Repositioning of FDA-approved drugs for the treatment of methicillin-resistant Staphylococcus aureus infection: Structure-based virtual screening and in vitro assay

Background: Computer-aided repositioning of approved drugs is an increasingly popular strategy for the discovery of effective therapies. The potency of the newly repositioned drugs can be optimized using them as a component of an effective drug combination, thereby achieving the desired therapeutic effect at a lower and more tolerable drug concentration. Aim and Objectives: The aim of the study was to perform structure-based virtual screening and repurposing of FDA-approved drugs for the treatment of methicillin resistance by Staphylococcus aureus (SA) and perform an in vitro validation of the prediction. Materials and Methods: Following ethical clearance at the Department of Pharmacology and Therapeutics, College of Health Sciences, Usmanu Danfodiyo University Sokoto, molecular docking was performed against 5 validated protein targets involved in the development of methicillin resistance by SA and an in vitro validation of the prediction was done using 3 of the top-ranking drug candidates against methicillin-resistant vancomycin-susceptible strain of the pathogen (ATCC 43300). Results: Desmopressin and docetaxel, two of the 20 top-ranking repurposed drugs discovered through virtual screening, enhanced the inhibitory effect of oxacillin against the ATCC 43300 SA strain in a ratio-dependent manner, although each of the two drugs singly was only weakly effective against the bacterial strain. The standard drug, vancomycin (also among the top-scoring candidates), alone, was effective against ATCC 43300 strain and in combination with oxacillin, the two drugs produced a ratio-dependent synergistic effect against the bacterial strain. Conclusion: These findings suggest that oxacillin-based combinations with desmopressin, docetaxel, and the standard drug vancomycin, three of the 20 top-ranking drugs, at optimum ratios, may be beneficial in reversing the resistance of the ATCC 43300 SA strain to oxacillin, thus supporting the prediction of the molecular docking results.

Analysis of a thermostable lipase from CTG-clade yeast: Molecular expression, characterization and structure prediction

Aims@#This study was aimed to express Meyerozyma guilliermondii strain RT lipase using Komagataella phaffii X-33 expression system and its biochemical characterization and analyse the predicted structure of the product.@*Methodology and results@#Meyerozyma guilliermondii strain RT obtained from the previous study was used as the source of RT lipase gene. Extracellular M. guilliermondii strain RT lipase expression has significantly been improved up to 56 U/mg at 24 h cultivation in Yeast extract-Peptone-Dextrose (YPD) medium containing (in w/v): 1% yeast extract, 2% peptone, 2% dextrose with 0.5% v/v methanol induction. Characterization of RT lipase showed optimum activity at 45 °C and pH 9. It exhibited stability in the alkaline pH range (8 to 10) and retained 50% of its residual activity at 30 °C for 30 min. Substrate specificity analysis revealed that it preferred short to medium-chain triacylglycerols (C2-C12) with the highest activity towards caprylic acid (C8). Pairwise alignment revealed three substitutions (S2L, S92L and S193L) present in non-CTG-clade hosts (K. phaffii). Homology modelling (YASARA) was used to predict the structures of RT lipase [wild type (wt) and recombinant (rc)]. Mutational analysis of the structures showed the differences in loops that might attribute to the reduction of the optimum temperature from 75 °C (wt) to 45 °C (rc).@*Conclusion, significance and impact of study@#RT lipase was successfully overexpressed extracellularly using K. phaffii expression system with 91.8-fold higher specific activity than the native host. The conceptual advances on the importance of codon optimization before expressing a protein from a CTG-clade species in a non-CTG-clade yeast have been highlighted and the effect of the rare codon usage in recombinant protein characteristics has been evident.

Identification of Bovine Growth Hormone (BGH) Gene Polymorphism Using PCR-RFLP Method in Buffalo Bulls

Growth Hormone (GH) is a single polypeptide chain synthesised and secreted from anterior pituitary gland by somatroph cells. The product of GH gene hastens metabolism and promotes the growth of many organs and tissues especially bone, muscle and visceral organs. It also regulates growth, mammary gland development and lactation. Polymorphism in this gene is associated with increase in growth and development of many tissues in the body. Aim: The objective of this study was to investigate the polymorphism of bovine growth hormone (bGH) gene in buffalo bulls (Bubalus bubalis) using the PCR-RFLP (polymerase chain reaction–restriction fragment length polymorphism) technique. Design: Genomic DNA was extracted from a total of 10 bulls, consisting of Murrah – Swamp crossbred and pure Swamp buffalo bulls. A The 446 segment of the bGH gene was amplified. The DNA amplicons were detected in 2% agarose gel following 45 minutes of electrophoresis. They were thereafter digesting with AluI endonuclease restriction enzyme, and the digested DNA were detected in 2% agarose gel following electrophoresis for about 45minutes in all samples Results: Similar bands of approximately 300 and 146-bp each, with no variation, were detected in 2% agarose gel following electrophoresis in all the animals tested. Conclusion: Based on the Alu1 digestion result, all samples produced the same allele of the gene, with no polymorphism detected.

