Development of respiratory function in the brine shrimp Artemia franciscana Kellogg 1908, cultured under different oxygenation regimes.

The brine shrimp Artemia has been a favourite subject of study for molecular biologists and is an extremely important economic resource. Despite this we know little of the physiology of brine shrimp as it relates to their natural environment. While some data are available on physiological responses to temperature and salinity, little is known of respiratory responses to hypoxia, particularly long-term and periodic hypoxia. Consequently the main aim of this thesis was to examine the development of respiratory function in the brine shrimp Artemia franciscana Kellogg 1908, cultured under different oxygenation regimes. Not only were developmental patterns documented but particular attention was given to possible underlying physiological mecruunsms. Culture of A. franciscana under chronic hypoxia (50 % normoxic saturation) resulted in accelerated development at least in the initial stages (5-9). The weight of individuals of any particular developmental stage was independent of experimental treatment, i.e. hypoxic cultured individuals did not increase developmental rate by producing smaller individuals. By the time they reached sexual maturity there was no difference in growth or development between experimental and control tre3:tments. Individuals cultured under chronic hypoxia contain~d considerably more hemoglobin than normoxic controls, with those cultured under periodic hypoxia being intermediate. This hemoglobin was present not only in the hemolymph but was also localised in many of the highly aerobic tissues ( appendage muscles). There was very little difference in the pattern of culture mortality between chronic hypoxia and normoxia, with a peak in mortality during the thoracic stage of development. Artemia franciscana cultured under periodic hypoxia (8 h, hypoxia, 16 h normoxia) showed a response intermediate to that of chronic hypoxia and normoxia. Culture under chronic hypoxia resulted in a shift from a mixed oviparity/ovoviviparity to oviparity alone. Although the total number of offspring produced was lower for individuals cultured under chronic hypoxia, the number of cysts· produced was the same as for the control treatments. The relationship between oxygen uptake and dry body weight in A. franciscana could be predicted on an allometric basis. The recorded decrease in oxygen uptake with development, between Stage 0 and Stage 3 could be explained by the fact that at this point development was accompanied by a decrease in body weight. the nauplii displayed a marked ability to regulate oxygen uptake when exposed acutely to declining oxygen tensions (critical oxygen tension or Pc= 6.5 ± 0.3 kPa). This ability improved from Stage 0 -6, with a decrease in Pc to 4.6 ± 0.3. This coincided with beginning of the thoracic stage of development, which was characterised by the formation of gills and a functional heart. Thereafter there was little change in regulatory ability with continuing development. Culture under conditions of periodic or chronic hypoxia had no significant effect on rates of oxygen uptake but did result in the improvement in respiratory performance which normally accompanies development being brought forward. Improved regulation under conditions of declining oxygen tension was achieved by Stage 3 and regulatory ability was more highly developed than normoxic controls. Individuals cultured under periodic hypoxia showed a response intermediate to hypoxic and normoxic individuals indicating that it was probably the duration of exposure to hypoxia that was important not the pattern. Regulation of oxygen uptake during conditions of declining oxygen tensions was compromised if the respiratory pigment hemoglobin was inactivated (using CO) in individuals cultured under hypoxic conditions but not in normoxic controls. Whether or not cysts were produced by hemoglobin-rich or hemoglobin-poor parents, made little· difference to the respiratory performance of the offspring. Furthermore this respiratory performance was not compromised by CO exposure. The aerobic capacity of the tissues of A. franciscana was improved by culture under chronic hypoxia. This was seen both in the dramatic increase in the total activity of cytochrome c oxidase in individual animals, determined enzymatically and by staining for the enzyme in thin sections, and also by the dramatic changes in mitochondria number and morphology observed, particularly for the most aerobic tissues. It was concluded that respiratory regulation of A. franciscana 'improved' early in development and that this 'improvement' could be 'brought forward' by culturing individuals under hypoxic conditions. The development of respiratory regulation in normoxia cultured animals could not be attributed to the presence of hemoglobin, as could its development in hypoxia cultured animals. Furthermore, as well as improving the uptake and transport of oxygen to the tissues hypoxic cultured A. franciscana also 'improved' the aerobic capacity of the tissues. The fact that A. franciscana cultured under periodic hypoxia showed an intermediate response for most of the features studied suggests that it is the duration not the pattern of hypoxic exposure that is important in modifying respiratory regulation. So A. franciscana in response to hypoxic exposure, hurries through early hypoxia-sensitive life stages, but also, and at the same time, develops a respiratory physiology which is better able to cope with hypoxia as an environmental stress. So this study has demonstrated that some animals, early in development may respond to environmental stress by increasing developmental rate to bring the adult pattern of physiological regulation nearer in time and also, if possible, bring that adult pattern of regulation forward in development itself

