Higienização de ambiente em agroindústria familiar de embutidos cárneos / Environmental hygienization in family meat product

A higienização é um procedimento importante na indústria de alimentos e sua realização deve ocorrer rotineiramente para evitar que os alimentos sejam contaminados. Além disso, todos os manipuladores de alimentos devem receber treinamentos de modo a entender como ocorrem as contaminações e como evitá-las, para que não ocorra deterioração antecipada dos alimentos e para que não exponham os consumidores ao risco de doenças transmitidas por alimentos em caso de contaminação. Esta pesquisa avaliou o processo de higienização e sua eficiência em superfícies presentes em uma agroindústria da agricultura familiar produtora de embutidos cárneos. Apesar de ter instalações adequadas a agroindústria apresentava inadequações quanto aos produtos utilizados e a frequência inadequada para uma higienização eficiente. Foi realizada análise microbiológica das superfícies dos equipamentos para contagem de aeróbios mesófilos e notou-se uma elevada carga microbiana que indicou uma baixa eficiência no processo de higienização. Sugeriu-se melhorias na higiene ambiental associado à instrução dos colaboradores, para contribuir na promoção da qualidade dos produtos, aumento dos lucros e salvaguardando a saúde do consumidor.

Hygiene is an important procedure in the food industry, and its performance must occur routinely to prevent food from being contaminated. In addition, all food handlers must receive training in order to understand how contamination occurs and how to avoid it, so that there is no anticipated deterioration of food and that consumers are not exposed to the risk of foodborne diseases. in case of contamination by pathogenic microorganisms. Thus, this research evaluated the cleaning process and its efficiency on surfaces present in a family farming agroindustry that produces meat products, which despite having adequate facilities, had some difficulties such as product use and inadequate frequency for eficiente cleaning. After performing a microbiological analysis to count surface mesophilic aerobes, a high level of contamination was noted, relating to low efficiency in the cleaning process. Improvements in environmental hygiene are suggested, associated with the instruction of employees for the implementation of the Standard Operating Hygiene Procedure, promoting improvements in product quality, increasing profits and safeguarding consumer health.

Dihalogenated nitrophenols exposure induces developmental neurotoxicity in zebrafish embryo.

2,6-Dihalogenated nitrophenols (2,6-DHNPs) are emerging halogenated nitroaromatic pollutants that have been detected in various water environments. However, there is currently limited research available regarding their potential impacts on locomotion behavior and neurotoxicity. Therefore, this study utilized zebrafish embryos to investigate the potential neurotoxic effects of 2,6-DHNPs by examining their impact on the nervous system at a concentration defined as 10% of the median lethal concentration. Our findings demonstrated that exposure to 2,6-DHNPs resulted in a significant 30 % decrease in the total swimming distance of zebrafish larvae, accompanied by notable impairments in motor neuron development and central nervous system. These effects were evidenced by a substantial 25% decrease in axonal growth, as well as disruptions in synapse formation and neuronal differentiation. Additionally, neurotransmitter analysis revealed marked decreases of 40%, 35%, and 30% in dopamine, 5-hydroxytryptamine, and acetylcholine levels respectively, highlighting disturbances in their synthesis, transport, and degradation mechanisms. These results emphasize the considerable neurotoxicity of 2,6-DHNPs at concentrations previously considered safe; thus necessitating a re-evaluation of environmental risk assessments and regulatory standards for such emerging contaminants.

Survival of highly related ESBL- and pAmpC- producing Escherichia coli in broiler farms identified before and after cleaning and disinfection using cgMLST.

