Growth of Escherichia coil, Salmonella enterica and Listeria spp., and their inactivation using ultraviolet energy and electrolyzed water, on 'Rocha' fresh-cut pears

The present study aimed at evaluating the growth of Escherichia coil, Salmonella enterica, and Listeria spp. and studying the efficacy of Ultraviolet-C (UV-C) irradiation, acidic electrolyzed (AEW) and neutral electrolyzed (NEW) waters in the reduction of these bacteria on 'Rocha' pear. Fresh-cut pieces were inoculated and incubated at 4-20 degrees C for 8 days. Inoculated pears were treated with UV-C (2.5-10 kJ/m(2)), AEW, NEW and sodium hypochlorite (SH) and microbiological and quality parameters were evaluated. The three bacteria, inoculated at 6.1-6.2 log cfu/g, grew on the pear at high growth rates at 12 and 20 degrees C reaching populations of 8.1-8.6 log cfu/g, in 24 h. At 8 degrees C the microorganisms increased their populations by at least 1 log cfu/g in three days. At 4 degrees C adaptation phases of less than 24 h for Listeria spp. were measured before exponential growth occurred and the enterobacteria did not grow despite having survived for 8 days. AEW and NEW caused microbial reductions similar to SH, of approximately 1 log cfu/ g, while the best UV-C dose (7.5 kJ/m(2)) of at least 2.4 log cfu/g. Fresh-cut pears were a good substrate for foodborne bacteria emphasizing the importance of preventing contaminations and cross contaminations. The UV-C was more effective than the chemical decontaminations, as it provided superior microbial reductions without greatly affecting the quality of pears. (C) 2017 Elsevier Ltd. All rights reserved.Fundacao para a Ciencia e Tecnologia (FCT) [PTDC-PTDC/AGR-ALI/111687/2009]FCT [SFRH/BD/76745/2011

Ciprofloxacin resistance in domestic wastewater treatment plants

The potential of domestic wastewater treatment plants to contribute for the dissemination of ciprofloxacin-resistant bacteria was assessed. Differences on bacterial counts and percentage of resistance in the raw wastewater could not be explained on basis of the size of the plant or demographic characteristics of population served. In contrast, the treated effluent of the larger plants had significantly more heterotrophs and enterobacteria, including ciprofloxacin-resistant organisms, than the smaller (p<0.01). Moreover, longer hydraulic retention times were associated with significantly higher percentages of resistant enterobacteria in the treated effluent (p<0.05). Independently of the size or type of treatment used, domestic wastewater treatment plants discharged per day at least 1010–1014 colony forming units of ciprofloxacin-resistant bacteria into the receiving environment.info:eu-repo/semantics/acceptedVersio

Insights into the relationship between antimicrobial residues and bacterial populations in a hospital-urban wastewater treatment plant system

The relationship between antimicrobial residues, antibiotic resistance prevalence and bacterial community composition in hospital effluent and in the receiving wastewater treatment plant was studied. Samples from hospital effluent, raw inflow and final effluent of the receiving wastewater treatment plant were characterized for amoxicillin and ciprofloxacin resistance prevalence, content of heavy metals and antimicrobial residues and bacterial community structure, based on 16S rRNA gene PCR-DGGE analysis. The concentration of fluoroquinolones, arsenic and mercury was in general higher in hospital effluent than in raw inflow, while the opposite was observed for tetracyclines, sulfonamides and penicillin G. The prevalence of ciprofloxacin resistance was significantly higher in hospital effluent than in raw inflow. The concentration of antimicrobial residues was observed to be significantly correlated with the prevalence of antibiotic resistant bacteria and with variations in the bacterial community. Hospital effluent was confirmed as a relevant, although not unique, source of antimicrobial residues and antibiotic resistant bacteria to the wastewater treatment plant. Moreover, given the high loads of antibiotic residues and antibiotic resistant bacteria that may occur in hospital effluents, these wastewater habitats may represent useful models to study and predict the impact of antibiotic residues on bacterial communities.info:eu-repo/semantics/acceptedVersio

Efficacy of electrolyzed water to inactivate foodborne pathogens on fresh-cut apples

Chlorine is the most common disinfectant used in the fresh-cut industry but nowadays environmental and health risks have led to the need to find new sanitizers. Electrolyzed water (EW) appears to be a promising alternative. In this work, disinfection efficacy of acidic (AEW) and neutral (NEW) electrolyzed water in fresh-cut apple slices inoculated with Escherichia coli, Listeria innocua or Salmonella choleraesuis was studied. Apple slices were inoculated with a 10(7) cfu/ml suspension of pathogens and treated with the sanitizer EW solutions, with 100 or 50 ppm of free chlorine solutions and with distilled water. Population reduction was determined 30 min after washings and untreated apple slices were used as control in all assays. AEW100 was the treatment with more effective bactericidal activity followed by NEW100 and AEW50. EW had higher or similar efficacy than chlorine treatments in all tested conditions

Preliminary feasibility study for the use of an adsorption/bio-regeneration system for molinate removal from effluents

