ABSTRACT
This research provides a detailed analysis of the COVID-19 spread across 14 Latin American countries. Using time-series analysis and epidemic models, we identify diverse outbreak patterns, which seem not to be influenced by geographical location or country size, suggesting the influence of other determining factors. Our study uncovers significant discrepancies between the number recorded COVID-19 cases and the real epidemiological situation, emphasizing the crucial need for accurate data handling and continuous surveillance in managing epidemics. The absence of a clear correlation between the country size and the confirmed cases, as well as with the fatalities, further underscores the multifaceted influences on COVID-19 impact beyond population size. Despite the decreased real-time reproduction number indicating quarantine effectiveness in most countries, we note a resurgence in infection rates upon resumption of daily activities. These insights spotlight the challenge of balancing public health measures with economic and social activities. Our core findings provide novel insights, applicable to guiding epidemic control strategies and informing decision-making processes in combatting the pandemic.
ABSTRACT
Livestock slurry has been reported to be a potential secondary raw material as it contains macronutrients nitrogen, phosphorus and potassium-, which could be valorised as high-quality fertilizers if proper separation and concentration of valuable compounds is performed. In this work, pig slurry liquid fraction was assessed for nutrient recovery and valorisation as fertilizer. Some indicators were used to evaluate the performance of proposed train of technologies within the framework of circular economy. As ammonium and potassium species are highly soluble at the whole pH range, a study based on phosphate speciation at pH from 4 to 8 was assessed to improve the macronutrients recovery from the slurry, resulting in two different treatment trains at acidic and alkaline conditions. The acidic treatment system based on centrifugation, microfiltration and forward osmosis was applied to obtain a nutrient-rich liquid organic fertilizer containing 1.3 % N, 1.3 % P2O5 and 1.5 % K2O. The alkaline path of valorisation was composed by centrifugation and stripping by using membrane contactors to produce an organic solid fertilizer -7.7 % N, 8,0 % P2O5 and 2.3 % K2O-, ammonium sulphate solution -1.4 % N- and irrigation water. In terms of circularity indicators, 45.8 % of the initial water content and <50 % of contained nutrients were recovered - 28.3 % N, 43.5 % P2O5 and 46.6 % K2O - in the acidic treatment resulting in 68.68 g fertilizer per kg of treated slurry. 75.1 % of water was recovered as irrigation water and 80.6 % N, 99.9 % P2O5, 83.4 % K2O was valorised in the alkaline treatment, as 219.60 g fertilizer per kg of treated slurry. Treatment paths at acidic and alkaline conditions yield promising results for nutrients recovery and valorisation as the obtained products (nutrient rich organic fertilizer, solid soil amendment and ammonium sulphate solution) fulfil the European Regulation for fertilizers to be potentially used in crop fields.
Subject(s)
Fertilizers , Nitrogen , Swine , Animals , Fertilizers/analysis , Ammonium Sulfate , Phosphorus , Acids , Potassium , Water , NutrientsABSTRACT
Avocados are popular fruits; however, contamination of whole fresh avocados and avocado products with foodborne pathogens has raised concern about their safety. Recalls and import alerts of avocado products due to contamination with Listeria monocytogenes cause important economic losses. The behavior of Salmonella, L. monocytogenes, and background microbiota on whole fresh avocados at 5 and 25 °C as affected by temperature and time of storage was investigated. Whole fresh avocados were inoculated by immersion in suspensions containing six rifampicin-resistant strains of Salmonella or L. monocytogenes, and stored at 5 °C for 48 d, or at 25 °C for 11 d. At selected sampling times, avocados were removed from storage and pathogens enumerated. The log counts of both pathogens at each temperature were fitted to the Weibull distribution nonlinear model to estimate kinetic parameters including the time for the first 1-log reduction (δ), the shape of the curve (ρ), and the time for two (2-D) and three (3-D) log reductions. Salmonella and L. monocytogenes initial populations (approx. 7 log CFU/avocado) decreased during storage at 5 and 25 °C; L. monocytogenes mean counts were higher than those observed for Salmonella (P < 0.05). L. monocytogenes showed a lower rate of decline at 5 °C when compared to Salmonella. In general, the ability of both pathogens to survive on the surface of avocados stored at room temperature was similar. Salmonella and L. monocytogenes counts decline over time on the epicarp of whole avocados; however, if the initial number of cells is large enough, the pathogens could be present for large periods of time. Simultaneously, psychrotrophic microorganisms (PM), aerobic plate count (APC), coliforms (C) and yeasts/molds (Y/M) were enumerated from non-inoculated avocados stored at 5 and 25 °C. Initial mean counts for PM, APC, C and Y/M ranged from 6.1 to 6.6 log CFU/avocado and showed no change (P > 0.05) during storage at both temperatures. Good agricultural and handling practices from farm to fork are crucial to prevent or minimize contamination of whole avocados; otherwise, if large numbers of pathogens contaminate the fruit, they could survive and be transferred to the pulp, or to other ready to eat foods, representing a risk for consumers.