BACKGROUND: Broiler chickens are frequently colonized with Extended-Spectrum Beta-Lactamase- (ESBL-) and plasmid mediated AmpC Beta-Lactamase- (pAmpC-) producing Enterobacterales, and we are confronted with the potential spread of these resistant bacteria in the food chain, in the environment, and to humans. Research focused on identifying of transmission routes and investigating potential intervention measures against ESBL- and pAmpC- producing bacteria in the broiler production chain. However, few data are available on the effects of cleaning and disinfection (C&D) procedures in broiler stables on ESBL- and pAmpC- producing bacteria. RESULTS: We systematically investigated five broiler stables before and after C&D and identified potential ESBL- and pAmpC- colonization sites after C&D in the broiler stables, including the anteroom and the nearby surrounding environment of the broiler stables. Phenotypically resistant E. coli isolates grown on MacConkey agar with cefotaxime were further analyzed for their beta-lactam resistance genes and phylogenetic groups, as well as the relation of isolates from the investigated stables before and after C&D by whole genome sequencing. Survival of ESBL- and pAmpC- producing E. coli is highly likely at sites where C&D was not performed or where insufficient cleaning was performed prior to disinfection. For the first time, we showed highly related ESBL-/pAmpC- producing E. coli isolates detected before and after C&D in four of five broiler stables examined with cgMLST. Survival of resistant isolates in investigated broiler stables as well as transmission of resistant isolates from broiler stables to the anteroom and surrounding environment and between broiler farms was shown. In addition, enterococci (frequently utilized to detect fecal contamination and for C&D control) can be used as an indicator bacterium for the detection of ESBL-/pAmpC- E. coli after C&D. CONCLUSION: We conclude that C&D can reduce ESBL-/pAmpC- producing E. coli in conventional broiler stables, but complete ESBL- and pAmpC- elimination does not seem to be possible in practice as several factors influence the C&D outcome (e.g. broiler stable condition, ESBL-/pAmpC- status prior to C&D, C&D procedures used, and biosecurity measures on the farm). A multifactorial approach, combining various hygiene- and management measures, is needed to reduce ESBL-/pAmpC- E. coli in broiler farms.

Impression Disinfection and Its Effect on Dimensional Accuracy and Surface Detail in the Times of COVID-19: An In Vitro Study.

Introduction The disinfection of impressions is crucial to eliminate the viral and other microbial loads to prevent the cross contamination of diseases. The aim of this study was to compare the effect of different virucidal disinfecting methods on the dimensional accuracy and surface detail reproduction (SDR) of impression materials. Methods A total of 160 samples were fabricated with different impression materials using zinc oxide eugenol (Group 1), alginate (Group 2), polyether (Group 3), and addition silicone (Group 4) impression materials, each containing 40 samples (n=40). These groups were further divided into Subgroups A, B, C, and D (n=10) based on the disinfecting method used. Disinfection was carried out using 0.2% peracetic acid (A), a natural polymer of glucosamine (B), ultraviolet (UV) radiation (C), and ozonated water (D). The disinfected impressions were poured in type IV gypsum, and the obtained casts were checked for dimensional accuracy and surface detail reproduction (SDR). For dimensional accuracy, a one-way analysis of variance (ANOVA) test and, for surface detail reproduction, the chi-square test were used to compare the different subgroups of each impression material separately. Results Zinc oxide eugenol samples showed the lowest mean dimensional change when disinfected with 0.2% peracetic acid (1A=154.1 µm), and alginate showed the lowest mean dimensional change when disinfected using ozonated water (2D=134.9 µm). On the other hand, the lowest mean dimensional change observed in polyether and addition silicone samples was those which were disinfected using UV radiation (3C=100.9 µm and 4C=113.5 µm). Surface detail was reproduced adequately in most of the samples. Conclusion A 0.2% peracetic acid could be used to disinfect zinc oxide eugenol impressions, ozonated water for alginate impressions, and UV radiation for polyether and addition silicone impressions.

Mixed exposure to haloacetaldehyde disinfection by-products exacerbates lipid aggregation in the liver of mice.

