact of residual organic matter (soils), biofilm, and ability to adapt to biocides was also evaluated. Food and food processing related isolates of L. monocytogenes (n = 240) were whole genome sequenced and assigned to sequence types (n = 53) and clonal complexes (n = 32). Isolates were screened for genetic elements associated with biocide tolerance and tested for their minimum inhibitory concentration (MIC) to benzalkonium chloride (BC), peracetic acid (PAA), sodium hypochlorite (SH) and ethanol (ET). Biocide tolerance under soiled conditions, in biofilm and in a broth suspension test (BST) was further tested for 19 representative isolates. Adaptation to sub-MICs of BC, PAA or SH (18 days, 15 °C) was tested for 15 isolates. MIC for PAA (62 mg/L) showed no variation, while for SH (47–94 mg/L) and ET (4.7–9.4% v/v) values differed 2 × among isolates. For BC, an 8 × difference (0.3–2.5 mg/L) was observed. Eighty-seven of 88 BC tolerant isolates (MIC of 2.5 mg/L) harbored known BC tolerance genes. Soiled conditions increased MIC-values 8–33 × for BC and 8 × for SH but not for PAA and ET. Biofilm increased minimum bactericidal concentrations 4–8 × for BC but not for PAA and SH. Survival of isolates with BC tolerance genes was not significantly (p > 0.05) improved in BSTs with PAA, SH or BC. Lineage I isolates (n = 7 of 19) showed significantly (p < 0.05) better survival than lineage II isolates (n = 12) when exposed to PAA (100 mg/L) in BSTs. Adaptation to BC (8 × MIC increase) occurred exclusively for originally sensitive isolates, while no adaptation to SH and PAA were observed. In conclusion, L. monocytogenes isolates showed limited variation in sensitivity to biocides in MIC assays. However, lineage I isolates were less sensitive to PAA than lineage II isolates in BSTs. The efficacy of SH and BC were affected by residual organic matter and/or biofilm, demonstrating the need for proper cleaning prior to biocide use with PAA being less perturbed.

Efficacy of sodium hypochlorite and peracetic acid against Aspergillus nomius in Brazil nuts

Introduction: Bacteria play a key role in pulp and periapical disease, making their complete removal essential in endodontic treatment. Calcium hydroxide (Ca(OH)₂) is commonly used as an intracanal medicament due to its antimicrobial properties, but its remnants can hinder sealer adhesion and affect treatment outcomes. This study evaluated the effectiveness of 0.5% peracetic acid (PAA), 10% citric acid (CA), 1% PAA, 3% sodium hypochlorite (NaOCl), and 17% ethylenediamine tetraacetic acid (EDTA) with passive ultrasonic irrigation (PUI), in removing Ca(OH)₂ from root canals. Materials and Method: Sixty teeth that had single roots were chosen and decoronated to set the length of the root at 12 mm. Canals were irrigated, followed by filling up with Ca(OH)₂ after biomechanical preparation. The samples were divided into seven groups: Group 1: Control (positive); Group 2: Control (negative); Group 3: 5 ml of 17% EDTA + PUI; Group 4: 5 ml of 3 % NaOCl+ PUI; Group 5: 5 ml of 0.5% PAA + PUI; Group 6: 5 ml of 1% PAA + PUI; Group 7: 10% CA + PUI. The radicular portions of teeth were split longitudinally, followed by examination beneath a stereomicroscope with a magnification of 50×. Results: The obtained data was statistically analyzed using the Kruskal–Wallis test to find out significant differences between the study groups. Pair-wise comparison for mean scores was done using the Mann–Whitney test. Friedman’s test was used for intra group differences between regions. Small amounts of Ca(OH)₂ residue were observed in the 1% PAA group compared to other irrigants in the coronal, middle, and apical thirds of the root canals, and the difference was statistically significant (p &lt; 0.05). Conclusion: About 1% PAA with PUI was superior in removing Ca(OH)₂ from root canals compared to other irrigants used in the present study.

