Evaluation of pathogen disinfection efficiency of electrochemical advanced oxidation to become a sustainable technology for water reuse.

Water treatment and reuse is gaining acceptance as a strategy to fight against water contamination and scarcity, but it usually requires complex treatments to ensure safety. Consequently, the electrochemical advanced processes have emerged as an effective alternative for water remediation. The main objective here is to perform a systematic study that quantifies the efficiency of a laboratory-scale electrochemical system to inactivate bacteria, bacterial spores, protozoa, bacteriophages and viruses in synthetic water, as well as in urban wastewater once treated in a wetland for reuse in irrigation. A Ti|RuO2-based plate and Si|BDD thin-film were comparatively employed as the anode, which was combined with a stainless-steel cathode in an undivided cell operating at 12 V. Despite the low resulting current density (<15 mA/cm2), both anodes demonstrated the production of oxidants in wetland effluent water. The disinfection efficiency was high for the bacteriophage MS2 (T99 in less than 7.1 min) and bacteria (T99 in about 30 min as maximum), but limited for CBV5 and TuV, spores and amoebas (T99 in more than 300 min). MS2 presented a rapid exponential inactivation regardless of the anode and bacteria showed similar sigmoidal curves, whereas human viruses, spores and amoebas resulted in linear profiles. Due the different sensitivity of microorganisms, different models must be considered to predict their inactivation kinetics. On this basis, it can be concluded that evaluating the viral inactivation from inactivation profiles determined for bacteria or some bacteriophages may be misleading. Therefore, neither bacteria nor bacteriophages are suitable models for the disinfection of water containing enteric viruses. The electrochemical treatment added as a final disinfection step enhances the inactivation of microorganisms, which could contribute to safe water reuse for irrigation. Considering the calculated low energy consumption, decentralized water treatment units powered by photovoltaic modules might be a near reality.

Aplicación internacional del programa “Intervención multidimensional para la ansiedad social” (IMAS): II. Eficacia del tratamiento para problemas relacionados con la ansiedad social / [International application of the program "Multidimensional intervention for social anxiety" (IMAS): II. Efficacy of treatment for problems related to social anxiety]

En un trabajo anterior (Caballo et al., 2021) comprobamos la eficacia del programa de Intervención multidimensional para la ansiedad social (IMAS) en la reducción de los síntomas de ansiedad social. En este estudio cuasiexperimental, con medidas pre/postratamiento y seguimiento, hallamos el impacto del programa IMAS en otros problemas relacionados con la ansiedad social. 57 personas diagnosticadas con un trastorno de ansiedad social (TAS), según el DSM-5, contestaron a cuestionarios que medían habilidades sociales, depresión, síntomas del trastorno de la personalidad por evitación, alcoholismo, autoestima, sensibilidad personal, preocupaciones y calidad de vida. Diferentes terapeutas llevaron a cabo el tratamiento en Ecuador, España y Paraguay. Los resultados mostraron importantes mejoras en el postratamiento en prácticamente todos los aspectos evaluados, mejoras que se mantenían a los seis meses. Los tamaños del efecto sobre la eficacia del tratamiento iban de medianos a grandes. Se comparó también el programa IMAS con terapia cognitivo conductual individual y tratamiento farmacológico, con resultados favorables para el programa IMAS. Este nuevo programa para el tratamiento de la ansiedad social tiene un impacto importante en otros problemas relacionados habitualmente con el TAS.

In a previous work (Caballo et al., 2021) we tested the effectiveness of the Multidimensional Intervention for Social Anxiety (MISA) program in reducing social anxiety symptoms. In this quasi-experimental study, with pre/post-treatment and follow-up measures, we examined the impact of the MISA program on other problems related to social anxiety. 57 people diagnosed with social anxiety disorder (SAD), according to DSM-5, were assessed with a diagnostic interview and questionnaires measuring social skills, depression, avoidant personality disorder symptoms, alcoholism, self-esteem, personal sensitivity, worries, and quality of life. Different therapists carried out the treatment in Ecuador, Spain, and Paraguay. The results showed significant improvements at post-treatment in virtually all measures assessing the above variables, improvements that were maintained at six months. Effect sizes on treatment effectiveness ranged from medium to large. The MISA program was also compared with individual cognitive behavioral therapy and pharmacological treatment, with favorable results for the MISA program. In conclusion, this new program for the treatment of social anxiety has a significant impact on other problems usually related to SAD.

Pulmonary function changes in older adults with and without metabolic syndrome.