Subject(s)
Listeria monocytogenes , Microbiota , Persea , Colony Count, Microbial , Food Microbiology , Salmonella , TemperatureABSTRACT
Alternative sanitising agents are required in the fruit and vegetable processing industry, capable of effectively disinfecting both the product and the washing water to increase its reuse, while not producing harmful by-products like chlorine-based agents. In the present work, electro-oxidation (EO) and ozone are proposed for vegetable process water reuse, being optimised for their individual and combined application. The application of hybrid electro-oxidation and ozone achieved 7 log reduction after 15 min of treatment in batch using boron-doped diamond (BDD) as anode material, showing important synergistic effects when compared with the individual treatments. When the process was applied in continuous mode, up to 6 log reduction of total bacteria was achieved using EO alone with Ru as the anode and stainless steel as the cathode, under 11 mA/cm2 of current density, a cell retention time of 12 s and no addition of chemical reagents (electrolyte). Under these conditions, the absence of microorganisms in water was maintained for more than 24 h, no harmful by-products (chlorate, bromate) were detected and no damage to lettuce seeds were observed when evaluating water reuse potential.
Subject(s)
Vegetables , Water Pollutants, Chemical , Diamond , Electrodes , Fruit/chemistry , Oxidation-Reduction , Technology , Water , Water Pollutants, Chemical/analysisABSTRACT
Salmonella is one of the major foodborne pathogens worldwide. The antimicrobial resistance (AMR) of this foodborne pathogen has raised a great concern in recent years. Studies on the frequency and characterization of Salmonella serotypes can help to improve our knowledge on the epidemiology of this pathogen. The purpose of this study was to compare the serotypes, AMR and genetic profiles of Salmonella isolates recovered from raw beef throughout the beef production chain and from human feces associated with clinical cases of salmonellosis. The serotype, AMR and pulsed-field gel electrophoresis profile of 243 Salmonella enterica isolates recovered from beef carcasses (n = 78), ground beef (n = 135), and human feces from clinical cases of salmonellosis (n = 30) were compared. Forty-three different Salmonella serotypes were identified and regardless of the source, the top five corresponded to Typhimurium, Give, Group B (partially serotyped), Infantis and Anatum. Twelve serotypes from beef carcasses were also found in ground beef, showing their presence throughout the beef production chain. Salmonella Typhimurium, Infantis, Anatum and Montevideo were the only serotypes identified in all sample types. Resistance to tetracyclines was the most frequent (41.2%) followed by resistance to aminoglycosides (37%), folate pathway inhibitors (21%), quinolones (20.2%), phenicols (17.1%), penicillins (15.6%) and cephems (7%). Multidrug resistance was observed in 28.8% of the isolates, and those from human feces showed resistance to a larger number of antimicrobials. Great concern arises from the resistance and reduced susceptibility observed to quinolones and cephalosporins because these drugs are the first line of treatment for invasive Salmonella infections. Twenty-seven distinct pulse-types were detected among 238 isolates. Clustering analysis for the most frequent serotypes identified groups of isolates with similar AMR profiles. Multidrug resistance spreading throughout the food production chain should be continually monitored and its importance emphasized.
