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The occurrence of acetaminophen, amoxicillin, diclofenac and methylparaben in Lagos and Ologe Lagoons was investigated by random sampling of the water bodies during rainy and dry seasons. Samples analysis was carried out using high performance liquid chromatography. For the two seasons, the mean environmental concentrations of acetaminophen in Lagos and Ologe Lagoons were 0.075 μg/L and 1.233 μg/L respectively. The mean environmental concentration of amoxicillin in Lagos Lagoon was 0.008 μg/L while 0.003 μg/L was the mean value in Ologe Lagoon. Diclofenac occurrence in Lagos Lagoon had a mean value of 0.136 μg/L while 0.519 μg/L was recorded in Ologe Lagoon. The environmental concentration of methylparaben in Lagos Lagoon was 0.453 μg/L while its means concentration in Ologe Lagoon was 0.089 μg/L. From the results, the environmental concentrations of acetaminophen and diclofenac in Ologe Lagoon were higher than their level of occurrence in Lagos Lagoon. However, the levels of occurrence of amoxicillin and methylparaben in Lagos Lagoon were higher than their environmental concentrations in Ologe Lagoon. Methylparaben was the most frequently detected in the water bodies with 87.5% detection frequency. This was followed by diclofenac with 75%. Also, 50% of the water samples analysed contained acetaminophen while amoxicillin had the least (37.5%) frequency of occurrence. The study established that there are active pharmaceuticals compounds and excipients present in the Nigerian aquatic environment which are micropollutants of emerging environmental concerns and of significant ecological risk. Therefore, there is need for environmental regulators to make concerted efforts towards environmental monitoring of this group of pollutants. [ABSTRACT FROM AUTHOR]

The use and abuse of analgesics, commonly referred to as painkillers is on the rise globally. This study examined the acute toxicity and sub-lethal effects on liver function (ALT, AST, ALP) and anti-oxidative stress enzymes of the African Catfish, Clarias gariepinus, exposed to two analgesics, acetaminophen and diclofenac. The fingerlings (4 weeks old), were exposed to high concentrations of both analgesics to determine their acute toxicity of a 96 h period. The results indicated that diclofenac was approximately 500 times more toxic to the catfishes with a 96 h LC50 of 2.6 mg/L compared to 1283.6 mg/L in those exposed to acetaminophen. Another batch of the catfishes was subsequently exposed to two sub-lethal concentrations (1/10th 96 h LC50 and 1/100th 96 h LC50) of both compounds for 28 days. The result of the sub-lethal assessment indicated that the responses were not always dose-dependent. The liver function enzyme assessments indicated a varied result with AST values slightly lower than control while ALP values were all higher in the exposed groups than the control. Only catfishes exposed to 1/10th 96h LC50 diclofenac showed significant inhibition (P<0.05) of ALT enzyme activities compared to control. The activities of the anti-oxidative stress enzyme catalase were lower in those exposed to acetaminophen compared to control and this was also the case for glutathione-S-transferase (GST) activities for exposures to both concentrations of both analgesics. The findings point to the need for the inclusion of pharmaceuticals in our national effluent quality standards so as to mitigate potential harm to aquatic life. [ABSTRACT FROM AUTHOR]

Candida auris and Staphylococcus aureus are associated with a wide range of infections, as they exhibit multidrug resistance - a growing health concern. In this study, gaseous ozone, and ultraviolet-C (UVC) radiation are applied as infection control measures to inactivate dry biofilms of these organisms on polystyrene surfaces. The dosages utilised herein are 1000 and 3000 ppm.min for ozone and 2864 and 11592 mJ.cm -2 for UVC. Both organisms showed an increased sensitivity to UVC relative to ozone exposure in a bespoke decontamination chamber. While complete inactivation of both organisms (>7.5 CFU log) was realized after 60 mins of UVC application, this could not be achieved with ozonation for the same duration. However, a combined application of ozone and UVC yielded complete inactivation in only 20 mins. For both treatment methods, it was observed that dry biofilms of S. aureus were more difficult to inactivate than dry biofilms of C. auris . Compared to dry biofilms of C. auris , micrographs of wet C. auris biofilms revealed the presence of an abundance of extracellular material after treatments. Interestingly, wet biofilms were more difficult to inactivate than dry biofilms. These insights are crucial to preventing recalcitrant and recurrent infections via contact with contaminated polymeric surfaces.

Background: Biofilms on dry hospital surfaces can enhance the persistence of micro-organisms on dry harsh clinical surfaces and can potentially act as reservoirs of infectious agents on contaminated surfaces., Aim: This study was conducted to quantify the transfer of viable Staphylococcus aureus cells from dry biofilms through touching and to investigate the impact of nutrient and moisture deprivation on virulence levels in S. aureus., Methods: Dry biofilms of S. aureus ATCC 25923 and a defective biofilm-forming ability mutant, S. aureus 1132, were formed in 24-well plates under optimized conditions mimicking dry biofilm formation on clinical surfaces. Microbial cell transfer was induced through the touching of the dry biofilms, which were quantified on nutrient agar. To investigate the impact of nutrient and moisture deprivation on virulence levels, dry and standard biofilms as well as planktonic cells of S. aureus ATCC 25923 were inoculated into Galleria mellonella and their kill rates compared., Findings: Results of this study showed that viable cells from dry biofilms of S. aureus ATCC 25923 were significantly more virulent and readily transferrable from dry biofilms through a touch test, therefore representing a greater risk of infection. The biofilm-forming capability of S. aureus strains had no significant impact on their transferability with more cells transferring when biofilm surfaces were wet., Conclusions: These findings indicate that dry biofilms on hospital surfaces may serve as a reservoir for the dissemination of pathogenic micro-organisms in hospitals, thus highlighting the importance of regular cleaning and adequate disinfection of hospital surfaces., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

