23 research outputs found
A review of environmental impacts of salts from produced waters on aquatic resources
Salts are frequently amajor constituent ofwastewaters produced during oil and gas production. These produced waters or brines must be treated and/or disposed and provide a daily challenge for operators and resourcemanagers. Some elements of salts are regulated with water quality criteria established for the protection of aquatic wildlife, e.g. chloride (Clâ), which has an acute standard of 860 mg/L and a chronic standard of 230 mg/L. However, data for establishing such standards has only recently been studied for other components of produced water, such as bicarbonate (HCO3 â), which has acute median lethal concentrations (LC50s) ranging from 699 to N8000 mg/L and effects on chronic toxicity from 430 to 657 mg/L. While Clâ is an ion of considerable importance inmultiple geographical regions, knowledge about the effects of hardness (calciumand magnesium) on its toxicity and about mechanisms of toxicity is not well understood. A multiple-approach design that combines studies of both individuals and populations, conducted both in the laboratory and the field, was used to study toxic effects of bicarbonate (as NaHCO3). This approach allowed interpretations about mechanisms related to growth effects at the individual level that could affect populations in the wild. However, additional mechanistic data for HCO3 â , related to the interactions of calcium (Ca2+) precipitation at the microenvironment of the gill would dramatically increase the scientific knowledge base about how NaHCO3 might affect aquatic life. Studies of the effects of mixtures of multiple salts present in produced waters and more chronic effect studies would give a better picture of the overall potential toxicity of these ions. Organic constituents in hydraulic fracturing fluids, flowback waters, etc. are a concern because of their carcinogenic properties and this paper is not meant to minimize the importance of maintaining vigilance with respect to potential organic contamination
A review of environmental impacts of salts from produced waters on aquatic resources
Salts are frequently amajor constituent ofwastewaters produced during oil and gas production. These produced waters or brines must be treated and/or disposed and provide a daily challenge for operators and resourcemanagers. Some elements of salts are regulated with water quality criteria established for the protection of aquatic wildlife, e.g. chloride (Clâ), which has an acute standard of 860 mg/L and a chronic standard of 230 mg/L. However, data for establishing such standards has only recently been studied for other components of produced water, such as bicarbonate (HCO3 â), which has acute median lethal concentrations (LC50s) ranging from 699 to N8000 mg/L and effects on chronic toxicity from 430 to 657 mg/L. While Clâ is an ion of considerable importance inmultiple geographical regions, knowledge about the effects of hardness (calciumand magnesium) on its toxicity and about mechanisms of toxicity is not well understood. A multiple-approach design that combines studies of both individuals and populations, conducted both in the laboratory and the field, was used to study toxic effects of bicarbonate (as NaHCO3). This approach allowed interpretations about mechanisms related to growth effects at the individual level that could affect populations in the wild. However, additional mechanistic data for HCO3 â , related to the interactions of calcium (Ca2+) precipitation at the microenvironment of the gill would dramatically increase the scientific knowledge base about how NaHCO3 might affect aquatic life. Studies of the effects of mixtures of multiple salts present in produced waters and more chronic effect studies would give a better picture of the overall potential toxicity of these ions. Organic constituents in hydraulic fracturing fluids, flowback waters, etc. are a concern because of their carcinogenic properties and this paper is not meant to minimize the importance of maintaining vigilance with respect to potential organic contamination
Production, optimization and characterization of extracellular amylase from halophilic Bacillus lichineformis AH214
Twenty one moderately halophilic bacterial strains were isolated from seawater and sediment in Alexandria Eastern Harbour, Egypt. The isolates were screened for the production of four extracellular degradative enzymes. The majority of isolates (57.1%) possessed significant enzyme activities, 43% of them have potentiality to produce amylase enzyme. The most active isolate for the production of amylase enzyme was identified by using a 16S rRNA sequence analysis as Bacillus lichineformis AH214. Optimization of the fermentation medium components and environmental factors using One Variable at a Time Approach and Plackett-Burman design was applied to enhance the amylase production by Bacillus lichineformis AH214. The maximum microbial amylase production could be achieved using an optimized medium of the following composition (g/l): 1.0 g yeast extract, 0.05 g K2HPO4, 0.25 g FeCl3, 15.0 g starch, 30.0 g NaCl, 0.75 g MgSO4.7H2O and inoculums size of 1.5 ml/50 ml and incubated at optimum conditions of pH 7, agitation speed 160 rpm, time 30 h and temperature 40°C. On applying optimized medium in the fermentation process, an enzyme productivity of 13.44 U/mg protein was achieved with two fold increase compared to the basal one. The crude amylase produced by Bacillus lichineformis was stable up to 40°C, pH 7.5 and 1.5 M NaCl.Key words: Halophiles, amylase, Bacillus lichineformis, Plackett-Burman, optimization