ABSTRACT
The characterization of pharmaceutical drugs and their transformation products have become an important analytical research field because its presence in the environment could induce bacterial resistance. Despite all efforts made by the scientific community, detection and structure identification of unknown chemicals still remains the most challenging task in non-targeted analytics. Given that, the objective of the present study was to develop an untargeted workflow to detect, quantify, identify and characterize ofloxacin and its transformation products (OFX TPs) after photocatalytic treatments based on TiO2 nanoparticles and TiO2 nanofibers. For the characterization and chemical structure assignment of OFX TPs, mass defect filters, mass accurate measurements (HRMS), tandem mass spectrometry in a q-Orbitrap (MS/HRMS) and the photocatalysis of the isotopically labelled ofloxacin (OFX-d3) were used. Since a large set of data was obtained in each run, data treatment based on statistical analysis and mass defect filtering was used to reduce the number of potential TP candidates from 2497 m/z peaks to 70. Moreover, ions generated by in-source CID and by redox reactions in the electrospray source (ESI) were also detected and discarded from the TP candidate list. Moreover, the whole kinetics evolution of the generated TPs provided a deeper insight into the degradation mechanism and was used to propose a degradation pathway for the OFX in the aqueous phase. The time evolution of the TPs generated during the photocatalytic process using both types of catalysts (NPs and NFs) and different set-ups (suspended and supported conditions) indicated that OFX was completely removed from the aqueous solution in less than 4h. Among the condition tested TiO2 nanoparticles in suspended conditions showed the fastest kinetics (k: 0.161 min(-1)).
Subject(s)
Chemistry Techniques, Analytical/methods , Chromatography, Liquid , Ofloxacin/analysis , Tandem Mass Spectrometry , Titanium/chemistry , Catalysis , Ions , Oxidation-Reduction , Water/chemistry , Water Pollutants, Chemical/analysisABSTRACT
Objetivo: Analizar el comercio electrónico de las farmacias online españolas, teniendo en cuenta la normativa legal de la venta por Internet de medicamentos. Material y métodos: Selección de las diez farmacias que venden en Internet mejor posicionadas de forma natural en el motor de búsqueda Google y utilización de las mejores herramientas online gratuitas para el análisis de cada uno de los sitios web de las farmacias seleccionadas. Resultados y conclusiones: Las farmacias objeto del estudio presentan un nivel de SEO elevado, al igual que de seguridad, usabilidad y visibilidad, con diseños y arquitecturas web muy similares, mostrando carencias en la accesibilidad y adaptación de sus diseños web al comercio electrónico móvil (AU)
Aims: electronic commerce of selected Spanish pharmacies is analized taking into account the legal aspects of the Internet sales of medicines. Material and methods: selection of ten top natural ranked pharmacies that sell in Internet better positioned naturally in Internet search engine Google and use of the best free online tools for the analysis of each of the web sites selected pharmacies. Results and conclusions: The pharmacies under study exhibit a high level of SEO, security, usability and visibility, with very similar designs and web architectures but show gaps in accessibility and adaptation of web design for mobile commerce (AU)
Subject(s)
Pharmacies/trends , Pharmaceutical Centers , Pharmaceutical Services, Online/trends , Technology, Pharmaceutical/trends , Pharmaceutical Trade , InternetABSTRACT
This study focused on the advanced oxidation of the hetero bi-functional reactive dye Sumifix Supra Yellow 3RF (CI Reactive Yellow 145) using dark Fenton and photo-Fenton conditions in a lab-scale experiment. A 2(3) factorial design was used to evaluate the effects of the three key factors: temperature, Fe(II) and H2O2 concentrations, for a dye concentration of 250â mgâ L(-1) with chemical oxygen demand (COD) of 172â mgâ L(-1) O2 at pH=3. The response function was the COD reduction. This methodology lets us find the effects and interactions of the studied variables and their roles in the efficiency of the treatment process. In the optimization, the correlation coefficients for the model (R2) were 0.948 and 0.965 for Fenton and photo-Fenton treatments, respectively. Under optimized reaction conditions: pH=3, temperature=298â K, [H2O2]=11.765â mM and [Fe(II)]=1.075â mM; 60â min of treatment resulted in a 79% and 92.2% decrease in COD, for the dye taken as the model organic compound, after Fenton and photo-Fenton treatments, respectively.
