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Although in Europe the quality of swimming pools (SPs) is dictated by regulations, microbiological and chemical hazards are described in the literature. Environmental bacteria or toxic disinfection by-product (DBP) compounds may indeed be recovered in waters even after disinfection. We evaluated the water quality from 26 outdoor seasonal SPs of the Versilia district, according to requirements of Regional Decree 54R/2015. In spring 2017, supply and reinstatement waters were collected after shock hyperchlorination (10 mg/L) while in summertime, a second sampling of waters before entering the pools, as well as in the pools, was performed after SPs were open to the public. In all samples, microbiological and chemical parameters were determined as defined by Directive 98/83/EC and the Italian Health Ministry. Microbiological data were within suggested limits. The first chemical analyses showed that in 35% of the feeding-pool seawater samples, the halogenated organic compounds were higher than the maximum permissible concentrations (30 µg/L). Pool waters were then dechlorinated and re-treated with hydrogen peroxide (10 mg/L) to ensure the abatement of DBPs (from 164 ± 107 to 0.9 ± 0.8 µg/L; p = 0.002). Results highlighted the need of self-controlled procedures for the SPs waters to prevent waterborne diseases and suggested hydrogen peroxide as the most appropriate disinfection method.
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Desinfetantes/análise , Piscinas/estatística & dados numéricos , Poluentes Químicos da Água/análise , Desinfecção , Itália , Estações do AnoRESUMO
Italian Directives recommend the good quality of natural mineral waters but literature data assert a potential risk from microorganisms colonizing wellsprings and mineral water bottling plants. We evaluated the presence of microorganisms in spring waters (SW) and bottled mineral waters (BMW) samples. Routine microbiological indicators, additional microorganisms like Legionella spp., Nontuberculous mycobacteria (NTM) and amoebae (FLA) were assessed in 24 SW and 10 BMW samples performing cultural and molecular methods. In 33 out of 34 samples, no cultivable bacteria ≥10 CFU/L was found. Cultivable FLA were detected in 50% of water samples. qPCR showed the presence of Legionella qPCR units in 24% of samples (from 1.1 × 102 to 5.8 × 102 qPCR units/L) and NTM qPCR units in 18% of samples (from 1 × 102 to 1 × 105 qPCR units/L). Vermamoeba vermiformis and Acanthamoeba polyphaga were recovered respectively in 70% of BMW samples (counts from 1.3 × 103 to 1.2 × 105 qPCR units/L) and 42% of SW samples (from 1.1 × 103 to 1.3 × 104 qPCR units/L). Vahlkampfia spp. was detected in 42% of SW and 70% of BMW samples (from 1.2 × 103 to 1.2 × 105 qPCR units/L). Considering the presence of FLA, we underline the importance of a wider microbiological risk assessment in natural mineral waters despite the absence of cultivable bacteria.
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Água Potável/microbiologia , Águas Minerais/microbiologia , Microbiologia da Água , Qualidade da Água/normas , Amoeba , Água Potável/parasitologia , Itália , Legionella , Águas Minerais/parasitologia , Micobactérias não TuberculosasRESUMO
In this paper we describe the laws and rules applying to swimming pools. Authorization activity title for recreational swimming pools is regulated according to articles 80 and 86 of the TULPS R.D.n°773/1931. In Regione Toscana periodic management of the hygienic requirements for swimming pools is regulated by Regional Decree 54R/2015. It requires the evaluation of physical-chemical and microbiological indicators. The law applies to structural and organizational requirements of swimming pools as well as defines responsabilities of managers.
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Higiene , Saúde Pública , Piscinas/legislação & jurisprudência , Piscinas/normas , Qualidade da Água/normas , Humanos , Higiene/legislação & jurisprudência , Água/análise , Microbiologia da ÁguaRESUMO
Food trade globalization and the growing demand for selected food varieties have led to the intensification of adulteration cases, especially in the form of species substitution and mixing with cheaper taxa. This phenomenon has huge economic impact and sometimes even public health implications. DNA barcoding represents a well-proven molecular approach to assess the authenticity of food items, although its use is hampered by analytical constraints and timeframes that are often prohibitive for the food market. To address such issues, we have introduced a new technology, named NanoTracer, that allows for rapid and naked-eye molecular traceability of any food and requires limited instrumentation and cost-effective reagents. Moreover, unlike sequencing, this method can be used to identify not only the substitution of a fine ingredient, but also its dilution with cheaper ones.
