ghanaopendata/ghanaian-research-english huggingface dataset:
The molecular and cellular signatures of the mouse eminentia thalami support its role as a signalling centre in the developing forebrain

The mammalian eminentia thalami (EmT) (or thalamic eminence) is an embryonic forebrain structure of unknown function. Here, we examined the molecular and cellular properties of the mouse EmT. We first studied mRNA expression of signalling molecules and found that the EmT is a structure, rich in expression of secreted factors, with Wnts being the most abundantly detected. We then examined whether EmT tissue could induce cell fate changes when grafted ectopically. For this, we transplanted EmT tissue from a tau-GFP mouse to the ventral telencephalon of a wild type host, a telencephalic region where Wnt signalling is not normally active but which we showed in culture experiments is competent to respond to Wnts. We observed that the EmT was able to induce in adjacent ventral telencephalic cells ectopic expression of Lef1, a transcriptional activator and a target gene of the Wnt/bcatenin pathway. These Lef1-positive;GFP-negative cells expressed the telencephalic marker Foxg1 but not Ascl1, which is normally expressed by ventral telencephalic cells. These results suggest that the EmT has the capacity to activate Wnt/b-catenin signalling in the ventral telencephalon and to suppress ventral telencephalic gene expression. Altogether, our data support a role of the EmT as a signalling centre in the developing mouse forebrain.

Source: UG
A Molecular and Epidemiological Study of Vibrio Cholerae Isolates from Cholera Outbreaks in Southern Ghana

The Bacteriology Department aims to improve the quality of life first for Ghanaians and the world at large by conducting research into bacterial diseases of public health importance to Ghana and globally. In addition to working on enteric pathogens and sexually transmitted diseases, the department’s current main focus is on the two most important mycobacterial diseases of public health importance to Ghana, namely Buruli ulcer (BU) and tuberculosis (TB).

Source: UG
Molecular characterisation of a novel cassava associated circular ssDNA virus

The application of sequence non-specific rolling circle amplification of circular single stranded (ss) DNA molecules to viral metagenomics has facilitated the discovery in various ecosystems of what is probably a diverse array of novel ssDNA viruses. Here we describe a putative novel ssDNA virus (at a genome level), cassava associated circular DNA virus (CasCV), isolated from cassava leaf samples infected with the fungi Collectotrichum and Plectosphaerella. CasCV has a circular ambisense genome and shares significant genome similarities with Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1), Mosquito VEM virus SDBVL and Meles meles faecal virus (MmFV). The CasCV genome (2220. nt) has three large open reading frames. While it is probable that one of these encodes a capsid protein, the other two probably express a replication associated protein (Rep) following the removal of an intron such as that found in the Rep encoding genes of some geminiviruses. This Rep would contain four conserved rolling circle replication (RCR) related motifs that have previously been identified in geminivirus, circovirus and nanovirus Reps. Given both that the CasCV Rep and CP share 62.7% and 39.8% amino acid identity respectively with the Rep and CP of SsHADV-1, and that CasCV was discovered associated with cassava infecting fungi, we suggest that CasCV should be classified within the mycovirus taxonomic family. However, host range studies using infectious clones will be required to demonstrate the novel virus' likely origin and actual host species. © 2012 Elsevier B.V.

Source: UG
Molecular characterisation of maize introgressed inbred lines bred in different environments

Establishing detailed information on genetic diversity and relationships among maize (Zea mays L.) inbred lines in a breeding programme help ensure effective utilization of germplasm. Introgression of temperate maize germplasm into 12 tropical elite maize inbred lines using a common donor inbred line and different selection environments might disrupt the heterotic grouping system. Therefore, the objective of the study was to determine the effect of introgression on the clustering pattern of the newly introgressed inbred lines and to identify unique genotypes for breeding. A total of 76 introgressed inbred lines derived through pedigree crosses of introgression of 12 elite tropical inbred lines from three major heterotic groups N3, SC and P with a common donor temperate maize inbred line (08CED6_7_B) were used in the study. In addition to the derived 76 introgressed inbred lines, 26 temperate parental inbred lines and 21 elite tropical parental inbred lines with known heterotic group classification were also included in the study as references samples for heterotic groupings to give a total of 123 inbred lines for the study. Introgressed inbred lines derived from four generations of pedigree selection in three distinct environments in Zimbabwe and South Africa were characterised using 20 SSR markers. The 20 SSR markers proved very effective in discriminating the introgressed inbred lines according to genetic distance and clustering. A total of 83 alleles were detected with an average of 4.15 alleles per locus, and had an allelic diversity of 0.53 and PIC of 0.47. Introgression of temperate maize germplasm into tropical elite inbred lines did not disrupt heterotic groupings, because introgressed inbred lines remained genetically inclined towards the original heterotic groups from which they were derived. However, there were some introgressed inbred lines (14%), which did not show any inclination to any of the heterotic groups. Marked genetic difference noted within and across heterotic groupings for the introgressed inbred lines provides germplasm variation that can be exploited for inbred line development and hybrid formation, respectively. © 2019, Springer Nature B.V.