The poultry industry uses several strategies during poultry processing to increase the safety and shelf life of fresh products. One possible intervention is the application of peracetic acid (PAA) on carcasses by spraying or immersion. This study aimed to evaluate the antimicrobial action of PAA and its capacity to prevent cross‐contamination when applied on chicken carcasses. First, the method of PAA application that achieved the greatest reduction against a Salmonella cocktail artificially inoculated into chicken carcasses and against naturally present microorganisms was determined. We used the maximum concentration allowed in the United States (0.02% PAA) determining that immersion method was more effective than spray. Next, the reduction of the same microorganisms was evaluated by immersing carcasses in 0.07% PAA. This concentration was defined in a previous study as the most effective post‐chiller without causing changes in quality. Finally, the reduction of cross‐contamination between 4 carcasses consecutively immersed in 0.07% PAA was investigated. The immersion in 0.07% PAA was able to reduce ~2.0 log CFU/ml of aerobic bacteria and Salmonella, and ~1.5 log CFU/ml of Enterobacteriaceae and Escherichia coli. The results of the cross‐contamination test suggest that rinse water containing 0.07% PAA could reduce contamination between carcasses and in the post‐chiller tank water. Therefore, 0.07% PAA showed potential to contribute to the safety and increased shelf life of chicken carcasses.

Introduction: Healthcare-associated infections are common problems found in healthcare systems in most of the countries. Proper use of antiseptics and disinfectants is useful in reducing the magnitude of such infections. The aim of this study was to evaluate the bactericidal effect of different concentrations of selected antiseptics and disinfectants. Methods: Bactericidal activity of different concentrations of antiseptics and disinfectants; isopropyl alcohol, povidone iodine, chlorhexidine gluconate, sodium hypochlorite, hypertonic saline, peracetic acid and mixture of 2-aminoethanol, dodecyl dimethyl ammonium chloride, potassium carbonate &amp; bis(3-aminopropyl) dodecylamine were evaluated against nine strains of American Type Culture Collections and 11 strains isolated from the hospitals. Bacterial suspensions were prepared equal to 0.5 McFarland turbidity standards and 100 μl of each was mixed with 3 ml of antiseptic/ disinfectant solution. After desired contact time (1 minute, 15 minutes and 24 hours), 20 μl of reaction mixer was transferred into 4 ml of sterile physiological saline, mixed well and 20 μl of solution was evenly spread throughout Muller Hinton agar/ blood agar plates. Growth control was done using 3 ml of distilled water instead of 3 ml of antiseptic/ disinfectant solution. All plates incubated at 35oC ± 2oC for 18 – 24 hours. Colonies were counted and reduction percentage was calculated. Results: All concentrations of isopropyl alcohol, povidone iodine, chorhexidine, sodium hypochlorite, peracetic acid and the mixture of 2-aminoethanol, didecyldimethylammonium chloride, potassium carbonate and bis(3-aminopropyl)dodecylamine showed 100% bactericidal activities against all tested bacterial strains in1-minute contact time. Bactericidal activity of hypertonic saline was varied against tested bacterial strains with higher bactericidal activity against Gram positive organisms than Gram negative organisms. Conclusions: Currently using concentrations of antiseptics and disinfectants evaluated in this study have 100% bactericidal activity other than hypertonic saline.

An environmentally safe and nondestructive process for bleaching birch veneer with peracetic acid

Objective: the purpose of this study was to evaluate the efficacy of disinfection of type III dental stone by immersion in 1% sodium hypochlorite and 0.25% peracetic acid at different periods of time (1, 5 and 10 min). MaterialandMethods: silicon dies were previously infected with strains of Bacillus subtilis for 15 min. Then, type III gypsum stone (Herodent, Vigodent COLTÈNE SA, Rio de Janeiro, Brazil) was inserted into the cavities to obtain contaminated specimens. A sterile silicone die was used to obtain uncontaminated specimens. The specimens were separated into positive and negative control groups, and further divided into the following groups: blocks immersed in sterile physiologic solution for 1, 5 or 10 min; blocks immersed in 1% sodium hypochlorite for 1, 5 or 10 min; and blocks immersed in 0.25% peracetic acid for 1, 5 or 10 min. All the groups were double-plated and incubated at 37 ?C for 24 h. Results: the results were expressed in colony forming units (CFU/ml) and the data were submitted to the Kruskal-Wallis test followed by Dunn’s test. The results showed that immersion in 1% sodium hypochlorite and 0.25% peracetic acid resulted in complete disinfection of the test specimens at all test periods (p &lt; 0.01), whereas immersion in saline did not provide effective disinfection. Conclusion: it can be concluded that both 1% sodium hypochlorite and 0.25% peracetic acid provided effective disinfection in dental stone specimens immersed in the solutions described above, at different periods of time.KeywordsDisinfection; Peracetic acid; Sodium hypochlorite; Stone casts.