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Colorimetria/métodos , Código de Barras de DNA Taxonômico , Contaminação de Alimentos/análise , Nanotecnologia , Comércio , Primers do DNA , Conjuntos de Dados como Assunto , Indicadores e Reagentes/química , Reação em Cadeia da Polimerase/métodos , Estudo de Prova de ConceitoRESUMO
The versatility of PCR, the gold standard for amplification of DNA targets, is hampered by the laborious, multi-step detection based on gel electrophoresis. We propose a one-step, one-tube method for the rapid (5â min) naked-eye detection of PCR products, based on controlled aggregation of gold nanoparticles. Our method is universal, instrument-free, and ultra-sensitive, as it could detect as low as 0.01 zeptomoles of HIV template DNA in an excess of interfering human genomic DNA.
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Ouro/química , Nanopartículas Metálicas/química , Reação em Cadeia da Polimerase/métodos , DNA/análise , DNA/genética , HIV/genética , HIV/isolamento & purificação , HumanosRESUMO
SINEUPs are natural and synthetic antisense long non-coding RNAs (lncRNAs) selectively enhancing target mRNAs translation by increasing their association with polysomes. This activity requires two RNA domains: an embedded inverted SINEB2 element acting as effector domain, and an antisense region, the binding domain, conferring target selectivity. SINEUP technology presents several advantages to treat genetic (haploinsufficiencies) and complex diseases restoring the physiological activity of diseased genes and of compensatory pathways. To streamline these applications to the clinic, a better understanding of the mechanism of action is needed. Here we show that natural mouse SINEUP AS Uchl1 and synthetic human miniSINEUP-DJ-1 are N6-methyladenosine (m6A) modified by METTL3 enzyme. Then, we map m6A-modified sites along SINEUP sequence with Nanopore direct RNA sequencing and a reverse transcription assay. We report that m6A removal from SINEUP RNA causes the depletion of endogenous target mRNA from actively translating polysomes, without altering SINEUP enrichment in ribosomal subunit-associated fractions. These results prove that SINEUP activity requires an m6A-dependent step to enhance translation of target mRNAs, providing a new mechanism for m6A translation regulation and strengthening our knowledge of SINEUP-specific mode of action. Altogether these new findings pave the way to a more effective therapeutic application of this well-defined class of lncRNAs.
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BACKGROUND AND PURPOSE: Cognitive and motor functions are modulated by dopaminergic signalling, which is shaped by several genetic factors. The biological effects of single genetic variants might differ depending on epistatic interactions that can be functionally multi-directional and non-linear. EXPERIMENTAL APPROACH: We performed behavioural and neurochemical assessments in genetically modified mice and behavioural assessments and genetic screening in human patients with 22q11.2 deletion syndrome (22q11.2DS). KEY RESULTS: Here, we confirm a genetic interaction between the Comt (catechol-O-methyltransferase, human orthologue: COMT) and Dtnbp1 (dystrobrevin binding protein 1, alias dysbindin, human orthologue: DTNBP1) genes that modulate cortical and striatal dopaminergic signalling in a manner not predictable by the effects of each single gene. In mice, Comt-by-Dtnbp1 concomitant reduction leads to a hypoactive mesocortical and a hyperactive mesostriatal dopamine pathway, associated with specific cognitive abnormalities. Like mice, in subjects with the 22q11.2DS (characterized by COMT hemideletion and dopamine alterations), COMT-by-DTNBP1 concomitant reduction was associated with analogous cognitive disturbances. We then developed an easy and inexpensive colourimetric kit for the genetic screening of common COMT and DTNBP1 functional genetic variants for clinical application. CONCLUSIONS AND IMPLICATIONS: These findings illustrate an epistatic interaction of two dopamine-related genes and their functional effects, supporting the need to address genetic interaction mechanisms at the base of complex behavioural traits.
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Síndrome de DiGeorge , Humanos , Camundongos , Animais , Síndrome de DiGeorge/genética , Catecol O-Metiltransferase/genética , Catecol O-Metiltransferase/metabolismo , Dopamina/metabolismo , Predisposição Genética para Doença , Relevância Clínica , Polimorfismo de Nucleotídeo Único , Disbindina/genéticaRESUMO
SINEUPs are a novel class of natural and synthetic non-coding antisense RNA molecules able to increase the translation of a target mRNA. They present a modular organization comprising an unstructured antisense target-specific domain, which sets the specificity of each individual SINEUP, and a structured effector domain, which is responsible for the translation enhancement. In order to design a fully functional in vitro transcribed SINEUP for therapeutics applications, SINEUP RNAs were synthesized in vitro with a variety of chemical modifications and screened for their activity on endogenous target mRNA upon transfection. Three combinations of modified ribonucleotides-2'O methyl-ATP (Am), N6 methyl-ATP (m6A), and pseudo-UTP (ψ)-conferred SINEUP activity to naked RNA. The best combination tested in this study was fully modified with m6A and ψ. Aside from functionality, this combination conferred improved stability upon transfection and higher thermal stability. Common structural determinants of activity were identified by circular dichroisms, defining a core functional structure that is achieved with different combinations of modifications.