Haloacetaldehyde disinfection by-products (HAL-DBPs) are among the top three unregulated DBPs found in drinking water. The cytotoxicity and genotoxicity of HALs are much higher than that of the regulated trihalomethanes and haloacetic acids. Previous studies have mainly focused on the toxic effects of single HAL, with few examining the toxic effects of mixed exposures to HALs. The study aimed to observe the effects of mixed exposures of 1∼1000X the realistic level of HALs on the hepatotoxicity and lipid metabolism of C57BL/6J mice, based on the component and concentration of HALs detected in the finished water of Shanghai. Exposure to realistic levels of HALs led to a significant increase in phosphorated acetyl CoA carboxylase 1 (p-ACC1) in the hepatic de novo lipogenesis (DNL) pathway. Additionally, exposure to 100X realistic levels of HALs resulted in significant alterations to key enzymes of DNL pathway, including ACC1, fatty acid synthase (FAS), and diacylglycerol acyltransferase 2 (DGAT2), as well as key proteins of lipid disposal such as carnitine palmitoyltransferase 1 (CPT-1) and peroxisome proliferator activated receptor α (PPARα). Exposure to 1000X realistic levels of HALs significantly increased hepatic and serum triglyceride levels, as well as total cholesterol, low-density lipoprotein, alanine aminotransferase, aspartate transaminase, alkaline phosphatase, and lactate dehydrogenase levels, significantly decreased high-density lipoprotein. Meanwhile, histopathological analysis demonstrated that HALs exacerbated tissue vacuolization and inflammatory cell infiltration in mice livers, which showed the typical phenotypes of non-alcoholic fatty liver disease (NAFLD). These results suggested that the HALs mixture is a critical risk factor for NAFLD and is significantly highly toxic to C57BL/6J mice.

Laser Applications in Regenerative Endodontics: A Review.

Introduction: Developing regenerative endodontic treatment (RET) is an exciting approach to managing immature permanent teeth with pulp necrosis. RET is usually performed in two clinical steps: disinfection (first step) and tissue engineering (second step). Recently, laser therapy has entered the field of RET. This study aimed to provide an overview of the literature that employed laser therapy for root regeneration. Methods: A comprehensive search was performed on four databases, including PubMed, Web of Science, Scopus, and Google Scholar. The searched keywords were laser, regenerative endodontics, immature permanent teeth, and dental pulp necrosis, and related English-published articles were included up to October 2023. Results: Thirteen studies utilized a laser for RET. In the first step of RET, both high-power and low-level lasers (through photodynamic therapy [PDT]) may be applied for canal disinfection. In contrast, regenerative procedures in the second step of RET are just accelerated by low-power lasers (biostimulation). The literature does not support the benefit of laser-assisted irrigation in improving the clinical success of RET. There is some evidence that laser-assisted disinfection with a diode laser may provide comparable results to triple antibiotic paste in reducing bacterial counts in root canals while providing slightly better clinical and radiographic outcomes. PDT may be an effective and suitable adjunct to conventional disinfection methods in immature, necrotic teeth. Conclusion: Low-power lasers may be beneficial tools for improving the results of regenerative endodontics through chemical disinfection in the first step (PDT) or by biostimulation in the second step of RET.

Hygiene requirements for cleaning and disinfection of surfaces: recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute.

This recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) addresses not only hospitals, but also outpatient health care facilities and compiles current evidence. The following criteria are the basis for the indications for cleaning and disinfection: Infectious bioburden and tenacity of potential pathogens on surfaces and their transmission routes, influence of disinfecting surface cleaning on the rate of nosocomial infections, interruption of cross infections due to multidrug-resistant organisms, and outbreak control by disinfecting cleaning within bundles. The criteria for the selection of disinfectants are determined by the requirements for effectiveness, the efficacy spectrum, the compatibility for humans and the environment, as well as the risk potential for the development of tolerance and resistance. Detailed instructions on the organization and implementation of cleaning and disinfection measures, including structural and equipment requirements, serve as the basis for their implementation. Since the agents for surface disinfection and disinfecting surface cleaning have been classified as biocides in Europe since 2013, the regulatory consequences are explained. As possible addition to surface disinfection, probiotic cleaning, is pointed out. In an informative appendix (only in German), the pathogen characteristics for their acquisition of surfaces, such as tenacity, infectious dose and biofilm formation, and the toxicological and ecotoxicological characteristics of microbicidal agents as the basis for their selection are explained, and methods for the evaluation of the resulting quality of cleaning or disinfecting surface cleaning are presented.

40-Year Outcome of Old-School, Non-Surgical Endodontic Treatment: Practice-Based Retrospective Evaluation.