The low-grade inflammation associated with metabolic syndrome (MS) triggers functional and structural alterations in several organs. Whereas lung function impairment is well reported for older adult population, the effect of MS on functional and immunological responses in the lungs remains unclear. In this cross-sectional study we determined whether MS alters pulmonary function, and immunological responses in older adults with MS. The study sample consisted of older adults with MS (68 ± 3 years old; n = 77) and without MS (67 ± 3 years old; n = 77). Impulse oscillometry was used to evaluate airway and tissue resistance, and reactance. Biomarkers of inflammation and fibrosis were assessed in the blood and in breath condensate. The total resistance of the respiratory system (R5Hz; p < 0.009), and the resistance of the proximal (R20Hz; p < 0.001) and distal (R5Hz-R20Hz; p < 0.004) airways were higher in MS individuals compared to those without MS. Pro-inflammatory (leptin, IL-1beta, IL-8, p < 0.001; TNF-alpha, p < 0.04) and anti-inflammatory cytokines (adiponectin, IL-1ra, IL-10, p < 0.001), anti-fibrotic (relaxin 1, relaxin 3, Klotho, p < 0.001) and pro-fibrotic (VEGF, p < 0.001) factors were increased in sera and in breath condensate individuals with MS. The results show that MS adversely affect lung mechanics, function, and immunological response in older adults. The data offer a metabolic basis for the inflammaging of the lungs and suggest the lungs as a potential therapeutic target for controlling the immune response and delaying the onset of impaired lung function in older adults with MS.

Aplicación internacional del programa “Intervención multidimensional para la ansiedad social” (IMAS): I. Eficacia del tratamiento en pacientes con ansiedad social / International application of the program Multidimensional intervention for social anxiety

El trastorno de ansiedad social (TAS) es uno de los trastornos más frecuentes a nivel mundial. El objetivo de este estudio fue comprobar la eficacia del nuevo programa “Intervención multidimensional para la ansiedad social” (IMAS) para el tratamiento del TAS. Participaron 57 personas diagnosticadas con TAS, según el DSM-5, evaluadas mediante una entrevista semiestructurada (Salazar y Caballo, 2018) y dos medidas de autoinforme para la ansiedad social, el CASO (Caballo, Salazar, Arias, et al., 2010) y la LSAS-SR (Liebowitz, 1987). Diferentes terapeutas llevaron a cabo el tratamiento en Ecuador, España y Paraguay. Los resultados mostraron importantes mejoras del pretratamiento al postratamiento, que se mantenían a los seis meses. El tamaño del efecto estaba entre 1 y 2 y, en muchas ocasiones, fue superior a 2. Aunque se comparó con un grupo de terapia cognitivo conductual y otro de tratamiento farmacológico, con resultados favorables para el programa IMAS, el bajo número de sujetos de estos últimos grupos no permite llegar a deducciones claras. En conclusión, este nuevo programa para el tratamiento de la ansiedad social parece altamente eficaz a corto y medio plazo y sus resultados positivos parecen generalizables a diferentes países (AU)

Social anxiety disorder (SAD) is one of the most prevalent disorders worldwide. The goal of this study was to test the effectiveness of the new program "Multidimensional Intervention for Social Anxiety" (MISA) for the treatment of SAD. Fifty-seven people diagnosed with SAD, according to the DSM-5, participated in this study, and they were assessed by means of a semi-structured interview (Salazar & Caballo, 2018) and two self-report measures for social anxiety, the SAQ (Caballo, Salazar, Arias, et al., 2010) and the LSAS-SR (Liebowitz, 1987). Different therapists delivered the treatment in Ecuador, Spain, and Paraguay. The results showed significant improvements from pre-treatment to post-treatment, which were maintained at six months. The effect size was between 1 and 2 and, on many occasions, was greater than 2. Although it was compared with a cognitive behavioral therapy group and a pharmacological treatment group, with favorable results for the MISA program, the low number of subjects in the latter groups does not allow clear deductions to be made. In conclusion, this new program for the treatment of social anxiety seems highly effective in the short and medium term and its positive results seem generalizable to different countries (AU)

Assessment of dead-end ultrafiltration for the detection and quantification of microbial indicators and pathogens in the drinking water treatment processes.