Subject(s)
Azo Compounds/isolation & purification , Hydrogen Peroxide/chemistry , Iron/chemistry , Minerals/chemical synthesis , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Water/chemistry , Azo Compounds/chemistry , Azo Compounds/radiation effects , Combinatorial Chemistry Techniques/methods , Computer Simulation , Hydrogen Peroxide/radiation effects , Iron/radiation effects , Light , Minerals/radiation effects , Models, Chemical , Photochemistry/methods , Solutions , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/radiation effectsABSTRACT
The occurrence, serotype diversity, and antimicrobial resistance of Salmonella bacteria in commercial ground beef at retail establishments were investigated. Salmonella was isolated from 135 (56.7%) of 238 ground beef samples collected at the same number of butcher's shops located in three municipalities of Jalisco State, Mexico, during an 11-month period. The isolation frequency differed by municipality (P < 0.05) and was higher (P < 0.05) during the warm season (68.5%) than during the cold season (43.2%). Overall, 25 serotypes and 8 serogroups were identified among 135 Salmonella isolates; predominant were Salmonella group B (9.6%), Salmonella Anatum (8.9%), Salmonella Agona (6.7%), Salmonella Infantis (6.7%), and Salmonella Typhimurium (5.9%). All Salmonella isolates were tested for susceptibility to 11 antimicrobial drugs of human and veterinary use. Resistance to tetracycline was the most commonly observed (40.7%), followed by resistance to streptomycin (35.6%), trimethoprim-sulfamethoxazole (20.7%), and nalidixic acid (19.3%). Thirty-seven Salmonella isolates (27.4%) were multidrug resistant, and the majority corresponded to Salmonella Group B, Salmonella Anatum, and Salmonella Typhimurium. Three Salmonella isolates were resistant to seven different antimicrobials. The frequency of Salmonella in ground beef samples (56.7%) was higher than that observed in our previous investigation on beef carcasses (15.4%) at small abattoirs in the same region of Mexico. This may be a result of increasing contamination at these two points of the raw-beef production chain or may be an effect of the grinding process that facilitates a more-homogeneous pathogen distribution in the product. Poor hygiene, temperature abuse, and practices allowing cross-contamination during ground beef fabrication at these retail establishments increase the consumer's exposure to Salmonella.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Food Contamination/analysis , Meat Products/microbiology , Salmonella , Abattoirs , Animals , Cattle , Colony Count, Microbial , Food Microbiology , Humans , Mexico/epidemiology , Microbial Sensitivity Tests , Prevalence , Salmonella/classification , Salmonella/drug effects , Salmonella/isolation & purification , Salmonella Food Poisoning/epidemiology , Salmonella Food Poisoning/prevention & control , SerotypingABSTRACT
Eggs or egg-based foods, either raw or undercooked, have been identified as vehicles of Salmonella outbreaks. The low numbers of Salmonella organisms in eggs makes it difficult to detect them in frequency studies. The nested-PCR (n-PCR) technique shows more sensitivity and specificity than bacteriological culture methods (BCMs). A preenrichment method followed by enrichment and n-PCR is a good alternative for the investigation of Salmonella and Listeria monocytogenes in eggs. A total of 2,650 chicken eggs representing five commercial brands were purchased from 10 grocery stores. Ten eggs of each brand were combined in order to obtain 265 pooled samples (53 per brand). The shells and yolks of 100 pooled samples were analyzed for Salmonella, while the shells of 65 pooled samples were analyzed for L. monocytogenes, using BCM and a combined method of enrichment and n-PCR (CM-n-PCR). Sixteen eggshell pooled samples tested positive for Salmonella by CM-n-PCR, compared with only two by BCM. Three egg yolk pooled samples tested positive for this pathogen by CM-n-PCR; none tested positive by BCM. Three eggshell pooled samples tested positive for L. monocytogenes by CM-n-PCR and none by BCM. In Mexico, as in other countries, official methods for detection of Salmonella and L. monocytogenes in foods are based on standard bacteriological culture techniques. The inclusion of more sensitive methods such as the one used in the present investigation would increase the probability of detecting positive samples, particularly in those foods in which a very low number of cells is expected.