(1) Background: Non-surgical endodontic treatment has been shown to be clinically successful; however, clinical long-term data are scarce. This practice-based retrospective clinical investigation evaluated endodontic outcomes over 40 years and identified relevant clinical co-factors. (2) Methods: Two experienced dental practitioners in two different private dental practices treated 174 patients with 245 teeth from 1969 to 1993. After root canal obturation, either a new direct restoration (amalgam, resin composite, or glass-ionomer cement) or the re-cementation of a pre-existing prosthetic restoration or renewal of prosthetic restoration followed. Metal posts (operator A) or metal screws (operator B) were inserted when coronal substance loss was significant. The primary outcome (i.e., tooth survival) was achieved when the endodontically treated tooth was, in situ, painless and had full function at the end of the observation period. A secondary outcome, the impact of different prognostic factors on survival rate, was evaluated. (3) Results: The overall mean survival was 56.1% of all treated teeth after 40 years of clinical service, resulting in an annual failure rate of 1.1%. Most investigated clinical co-factors (jaw, tooth position, intracanal dressings, post/screw placement, and gender) showed no significant influence on survival. (4) Conclusions: Even with materials and techniques from the 1970s and 1980s, successful root canal treatment was achievable. Except for post-endodontic restorations, most of the evaluated factors had no significant influence on the clinical long-term survival of root canal-treated teeth.

Tensile Strength and Elastic Modulus of Gutta-percha Cones Disinfected with Sodium Hypochlorite at Different Immersion Times: An In Vitro Comparative Study.

Aim: The tensile strength and modulus of elasticity of gutta-percha cones can be chemically altered due to disinfectant solutions. Therefore, the aim of the present study was to compare tensile strength and elastic modulus of gutta-percha cones subjected to sodium hypochlorite (NaOCl) disinfection at different times. Materials and Methods: This in vitro and longitudinal experimental study consisted of 45 gutta-percha cones, divided equally into three groups: Group 1 (disinfection with 2.5% NaOCl), Group 2 (disinfection with 5.25% NaOCl), and control group. All groups were subdivided according to immersion times for 1, 5, and 10 minutes. Tensile strength and elastic modulus were measured with a universal testing machine. For comparing more than two independent groups, parametric analysis of variance test with Sheffe's post hoc was used and for multivariate analysis, and multivariate analysis of variance test based on Pillai's Trace was used. In all statistical analysis, a significance level P ≤ 0.05 was considered. Results: When comparing the tensile strength of gutta-percha cones, no significant differences were observed after being immersed at 1, 5, and 10 minutes in NaOCl 2.5% (P = 0.715) and 5.25% (P = 0.585). Regarding the elastic modulus, a significant decrease (P < 0.05) was observed in those that were immersed in NaOCl 2.5% and 5.25% for 1, 5, and 10 minutes. Furthermore, increased NaOCl concentration significantly reduced the elastic modulus (P < 0.001). However, there were no significant differences in tensile strength (P > 0.05) and elastic modulus (P > 0.05), when evaluating the interaction between NaOCl concentration and time. Conclusion: Increasing NaOCl concentration significantly reduced the modulus of elasticity without affecting the tensile strength of gutta-percha cones, regardless of immersion time. Furthermore, the interaction of time and NaOCl concentration did not significantly affect the tensile strength and elastic modulus.

Regulating charge transfer for enhanced PAA activation over sulfur-doped magnetic CoFe2O4: A novel strategy for simultaneous micropollutants degradation and bacteria inactivation.