A safe water supply requires distinct treatments and monitoring to guarantee the absence of pathogens and substances potentially hazardous for human health. In this study we assessed the efficiency of the dead-end ultrafiltration (DEUF) method to concentrate faecal indicator organisms (FIO) and pathogens in water samples with different physicochemical characteristics. Water samples were collected at the treatment stages of two drinking water treatment plants to analyse the concentration of a variety of 7 FIO and 4 reference microbes which have some species that are pathogenic to humans: Campylobacter spp., enteroviruses, Cryptosporidium spp. and Giardia spp. The samples were analysed before and after concentration by DEUF, detecting FIO concentrations about 1 log10 higher in non-concentrated samples from both catchments. Percent recoveries were highly variable with a mean of 43.8 ± 17.5%, depending on the FIO and inherent sample characteristics. However, DEUF enabled FIO concentration in high volumes of water (100-500 l), allowing a reduction in the detection limit compared to the non-concentrated samples due to the high volume processing capabilities of the method. As a consequence, the detection of FIO removal from water in the drinking water treatment process was 1.0-1.5 logarithms greater in DEUF-treated water compared to unfiltered samples. The DEUF method improved the detection of target indicators and allowed for the detection of pathogens in low concentrations in water after the treatment stages, confirming the suitability of DEUF to concentrate high volumes of different types of water. This method could be useful for microbial analysis in water treatment monitoring and risk assessment, allowing the identification of critical points during the water treatment process and potential hazards in water destined for several uses.

Detection of Oral Entamoeba Gingivalis and Trichomonas Tenax in Adult Quilombola Population with Periodontal Disease / Detección de Entamoeba Gingivalis oral y Trichomonas Tenax en población de quilombola adulta con enfermedad periodontal

Abstract: The objective was to analyze the periodontal condition severity and the occurrence of pathogenic microorganisms in the oral cavity of an adult population of an Afrodescent Community of northeastern Brazil. This is an observational and cross- sectional study performed through an oral clinical examination, using a standardized clinical record. For the subjects with periodontal disease, the bacterial biofilm was collected in a Petri dish containing 0.9% physiological solution to detect the presence of microorganisms Entamoeba gingivalis and Trichomonas tenax, and later observed under an optical microscope. Statistical analysis was performed by calculating the prevalence of periodontal disease and the frequency of the protozoa in the bacterial biofilm. Statistical significance of the relationships researched was verified by Fisher's exact test. It was evaluated 29 subjects pertaining to the Quilombola Patioba community, aged 35 to 44 years. The results showed that among the adults of the community, there was a high prevalence of periodontal disease (75.86%), being higher in the 1st and 6th sextants of the Community Periodontal Index (CPI). E. gingivalis positivity occurred in most sextants affected by gingivitis, while in the condition of periodontitis, this microorganism was not present in the 3rd, 4th and 6th sextants. In all sextants affected by periodontal disease, T. Tenax was observed when associated with gingivitis. It is worth mentioning the begging of the elaboration of health policies, social and professional commitment that foster a greater promotion of oral health and quality of life for the quilombolas of northeastern Brazil.

Resumen: El objetivo fue analizar la severidad de la condición periodontal y la aparición de microorganismos patógenos en la cavidad oral de una población adulta de una comunidad afrodescente del noreste de Brasil. Este es un estudio observacional y transversal realizado a través de un examen clínico oral, utilizando un registro clínico estandarizado. Para los sujetos con enfermedad periodontal, la biopelícula bacteriana se recogió en una placa de Petri que contenía una solución fisiológica al 0,9% para detectar la presencia de microorganismos Entamoeba gingivalis y Trichomonas tenax, y luego se observó bajo un microscopio óptico. El análisis estadístico se realizó calculando la prevalencia de la enfermedad periodontal y la frecuencia de los protozoos en la biopelícula bacteriana. La significación estadística de las relaciones investigadas se verificó mediante la prueba exacta de Fisher. Se evaluaron 29 sujetos pertenecientes a la comunidad Quilombola Patioba, de 35 a 44 años. Los resultados mostraron que entre los adultos de la comunidad, hubo una alta prevalencia de enfermedad periodontal (75.86%), siendo mayor en el sexto sexto y sexto del Índice periodontal comunitario (IPC). La positividad de E. gingivalis se produjo en la mayoría de los sextantes afectados por gingivitis, mientras que en la condición de periodontitis, este microorganismo no estaba presente en los sextantes tercero, cuarto y sexto. En todos los sextantes afectados por enfermedad periodontal, se observó T. Tenax cuando se asoció con gingivitis. Vale la pena mencionar el inicio de la elaboración de políticas de salud, compromiso social y profesional que promuevan una mayor promoción de la salud oral y la calidad de vida de las quilombolas del noreste de Brasil.