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Sustainable coatings for metal food packaging were prepared from ZnO nanoparticles (obtained by the thermal decomposition of zinc acetate) and a naturally occurring polyhydroxylated fatty acid named aleuritic (or 9,10,16-trihydroxyhexadecanoic) acid. Both components reacted, originating under specific conditions zinc polyaleuritate ionomers. The polymerization of aleuritic acid into polyaleuritate by a solvent-free, melt polycondensation reaction was investigated at different times (15, 30, 45, and 60 min), temperatures (140, 160, 180, and 200 °C), and proportions of zinc oxide and aleuritic acid (0:100, 5:95, 10:90, and 50:50, w/w). Kinetic rate constants calculated by infrared spectroscopy decreased with the amount of Zn due to the consumption of reactive carboxyl groups, while the activation energy of the polymerization decreased as a consequence of the catalyst effect of the metal. The adhesion and hardness of coatings were determined from scratch tests, obtaining values similar to robust polymers with high adherence. Water contact angles were typical of hydrophobic materials with values ≥94°. Both mechanical properties and wettability were better than those of bisphenol A (BPA)-based resins and most likely are related to the low migration values determined using a hydrophilic food simulant. The presence of zinc provided a certain degree of antibacterial properties. The performance of the coatings against corrosion was studied by electrochemical impedance spectroscopy at different immersion times in an aqueous solution of NaCl. Considering the features of these biobased lacquers, they can be potential materials for bisphenol A-free metal packaging.
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RNA molecules have emerged as a new class of promising therapeutics to expand the range of druggable targets in the genome. In addition to 'canonical' protein-coding mRNAs, the emerging richness of sense and antisense long non-coding RNAs (lncRNAs) provides a new reservoir of molecular tools for RNA-based drugs. LncRNAs are composed of modular structural domains with specific activities involving the recruitment of protein cofactors or directly interacting with nucleic acids. A single therapeutic RNA transcript can then be assembled combining domains with defined secondary structures and functions, and antisense sequences specific for the RNA/DNA target of interest. As the first representative molecules of this new pharmacology, we have identified SINEUPs, a new functional class of natural antisense lncRNAs that increase the translation of partially overlapping mRNAs. Their activity is based on the combination of two domains: an embedded mouse inverted SINEB2 element that enhances mRNA translation (effector domain) and an overlapping antisense region that provides specificity for the target sense transcript (binding domain). By genetic engineering, synthetic SINEUPs can potentially target any mRNA of interest increasing translation and therefore the endogenous level of the encoded protein. In this review, we describe the state-of-the-art knowledge of SINEUPs and discuss recent publications showing their potential application in diseases where a physiological increase of endogenous protein expression can be therapeutic.
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Biossíntese de Proteínas , RNA Longo não Codificante , Animais , Camundongos , Proteínas/metabolismo , RNA Antissenso/genética , RNA Antissenso/metabolismo , RNA Longo não Codificante/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
BACKGROUND: An essential event during the replication cycle of HIV-1 is the integration of the reverse transcribed viral DNA into the host cellular genome. Our former report revealed that HIV-1 integrase (IN), the enzyme that catalyzes the integration reaction, is positively regulated by acetylation mediated by the histone acetyltransferase (HAT) p300. RESULTS: In this study we demonstrate that another cellular HAT, GCN5, acetylates IN leading to enhanced 3'-end processing and strand transfer activities. GCN5 participates in the integration step of HIV-1 replication cycle as demonstrated by the reduced infectivity, due to inefficient provirus formation, in GCN5 knockdown cells. Within the C-terminal domain of IN, four lysines (K258, K264, K266, and K273) are targeted by GCN5 acetylation, three of which (K264, K266, and K273) are also modified by p300. Replication analysis of HIV-1 clones carrying substitutions at the IN lysines acetylated by both GCN5 and p300, or exclusively by GCN5, demonstrated that these residues are required for efficient viral integration. In addition, a comparative analysis of the replication efficiencies of the IN triple- and quadruple-mutant viruses revealed that even though the lysines targeted by both GCN5 and p300 are required for efficient virus integration, the residue exclusively modified by GCN5 (K258) does not affect this process. CONCLUSIONS: The results presented here further demonstrate the relevance of IN post-translational modification by acetylation, which results from the catalytic activities of multiple HATs during the viral replication cycle. Finally, this study contributes to clarifying the recent debate raised on the role of IN acetylated lysines during HIV-1 infection.