Subject(s)
Eggs/microbiology , Food Contamination/analysis , Listeria monocytogenes/isolation & purification , Polymerase Chain Reaction/methods , Salmonella/isolation & purification , Animals , Colony Count, Microbial/methods , Egg Shell/microbiology , Food Microbiology , Humans , Sensitivity and Specificity , Time FactorsABSTRACT
The prevalence and antimicrobial resistance of Salmonella serotypes on beef carcasses from four small abattoirs in Jalisco State, Mexico, were investigated during a 10-month period. Following U.S. Department of Agriculture Food Safety and Inspection Service protocols, Salmonella was isolated from 78 (15.4%) beef carcasses (n = 505) after the final carcass water wash. Isolation frequency differed by establishment (P < 0.05) and was higher (P < 0.05) during the wet season (May through September) for all establishments. Thirteen Salmonella serotypes and four serogroups (partially serotyped isolates) were identified. The most prevalent were Salmonella enterica Give (24.4%), Salmonella Typhimurium (17.9%), and Salmonella Group B (14.1%). Antimicrobial susceptibility was tested against 11 drugs, and results indicated that 46.2% of the isolates were resistant to tetracycline, 42.3% were resistant to streptomycin, 23.1% were resistant to chloramphenicol, 21.8% were resistant to trimethoprim-sulfamethoxazole, and 19.2% were resistant to gentamicin. No resistance to ceftriaxone or ciprofloxacin was observed, and 33% of the isolates were resistant to three or more antimicrobials. Although Salmonella Give was the most prevalent serotype, 95% of the isolates of this serotype were susceptible to all antimicrobials tested. Antimicrobial resistance was more common in Salmonella Typhimurium, and 93% (13 of 14) of the isolates of this serotype were resistant to at least five antimicrobials. The frequency of multidrug-resistant Salmonella isolates differed among establishments (P < 0.05) and may be related to the origin of the cattle presented for harvesting. These findings highlight the need for control measures to reduce Salmonella prevalence on beef carcasses in small abattoirs in Mexico and for strategies to ensure the cautious use of antimicrobials in animal production to prevent and control the spread of antimicrobial-resistant foodborne pathogens.
Subject(s)
Abattoirs , Cattle/microbiology , Drug Resistance, Bacterial , Food Contamination/analysis , Salmonella/classification , Salmonella/drug effects , Animals , Anti-Bacterial Agents/pharmacology , Colony Count, Microbial , Drug Resistance, Multiple, Bacterial , Food Microbiology , Humans , Mexico , Prevalence , Salmonella/isolation & purification , SerotypingABSTRACT
Reactive azo dye Procion Red H-E7B solutions have been submitted to solar-assisted photo-Fenton degradation. The solution color quickly disappears, indicating a fast degradation of the azo group. Nevertheless, complete DOC removal was not accomplished, in accordance with the presence of resistant triazine rings at the end of the reaction. The intermediates generated along the reaction time have been identified and quantified. LC-(ESI)-TOF-MS analysis allowed the detection of 18 aromatic compounds of different size and complexity. Some of them shared the same accurate mass, and consequently, the same empirical formula, but appeared at different chromatographic retention times, evidencing their different molecular structures. Heteroatom oxidation products like NH4+, NO3-, Cl-, and SO4(2-) have also been quantified and explanations of their release are proposed. Short chain carboxylic acids are also detected at long reaction times, as a previous step to complete dye mineralization. A link between the disappearance of the largest intermediate products and the increase of the solutions biodegradability has been established. Finally, taking into account all the findings of the present study and previous related works, the evolution from the original dye to the final products (triazine and CO2) is proposed in a general reaction scheme.