Agarase Production by Marine Pseudoalteromonas sp. MHS: Optimization, and Purification

Agar is an essential polysaccharide that has been utilized in numerous fields. Many kinds of literature have been published regarding agarolytic microorganisms’ isolation and agarases biochemical studies. In this search, a local marine agarolytic bacterium associated with marine alga Ulva lactuca surface was isolated and identified as Pseudoalteromonas sp. MHS. The agarase production was parallel to the growth of Pseudoalteromonas sp. MHS as cells displayed a lag phase (2 h), subsequently an exponential growth that prolonged till 10 h where maximum growth (OD550nm = 3.9) was achieved. The enzyme activity increased rapidly as cells increased exponentially where the maximum activity of 0.22 U/mL was achieved after 8h and remained constant till 12 h during the stationary phase of growth. Agarase production was optimized using Plackett-Burman statistical design by measuring enzyme activity as a response and the design was validated using a verification experiment; the activity of the enzyme increased from 0.22 U/mL to 0.29 U/mL. Pseudoalteromonas sp. MHS agarase was partially purified and its molecular weight (MW) was determined by SDSPAGE (15-25 kDa). Agarase showed approximately 94% of its activity at 40 °C. The enzyme stability decreased as the temperature increased; the enzyme could retain about 98, 90, 80, 75, and 60% of its activity at 20, 30, 40, 50, and 60 °C, respectively. Biomass of the red alga Pterocladia capillacea proved to be a suitable substrate for agarase production using Pseudoalteromonas sp. MHS; the enzyme activity recorded after 24 h of incubation was 0.35 U/mL compared to 0.29 U/mL from the optimized medium

FORMULATION AND ASSESSMENT OF A HERBAL HAIR CREAM AGAINST CERTAIN DERMATOPHYTES

Objective: Developing an herbal antifungal formulation containing eruca and garlic oils against highly resistant dermatophytes (Malassezia fufur AUMC No. 5173, Microsporum canis bodin AUMC No. 5490 and Trichophyton mentagrophytes AUMC No. 5501. 5501) and assessment of garlic oil thiosulfonates during the ex vivo percutaneous permeation through albino rat skin.Methods: Assay of antifungal activity was performed by filter paper disc method and agar well diffusion method. The components of volatile constituents and fixed oil of eruca seeds were studied using GC/MS. Thiosulfinates in garlic oil were analyzed by HPLC/UV. Both oils were incorporated into hair cream using span 60 and brij 58 at three different concentrations (2, 4 and 6% w/w) and alliin, was ex vivo evaluated using albino rat skin mounted on Franz diffusion cells.Results: The two oils have a synergistic effect on the first and additive effect on the second and the third fungi. The main constituents in eruca are 4-(methyl thio) butyl isothiocyanate (82%) for volatile constituents and erucic acid (40%) for the fixed one. The highest flux for alliin (0.337±0.0015 mg/cm2/hr) was obtained at a 4% surfactant concentration.Conclusion: Combination of oils has a high activity on the selected dermatophytes. Formulation of an herbal hair cream using span 60 and Brij 58 with a concentration 4% gives the highest permeation rate for alliin in garlic oil.Keywords: Eruca, Garlic, Dermatophytes, Quantitative determination and Ex-vivo permeatio

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

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 1·05–2·37; 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

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Isolation and characterization of a phenol-degrading strain of Alcaligenes sp. AM4

Six isolates with phenol degrading ability were obtained from marine sediments by enrichment procedures and an isolate, AM4, was identified as Alcaligenes sp. by 16S rDNA sequencing. The Plackett-Burman design was applied to estimate the significance of culture medium components and conditions for phenol degradation by Alcaligenes sp. AM4. The resulting medium formula which was predicted to be near optimal was: phenol conc. (240 μg/ml), culture volume (37.5 ml), inoculum’s size (0.15 ml), NH4SO4 (0.5 g/l), K2HPO4 (0.75 g/l), KH2PO4 (0.75 g/l), MgSO4 (0.3 g/l) and NaCl (0.25 g/l). Scanning electron microscopy was applied to cells exposed to phenol, and a larger cell size was detected, resulting in a reduced cell surface. This relative reduction of the cell surface represents a cellular mechanism to reduce the toxic effect of this environmental stress factor