Micropollutants and bacteria are prevalent pollutants in wastewater, posing significant risks to ecosystems and human health. As peracetic acid (PAA) is being increasingly used as a disinfectant, activation of PAA by low-cost and high-performance activators is a promising strategy for wastewater treatment. In this study, the sulfur-doped magnetic CoFe2O4 (SCFO) is successfully developed for efficient PAA activation to simultaneously decontaminate and disinfect wastewater. PAA/SCFO-0.3 exhibits exceptional performance, degrading 100 % of 8 µM sulfamethoxazole (SMX) with a first-pseudo reaction rate of 1.275 min-1, and achieving 5.3-log inactivation of Escherichia coli (E. coli) within 3 min at a PAA dosage of 0.2 mM and catalyst dosage of 0.025 g/L (initial pH 6.5). Scavenging experiments and electron paramagnetic resonance (EPR) analysis identify CH3C(O)O• and CH3C(O)OO• as the dominant reactive species for SMX degradation. The sulfur species in SCFO-0.3 facilitate Co2+ regeneration and regulate charge transfer, promoting PAA activation for SMX degradation. Moreover, the PAA/SCFO-0.3 system demonstrates operational feasibility over a broad range of water matrices and has excellent stability and reusability (maintaining 93 % removal of SMX after 5 cycles), demonstrating its potential for industrial applications. This study provides insights into enhancing PAA activation through sulfur doping in transition metal catalysts and highlights the practical applicability of the PAA/SCFO-0.3 system as an advanced alternative to conventional disinfection for simultaneous decontamination and disinfection in wastewater.

Landscape of plasmids encoding ß-lactamases in disinfection residual Enterobacteriaceae from wastewater treatment plants.

Conventional disinfection processes, such as chlorination and UV radiation, are ineffective in controling antibiotic-resistant bacteria, especially disinfection residual Enterobacteriaceae (DRE) encoding ß-lactamases, some of which have been classified as "critical priority pathogens" by the World Health Organization. However, few studies have focused on the transferability, phenotype, and genetic characteristics of DRE-derived plasmids encoding ß-lactamases, especially extended-spectrum ß-lactamases and carbapenemases. In this study, we isolated 10 typical DRE harboring plasmid-mediated blaNDM, blaCTX-M, or blaTEM in post-disinfection effluent from two wastewater treatment plants (WWTPs), with transfer frequency ranging from 1.69 × 10-6 to 3.02 × 10-5. According to genomic maps of plasmids, all blaNDM and blaTEM were cascaded with IS26, and blaCTX-M was adjacent to ISEcp1 or IS26, indicating the important role of these elements in the movement of ß-lactamase-encoding genes. The presence of intact class 1 integrons on pWTPN-01 and pWTPC-03 suggested the ability of these DRE-derived plasmids to integrate other exogenous antibiotic resistance genes (ARGs). The coexistence of antibiotic, disinfectant, and heavy metal resistance genes on the same plasmid (e.g., pWTPT-03) implied the facilitating role of disinfectants and heavy metals in the transmission of DRE-derived ARGs. Notably, two plasmid transconjugants exhibited no discernible competitive fitness cost, suggesting a heightened environmental persistence. Furthermore, enhanced virulence induced by ß-lactamase-encoding plasmids in their hosts was confirmed using Galleria mellonella infection models, which might be attributed to plasmid-mediated virulence genes. Overall, this study describes the landscape of ß-lactamase-encoding plasmids in DRE, and highlights the urgent need for advanced control of DRE to keep environmental and ecological security.

Suppression of photoreactivation of E. coli by excimer far-UV light (222 nm) via damage to multiple targets.

Low-pressure mercury lamps emitting at 254 nm (UV254) are used widely for disinfection. However, subsequent exposure to visible light results in photoreactivation of treated bacteria. This study employed a krypton chloride excimer lamp emitting at 222 nm (UV222) to inactivate E. coli. UV222 and UV254 treatment had similar E. coli-inactivation kinetics. Upon subsequent irradiation with visible light, E. coli inactivated by UV254 was reactivated from 2.71-log to 4.75-log, whereas E. coli inactivated by UV222 showed negligible photoreactivation. UV222 treatment irreversibly broke DNA strands in the bacterium, whereas UV254 treatment primarily formed nucleobase dimers. Additionally, UV222 treatment caused cell membrane damage, resulting in wizened, pitted cells and permeability changes. The damage to the cell membrane was mainly due to the photolysis of proteins and lipids by UV222. Furthermore, the photolysis of proteins by UV222 destroyed enzymes, which blocked photoreactivation and dark repair. The multiple damages can be further evidenced by 4.0-61.1 times higher quantum yield in the photolysis of nucleobases and amino acids for UV222 than UV254. This study demonstrates that UV222 treatment damages multiple sites in bacteria, leading to their inactivation. Employing UV222 treatment as an alternative to UV254 could be viable for inhibiting microorganism photoreactivation in water and wastewater.