Chronic alteration of circadian rhythm is related to impaired lung function and immune response.

BACKGROUND: Alterations of the circadian rhythm negatively impact several aspects of the health, including the lung function. Chronic shiftwork scale classically induces alterations in the circadian rhythm. However, its effects on pulmonary immune response are unknown. AIMS: To evaluate the impact of chronic alteration of circadian rhythm on pulmonary function and immune response. METHODS: In this context, a 12 × 24 hours and 12 × 48 hours work scale in shiftwork scale policemen (n = 25; 38.73 ± 6.92 years old) were compared with fixed work scale (8 h/d) civil men (n = 25; 34.00 ± 9.60 years old) who were evaluated for perceived stress, sleepiness, physical activity levels, anthropometric characteristics, lung function, pulmonary and systemic cellular and humoral immune response. RESULTS: Policemen presented increased levels of perceived stress (P < .0008), impaired sleepiness (P < .04) and lung function as demonstrated by reduced forced vital capacity (FVC) (P < .053) and FEV1 (P < .043) when compared with civil men. In addition, increased levels of exhaled nitric oxide (P < .037) and of IL-2 (P < .0046) in the breath condensate revealed that policemen presented chronic lung inflammation compared with civil men. Although the whole blood analysis did not showed any differences between the two groups concerning the number of leucocytes, the humoral response revealed that policemen presented increased levels of IL-2 (P < .002) and lower levels of IL-10 (P < .001), clearly displaying a clinical status of low-grade inflammation. CONCLUSIONS: Chronic alteration of circadian rhythm in shiftwork scale policemen results in impaired lung function, beyond to impair pulmonary and systemic immune function.

Microbiological contamination of conventional and reclaimed irrigation water: Evaluation and management measures.

The wide diversity of irrigation water sources (i.e., drinking water, groundwater, reservoir water, river water) includes reclaimed water as a requested measure for increasing water availability, but it is also a challenge as pathogen exposure may increase. This study evaluates the level of microbial contamination in different irrigation waters to improve the knowledge and analyses management measures for safety irrigation. Over a one-year period, the occurrence of a set of viruses, bacteria and protozoa, was quantified and the performance of a wetland system, producing reclaimed water intended for irrigation, was characterized. Human fecal pollution (HAdV) was found in most of the irrigation water types analysed. Hepatitis E virus (HEV), an emerging zoonotic pathogen, was present in groundwater where porcine contamination was identified (PAdV). The skin-carcinoma associated Merkel cell polyomavirus (MCPyV), was found occasionally in river water. Noroviruses were detected, as expected, in winter, in river water and reclaimed water. Groundwater, river water and reservoir water also harboured potential bacterial pathogens, like Helicobacter pylori, Legionella spp. and Aeromonas spp. that could be internalized and viable inside amoebas like Acanthamoeba castellanii, which was also detected. Neither Giardia cysts, nor any Cryptosporidium oocysts were detected. The wetland system removed 3 Log10 of viruses and 5 Log10 of bacteria, which resembled the river water quality. Irrigation waters were prone to variable contamination levels and according to the European guidance documents, the E. coli (EC) levels were not always acceptable. Sporadic detection of viral pathogens as NoV GII and HAdV was identified in water samples presenting lower EC than the established limit (100MNP/100 mL). When dealing with reclaimed water as a source of irrigation the analysis of some viral parameters, like HAdV during the peak irrigation period (summer and spring) or NoV during the coldest months, could complement existing water management tools based on bacterial indicators.

Comparison of several non-specific skin mucus immune defences in three piscine species of aquaculture interest.