The role of MgBr2 to enhance the ionic conductivity of PVA/PEDOT:PSS polymer composite

A solid polymer electrolyte system based on poly(vinyl alcohol) (PVA) and poly(3,4-Etylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) complexed with magnesium bromide (MgBr2) salt was prepared using solution cast technique. The ionic conductivity is observed to increase with increasing MgBr2 concentration. The maximum conductivity was found to be 9.89 × 10−6 S/cm for optimum polymer composite film (30 wt.% MgBr2) at room temperature. The increase in the conductivity is attributed to the increase in the number of ions as the salt concentration is increased. This has been proven by dielectric studies. The increase in conductivity is also attributable to the increase in the fraction of amorphous region in the electrolyte films as confirmed by their structural, thermal, electrical and optical properties

Challenge of Moringa peregrina Forssk as an antimicrobial agent against multi-drug-resistant Salmonella sp.

The emergence of multi-drug-resistant (MDR) pathogenic bacteria is considered as a global problem. The aim of this study was to evaluate the antimicrobial inhibitory effects of the oily aqueous extract of Moringa peregrina Forssk against MDR clinical Salmonella enterica isolates. Four MDR S. enterica isolates were proved to have a gene mutation in amino acids codon 83 and 87 of gyrA and 67, 76 and 80 of parC gene by polymerase chain reaction (PCR) amplification and sequencing. The active components of M. pregrina extract were purified using GLC and TLC techniques and by using IR, NMR and mass spectra. The M. peregrina Forssk extract effect on bacterial cells was determined using scanning and transmission electron microscopies. Results demonstrated that M. peregrina Forssk have an excellent inhibitory effect against 34 MDR S. enterica isolates with different minimum inhibitory concentration (MIC) (109.37–437.5 mg/mL). The active component was identified as oleic acid-3 hydroxy propyl ester. The main abnormalities of Salmonella cells were observed – destruction in the cell wall that led to a reduction of protoplast besides, disruption of cytoplasmic membranes and, consequently, loss in their metabolic functions and death. This is the first report that deeply highlights the antimicrobial activity of M. peregrina Forssk against MDR clinical S. enterica isolates

New biomarkers of post-settlement growth in the sea urchin Strongylocentrotus purpuratus

Some sea urchins, including the purple sea urchin Strongylocentrotus purpuratus, have been successfully used in aquaculture, but their slow growth and late reproduction are challenging to overcome when developing efficient aquaculture production techniques. S. purpuratus develops via an indirect life history that is characterized by a drastic settlement process at the end of a larval period that lasts for several weeks. During this transition, the bilateral larva is transformed into a pentaradial juvenile, which will start feeding and growing in the benthic habitat. Due to predation and other ecological factors, settlement is typically associated with high mortality rates in juvenile populations. Additionally, juveniles require several days to develop a functional mouth and digestive system. During this perimetamorphic period, juveniles use up larval resources until they are capable to digest adult food. Mechanisms underlying the onset of juvenile feeding and metabolism have implications for the recruitment of natural populations as well as aquaculture and are relatively poorly understood in S. purpuratus. The insulin/insulin-like growth factor signalling (IIS)/Target of Rapamycin (TOR) pathway (IIS/TOR) is well conserved among animal phyla and regulates physiological and developmental functions, such as growth, reproduction, aging and nutritional status. We analyzed the expression of FoxO, TOR, and ILPs in post-settlement juveniles in conjunction with their early growth trajectories. We also tested how pre-settlement starvation affected post-settlement expression of IIS. We found that FoxO provides a useful molecular marker in early juveniles as its expression is strongly correlated with juvenile growth. We also found that pre-settlement starvation affects juvenile growth trajectories as well as IIS. Our findings provide preliminary insights into the mechanisms underlying post-settlement growth and metabolism in S. purpuratus. They also have important implications for sea urchin aquaculture, as they show that pre-settlement nutrient environment significantly affects both early growth trajectories and gene expression. This information can be used to develop new biomarkers for juvenile health in sea urchin population ecology and aquaculture aquaculture