Evaluating the Performance of UV Disinfection across the 222-365 nm Spectrum against Aerosolized Bacteria and Viruses.

Bioaerosols play a significant role in the transmission of many infectious diseases, especially in enclosed indoor environments. Ultraviolet (UV) disinfection has demonstrated a high efficacy in inactivating microorganisms suspended in the air. To develop more effective and efficient UV disinfection protocols, it is necessary to evaluate and optimize the effectiveness of UV disinfection against aerosolized bacteria and viruses across the entire UV spectrum. In this study, we evaluated the performance of UV disinfection across the UV spectrum, ranging from 222 to 365 nm, against aerosolized bacteria and viruses, including Escherichia coli, Staphylococcus epidermidis, Salmonella enterica, MS2, P22, and Phi6. Six commonly available UV sources, including gas discharge tubes and light-emitting diodes with different emission spectra, were utilized, and their performance in terms of inactivation efficacy, action spectrum, and energy efficiency was determined. Among these UV sources, the krypton chloride excilamp emitting at a peak wavelength of 222 nm was the most efficient in inactivating viral bioaerosols. A low-pressure mercury lamp emitting at 254 nm performed well on both inactivation efficacy and energy efficiency. A UV light-emitting diode emitting at 268 nm demonstrated the highest bacterial inactivation efficacy, but required approximately 10 times more energy to achieve an equivalent inactivation level compared with that of the krypton chloride excilamp and low-pressure mercury lamp. This study provides insights into UV inactivation on bioaerosols, which can guide the development of effective wavelength-targeted UV air disinfection technologies and may significantly help reduce bioaerosol transmission in public areas.

Deciphering the Roles of Extracellular Polymeric Substances (EPS) in Shaping Disinfection Kinetics through Permanent Removal via Genetic Disruption.

Extracellular polymeric substances (EPS) ubiquitously encapsulate microbes and play crucial roles in various environmental processes. However, understanding their complex interactions with dynamic bacterial behaviors, especially during the disinfection process, remains very limited. In this work, we investigated the impact of EPS on bacterial disinfection kinetics by developing a permanent EPS removal strategy. We genetically disrupted the synthesis of exopolysaccharides, the structural components of EPS, in Pseudomonas aeruginosa, a well-known EPS-producing opportunistic pathogen found in diverse environments, creating an EPS-deficient strain. This method ensured a lasting absence of EPS while maintaining bacterial integrity and viability, allowing for real-time in situ investigations of the roles of EPS in disinfection. Our findings indicate that removing EPS from bacteria substantially lowered their susceptibility threshold to disinfectants such as ozone, chloramine B, and free chlorine. This removal also substantially accelerated disinfection kinetics, shortened the resistance time, and increased disinfection efficiency, thereby enhancing the overall bactericidal effect. The absence of EPS was found to enhance bacterial motility and increase bacterial cell vulnerability to disinfectants, resulting in greater membrane damage and intensified reactive oxygen species (ROS) production upon exposure to disinfectants. These insights highlight the central role of EPS in bacterial defenses and offer promising implications for developing more effective disinfection strategies.

Reviewing the evidence of antimicrobial activity of glycols.

