Browsing by Author "Adeyemi, Oluwapelumi"
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Item The broad-spectrum antiviral drug arbidol inhibits foot-and-mouth disease virus replication(Microbiology Society, UK, 2012) Polyak, Stephen; Adeyemi, Oluwapelumi; Ward, Joseph; Tuthill, TobiArbidol (arb, umifenovir) is used clinically in several countries as an anti-influenza virus drug. We have previously shown that arb inhibits many viruses including hepatitis C virus, Ebola and Zika, and that the primary mode of action appears to be via inhibition of virus entry and/or fusion of viral membranes with intracellular endosomal membranes. We have also shown that arb is a good inhibitor of (non-enveloped) poliovirus types 1 and 3. Here, we evaluate the antiviral potential of arb against another picornavirus, foot-and-mouth disease virus (FMDV), an important veterinary pathogen. Sub-cytotoxic concentrations of arb inhibited the replication of FMDV replicon RNA. arb inhibition of FMDV RNA replication was not a result of generalised inhibition of uptake of cargo (e.g. plasmid DNA or RNA), nor did arb inhibit FMDV replication when added at 4 h post-transfection of FMDV replicon RNA. FMDV replication was blocked by the replication inhibitor guanidium hydrochloride (GuHCl). Upon GuHCl removal, FMDV replication was restored, and arb suppressed this recovery of virus replication. For other picornaviruses, recovery of virus replication upon GuHCl removal has been shown to require translation. However, arb did not suppress cap- or internal ribosome entry site (IRES)-dependent translation. arb also inhibited infectious equine rhinitis associated virus (ERAV), a close relative of FMDV. Testing of arb against infectious FMDV is in progress. Collectively, the data demonstrate that arb inhibits certain picornaviruses by a mechanism that appears to be independent of effects on virus entry but involves inhibition of genome replication.Item Comparative molecular biology approaches for the production of poliovirus virus-like particles using Pichia pastoris.(Microbiology Society, UK., 2020) Sherry, Lee; Grehan, Keith; Snowden, Joseph; Knight, Michael; Adeyemi, Oluwapelumi; Rowlands, David; Stonehouse, NicolaFor enteroviruses such as poliovirus (PV), empty capsids, which are antigenically indistinguishable from mature virions, are produced naturally during viral infection. The production of such capsids recombinantly, in heterologous systems such as yeast, have great potential as virus-like particle (VLP) vaccine candidates. Here, using PV as an exemplar, we show the production of VLPs in Pichia pastoris by coexpression of the structural precursor protein P1 and the viral protease 3CD. The level of expression of the potentially cytotoxic protease relative to that of the P1 precursor was modulated by three different approaches: expression of the P1 precursor and protease from different transcription units, separation of the P1 and protease proteins using the Thosea asigna virus (TaV) 2A translation interruption sequence, or separation of the P1 and protease-coding sequences by an internal ribosome entry site sequence from Rhopalosiphum padi virus (RhPV). We also investigate the antigenicity of VLPs containing previously characterized mutations when produced in Pichia. Finally, using transmission electron microscopy and twodimensional classification, we show that Pichia-derived VLPs exhibited the classical icosahedral capsid structure displayed by enteroviruses.Item Increasing Type 1 Poliovirus Capsid Stability by Thermal Selection(American Society for Microbiology, USA, 2017) Adeyemi, Oluwapelumi; Nicole, Clare; Stonehouse, Nicola; Rowlands, DavidPoliomyelitis is a highly infectious disease caused by poliovirus (PV). It can result in paralysis and may be fatal. Integrated global immunization programs using live-attenuated oral (OPV) and/or inactivated (IPV) PV vaccines have systematically reduced its spread and paved the way for eradication. Immunization will continue posteradication to ensure against reintroduction of the disease, but there are biosafety concerns for both OPV and IPV. They could be addressed by the production and use of virus-free virus-like particle (VLP) vaccines that