Fish skin mucus is a viscous and semipermeable barrier made mainly of water, glycoproteins and soluble proteins. It represents an important defence against the environment and previous studies have reported the presence of different substances involved in immune defence responses in it. The aim of the present work was to characterize skin mucus protease activity by zymography and esterase activity of the subfamily of carboxylesterases in three species of interest for aquaculture: gilthead sea bream, sea bass and meagre. Mucus antioxidant power was also determined by adapting ferric reducing antioxidant power (FRAP) analysis. As a result of these non-specific immune defence parameters, we compared the antibacterial capacity of skin mucus in these species via in vitro dual bacteria strains-skin mucus co-culture growths. We used Pseudomonas anguilliseptica and Vibrio anguillarum as marine pathogenic bacteria and Escherichia coli as non-pathogenic. For each fish species, in the respective zymograms, we determined a pattern of proteolytic digestion bands. A high-molecular-weight band (around 200 kDa; H-band) was evident in sea bream and sea bass, and showed chymotrypsin activity. One or two intermediate-molecular-weight bands (around 75 kDa; I-bands) with non-trypsin and non-chymotrypsin activity, and putatively with metalloprotease activity, were evident in all species. Finally, low-molecular-weight bands (between 14 and 30 kDa; L-bands) showed distinct patterns for each species and matched trypsin activity. Despite the conservative pattern of digestion bands, the levels of total proteolytic activity (TPA) were 5 and 10 times higher in meagre than in sea bass and sea bream, respectively. In parallel, three carboxylesterase activities were detected in the mucus of the three fish species, using myristate (pNPM-CE activity), butyrate (pNPB-CE activity) and acetate (pNPA-CE activity) as substrates. Both pNPB-CE and pNPA-CE were the most abundant in fish mucus, and meagre was again the species with the highest levels. In contrast, the antioxidant power of meagre skin mucus was the lowest. We established the capacity of skin mucus to block or limit bacterial growth (lytic activity) using 24 h growth curves. The log-growth phase of V. anguillarum was strongly blocked by sea bream and meagre mucus for a few hours; but not by sea bass mucus. However, if mucus was not renewed, log-growth was at the end of 24 h studied period. For its part, P. anguilliseptica growth curve was delayed by the three mucus types during the entire growth period. Only meagre achieved lytic activity against E. coli growth. All parameters studied here will be of a great interest as non-invasive bioindicators of non-specific immune defences in fish skin mucus.

Characterization of nutrient-removing microbial communities in two full-scale WWTP systems using a new qPCR approach.

Biological wastewater treatment processes involve very complex microbial communities. Culture-independent molecular methods are feasible tools used to analyze and control the structure of different microbial communities, such as bacterial communities that remove nutrients. Here, we used the gBlocks gene fragments method, a new real-time PCR approach for the development of DNA standards, to quantify total bacterial cells, AOB, NOB, and Archaeal genes at two different WWTPs. PAOs were also quantified using the FISH technique. Our findings highlight a significant improvement in real-time PCR detection for the microorganisms studied. The qPCR and FISH technique applied allowed characterization of the microbial composition of two WWTPs operated as a conventional WWTP and a biological nutrient-removal WWTP. The results revealed a significant difference in the microbial profiles of the WWTPs, with a higher abundance of nitrifying bacterial communities and PAOs in the nutrient removal plant, which were in accordance with operational performance.

Inactivation of microbiota from urban wastewater by single and sequential electrocoagulation and electro-Fenton treatments.

This work aims at comparing the ability of two kinds of electrochemical technologies, namely electrocoagulation (EC) and electro-Fenton (EF), to disinfect primary and secondary effluents from municipal wastewater treatment plants. Heterotrophic bacteria, Escherichia coli, enterococci, Clostridium perfringens spores, somatic coliphages and eukaryotes (amoebae, flagellates, ciliates and metazoa) were tested as indicator microorganisms. EC with an Fe/Fe cell at 200 A m-2 and natural pH allowed >5 log unit removal of E. coli and final concentration below 1 bacteria mL-1 of coliphages and eukaryotes from both effluents in ca. 60 min, whereas heterotrophic bacteria, enterococci and spores were more resistant. A larger removal was obtained for the primary effluent, probably because the flocs remove higher amount of total organic carbon (TOC), entrapping more easily the microbiota. EF with a boron-doped diamond (BDD) anode and an air-diffusion cathode that produces H2O2 on site was first performed at pH 3.0, with large or even total inactivation of microorganisms within 30 min. A more effective microorganism removal was attained as compared to EC thanks to •OH formed from Fenton's reaction. A quicker disinfection was observed for the secondary effluent owing to its lower TOC content, allowing the attack of greater quantities of electrogenerated oxidants on microorganisms. Wastewater disinfection by EF was also feasible at natural pH (∼7), showing similar abatement of active microorganisms as a result of the synergistic action of generated oxidants like active chlorine and coagulation with iron hydroxides. A sequential EC/EF treatment (30 min each) was more effective for a combined decontamination and disinfection of urban wastewater.

Characterization of the efficiency and uncertainty of skimmed milk flocculation for the simultaneous concentration and quantification of water-borne viruses, bacteria and protozoa.