In the 1940s and 1950s, researchers seeking safe and novel ways to eliminate airborne pathogens from enclosed spaces, investigated glycol vapours as a method of disinfection. More recently, the COVID-19 pandemic highlighted the need for a non-toxic aerial disinfectant that can be used in the presence of people. This scoping review is intended to analyse the early and more recent literature on glycol disinfection, scrutinizing the methodologies used, and to determine if the use of glycols as modern-day disinfectants is justified PRISMA-ScR guidelines were used to assess the 749 articles retrieved from the Web of Science platform, with 46 articles retained after the search strategy was applied. Early studies generally demonstrated good disinfection capabilities against airborne bacteria and viruses, particularly with propylene glycol (PG) vapour. Vapour pressure, relative humidity, and glycol concentration were found to be important factors affecting the efficacy of glycol vapours. Contact times depended mainly on the glycol application method (i.e. aerosolization or liquid formulation), although information on how glycol efficacy is impacted by contact time is limited. Triethylene glycol (TEG) is deemed to have low toxicity, carcinogenicity, and mutagenicity and is registered for use in air sanitization and deodorization by the US Environmental Protection Agency. Glycols are also used in liquid formulations for their antimicrobial activity against a wide range of microorganisms, although when used as a non-active excipient in products, their contribution to antimicrobial efficacy is rarely assessed. The appropriate use of liquid glycol-containing formulations was found to positively impact the antimicrobial capabilities of disinfectants when used at temperatures <0, food preservatives, and dental medicaments. Providing modern delivery technology can accurately control environmental conditions, the use of aerosolized glycol formulations should lead to successful disinfection, aiding infection prevention, and control regimens.

Deciphering Multidrug-Resistant Plasmids in Disinfection Residual Bacteria from a Wastewater Treatment Plant.

Current disinfection processes pose an emerging environmental risk due to the ineffective removal of antibiotic-resistant bacteria, especially disinfection residual bacteria (DRB) carrying multidrug-resistant plasmids (MRPs). However, the characteristics of DRB-carried MRPs are poorly understood. In this study, qPCR analysis reveals that the total absolute abundance of four plasmids in postdisinfection effluent decreases by 1.15 log units, while their relative abundance increases by 0.11 copies/cell compared to investigated wastewater treatment plant (WWTP) influent. We obtain three distinctive DRB-carried MRPs (pWWTP-01-03) from postdisinfection effluent, each carrying 9-11 antibiotic-resistant genes (ARGs). pWWTP-01 contains all 11 ARGs within an ∼25 Kbp chimeric genomic island showing strong patterns of recombination with MRPs from foodborne outbreaks and hospitals. Antibiotic-, disinfectant-, and heavy-metal-resistant genes on the same plasmid underscore the potential roles of disinfectants and heavy metals in the coselection of ARGs. Additionally, pWWTP-02 harbors an adhesin-type virulence operon, implying risks of both antibiotic resistance and pathogenicity upon entering environments. Furthermore, some MRPs from DRB are capable of transferring and could confer selective advantages to recipients under environmentally relevant antibiotic pressure. Overall, this study advances our understanding of DRB-carried MRPs and highlights the imminent need to monitor and control wastewater MRPs for environmental security.

Applications of artificial intelligence (AI) in drinking water treatment processes: Possibilities.

In water treatment processes (WTPs), artificial intelligence (AI) based techniques, particularly machine learning (ML) models have been increasingly applied in decision-making activities, process control and optimization, and cost management. At least 91 peer-reviewed articles published since 1997 reported the application of AI techniques to coagulation/flocculation (41), membrane filtration (21), disinfection byproducts (DBPs) formation (13), adsorption (16) and other operational management in WTPs. In this paper, these publications were reviewed with the goal of assessing the development and applications of AI techniques in WTPs and determining their limitations and areas for improvement. The applications of the AI techniques have improved the predictive capabilities of coagulant dosages, membrane flux, rejection and fouling, disinfection byproducts (DBPs) formation and pollutants' removal for the WTPs. The deep learning (DL) technology showed excellent extraction capabilities for features and data mining ability, which can develop an image recognition-based DL framework to establish the relationship among the shapes of flocs and dosages of coagulant. Further, the hybrid techniques (e.g., combination of regression and AI; physical/kinetics and AI) have shown better predictive performances. The future research directions to achieve better control for WTPs through improving these techniques were also emphasized.

Resource recovery from soiled sanitary napkin waste-a state-of-the-art review.