mimic the “empty” capsids (ECs) normally produced in viral infection. Although ECs are antigenically indistinguishable from mature virus particles, they are less stable and readily convert into an alternative conformation unsuitable for vaccine purposes. Stabilized ECs, expressed recombinantly as VLPs, could be ideal candidate vaccines for a polio-free world. However, although genome-free PV ECs have been expressed as VLPs in a variety of systems, their inherent antigenic instability has proved a barrier to further development. In this study, we selected thermally stable ECs of type 1 PV (PV-1). The ECs are antigenically stable at temperatures above the conversion temperature of wild-type (wt) virions. We have identified mutations on the capsid surface and in internal networks that are responsible for EC stability. With reference to the capsid structure, we speculate on the roles of these residues in capsid stability and postulate that such stabilized VLPs could be used as novel vaccines.Item Microbial Contamination of Fresh Vegetable Salads from Food Vendors in Oyo Metropolis(Faculty of Physical Sciences and Faculty of Life Sciences, University of Ilorin, Ilorin, Nigeria., 2019) Adeyemi, Oluwasanmi; Fejukui, Boluwatife; Adeyemi, OluwapelumiVegetables provide humans with essential vitamins and minerals with enough ability to help reduce the risk of diseases and infections. However, a major issue associated with the consumption of fresh vegetable salad is their contamination with pathogenic microorganisms. Thus, this study was aimed at assessing the microbial contamination levels and evaluating the microbiological risk associated with the consumption of ready to eat mixed vegetable salads from food vendors in Oyo, Oyo state. Microbiological analysis was done using standard methods. Results showed that from 20 samples, a total of fifty-five (55) isolates were gotten, while 91% of the isolates were bacteria, 9% were fungi. The total bacteria count obtained in this study ranged from 6.00×105 to 7.30×105 cfu/ml. The bacterial isolates identified from the samples were: Aeromonas sp. (50%); Serratia sp. (20%); Pseudomonas sp. (21%); Escherichia coli (3%); Lactobacillus sp. (3%); and Staphylococcus sp. (3%). The fungal count realized in this study ranged from 1.67 × 104 cfu/ml to 2.90 × 104 cfu/ml. The fungal isolates were: Aspergillus sp.; and Rhizopus sp.; (78%) and (22%) respectively. The high microbial load found in the vegetable salad samples shows that there is an urgent need for food handlers to employ appropriate decontamination methods. Consumed food being sold by vendors must always meet up with stipulated microbiological standards for consumed food.Item A multi-template multiplex PCR assay for hepatitis B virus and human β-globin(Wiley-Blackwell, USA, 2017) Adeyemi, Oluwapelumi; Herod, Morgan; Oladiji, Femi; Fakunle, Yisa; Babatunde, Abiola; Agbede, OlajideThe Hepatitis B surface antigen (HBsAg) is the hallmark of HBV infection. Detection of antibodies to HBs and the core (ie, HBsAg and HBcAb) are primary serological algorithms in the laboratory diagnosis of HBV. Detection of HBsAg DNA is an important supplement to serological diagnosis especially in clinical cases. Simultaneous amplification of internal cellular controls is a good indicator of sample quality. Human β-globin is a well characterized housekeeping gene (HKG) that is often applied as internal controls (IC) in molecular diagnosis. In this study, individual plasmid clones of the human β-globin and HBs genes were constructed. These plasmid constructs have been applied to characterize a multiplex PCR assays for HBs and β-globin genes. The findings suggest detection limits of less than 10 genome copies of either template In vitro using conventional and multiplex PCR conditions. Under the multiplex conditions, co-amplification of β-globin and HBsAgDNAhad a resultant effect on assay sensitivity. This study further highlights the importance of molecular diagnosis in HBV infectious individuals. If fully optimized, this assay could provide a possible diagnostic complement to serological detection in developing countries.Item The Oxysterol 25-Hydroxycholesterol Inhibits Replication of Murine Norovirus(Molecular Diversity Preservation International and Multidisciplinary Digital Publishing Institute, 2019) Ghada, Shawli; Adeyemi, Oluwapelumi; Stonehouse, Nicola; Herod, MorganCholesterol, an essential component of mammalian cells, is also an important factor in the replicative-cycles of several human and animal viruses. The oxysterol, 25-hydroxycholesterol, is produced from cholesterol by the enzyme, cholesterol 25-hydroxylase. 