Subject(s)
Photochemistry , Sunlight , Triazines/chemistryABSTRACT
Several biological and chemical coupled treatments for Cibacron Red FN-R reactive azo dye degradation have been evaluated. Initially, a two-stage anaerobic-aerobic biotreatment has been assessed for different dye concentrations (250, 1250 and 3135 mg l(-1)). 92-97% decolourisation was attained during the anaerobic digestion operating in batch mode. However, no dissolved organic carbon (DOC) removal neither biogas production was observed during the process, indicating that no methanogenesis occurred. Additionally, according to Biotox and Zahn-Wellens assays, the anaerobically generated colourless solutions (presumably containing the resulting aromatic amines from azo bond cleavage) were found to be more toxic than the initial dye as well as aerobically non-biodegradable, thus impeding the anaerobic-aerobic biological treatment. In a second part, the use of an advanced oxidation process (AOP) like photo-Fenton or ozonation as a chemical post-treatments of the anaerobic process has been considered for the complete dye by-products mineralisation. The best results were obtained by means of ozonation at pH 10.5, achieving a global 83% mineralisation and giving place to a final harmless effluent. On the contrary, the tested photo-Fenton conditions were not efficient enough to complete oxidation.
Subject(s)
Azo Compounds , Coloring Agents , Waste Disposal, Fluid/methods , Water Pollutants, Chemical , Aerobiosis , Aliivibrio fischeri/drug effects , Aliivibrio fischeri/metabolism , Anaerobiosis , Azo Compounds/chemistry , Azo Compounds/metabolism , Azo Compounds/radiation effects , Azo Compounds/toxicity , Biodegradation, Environmental , Coloring Agents/chemistry , Coloring Agents/metabolism , Coloring Agents/radiation effects , Coloring Agents/toxicity , Hydrogen Peroxide/chemistry , Iron/chemistry , Luminescence , Oxidants/chemistry , Ozone/chemistry , Ultraviolet Rays , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/metabolism , Water Pollutants, Chemical/radiation effects , Water Pollutants, Chemical/toxicityABSTRACT
An environmental study using life cycle assessment (LCA) has been applied to three bench-scale wastewater treatments for Cibacron Red FN-R hetero-bireactive dye removal: artificial light photo-Fenton process, solar driven photo-Fenton process and artificial light photo-Fenton process coupled to a biological treatment. The study is focused on electricity and chemicals consumption, transports and atmosphere and water emissions generated by the different processes involved. Results show that the artificial light photo-Fenton process is the worst treatment in terms of environmental impact. On the other hand, both solar driven and coupled to biological photo-Fenton processes reduce significantly the environmental damage, although none can be identified as the best in all impact categories. The major environmental impact is attributed to the H2O2 consumption and to the electrical energy consumption to run the UVA lamp. An economic analysis of the different photo-Fenton processes has also been performed and the results are discussed together with those obtained from the environmental assessment.
Subject(s)
Coloring Agents , Environment , Hydrogen Peroxide , Iron , Triazines , Waste Disposal, Fluid/methods , Biodegradation, Environmental , Coloring Agents/chemistry , Electricity , Hydrogen Peroxide/economics , Iron/economics , Light , TextilesABSTRACT
A bench-scale study combining photo-Fenton reaction with an aerobic sequencing batch reactor (SBR) to degrade a commercial homo-bireactive dye (Procion Red H-E7B, 250mgl(-1)) was investigated. The photo-Fenton process was applied as a pre-treatment, avoiding complete mineralisation, just to obtain a bio-compatible water able to be treated by means of the SBR in a second step. In this sense, different Fenton reagent concentrations were assessed by following dye solution biodegradability enhancement (BOD(5)/COD), as well as the toxicity (EC(50)), DOC, colour (Abs(543.5)) and H(2)O(2) evolution with photo-Fenton irradiation time. Obtained pre-treated solutions were biologically oxidized in a SBR containing non-acclimated activated sludge. Different hydraulic retention time (HRT) in the bioreactor were tested to attain the maximum organic load removal efficiency. Best results were obtained with 60min of 10mgl(-1) Fe(II) and 125mgl(-1) H(2)O(2) photo-Fenton pre-treatment and 1 day HRT in SBR.