With ever-improving social and medical awareness about menstrual hygiene in India, the demand for sanitary napkins has increased significantly. The utilization of high-quality and environment-friendly raw materials to produce these pads is further supporting the growth of the market. However, with improving demand and usage, the need for proper disposal techniques becomes more relevant, since all of these pads get contaminated with human blood which makes them a biohazard and can cause significant damage to human health and the environment. One sanitary pad takes around 800 years to degrade naturally and the plastic and super absorbent polymers (SAPs) in sanitary pads are non-biodegradable and can take multiple decades to degrade. Waste management technologies such as pyrolysis, gasification, and resource recovery can be adopted to manage tons of sanitary waste. Currently, sanitary waste treatment mainly focuses on landfilling, incineration, and composting, where biohazard wastes are mixed with tons of solid waste. Disposable sanitary pads have a high carbon footprint of about 5.3 kg CO2 equivalent every year. Innovative solutions for sanitary pad disposal are discussed in the manuscript which includes repurposing of derived waste cellulose and plastic fraction into value-added products. Future aspects of disinfection strategies and value addition to waste cellulose recovered from napkins were systematically discussed to promote a circular economy.

Effect of ozone gas on cultures of Candida albicans and Aspergillus fumigatus: evaluation of two ozonation devices.

INTRODUCTION: Candida albicans and Aspergillus fumigatus are two important agents of Healthcare-associated infections. This study aimed to evaluate the antifungal activity of ozone (O3) gas produced by two commercial devices against cultures of these two species. METHODOLOGY: Sterile plastic plates were inoculated with C. albicans and A. fumigatus and placed on a countertop at three distances (30 cm, 1 m, and 2 m) and three positions in relation to the wall (near, middle, and away), considering the source of O3. Plates were exposed to O3 for one hour and incubated. After incubation, the counting of colony-forming units was performed. As a control, an inoculated plate was incubated, without being exposed to O3. Tests were carried out with two different devices (namely, Mod.I and Mod.II), with the air conditioner on and off, in triplicate. RESULTS: Both devices showed antifungal activity. Mod. I presented better results, due to a higher flow rate. The best activity was on plates at 30 cm, middle position. Contrarily, on plates at 2m, near the wall, the inhibition activity was lower. The best results were obtained with the air conditioner off. Candida albicans was more sensitive to O3 than A. fumigatus. CONCLUSIONS: This method of decontamination by O3 gas shows potential due to its fast and easy execution. The establishment of new protocols for hygiene and hospital disinfection using this approach should be considered, which may reduce environmental contamination by fungi and, consequently, the burden of fungal infections.

Comparing resistance of bacterial spores and fungal conidia to pulsed light and UVC radiation at a wavelength of 254 nm.

Pulsed light (PL) inactivates microorganisms by UV-rich, high-irradiance and short time pulses (250 µs) of white light with wavelengths from 200 nm to 1100 nm. PL is applied for disinfection of food packaging material and food-contact equipment. Spores of seven Bacillus ssp. strains and one Geobacillus stearothermophilus strain and conidia of filamentous fungi (One strain of Aspergillus brasiliensis, A. carbonarius and Penicillium rubens) were submitted to PL (fluence from 0.23 J/cm2 to 4.0 J/cm2) and UVC (at λ = 254 nm; fluence from 0.01 J/cm2 to 3.0 J/cm2). One PL flash at 3 J/cm2 allowed at least 3 log-reduction of all tested microorganisms. The emetic B. cereus strain F4810/72 was the most resistant of the tested spore-forming bacteria. The PL fluence to 3 log-reduction (F3 PL) of its spores suspended in water was 2.9 J/cm2 and F3 UVC was 0.21 J/cm2, higher than F3 PL and F3 UVC of spores of B. pumilus SAFR-032 2.0 J/cm2 and 0.15 J/cm2, respectively), yet reported as a highly UV-resistant spore-forming bacterium. PL and UVC sensitivity of bacterial spores was correlated. Aspergillus spp. conidia suspended in water were poorly sensitive to PL. In contrast, PL inactivated Aspergillus spp. conidia spread on a dry surface more efficiently than UVC. The F2 PL of A. brasiliensis DSM1988 was 0.39 J/cm2 and F2 UVC was 0.83 J/cm2. The resistance of spore-forming bacteria to PL could be reasonably predicted from the knowledge of their UVC resistance. In contrast, the sensitivity of fungal conidia to PL must be specifically explored.