Biocide inactivation of Bacillus anthracis spores in the presence of food residues after a 10-min treatment time was investigated. Spores of nonvirulent Bacillus anthracis strains 7702, ANR-1, and 9131 were mixed with water, flour paste, whole milk, or egg yolk emulsion and dried onto stainless-steel carriers. The carriers were exposed to various concentrations of peroxyacetic acid, sodium hypochlorite (NaOCl), or hydrogen peroxide (H(2)O(2)) for 10 min at 10, 20, or 30 degrees C, after which time the survivors were quantified. The relationship between peroxyacetic acid concentration, H(2)O(2) concentration, and spore inactivation followed a sigmoid curve that was accurately described using a four-parameter logistic model. At 20 degrees C, the minimum concentrations of peroxyacetic acid, H(2)O(2), and NaOCl (as total available chlorine) predicted to inactivate 6 log(10) CFU of B. anthracis spores with no food residue present were 1.05, 23.0, and 0.78%, respectively. At 10 degrees C, sodium hypochlorite at 5% total available chlorine did not inactivate more than 4 log(10) CFU. The presence of the food residues had only a minimal effect on peroxyacetic acid and H(2)O(2) sporicidal efficacy, but the efficacy of sodium hypochlorite was markedly inhibited by whole-milk and egg yolk residues. Sodium hypochlorite at 5% total available chlorine provided no greater than a 2-log(10) CFU reduction when spores were in the presence of egg yolk residue. This research provides new information regarding the usefulness of peroxygen biocides for B. anthracis spore inactivation when food residue is present. This work also provides guidance for adjusting decontamination procedures for food-soiled and cold surfaces.

SARS-CoV-2 is primarily a respiratory virus that can potentially be transmitted through fomites. Sodium hypochlorite (NaOCl) and peracetic acid (PAA) are widely used disinfectants on surfaces in diverse settings such as hospitals and food production facilities. The objectives of this study were to investigate the virucidal efficacy of NaOCl and PAA against SARS-CoV-2 using the ASTM standard methods. In the suspension assay, NaOCl and PAA (5, 50, and 200 ppm) were tested against SARS-CoV-2 in the presence/absence of soil load after 1 min of contact time. In the carrier assay, NaOCl and PAA were tested at 200, 400, 600, and 1,000 ppm for 1 min and 200 and 1,000 ppm for 5 and 10 min. Stainless steel (SS) and high-density polyethylene (HDPE) disks were used as carriers. The virus was suspended in soil load and the disinfectants were prepared in 300 ppm of hard water. Virus quantification was done by TCID50 assay using Vero-E6 cell line. NaOCl and PAA were effective (> 3 log reduction in infectious virus) at 50 ppm in the absence of soil load. However, in the presence of soil load, 200 ppm was required for > 3 log reduction in virus infectivity. In contrast, NaOCl and PAA at 200 ppm and with a 1-min contact time were not effective against SARS-CoV-2 on either SS or HDPE surfaces. PAA at 200 ppm for 10 min was effective against SARS-CoV-2 on SS and HDPE surfaces, whereas NaOCl required 1,000 ppm for 10 min to be effective against SARS-CoV-2 on both surfaces. IMPORTANCE In the context of the COVID-19 pandemic, the World Health Organization (WHO) recommended the use of chlorine-based products such as sodium hypochlorite (NaOCl) at 1,000 ppm for a minimum of 1 min to disinfect environmental surfaces. However, this recommendation was not based on validated studies on the actual SARS-CoV-2 itself. In fact, over half of the chemical disinfectants, including many peracetic acid products, listed in EPA List N were approved based on "kills a harder-to-kill pathogen" without further validation on SARS-CoV-2. Research on SARS-CoV-2 is restricted to BSL3 laboratories and the urgency of tackling the pandemic might explain the lack of studies on the actual virus. Our results show that the WHO recommendation of 1 min contact time with 1,000 ppm NaOCl is not effective against SARS-CoV-2 on surfaces. Also, our results indicate that PAA is effective against SARS-CoV-2 on surfaces and can be used as safer and more environmentally friendly alternative to NaOCl at a lower concentration.