In this study, the use of skimmed milk flocculation (SMF) to simultaneously concentrate viruses, bacteria and protozoa was evaluated. We selected strains of faecal indicator bacteria and pathogens, such as Escherichia coli and Helicobacter pylori. The viruses selected were adenovirus (HAdV 35), rotavirus (RoV SA-11), the bacteriophage MS2 and bovine viral diarrhoea virus (BVDV). The protozoa tested were Acanthamoeba, Giardia and Cryptosporidium. The mean recoveries with q(RT)PCR were 66% (HAdV 35), 24% (MS2), 28% (RoV SA-11), 15% (BVDV), 60% (E. coli), 30% (H. pylori) and 21% (Acanthamoeba castellanii). When testing the infectivity, the mean recoveries were 59% (HAdV 35), 12% (MS2), 26% (RoV SA-11) and 0.7% (BVDV). The protozoa Giardia lamblia and Cryptosporidium parvum were studied by immunofluorescence with recoveries of 18% and 13%, respectively. Although q(RT)PCR consistently showed higher quantification values (as expected), q(RT)PCR and the infectivity assays showed similar recoveries for HAdV 35 and RoV SA-11. Additionally, we investigated modelling the variability and uncertainty of the recovery with this method to extrapolate the quantification obtained by q(RT)PCR and estimate the real concentration. The 95% prediction intervals of the real concentration of the microorganisms inoculated were calculated using a general non-parametric bootstrap procedure adapted in our context to estimate the technical error of the measurements. SMF shows recoveries with a low variability that permits the use of a mathematical approximation to predict the concentration of the pathogen and indicator with acceptable low intervals. The values of uncertainty may be used for a quantitative microbial risk analysis or diagnostic purposes.

The ability of electrochemical oxidation with a BDD anode to inactivate Gram-negative and Gram-positive bacteria in low conductivity sulfate medium.

The disinfection of 100 mL of synthetic water containing 7 mM Na2SO4 with 10(6) CFU mL(-1) of either Gram-negative or Gram-positive bacteria has been studied by electrochemical oxidation. The electrolytic cell was a stirred tank reactor equipped with a boron-doped diamond (BDD) anode and a stainless steel cathode and the trials were performed at acidic and neutral pH, at 33.3 mA cm(-2) and 25 °C. Reactive oxygen species, pre-eminently hydroxyl radicals, were efficiently produced in both media from water oxidation at the BDD anode and the bacteria concentration was reduced by ≥ 5 log units after 60 min of electrolysis, thus constituting a good chlorine-free disinfection treatment. All the inactivation kinetics were described by a logistic model, with no significant statistical differences between acidic and neutral suspensions. The electrochemical disinfection with BDD was very effective for Gram-negative bacilli like Escherichia coli and Pseudomonas aeruginosa and Gram-positive ones like Bacillus atrophaeus, whereas the Gram-positive cocci Staphylococcus aureus and Enterococcus hirae were more resistant. Thus, the latter organisms are a better choice than E. coli as process indicators. Scanning electron microscopy highlighted a transition from initial cells with standard morphology supported on clean filters to inactivated cells with a highly altered morphology lying on dirty filters with plenty of cellular debris. Larger damage was observed for Gram-negative cells compared to Gram-positive ones. The inactivation effect could then be related to the chemical composition of the outer layers of the cell structure along with the modification of the transmembrane potentials upon current passage.

Tracking and quantification of nitrifying bacteria in biofilm and mixed liquor of a partial nitrification MBBR pilot plant using fluorescence in situ hybridization.

A moving bead biofilm reactor (MBBR) pilot plant was implemented as a partial nitrification process for pre-treatment of ammonium-rich liquors (676 ± 195 mg L(-1)), and studied for 479 days under variations in hydraulic retention time. The main purpose of this work, was the study of dynamics abundance of total bacteria and single-cells nitrifying bacteria belonging to ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in biofilms and mixed liquor of the plant. The microbial monitoring was successfully achieved using fluorescence in situ hybridization combined with flocs disaggregation protocol as a useful microbial monitoring tool. A partial nitrification process with a N-NH4(+) removal rate of about 38.6 ± 14.8% was successfully achieved at 211 days after start-up, with a clear dominance of AOB, which accounted for 11.3 ± 17.0% of total bacterial cells compared with only 2.1 ± 4.0% of NOB. The effluent obtained was subsequently supplied to an Anammox reactor for complete ammonium treatment.

Perioperative Drainage of Cerebrospinal Fluid for Endovascular Aortic Surgery.