25-hydroxycholesterol (25-HC) has been shown to have anti-viral activities against a wide range of viruses, including a range of positive-sense RNA viruses. In this study, we have investigated the role of 25-HC in norovirus replication using murine norovirus (MNV) as a model system. As a control, we employed herpes simplex virus-1 (HSV-1), a pathogen previously shown to be inhibited by 25-HC. Consistent with previous studies, 25-HC inhibited HSV-1 replication in the MNV-susceptible cell line, RAW264.7. Treating RAW264.7 cells with sub-cytotoxic concentrations of 25-HC reduced the MNV titers. However, other sterols such as cholesterol or the oxysterol, 22-S-hydroxycholesterol (22-S-HC), did not inhibit MNV replication. Moreover, treating MNV-infected RAW264.7 cells with 25-HC-stimulated caspase 3/7 activity, which leads to enhanced apoptosis and increased cell death. Our study adds noroviruses to the list of viruses inhibited by 25-HC and begins to offer insights into the mechanism behind this inhibition.Item Photodynamic inactivation of bacteriophage MS2: The A-protein is the target of virus inactivation(Elsevier, 2018) Majiya, Hussaini; Adeyemi, Oluwapelumi; Stonehouse, Nicola; Millner, PaulSinglet oxygen mediated oxidation has been shown to be responsible for photodynamic inactivation (PDI) of viruses in solution with photosensitisers such as 5, 10, 15, 20-tetrakis (1-methyl-4-pyridinio) porphyrin tetra ptoluenesulfonate (TMPyP). The capsids of non-enveloped viruses, such as bacteriophage MS2, are possible targets for viral inactivation by singlet oxygen oxidation. Within the capsid (predominantly composed of coat protein), the A-protein acts as the host recognition and attachment protein. The A-protein has two domains; an α-helix domain and a β-sheet domain. The α-helix domain is attached to the viral RNA genome inside the capsid while the β-sheet domain, which is on the surface of the capsid, is believed to be the site for attachment to the host bacteria pilus during infection. In this study, 4 sequence-specific antibodies were raised against 4 sites on the A-protein. Changes induced by the oxidation of singlet oxygen were compared to the rate of PDI of the virus. Using these antibodies, our results suggest that the rate of PDI is relative to loss of antigenicity of two sites on the A-protein. Our data further showed that PDI caused aggregation of MS2 particles and crosslinking of MS2 coat protein. However, these inter- and intra-capsid changes did not correlate to the rate of PDI we observed in MS2. Possible modes of action are discussed as a means to gaining insight to the targets and mechanisms of PDI of viruses.Item Photodynamic inactivation of non-enveloped RNA viruses(Elsevier, 2018) Majiya, Hussaini; Adeyemi, Oluwapelumi; Herod, Morgan; Stonehouse, NicolaWe recently reported the photodynamic inactivation (PDI) of bacteriophage MS2 with a photosensitiser- 5, 10, 15, 20-tetrakis (1-methyl-4-pyridinio) porphyrin- tetra- p-toluene sulfonate (TMPyP) in solution and concluded that the A-protein of the virus is the main target of inactivation. Here, we have extended these studies and carried out PDI of bacteriophage Qβ, bovine enterovirus 2 (BEV-2) and type 1 murine norovirus (MNV-1). The rate of inactivation observed was in the order MS2 > Qβ > MNV-1 > BEV-2. Data suggested that TMPyPtreatment could also target the viral genome as well as result in disintegration/disassembly of viral particles. Although emergence of viral drug resistance is a well-documented phenomenon, it was not possible to generate PDI-resistant MS2. However, emergence of a mutation in the lysis protein was detected after serial exposure to PDI.Item Polio – what are the prospects for eradication?(Microbiology Society, UK., 2017) Adeyemi, Oluwapelumi; Stonehouse, Nicola