Source: UG
Molecular characterisation of plasma membrane-derived vesicles

Plasma membrane-derived vesicles (PMVs) are released into circulation in response to normal and stress/pathogenic conditions. They are of tremendous significance for the prediction, diagnosis, and observation of the therapeutic success of many diseases. Knowledge of their molecular characteristics and therefore functional properties would contribute to a better understanding of the pathological mechanisms leading to various diseases in which their levels are raised. The review aims at outlining and discussing the molecular characteristics of PMVs in order to bring to the fore some aspects/characteristics of PMVs that will assist the scientific community to properly understand the role of PMVs in various physiological and pathological processes. The review covers PMVs characterisation and discusses how distinct they are from exosomes and endosomes. Also, methods of PMVs analysis, importance of proper PMV level estimation/characterisation, PMVs and their constituents as well as their therapeutic significance are discussed. The review concludes by drawing attention to the importance of further study into the functions of the characteristics discussed which will lead to understanding the general role of PMVs both in health and in disease states.

Source: UG
Molecular characterisation of the NDM-1-encoding plasmid p2189-NDM in an Escherichia coli ST410 clinical isolate from Ghana

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
Molecular characteristics of hepatitis B virus among students and pregnant women in Chad

The Bacteriology Department aims to improve the quality of life first for Ghanaians and the world at large by conducting research into bacterial diseases of public health importance to Ghana and globally. In addition to working on enteric pathogens and sexually transmitted diseases, the department’s current main focus is on the two most important mycobacterial diseases of public health importance to Ghana, namely Buruli ulcer (BU) and tuberculosis (TB).

Source: UG
Molecular Characterization of Circulating Yellow Fever Viruses from Outbreak in Ghana, 2021–2022

Most research activities involve the use of molecular methods such as regular PCR (PCR), quantitative PCR (Q-PCR), genomic sequence and analysis using different software, genetic engineering, probe hybridization techniques, biological and molecular cloning, evaluation of immune markers for laboratory diagnosis of infections, serological assays involving the use of rapid tests, ELISA-based evaluations and immunofluorescent assay techniques.

Source: UG
Molecular characterization of antibiotic resistance in clinical Salmonella typhi isolated in Ghana

Fifty-eight clinical Salmonella typhi strains isolated from patients suspected of suffering from typhoid fever were obtained at the Korle-Bu Teaching Hospital and the Noguchi Memorial Institute for Medical Research, both located in Ghana, Africa. Each isolate was examined for susceptibility to ampicillin, chloramphenicol, streptomycin, tetracycline, and trimethoprim/sulfamethoxazole by the disk diffusion assay. Five of the isolates were resistant to all five antibiotics while 10 isolates were resistant to ampicillin, chloramphenicol, and trimethoprim/sulfamethoxazole, which are considered 'first line' antibiotics in the treatment of typhoid fever. Thirty-four isolates were resistant to at least one of the antibiotics tested and 62% of these isolates possessed conjugable plasmids belonging to incompatibility group IncHI. Ninety percent of the conjugable plasmids conferred a multiple drug-resistant phenotype on the strains harboring them. Additionally, 14 strains contained plasmids that were transformable and six of them encoded multiple drug resistance. Our findings indicate that multiple drug resistance to the 'first line' antibiotics in S. typhi may be more prevalent in Africa than previously thought. © 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

Source: UG
Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

The Bacteriology Department aims to improve the quality of life first for Ghanaians and the world at large by conducting research into bacterial diseases of public health importance to Ghana and globally. In addition to working on enteric pathogens and sexually transmitted diseases, the department’s current main focus is on the two most important mycobacterial diseases of public health importance to Ghana, namely Buruli ulcer (BU) and tuberculosis (TB).

Source: UG
Molecular characterization, pathogenicity and copper sensitivity of Xanthomonas citri pv mangiferaeindicae, the causal agent of mango bacterial black spot disease in Ghana

Recent outbreak of the mango bacterial black spot disease has resulted in massive damages to the Ghanaian mango industry. Research was carried out to confirm the etiology of the disease. Diseased mango fruits and leaves were collected from Greater Accra (Asutuare and Dodowa), Eastern (Akuse, Somanya) and Volta (Juapong) regions, and the sus pected causal bacterium was isolated. The pathogen was identified as Xanthomonas citri pv mangiferaeindicae based on cultural and morphological characteristics and sequence analysis of the cpn60 gene. The pathogenicity of the bacterial pathogen on mango and cashew was determined and its sensitivity to some selected copper based fungicides available in Ghana was evaluated by the agar diffusion bio-assay. All strains of the pathogen were able to cause disease symptoms on artificially inoculated mango and cashew leaves. The pathogen was highly sensitive to Copper oxychloride, Copper hydroxide and Coprous oxide at very low concentrations.