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Integrase de HIV/metabolismo , HIV-1/patogenicidade , Interações Hospedeiro-Patógeno , Integração Viral , Fatores de Transcrição de p300-CBP/metabolismo , Acetilação , Substituição de Aminoácidos , Linhagem Celular , Técnicas de Silenciamento de Genes , Integrase de HIV/genética , Humanos , Lisina/genética , Lisina/metabolismo , Mutagênese Sítio-Dirigida , Fatores de Transcrição de p300-CBP/genéticaRESUMO
Targeted therapies for cutaneous melanoma, such as those based on specific BRAF inhibitors, have improved the treatment and enhanced the survival rate of patients who harbor the V600E point mutation in the BRAF gene. However, tissue biopsies to characterize BRAF mutation status are prone to sampling bias, due to the intrinsic heterogeneity of a tumor mass. In contrast, blood biopsies, which analyze circulating tumor DNA (ctDNA), offer the most complete and sensitive characterization of the mutation status of a tumor, provide early and more accurate diagnosis, but they require instrumental and costly molecular tests. Therefore, the development of low-cost but highly sensitive tests for the non-invasive identification of BRAFV600E mutation in ctDNA would be of great clinical utility as a routine screening for the early identification of responsive patients and the follow-up of targeted therapy's response. The present work developed a naked-eye, inexpensive, yet very specific colorimetric assay, whose sensitivity is suitable for the detection of BRAFV600E rare mutation in ctDNA. Such test potentially may detect at an early stage the mutation in the tumor mass, when the first mutated cells appear in the blood, by using minimal instrumentation and thus enabling its widespread implementation in the clinics, even in local, minimally equipped laboratories. Indeed, the test detects 0.5% of BRAFV600E in an excess of BRAFWT DNA, which matches the sensitivity of some commercial instrumental assays. Such sensitivity is thus clinically relevant for diagnostic purposes, allowing the early identification of drug-sensitive patients.
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DNA de Neoplasias/genética , Melanoma/genética , Mutação de Sentido Incorreto , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/genética , Substituição de Aminoácidos , Linhagem Celular Tumoral , Colorimetria , Análise Mutacional de DNA , Humanos , Melanoma Maligno CutâneoRESUMO
A nanocomposite material characterized by peroxidase-like properties was developed through the dispersion of platinum nanoparticles (PtNPs) inside a hydrogelic matrix. The integration of the PtNP catalysts within the matrix resulted in their stabilization, preventing aggregation and precipitation in media of environmental interest, characterized by high ionic strength and by the presence of organic solutes. A thorough optimization of the matrix design was aimed at granting optimal diffusion of the reagents, in order to maintain the efficiency of the catalytic action. Such combined features allowed the implementation and prototyping of a colorimetric method for the detection of mercury in environmental water samples. The assay was based on a chromogenic reaction catalyzed by the peroxidase-like activity of PtNPs and its specific inhibition caused by trace amounts of mercury.
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The protocol describes a naked-eye colorimetric test for the detection of somatic point mutations in an excess of wild type DNA. The future foreseen application of the method is the identification of rare mutations in circulating cell-free DNA from liquid biopsies, with a relevance in cancer diagnostics and stratification of oncological patients for personalized therapy. As a proof of concept, the test has been designed to detect the BRAFV600E mutation in the BRAF gene, which is important to identify the sub-group of melanoma patients that can benefit from targeted therapies with BRAF inhibitors. However, this colorimetric test can be easily generalized to other somatic mutations of clinical relevance due to the use of universal detection probes, thus providing strong potential in oncological diagnostics. The test detects 0.5% of BRAFV600E in an excess of BRAFWT DNA, which matches the sensitivity of some commercial instrumental assays. Such sensitivity is clinically relevant for diagnostic purposes, allowing the early identification of drug-sensitive patients. In contrast to commercial assays based on real-time PCR, this test requires minimal instrumentation and processing, as it can be performed on DNA amplified with a standard PCR (or isothermal techniques) and provides a naked-eye readout with a one-tube reaction of a few steps in only one hour. At present, the test has been used only on synthetic DNA samples. However, the latter have been designed to mimic a real sample amplified from circulating cell-free DNA, to favor the translation of the test to clinical diagnostics.