SARS-CoV-2 virus mutations might increase its virulence, and thus the severity and duration of the ongoing pandemic. Global drug discovery campaigns have successfully developed several vaccines to reduce the number of infections by the virus. However, finding a small molecule pharmaceutical that is effective in inhibiting SARS-CoV-2 remains a challenge. Natural products are the origin of many currently used pharmaceuticals and, for this reason, a library of in-house fungal extracts were screened to assess their potential to inhibit the main viral protease M pro in vitro. The extract of Penicillium citrinum , TDPEF34, showed potential inhibition and was further analysed to identify potential M pro inhibitors. Following bio-guided isolation, a series of benzodiazepine alkaloids cyclopenins with good-to-moderate activity against SARS-CoV-2 M pro were identified. The mode of enzyme inhibition of these compounds was predicted by docking and molecular dynamic simulation. Compounds 1 (isolated as two conformers of S- and R-isomers), 2 , and 4 were found to have promising in vitro inhibitory activity towards M pro , with an IC 50 values range of 0.36-0.89 µM comparable to the positive control GC376. The in silico investigation revealed compounds to achieve stable binding with the enzyme active site through multiple H-bonding and hydrophobic interactions. Additionally, the isolated compounds showed very good drug-likeness and ADMET properties. Our findings could be utilized in further in vitro and in vivo investigations to produce anti-SARS-CoV-2 drug candidates. These findings also provide critical structural information that could be used in the future for designing potent M pro inhibitors., Competing Interests: The authors declare no conflict of interest.

Introduction: The reduced susceptibility of biofilms to disinfectants presents a challenge to the successful reprocessing of medical equipment. This study examined the effect of residual biomass remaining after previous disinfection with peracetic acid (PAA) on the tolerance of subsequent mature Pseudomonas aeruginosa biofilms to PAA. The effect of enzymatic degradation of specific components of the extracellular polymeric substance (EPS) of P. aeruginosa biofilm on the effectiveness of PAA disinfection was also evaluated., Methods: The susceptibility of biofilm grown on the biomass of PAA-killed biofilm to PAA was compared with the PAA susceptibility of biofilm grown in wells of a 24-well plate by evaluating their viability using the plate count assay. The effect of PAA on biofilm biomass was measured using crystal violet quantification of total biofilm biomass, while its effect on the polysaccharide and protein components of biofilm EPS was quantified using the phenol-sulphuric acid assay or Bradford assay, respectively. A confocal microscope was used to visualize the distribution of living and dead cells in biofilms grown on residual biofilm biomass., Findings: The presence of residual biomass from previously disinfected biofilms significantly enhanced the tolerance of subsequent biofilms. A 96-h-old 'secondary biofilm' formed on disinfected biomass survived PAA concentrations of 4000 ppm, which exceeds the concentrations used in practice for high-level disinfection., Conclusion: These observations indicate that, under certain circumstances, recolonization of residual EPS can cause failure of disinfection of medical equipment such as endoscopes, and emphasizes the importance of cleaning endoscopes prior to disinfection., (Copyright © 2020 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Introduction: The ability of healthcare-associated infection pathogens to survive on environmental surfaces is well known. Disinfection is employed to reduce or remove these pathogens but disinfection failures still occur. One method with the potential to improve disinfection efficacy is whole-room disinfection with hydrogen peroxide (H 2 O 2 )., Aim: To determine the influence of delivery system on the efficacy of low-concentration H 2 O 2 on common healthcare-associated infection pathogens., Methods: SanoStatic (electrostatic spray) was compared with SanoFog (fogging) in terms of performance for delivery of 5% H 2 O 2 and trace silver ions for disinfection. The bacterial test challenges were vancomycin-resistant Enterobacterales (VRE), extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae (ESBLK), carbapenemase-producing Enterobacterales (CPE), meticillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile spores, Bacillus atropheus and Geobacillus stearothermophilus commercial spore strips., Findings: SanoFog and SanoStatic were effective when tested under the conditions of experimentation reported here. For VRE, ESBLK, CPE and MRSA, SanoFog and SanoStatic were comparable in performance. For C. difficile we concluded the following: SanoFog was most effective for disinfection of C. difficile spores when compared to SanoStatic., Conclusion: Whereas SanoFog and SanoStatic were effective against bacterial cells, the current practice of using SanoFog and SanoStatic together would be effective for disinfection of C. difficile spores based on investigations under the conditions of experimentation reported here. The spore strips results were not comparable to the results either for the vegetation cells (VRE, ESBLK, CPE, and MRSA) or for C. difficile spores., (Copyright © 2020 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

The persistence of microorganisms as biofilms on dry surfaces resistant to the usual terminal cleaning methods may pose an additional risk of transmission of infections. In this study, the Centre for Disease Control (CDC) dry biofilm model (DBM) was adapted into a microtiter plate format (Model 1) and replicated to create a novel in vitro model that replicates conditions commonly encountered in the healthcare environment (Model 2). Biofilms of Staphylococcus aureus grown in the two models were comparable to the biofilms of the CDC DBM in terms of recovered log 10 CFU well -1 . Assessment of the antimicrobial tolerance of biofilms grown in the two models showed Model 2 a better model for biofilm formation. Confirmation of the biofilms' phenotype with an extracellular matrix deficient S. aureus suggested stress tolerance through a non-matrix defined mechanism in microorganisms. This study highlights the importance of conditions maintained in bacterial growth as they affect biofilm phenotype and behaviour.