INTRODUCTION: Spinal cord ischemia (SCI) is a feared complication following thoracic endovascular aortic aneurysm repair (TEVAR). European Society for Vascular Surgery guidelines suggest lumbar drainage of cerebrospinal fluid (CSF) in high-risk patients. The institutional protocol proposes as indications for CSF drainage: coverage of Adamkiewicz artery origin (T9-T12), aortic length of coverage >15 cm, compromise of collateral arteries (left subclavian or internal iliac occlusion) and symptomatic SCI. The aim of this study is to demonstrate CSF drainage efficacy and safety in the prevention or treatment of TEVAR-related SCI. METHODS: Patients submitted to TEVAR with perioperative CSF drainage between May 2015 and April 2017 at our hospital were prospectively included. The primary outcome consisted of prevention or regression of neurological symptoms (efficacy). Other complications were recorded as secondary outcomes (safety). RESULTS: Nine patients, aged between 63 and 75 years, were included. Eight surgeries were elective and one was emergent. Eight lumbar catheters were placed before surgery and one in the postoperative period due to SCI symptomatology that reverted after CSF drainage. Of those placed preoperatively, 2 developed postoperative SCI symptoms that alleviated with increased drainage or haemoglobin optimization. All patients were submitted to general anaesthesia. The patient treated in the emergent setting progressed with multiorgan dysfunction and death 24 hours after surgery. There were no other complications. CONCLUSION: In this group of patients, CSF drainage was safe and effective in the prevention and treatment of TEVAR-related SCI.

Introdução: A isquemia medular (IM) é uma complicação temida após correção endovascular de aneurismas da aorta torácica (TEVAR). As guidelines da Sociedade Europeia de Cirurgia Vascular recomendam drenagem lombar (DL) de líquido cefalorraquidiano em doentes de alto risco. O protocolo institucional considera como indicações para DL: cobertura da origem da artéria de Adamkiewicz (T9-T12), cobertura aórtica >15 cm, comprometimento de colaterais (oclusão da artéria subclávia esquerda ou ilíaca interna) e IM sintomática. O objetivo do trabalho foi demonstrar a eficácia e segurança da DL na prevenção ou tratamento da IM após TEVAR. Métodos: Doentes submetidos a DL no perioperatório de TEVAR entre maio de 2015 e abril de 2017 no nosso hospital foram prospetivamente incluídos. Outcome primário: prevenção e/ou reversão de sintomas neurológicos (eficácia). Outcome secundário: complicações relacionadas com a técnica (segurança). Resultados: Incluíram-se 8 doentes com aneurismas tóraco-abdominais e 1 com disseção aórtica tipo B, com idade entre 63-75 anos. Oito cirurgias foram eletivas e uma urgente. O cateter foi colocado previamente à cirurgia em 8 casos e no pós-operatório em 1 caso por sintomatologia de IM que reverteu após a colocação. Dos colocados pré-operatoriamente, 2 tiveram sintomas de IM no pós-operatório, que aliviaram com aumento da drenagem e optimização da hemoglobina. A TEVAR urgente resultou na perfusão insuficiente de ramos viscerais com disfunção multiorgânica e morte 24h após a cirurgia. Não se registaram outras complicações. Conclusão: A colocação de DL revelou-se segura e eficaz na prevenção e tratamento de IM após TEVAR.

Effect of Common Drinking Water Disinfectants, Chlorine and Heat, on Free Legionella and Amoebae-Associated Legionella.

Chlorine and thermal treatments are the most commonly used procedures to control and prevent Legionella proliferation in drinking water systems of large buildings. However, cases of legionellosis still occur in facilities with treated water. The purpose of this work was to model the effect of temperature and free chlorine applied in similar exposure conditions as in drinking water systems on five Legionella spp. strains and two amoebal strains of the genera Acanthamoeba. Inactivation models obtained were used to determine the effectiveness of the treatments applied which resulted more effective against Legionella than Acanthamoeba, especially those in cystic stages. Furthermore, to determine the influence of the relationship between L. pneumophila and Acanthamoeba spp. on the treatment effectiveness, inactivation models of the bacteria-associated amoeba were also constructed and compared to the models obtained for the free living bacteria state. The Legionella-amoeba association did not change the inactivation models, but it reduced the effectiveness of the treatments applied. Remarkably, at the lowest free chlorine concentration, 0.5 mg L-1, as well as at the lowest temperatures, 50°C and 55°C, the influence of the Legionella-amoeba associate state was the strongest in reducing the effectiveness of the treatments compared to the free Legionella state. Therefore, the association established between L. pneumophila and amoebae in the water systems indicate an increased health risk in proximal areas of the system (close to the tap) where lower free chlorine concentrations and lower temperatures are commonly observed.