This work studies the feasibility of the use of a combined physical-biological remediation procedure for treatment of effluents contaminated with molinate, where the herbicide is removed through adsorption and biodegraded in a subsequent stage, with the regeneration of the adsorbent. In order to select the most adequate absorbent for molinate, different materials were tested, namely pine bark, activated carbon and resin Amberlite XAD-4. Activated carbon and resin Amberlite XAD-4 were the most efficient on the removal of molinate from solutions, although the activated carbon used proved not to be bio-regenerable. It was also observed that factors such as temperature, pH, and conductivity did not affect significantly molinate adsorption onto resin Amberlite XAD-4. Resin Amberlite XAD-4 was successfully bio-regenerated, being observed that biodegradation was mainly dependent on spontaneous desorption of the molinate. After bio-regeneration, the resin could be re-utilised as adsorbent

Paludibacterium

Curved rods, non-spore forming and Gram-negative. Motile by means of a single polar flagellum. Facultative anaerobe. Reacts positively for the catalase and cytochrome c oxidase tests. Nitrate reduction is variable among genus members and indole is not produced. The major respiratory quinone is ubiquinone 8 (Q-8). Fatty acid composition is variable within the genus, although summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and C16:0 are predominant in all species. The polar lipid profile consists of phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), among other unidentified aminophospholipids, phospholipids, and polar lipids.info:eu-repo/semantics/acceptedVersio

Modeling fitness variable responses to training In prepubescent children

The aim of this study was to determine strength and oxygen uptake (VO2max) performances according to different training program intervention design with 8-weeks duration in prepubescent children through a multiple linear regression models. Two hundred and forty-five healthy prepubescent children (aged 10.9 ± 0.5 years) were randomly assigned to a specific training program (strength training only - S; aerobic training only - A; intra-session aerobic and strength training - AS; intra-session strength and aerobic training - SA; or concurrent training performed in different sessions - CT) or a control group (no training regimen - C). It was possible to develop indirect predictive models for each training method, by including each variable pre-training, body fat percentage and body mass index. The models provided explained 82% of variance in the VO2max, 98% in the 1kg ball-throw, 96% in the 3kg ball-throw, 92% in the counter-movement jump, 93% in the standing long jump and 98% in the 20m sprint performances. This novel approach to training evaluation and control aims to provide a tool to allow professionals to calculate changes with a high confidence level (CI 95%), to control gains and to choose the best training methodology to apply according to the defined purposes. The results of this study could be a great support to teachers, coaches and professionals providing important tools to improve the efficacy and individualization of training

Microbacterium luticocti sp. nov., isolated from sewage sludge compost

Strain SC-087BT, isolated from sewage sludge compost during a study of bacterial diversity in composts, was characterized. The isolate was a Gram-positive, short rod that was motile, catalase- and oxidase-negative and able to grow at 27–45 6C, pH 5.5–9.7 and in up to 10% NaCl. The peptidoglycan was of the B2b type, containing the characteristic amino acids ornithine, homoserine and hydroxyglutamic acid. The muramic acid residues of the peptidoglycan were partially glycolylated. The major cell-wall sugar was mannose; traces of xylose were also detected. The predominant fatty acids, comprising more than 70% of the total, were anteiso-C17 : 0 and anteiso-C15 : 0, the major respiratory quinone was menaquinone-12 (MK-12) and the G+C content of the genomic DNA was 72 mol%. Based on analysis of the 16S rRNA gene sequence, the closest phylogenetic neighbours of strain SC-087BT were members of the family Microbacteriaceae, showing sequence similarity values of around 96% with members of the species Microbacterium barkeri (96.0 %), Microbacterium gubbeenense (95.6 %) and Microbacterium indicum (95.7 %). The chemotaxonomic and phenotypic traits analysed supported the inclusion of this strain within the genus Microbacterium and the proposal of a novel species. The name Microbacterium luticocti sp. nov. is proposed and the type strain is SC-087BT (5DSM 19459T5CCUG 54537T)

Comparative study of the microbial diversity of bulk paddy soil of two rice fields subjected to organic and conventional farming

Two adjacent paddies of an experimental rice field, subjected to organic and conventional farming, were characterized aiming the comparative assessment of microbiological variations occurring in the bulk paddy soil over the rice cycle. This study comprehended the simultaneous characterization of general physicochemical soil properties [total carbon and nitrogen, pH (H2O and KCl), C:N ratio and water content], biochemical properties [enzymatic activities and Community Level Physiological Profiles (CLPP)], the estimation of cultivable organisms (enumeration of fast growing heterotrophic bacteria, actinomycetes and fungi) and the assessment of bacterial diversity using a culture-independent method (PCR-DGGE fingerprinting). The linkage of the parameters measured was analysed by canonical correspondence analysis (CCA). CCA ordination plots of the CLPP showed a similar pattern of microbial functional activity in both agronomic management systems, except in June. Enzymatic activity, water content and fungi counts were the main factors affecting the observed CLPP time variation. Such a variation was not expressed by the Shannon and evenness indices, which did not evidence significant differences in the bacterial and functional diversity between or within farming type over the analysed period. The cluster and CCA analyses of the DGGE profiles allowed the distinction of the bacterial communities of both paddies, with temporal variations being observed in the organically managed field but not in the conventional paddy. Enzymatic activity, pH and molinate content were the factors which most contributed to the observed variations. Altogether these results underline the functional redundancy of the rice paddy soil and evidence the temporal variations on the metabolic activity of soil, irrespective of farming type.info:eu-repo/semantics/acceptedVersio