Source: UG
Molecular confirmation of Lassa fever imported into Ghana

Most research activities involve the use of molecular methods such as regular PCR (PCR), quantitative PCR (Q-PCR), genomic sequence and analysis using different software, genetic engineering, probe hybridization techniques, biological and molecular cloning, evaluation of immune markers for laboratory diagnosis of infections, serological assays involving the use of rapid tests, ELISA-based evaluations and immunofluorescent assay techniques.

Source: UG
Molecular detection of dengue virus in patients suspected of Ebola virus disease in Ghana

Most research activities involve the use of molecular methods such as regular PCR (PCR), quantitative PCR (Q-PCR), genomic sequence and analysis using different software, genetic engineering, probe hybridization techniques, biological and molecular cloning, evaluation of immune markers for laboratory diagnosis of infections, serological assays involving the use of rapid tests, ELISA-based evaluations and immunofluorescent assay techniques.

Source: UG
Molecular determinants of multidrug-resistant tuberculosis in Sierra Leone

Multidrug-resistant tuberculosis (MDR-TB) management has become a serious global health challenge. Understanding its epidemic determinants on the regional level is crucial for developing effective control measures. We used whole genome sequencing data of 238 of Mycobacterium tuberculosis complex (MTBC) strains to determine drug resistance profiles, phylogeny, and transmission dynamics of MDR/ rifampicin-resistant (RR) MTBC strains from Sierra Leone. Forty-two strains were classified as RR, 196 as MDR, 5 were resistant to bedaquiline (BDQ) and clofazimine (CFZ), but none was found to be resistant to fluoroquinolones. Sixty-one (26%) strains were resistant to all first-line drugs, three of which had additional resistance to BDQ/CFZ. The strains were classified into six major MTBC lineages (L), with strains of L4 being the most prevalent, 62% (n = 147), followed by L6 (Mycobacterium africanum) strains, (21%, n = 50). The overall clustering rate (using ≤d12 single-nucleotide polymorphism threshold) was 44%, stratified into 31 clusters ranging from 2 to 16 strains. The largest cluster (n = 16) was formed by sublineage 2.2.1 Beijing Ancestral 3 strains, which developed MDR several times. Meanwhile, 10 of the L6 strains had a primary MDR transmission. We observed a high diversity of drug resistance mutations, including borderline resistance mutations to isoniazid and rifampicin, and mutations were not detected by commercial assays. In conclusion, one in five strains investigated was resistant to all first-line drugs, three of which had evidence of BDQ/CFZ resistance. Implementation of interventions such as rapid diagnostics that prevent further resistance development and stop MDR-TB transmission chains in the country is urgently needed.

Source: UG
Molecular diagnosis of Schistosoma infections in urine samples of school children in Ghana

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
Molecular Docking and Dynamics Simulation Studies Predict Munc18b as a Target of Mycolactone: A Plausible Mechanism for Granule Exocytosis Impairment in Buruli Ulcer Pathogenesis

Ulcers due to infections with Mycobacterium ulcerans are characterized by complete lack of wound healing processes, painless, an underlying bed of host dead cells and undermined edges due to necrosis. Mycolactone, a macrolide produced by the mycobacterium, is believed to be the toxin responsible. Of interest and relevance is the knowledge that Buruli ulcer (BU) patients remember experiencing trauma previously at the site of the ulcers, suggesting an impairment of wound healing processes, the plausible effect due to the toxin. Wound healing processes involve activation of the blood platelets to release the contents of the dense granules mainly serotonin, calcium ions, and ADP/ATP by exocytosis into the bloodstream. The serotonin release results in attracting more platelets and mast cells to the wound site, with the mast cells also undergoing degranulation, releasing compounds into the bloodstream by exocytosis. Recent work has identified interference in the co-translational translocation of many secreted proteins via the endoplasmic reticulum and cell death involving Wiskott-Aldrich syndrome protein (WASP), Sec61, and angiotensin II receptors (AT2R). We hypothesized that mycolactone by being lipophilic, passively crosses cell membranes and binds to key proteins that are involved in exocytosis by platelets and mast cells, thus inhibiting the initiation of wound healing processes. Based on this, molecular docking studies were performed with mycolactone against key soluble n-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and regulators, namely Vesicle-associated membrane protein (VAMP8), Synaptosomal-associated protein (SNAP23, syntaxin 11, Munc13-4 (its isoform Munc13-1 was used), and Munc18b; and also against known mycolactone targets (Sec61, AT2R, and WASP). Munc18b was shown to be a plausible mycolactone target after the molecular docking studies with binding affinity of −8.5 kcal/mol. Structural studies and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) binding energy calculations of the mycolactone and Munc18b complex was done with 100 ns molecular dynamics simulations using GROMACS. Mycolactone binds strongly to Munc18b with an average binding energy of −247.571 ± 37.471 kJ/mol, and its presence elicits changes in the structural conformation of the protein. Analysis of the binding interactions also shows that mycolactone interacts with Arg405, which is an important residue of Munc18b, whose mutation could result in impaired granule exocytosis. These findings consolidate the possibility that Munc18b could be a target of mycolactone. The implication of the interaction can be experimentally evaluated to further understand its role in granule exocytosis impairment in Buruli ulcer.