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Análise Mutacional de DNA/métodos , DNA/genética , Mutação Puntual/genética , Colorimetria , Sondas de DNA/metabolismo , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/genética , Espectrofotometria UltravioletaRESUMO
International literature data report that the increase of infectious risk may be due to heating, ventilation and air conditioning (HVAC) systems contaminated by airborne pathogens. Moreover, the presence of complex rotating dehumidification wheels (RDWs) may complicate the cleaning and disinfection procedures of the HVAC systems. We evaluated the efficacy of a disinfection strategy applied to the RDW of two hospitals' HVAC systems. Hospitals have four RDW systems related to the surgical areas (SA1 and SA2) and to the intensive and sub-intensive care (IC and sIC) units. Microbiological air and surface analyses were performed in HVAC systems, before and after the disinfection treatment. Hydrogen peroxide (12%) with silver ions (10 mg/L) was aerosolized in all the air sampling points, located close to the RDW device. After the air disinfection procedure, reductions of total microbial counts at 22 °C and molds were achieved in SA2 and IC HVAC systems. An Aspergillus fumigatus contamination (6 CFU/500 L), detected in one air sample collected in the IC HVAC system, was eradicated after the disinfection. The surface samples proved to be of good microbiological quality. The results suggest the need for a disinfection procedure to improve the microbiological quality of the complex HVAC systems, mostly in surgical and intensive care areas.
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A new and straightforward single-step route to decorate melamine foams with silver nanoparticles (ME/Ag) is proposed. Uniform coatings of silver nanoparticles with diameters less than 10 nm are formed in situ directly on the struts surface of the foams, after their dipping in an AgNO3 solution. We prove that the nanoparticles are stably adhered on the foams, and that their amount can be directly controlled by the concentration of the AgNO3 solution and the dipping time. Following this production route, ME/Ag foams can be obtained with silver content ranging between 0.2 and 18.6 wt % and excellent antibacterial performance, making them appropriate for various applications. Herein we explore the possibility to use them as antibacterial filters for water treatment, proving that they are able to remove completely Escherichia coli bacteria from water when filtered at flow rates up to 100 mL/h·cm2 due to the release of less than 1 ppm of Ag+ ions by the foams. No bacterial regrowth was observed after further dilution of the treated water, to arrive below the safety threshold of Ag+ for drinking water (0.1 ppm), demonstrating the excellent bactericide performance of the ME/Ag filters.
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Triazinas/química , Antibacterianos , Nanopartículas Metálicas , PrataRESUMO
Aims: High-touch surfaces cleaning and disinfection require the adoption of effective and proper executed protocols, especially during carbapenem-resistant Acinetobacter baumannii (CRAB) endemo-epidemic situations. We evaluated the effectiveness and residual disinfectant activity of disposable pre-impregnated wipes (Modified Operative Protocol, MOP) in reducing environmental bioburden versus a two-step Standard Operative Protocol (SOP) in a 12-bed Intensive Care Unit. Methods: Five high-touch surfaces were cleaned and disinfected either according to the SOP (alcohol-based cleaning and chlorine-based disinfection) or using quaternary ammonium compounds-based disposable wipes (MOP). Sampling was performed before each procedure and at 0.5, 2.5, 4.5 and 6.5 h after (560 sites). Total viable count (TVC) was evaluated according to Italian hygiene standard (<50 CFU/24 cm²). Clinical and environmental CRAB strains isolated were genotyped. Results: On non-electromedical surfaces the difference between TVC before procedure and at each of the following times was significant only for the MOP (p < 0.05, Wilcoxon test). Using the MOP, only 7.4% (10/135) of sites showed TVC >50 CFU/24 cm² (hygiene failures) versus 18.9% (25/132) after SOP (p < 0.05, Fisher's Exact test). On infusion pumps a higher number of hygiene failures was observed after the SOP (7/44, 15.9%) compared with the MOP (4/45, 8.9%). Genotyping highlighted a common source of infection. Conclusion: On high-touch surfaces, the use of disposable wipes by in-house auxiliary nurses may represent a more effective alternative to standard cleaning and disinfection procedure performed by outsourced cleaning services, showing effectiveness in reducing microbial contamination and residual disinfection activity up to 6.5 h.
