Effect of Initial pH on Sulphate and Phosphate Uptake from Wastewater by Selected Bacterial and Fungal Species

This study was aimed at investigating the effect of pH on sulphate and phosphate uptake from wastewater by selected bacterial and fungal species. A total of four each of bacterial and fungal isolates were used under shaking flasks conditions. The wastewater was supplemented with sodium acetate to serve as external carbon source at a concentration of 5 g/L. Immediately after inoculation with the respective isolates and at 24 h intervals, for the next 96 h, aliquot wastewater samples were taken from each flask for the estimation of total phosphate and sulphate in the wastewater, using standard procedures. The results revealed remarkable sulphate removal at pH 12. Apart from the Klebsiellasp. which showed high phosphate removal at pH 6, none of the isolates showed high phosphate removal at the different pH ranges. From an initial concentration of 480.22 mg/L, sulphate levels in the wastewater inoculated with the respective isolates were observed to decrease after 24 h incubation to 256.23 mg/L, 271.23 mg/L, 234.30 mg/L and 254.77 mg/L, in the presence of the Aspergillusniger, Aspergillusflavus, Fusarium and Absidiaspecies, respectively. For bacterial isolates, concentrations of sulphate after 24 h incubation were 290.85 mg/L, 218.14 mg/L, 278.16 mg/L and 298.93 mg/L, in the presence of the Pseudomonas, Klebsiella, Lysinibacillus and Staphylococcus species, respectively. The study was able to reveal the optimum pH for sulphate and phosphate uptake by the test microbial species

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Effects of External Carbon Source Concentration on Sulphate Removal by Selected Bacterial and Fungal species

The aim of this study was to investigate the role of initial external carbon source concentration on sulphate removal by four bacterial and four fungal isolates under shake flask conditions. The test wastewater was filtered and supplemented with sodium acetate as the external carbon source at respective concentrations of 5 g/L, 10 g/L, 15 g/L and 20 g/L, before dispensing in 200 mL quantity in 250 mL capacity conical flasks, sterilised and inoculated with the test microbial isolates. Prior inoculation and at 24 h interval, for 96 h for the estimation of sulphate concentration in the wastewater using standard methods. The results revealed remarkable sulphate removal in the absence of the sodium acetate and on its 5 g/L addition. An increase in the concentration of the sodium acetate caused a corresponding decrease in the level of sulphate removal. Percentage sulphate removals in presence of the test isolates were observed to range from 47.01 to 57.81%, 18.66 to 51.66%, -1.64 to 11.03%, 5,38 to 22.37% and -3.59 to 5.18%, at sodium acetate concentrations of 0 g/L, 5 g/L, 10 g/L, 15 g/L and 20 g/L, respectively. This trend was irrespective of the isolates used for investigation. The study was able to provide an insight to the role of carbon concentration on sulphate removal by the test microbial isolates

Production of biodiesel by transesterification of refined soybean oil

This study focused on the production of biodiesel via transesterification of refined soybean oil obtained locally. Sodium hydroxide was used as the alkali catalyst and methanol (as alcohol) was used in the transesterification process due to its low cost. The methanol-to-oil molar ratio was maintained at 6:1. The effect of reaction temperature with time and the catalyst loading were studied. The reaction temperature and the catalyst loading were varied at 30, 40, 50, 60 and 70 oC; and at 0.5 and 1.0% weight of oil, respectively. After transesterification of the soybean oil, the fatty acid methyl esters [FAMEs (biodiesel)] conversion was found to rise with an increase in the catalyst loading and also with the reaction temperature but no significant difference (P > 0.05) was found between the temperatures of 60 oC and 70 oC. The optimum methyl esters conversion of 97.89% was achieved at 60 oC for 3 h with 1% (w/w) catalyst. The viscosity (at 40 oC), density, cloud point, pour point, flash point and acid number were 3.40 cSt, 0.86 g/ml, -1 oC, -7 oC, 175 oC and 0.19, respectively. This optimum methyl esters conversion obtained met ASTM standard of D-6751. Therefore, soybean oil has been shown in this study as a good candidate for biodiesel production and the data acquired can be scaled up for large scale production. © 2010 International Formulae Group. All rights reserved. Keywords: Renewable energy, fatty acid methyl esters, diesel, catalyst

Biofilms of pathogenic bacteria and emerging antibiofilm strategies

Biofilms act as physical barriers to the immune system and drugs used by the host, resulting in antimicrobial resistance. Biofilms reduce the chances of eradicating infections and can result in relapses and backsliding after conventional treatment. Biofilms have a big impact on food safety in the food industry; many foodborne outbreaks have been linked to pathogenic bacteria that can form a biofilm. Biofilm-associated infections can cause not only severe symptoms but also serious side effects and even death. The findings of an experimental study of pathogenic bacteria like Pseudomonas aeruginosa, Salmonella enteritidis, and Staphylococcus aureus forming biofilms are presented in this article. The process of biofilm formation and its development phases were displayed with preserved architectonics using light and scanning electron microscopes. The amount of biofilm formed was influenced by the growth medium as well as the incubation conditions and time. Biofilm-forming microbes are a common cause of complicated and recurrent diseases, and they're usually linked to MDR bacteria, which account for nearly 80% of all refractory nosocomial infections. Medical device- and tissue-associated biofilm infections are two types of biofilm infections. Understanding the pathogenesis and factors that contribute to biofilm formation, as well as the disruption and dispersal mechanisms of biofilms, will aid in the development of improved anti-biofilm strategies. Overall, this literature review can serve as a single source of information about microbial biofilm formation and mitigation strategies, which could be extremely useful to biofilm researchers. Keywords: biofilm; pathogenic bacteria; infection; anti-biofilm