Drinking water quality, sanitation and hygiene practices in a rural community of Sokoto State, Nigeria

Background: In many developing countries, Nigeria inclusive, water quality and the risk of waterborne diseases are critical public health concerns. Safe drinking water, sanitation and hygiene are among the five key strategies aimed at combating neglected tropical diseases. Objective: The objective of the study was to assess drinking water quality, household sanitation, and hygiene practices in a rural community. Materials and Methods: A descriptive cross-sectional study was carried out at Tunga Magaji, a rural community of Wamakko local government area, which is one of the Metropolitan Local Government Area of Sokoto state. A total of 391 households participated and were selected using a multistage sampling technique. Household questionnaires and checklist were used to collect data, which were analyzed using IBM Statistical Package for the Social Sciences version 20.0. Results were presented in tables and chart. Univariate analysis in the form of mean and standard deviation was carried out on continuous data. The categorical and grouped data were summarized using frequencies and percentage. Results: River/stream is the major source of their drinking water followed by dung well. Almost all the respondents (97.0%) perceived the water source to be safe for drinking even though more than half said the water has taste. All water samples were weakly basic and had a specific gravity of one. A tap point, dung well and borehole source demonstrated a significant coliform organisms (Escherichia coli) growth. Only 58% of the households have toilet facilities while the remaining uses different unsanitary methods. More than half (59%) reported washing hand always after toilet use and after handling children’s feces, although only 37% of them reported the use of soap and water. The most common health problem in the community was diarrheal diseases with a prevalence rate of 61%. Conclusion: Some drinking water source had significant coliform counts, and large proportion of households does not have sanitary facilities with the diarrheal disease being the major health problem.

Ear Foreign Bodies: Observations on the Clinical Profile in Sokoto; Nigeria

Background/objectives: Ear foreign bodies are common otorhinolaryngological emergencies which must be removed otherwise they may present with various complications. This paper reviews cases of ear foreign bodies seen over a seven year period from January 1995 to December 2001 in the Ear; Nose and Throat (ENT) department of Usmanu Danfodiyo University Teaching Hospital Sokoto; Nigeria. Method: This is a retrospective study of all case folders of patients who presented with ear foreign bodies whose clinical features and management modalities were analyzed . Results: The total number of patients reviewed were 207.There were 126 males (60) and 81 females (40) with a male to female ratio of 1.5:1. Their ages ranged from 1 to 65 years with 61.8being children under 10 years old. Agricultural seed was the commonest documented foreign body (15). Deliberate insertion by patients accounted for 70of the cases while accidental insertion accounted for 30. Ear foreign bodies became complicated in 41 patients (19.8) at presentation one of them requiring a major surgical operation (posterior tympanotomy) to remove the foreign body. About 99.5of the foreign bodies were removed through the per meatal approach with 79.8being carried out by the nurses and doctors who had received basic training to do so. Conclusion: Ear foreign bodies may become complicated and so needs to be removed using standard methods which should be carried out by those specially trained to do so

Ear Foreign Bodies: : Observations on the Clinical Profile in Sokoto; Nigeria

Background/objectives: Ear foreign bodies are common otorhinolaryngological emergencies which must be removed otherwise they may present with various complications. This paper reviews cases of ear foreign bodies seen over a seven year period from January 1995 to December 2001 in the Ear; Nose and Throat (ENT) department of Usmanu Danfodiyo University Teaching Hospital Sokoto; Nigeria. Method: This is a retrospective study of all case folders of patients who presented with ear foreign bodies whose clinical features and management modalities were analyzed . Results: The total number of patients reviewed were 207.There were 126 males (60) and 81 females (40) with a male to female ratio of 1.5:1. Their ages ranged from 1 to 65 years with 61.8being children under 10 years old. Agricultural seed was the commonest documented foreign body (15). Deliberate insertion by patients accounted for 70of the cases while accidental insertion accounted for 30. Ear foreign bodies became complicated in 41 patients (19.8) at presentation one of them requiring a major surgical operation (posterior tympanotomy) to remove the foreign body. About 99.5of the foreign bodies were removed through the per meatal approach with 79.8being carried out by the nurses and doctors who had received basic training to do so. Conclusion: Ear foreign bodies may become complicated and so needs to be removed using standard methods which should be carried out by those specially trained to do so