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Acinetobacter baumannii/efeitos dos fármacos , Carga Bacteriana , Carbapenêmicos , Desinfetantes , Desinfecção/métodos , Doença Iatrogênica/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Unidades de Terapia Intensiva , Itália , Masculino , Pessoa de Meia-IdadeRESUMO
Cinnamoly compounds 1a-c and 2a-d were designed, synthesized, and in vitro tested as p300 inhibitors. At different degrees, all tested compounds were proven to inactivate p300, particularly, derivative 2c was the most active inhibitor, also showing high specificity for p300 as compared to other histone acetyltransferases. Most notably, 2c showed anti-acetylase activity in mammalian cells. These compounds represent a new class of synthetic inhibitors of p300, characterized by simple chemical structures.
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Compostos de Benzilideno/síntese química , Proteínas de Ciclo Celular/antagonistas & inibidores , Cinamatos/síntese química , Cicloexanonas/síntese química , Histona Acetiltransferases/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Acetilação , Compostos de Benzilideno/farmacologia , Permeabilidade da Membrana Celular , Cinamatos/farmacologia , Curcumina/análogos & derivados , Curcumina/síntese química , Curcumina/farmacologia , Cicloexanonas/farmacologia , Células HeLa , Histonas/metabolismo , Humanos , Proteínas Recombinantes/antagonistas & inibidores , Fatores de Transcrição de p300-CBPRESUMO
Water insoluble monohydrochloride monohydrate free ciprofloxacin (Cipro) antibiotic was incorporated in polyvinylpyrrolidone (PVP) polymer matrix by using acetic acid co-solvent in water. The resultant solutions were cast into fully transparent antimicrobial films. Proper concentrations of acetic acid eliminated in situ crystallization of the antibiotic and the resultant phase separation upon solvent evaporation. The solutions could also be electrospun into nanofiber mats (non-transparent). Presence of residual PVP-bound acetic acid in dry PVP films induced unprecedented levels of plasticity (stretching capacity) and softness to the films. Additionally, PVP-bound acetic acid also acted as an antiseptic. Antibacterial properties of the films and fiber mats were confirmed on Escherichia coli and Bacillus subtilis (growth and viability). Films and nanofiber mats demonstrated promising wound resorption characteristics by using in vivo full-thickness excisional skin wound healing mice model. Nanofiber mats were resorbed much faster than transparent films. Wound exudate absorption in the films and resorption rate of the nanofiber mats were dependent on the starting acetic acid concentrations. The fact that PVP/Cipro solutions in aqueous acetic acid can be used either to produce transparent soft films or nanofiber mats renders this process highly suitable for the fabrication of new-generation potential dressings for wound management and care.
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Antibacterianos/administração & dosagem , Bandagens , Ciprofloxacina/administração & dosagem , Nanofibras , Povidona/administração & dosagem , Ferimentos e Lesões/terapia , Animais , Bacillus subtilis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Ferimentos e Lesões/microbiologiaRESUMO
OBJECTIVES: To evaluate the effectiveness of hydrogen peroxide (HP) use as a disinfectant in the hospital water network for the control of Legionella spp. colonization. METHODS: Following the detection of high levels of Legionella contamination in a 136-bed general hospital water network, an HP treatment of the hot water supply (25 mg/L) was adopted. During a period of 34 months, the effectiveness of HP on Legionella colonization was assessed. Legionella was isolated in accordance with ISO-11731 and identification was carried out by sequencing of the mip gene. RESULTS: Before HP treatment, L. pneumophila sg 2-15 was isolated in all sites with a mean count of 9950 ± 8279 cfu/L. After one-month of HP treatment, we observed the disappearance of L. pneumophila 2-15, however other Legionella species previously not seen were found; Legionellapneumophila 1 was isolated in one out of four sampling sites (2000 cfu/L) and other non-pneumophila species were present in all sites (mean load 3000 ± 2887 cfu/L). Starting from September 2013, HP treatment was modified by adding food-grade polyphosphates, and in the following months, we observed a progressive reduction of the mean load of all species (p < 0.05), resulting in substantial disappearance of Legionella colonization. CONCLUSION: Hydrogen peroxide demonstrated good efficacy in controlling Legionella. Although in the initial phases of treatment it appeared unable to eliminate all Legionella species, by maintaining HP levels at 25 mg/L and adding food-grade polyphosphates, a progressive and complete control of colonization was obtained.