Source: UG
Molecular docking and dynamics simulations studies of OmpATb identifies four potential novel natural product-derived anti-Mycobacterium tuberculosis compounds

The outer membrane protein A (OmpATb) of Mycobacterium tuberculosis is a virulence factor that neutralizes the host pH to impede the uptake of hydrophilic antitubercular drugs. Identifying natural compounds with the potential to inhibit OmpATb could allow circumvention of the porin-like activities of OmpATb. Four potential leads comprising ZINC000003958185, ZINC000000157405, ZINC000000001392 and ZINC000034268676 were obtained by virtual screening of 6394 diverse natural products. Characterization of the binding interactions of the potential leads with OmpATb revealed nine critical residues comprising ARG86, LEU110, LEU113, LEU114, ALA115, PHE142, SER145, VAL146, and PHE151. Molecular dynamics simulations also revealed very stable protein-lead complexes. Most residues contributed lower binding energies to the overall molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) binding free energies of the interactions between the molecules and OmpATb protein. Induced Fit Docking (IFD) of the compounds regenerated poses of the molecular docking using AutoDock Vina. These molecules could be starting templates for designing inhibitors to bypass the pore mediating activities of OmpATb. Based on structural similarity, ZINC000034268676 was suggested as a potential scaffold for designing efflux pump inhibitors of the gate mediating activities of OmpATb and may enhance the uptake of hydrophilic drugs to reduce the duration time of tuberculosis treatment. Furthermore, structurally similar compounds available in the DrugBank database with a similarity threshold of 0.7 have been reported to exhibit antitubercular and anti-mycobacterial activities. These biomolecules can be further characterized experimentally to corroborate their antitubercular activity. Also, the skeletons of the molecules can be adopted as sub-structures for the design of future anti-mycobacterial drugs.

Source: UG
Molecular Epidemiology and Antibiotic Susceptibility of Vibrio cholerae Associated with a Large Cholera Outbreak in Ghana in 2014

Background: Ghana is affected by regular cholera epidemics and an annual average of 3,066 cases since 2000. In 2014, Ghana experienced one of its largest cholera outbreaks within a decade with more than 20,000 notified infections. In order to attribute this rise in cases to a newly emerging strain or to multiple simultaneous outbreaks involving multi-clonal strains, outbreak isolates were characterized, subtyped and compared to previous epidemics in 2011 and 2012. Methodology/Principal Findings: Serotypes, biotypes, antibiotic susceptibilities were determined for 92 Vibrio cholerae isolates collected in 2011, 2012 and 2014 from Southern Ghana. For a subgroup of 45 isolates pulsed-field gel electrophoresis, multilocus sequence typing and multilocus-variable tandem repeat analysis (MLVA) were performed. Eighty-nine isolates (97%) were identified as ctxB (classical type) positive V. cholerae O1 biotype El Tor and three (3%) isolates were cholera toxin negative non-O1/non-O139 V. cholerae. Among the selected isolates only sulfamethoxazole/trimethoprim resistance was detectable in 2011, while 95% of all 2014 isolates showed resistance towards sulfamethoxazole/trimethoprim, ampicillin and reduced susceptibility to ciprofloxacin. MLVA achieved the highest subtype discrimination, revealing 22 genotypes with one major outbreak cluster in each of the three outbreak years. Apart from those clusters genetically distant genotypes circulate during each annual epidemic. Conclusions/Significance: This analysis suggests different endemic reservoirs of V. cholerae in Ghana with distinct annual outbreak clusters accompanied by the occurrence of genetically distant genotypes. Preventive measures for cholera transmission should focus on aquatic reservoirs. Rapidly emerging multidrug resistance must be monitored closely. © 2016 Eibach et al.

Source: UG
Molecular epidemiology and antimicrobial susceptibility of clinical Staphylococcus aureus from healthcare institutions in Ghana

The Bacteriology Department aims to improve the quality of life first for Ghanaians and the world at large by conducting research into bacterial diseases of public health importance to Ghana and globally. In addition to working on enteric pathogens and sexually transmitted diseases, the department’s current main focus is on the two most important mycobacterial diseases of public health importance to Ghana, namely Buruli ulcer (BU) and tuberculosis (TB).

Source: UG