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Functional immune responses against SARS-CoV-2 variants of concern after fourth COVID-19 vaccine dose or infection in patients with blood cancer
Summary
Patients with blood cancer continue to have a greater risk of inadequate immune responses following three COVID-19 vaccine doses and risk of severe COVID-19 disease. In the context of the CAPTURE study (NCT03226886) we report immune responses in 80 patients with blood cancer who received a fourth dose of BNT162b2. We measured neutralising antibody titres (NAbT) using a live virus microneutralization assay against wild-type (WT), Delta, Omicron BA.1 and BA.2 and T cell responses against WT and Omicron BA.1 using an activation-induced marker (AIM) assay. The proportion of patients with detectable NAb titres and T cell responses after the fourth vaccine dose increases compared to those after the third vaccine dose. Patients who received B cell-depleting therapies within 12 months before vaccination have the greatest risk of not having detectable NAbT. In addition, we report immune responses in 57 patients with breakthrough infections after vaccination
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05â2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Production, optimization, characterization and antifungal activity of chitinase produced by Aspergillus terrus
Chitin is one of the most abundant biopolymers widely distributed in the marine and terrestrial environments. Chitinase enzyme has received increased attention due to its wide range of biotechnological applications. Aspergillus terrus was found to be a good chitinase producer among the five fungi isolated from different soil samples from Al-Jouf city, Saudi Arabia. Maximum production of chitinase was obtained when using 2% of Shrimp-shell powder as a sole carbon source in the fermentation medium. The high level of chitinase production was observed in the culture medium with pH 5 at 30°C for five days at shaking conditions. Some properties of the crude chitinase were studied. In the present study, the antifungal activity of crude A. terrus chitinase was investigated against Apergillus niger, Aspergillus oryzae, Pencillum oxysporium, Rhizoctonia solani, Fusarium oxysporium, Rhizopus sp. and Mucor sp. and also estimated. The chitinase was found to inhibit the growth of some phytopathogenic fungi tested. The present work provides a suitable medium composition for enhancement of chitinase production by A. terrus and some properties of crude enzyme. Moreover, the study reflects the potential of A. terrus chitinase for biotechnological application.Keywords: Chitinase, Aspergillus terrus, optimization, antifungal activityAfrican Journal of Biotechnology, Vol 13(14), 1567-157
Degradation of Phenol by A New-Degradable Marine Halophilic Fungus Fennellia Flavipes Isolated From Mangrove Sediments
Abstract: Phenol and its derivatives are one of the largest groups of environmental pollutants. Intensive efforts to screen species with high-degradation activity are needed to study their capabilities of degrading phenol and phenolic derivatives. Six different halophilic fungi were isolated from sediments along Suez Gulf and mangrove sediments in Red Sea coasts, Egypt, All tested fungal isolates exhibited the ability to grow and degrade phenol and phenolic derivatives as sole carbon source, these fungal isolates belonging to three genera (Aspergillus, Pencillium and Fusarium). The most potent isolate identified as F. flavipes exhibited the highest efficiency to phenol degradation
Purification, Characterization and Anticancer Activity of L-asparaginase Produced by Marine Aspergillus terreus
L-asparaginase (E.C.3.5.1.1) is an enzyme responsible for hydrolysis of L-asparagine into aspartic acid and
ammonia, and has its significant applications in the therapeutics and food technology. It was produced
by the marine Aspergillus terreus and precipitated by 65% ammonium sulphate, followed by purification
using gel filtration on Sephadex G-100 and DEAE-cellulose ion exchange chromatography, which yielded
11.96 fold purification. The molecular weight of the purified L-asparaginase was approximately 85
kDa, determined by a sodium dodecyl sulphate polyacrylamide gel electrophoresis. L-asparaginase
showed high affinity for L-asparagine with a Km of 31.5 mM and Vmax of 500 U/ml. The optimum pH
and temperature of the purified enzyme were 5.8 and 40 o
C, respectively. The L-asparaginase enzyme
was stable from pH 4 to 5.8 and stable up to 70 o
C. The effect of activators and inhibitors was studied
providing that CdCl2
, Pb Cl2
, and Hg Cl2
strongly inhibited the enzyme activity, while Na Cl highly enhanced
activity. Anticancer activity of the purified L-asparaginase was detected against HCT-116, Hep-G2 and
MCF-7 cell lines with IC50 ranged from 3.79-12.6 ”g/ml