Assessment of total bacterial cells in extended aeration activated sludge plants using flow cytometry as a microbial monitoring tool.

The extended aeration activated sludge (EAAS) process is one of the most applied biological processes in small towns. Here, we study the abundance and viability of total bacterial cells in two wastewater treatment plants (WWTPs) operating with an EAAS process. We use flow cytometry (FCM) combined with SYTO13 and propidium iodide (PI) dyes as a rapid, easy, reliable and accurate microbial monitoring tool. A disaggregation procedure with an ultrasonic bath was designed to detach total bacterial cells from activated sludge flocs for subsequent FCM analysis. This procedure permitted the recovery of total bacterial cells from sludge flocs without affecting bacterial viability, as indicated by bacterial strain controls. Since FCM is a multi-parameter technique, it was possible to determine total bacterial abundance and their viability in the activated sludge. As a comparative method, epifluorescence microscopy was also used to quantify total bacterial cells; both methods produced similar results. The FCM analysis revealed relative microbial stability in both the WWTPs. The total bacterial abundance quantified by FCM in the two plants studied was 1.02-6.23 × 10(11) cells L(-1) with 70-72% viability, one logarithm less than that reported in the literature for WWTPs using the conventional activated sludge process. This can be explained by the difference in the operational parameters between the conventional plant and EAAS, mainly the organic loading rate.

Effect of chlorine and temperature on free-living protozoa in operational man-made water systems (cooling towers and hot sanitary water systems) in Catalonia.

In recent decades, free-living protozoa (FLP) have gained prominence as the focus of research studies due to their pathogenicity to humans and their close relationship with the survival and growth of pathogenic amoeba-resisting bacteria. In the present work, we studied the presence of FLP in operational man-made water systems, i.e. cooling towers (CT) and hot sanitary water systems (HSWS), related to a high risk of Legionella spp. outbreaks, as well as the effect of the biocides used, i.e. chlorine in CT and high temperature in HSWS, on FLP. In CT samples, high-chlorine concentrations (7.5 ± 1.5 mg chlorine L(-1)) reduced the presence of FLP by 63.8 % compared to samples with low-chlorine concentrations (0.04 ± 0.08 mg chlorine L(-1)). Flagellates and amoebae were observed in samples collected with a level of 8 mg chlorine L(-1), which would indicate that some FLP, including the free-living amoeba (FLA) Acanthamoeba spp., are resistant to the discontinuous chlorine disinfection method used in the CT studied. Regarding HSWS samples, the amount of FLP detected in high-temperatures samples (53.1 ± 5.7 °C) was 38 % lower than in low-temperature samples (27.8 ± 5.8 °C). The effect of high temperature on FLP was chiefly observed in the results obtained by the culture method, in which there was a clear reduction in the presence of FLP at temperatures higher than 50 °C, but not in those obtained by PCR. The findings presented here show that the presence of FLP in operational man-made water systems should be taken into account in future regulations.

Effect of UV irradiation (253.7 nm) on free Legionella and Legionella associated with its amoebae hosts.

Water systems are the primary reservoir for Legionella spp., where the bacteria live in association with other microorganisms, such as free-living amoebae. A wide range of disinfection treatments have been studied to control and prevent Legionella colonization but few of them were performed considering its relation with protozoa. In this study, the effectiveness of UV irradiation (253.7 nm) using low-pressure lamps was investigated as a disinfection method for Legionella and amoebae under controlled laboratory conditions. UV treatments were applied to 5 strains of Legionella spp., 4 strains of free-living amoeba of the genera Acanthamoeba and Vermamoeba, treating separately trophozoites and cysts, and to two different co-cultures of Legionella pneumophila with the Acanthamoeba strains. No significant differences in the UV inactivation behavior were observed among Legionella strains tested which were 3 logs reduced for fluences around 45 J/m(2). UV irradiation was less effective against free-living amoebae; which in some cases required up to 990 J/m(2) to obtain the same population reduction. UV treatment was more effective against trophozoites compared to cysts; moreover, inactivation patterns were clearly different between the genus Acanthamoeba and Vermamoeba. For the first time data about Vermamoeba vermiformis UV inactivation has been reported in a study. Finally, the results showed that the association of L. pneumophila with free-living amoebae decreases the effectiveness of UV irradiation against the bacteria in a range of 1.5-2 fold. That fact demonstrates that the relations established between different microorganisms in the water systems can modify the effectiveness of the UV treatments applied.