Virology
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Item In vitro antiviral activity of peptide‑rich extracts from seven Nigerian plants against three non‑polio enterovirus species C serotypes(Springer Nature, 2021) Ogbole, O. O.; Akinleye, T. E.; Nkumah, A. O.; Awogun, A.O.; Attah, A. F.; Adewumi, M. O.; Adeniji, A.J.Background: As frequent viral outbreaks continue to pose threat to public health, the unavailability of antiviral drugs and challenges associated with vaccine development underscore the need for antiviral drugs discovery in emergent moments (endemic or pandemic). Plants in response to microbial and pest attacks are able to produce defence molecules such as antimicrobial peptides as components of their innate immunity, which can be explored for viral therapeutics. Methods: In this study, partially purified peptide-rich fraction (P-PPf ) were obtained from aqueous extracts of seven plants by reverse-phase solid-phase extraction and cysteine-rich peptides detected by a modified TLC method. The peptide-enriched fractions and the aqueous (crude polar) were screened for antiviral effect against three non-polio enterovirus species C members using cytopathic effect reduction assay. Results: In this study, peptide fraction obtained from Euphorbia hirta leaf showed most potent antiviral effect against Coxsackievirus A13, Coxsackievirus A20, and Enterovirus C99 (EV-C99) with IC50< 2.0 μg/mL and selective index ≥ 81. EV-C99 was susceptible to all partially purified peptide fractions except Allamanda blanchetii leaf. Conclusion: These findings establish the antiviral potentials of plants antimicrobial peptides and provides evidence for the anti-infective use of E. hirta in ethnomedicine. This study provides basis for further scientific investigation geared towards the isolation, characterization and mechanistic pharmacological study of the detected cysteine-richpeptides.Item Microbiological Assessment and Detection of Adenovirus in Sachet Water Sold In Abeokuta, Nigeria(Nigerian Society for Microbiology (NSM), 2021) Shittu, O. B.; Adekunle, O. T.; Olufemi, F. O.; Faleye, T. O. C.; Adewumi, M. O.; Adeniji, J. A.Microbiological safety of sachet water remains a public health problem in Nigeria. This study was aimed at investigating some packaged sachet water sold in Abeokuta, South-West Nigeria for the microbiological safety including some of the enteric viruses on contaminant candidate list. Sachet water samples from five different producers were obtained over three month’s period. Bacterial and fungal analyses were conducted with standard culture method. Targeted protozoans were investigated by microscopic examination of sediments obtained after centrifugation. Nested and semi-nested polymerase chain reaction (PCR) techniques targeting specific genes in adenovirus, norovirus and rotavirus were used for viral analyses. Results were presented in presence-absence score. Contingency table was used to establish relationship between viruses, Escherichia coli and protozoans. Out of a total twenty pooled samples analysed, adenovirus had a prevalence rate of 10% across the study period, whereas rotavirus and norovirus were absent. Giardia cysts and Cryptosporidium oocysts were also absent. Escherichia coli was present in 40% of the brands. Other bacteria identified were Salmonella enterica serovar Typhi, Shigella dysentariae, and Pseudomonas aeruginosa. Aspergillus sp, Mucor and Rhizopus sp. were present in some samples collected. Adenovirus was detected by PCR in a pooled sample of sachet water thattested negative for Escherichia coli, Cryptosporidium oocysts and Giardia cysts. There is need for microbiological screening of sachet water periodically in order to enhance public health safety.Item Expanding the frontiers of bacterial diagnosis through bacteriophage biotechnology(AIMS Press, 2020) Majumdar, M.; Klapsa, D.; Wilton, T.; Bujaki, E.; Fernandez‐Garcia, E. M. D.; Faleye, T. O. C.; Oyero , A. O.; Adewumi, M. O.; Ndiaye, K.; Adeniji, J. A.; Martin, J.In a bid to achieve microbial diagnostic precision and reduce diagnostic turn-around time, the development of technologically advanced,novel techniques has been on the rise. There is a gradual phasing out of traditional diagnostic methods by more specific and highly sensitive molecular techniques. Asides from being technically demanding and cost-ineffective, these molecular methods have themselves not fulfilled perhaps the most essential diagnostic criterion of distinguishing between viable and dead bacterial cells. The use of bacteriophages as biorecognition elements for bacterial detectors offers numerous advantages in terms of cost, ease of accessibility, and high specificity binding of bacteriophages to their bacterial host. Biotechnological advancements further give bacteriophage use the leading edge as genetic modification of bacteriophage genome through the fluorescent gene insertion produces reporter bacteriophages. These recombinants can produce detectable fluorescent signals through intracellular lytic action, strictly in metabolically active bacteria cells. Fluorescent labelled enzyme-active and cell wall binding domains of bacteriophages also offer better alternatives to the use of antibodies as diagnostic markers because they are resistant to pH and temperature sensitivities. Overall, bacteriophage-based detection systems are less prone to detection errors and significantly reduce diagnostic time while also attaining high test sensitivity.Item A possible risk of environmental exposure to HEV in Ibadan, Oyo State, Nigeria(Taylor & Francis, 2020-08-13) Olayinka, A.; Ifeorah, I. M.; Omotosho, O.; Faleye, T. O. C.; Odukaye, O.; Bolaji, O.; Ibitoye, I.; Ope-Ewe, O.; Adewumi, M. O.; Adeniji, J. A."Hepatitis E virus (HEV) infection is both a major public health concern and emerging global health concern, with a documented incidence of 20 million, 3.4 million clinical cases, 70,000 deaths, and 3,000 stillbirths. The aetiologic agent, HEV is a primarily enterally transmitted hepatotropic virus. Fecal samples were collected from three selected pig farms across Ibadan, South-west Nigeria. Randomly picked samples were pooled per unit pen and fecal suspensions prepared were subjected to HEV Antigen (Ag) enzyme-linked immunosorbent assay. Molecular probing was done by Reverse Transcription and nested polymerase reaction (RT-nPCR) and deep sequencing. Sequencing was done paired-end for 300 cycles using the HiSeq system. Overall farm prevalence of 66.7% (2/3) and prevalence at individual level of 13.2% (9/68) were recorded. All nine samples positive for the ELISA screen were negative when subjected to RT-nPCR assays. Further, on deep sequencing, no HEV genomic fragment was found in the sample using de-novo assembly. Findings suggest possibly inapparent HEV in the pigs studied or a yet to be identified protein with HEV-Ag cross-reactivity ability on ELISA, thus constituting a possible risk of exposure to HEV infection in the population. Consequently, we recommend prompt intervention to unravel the mystery and break the chain of transmission.Item Hepatitis B virus infection in low and middle – income Countries: combined serological markers for efficient diagnosis(Nigerian Society for Microbiology, 2020) Japhet, M. O.; Adesina, O. O.; Olateru-Olugbegi, O.; Adewumi, M. O.Hepatitis B virus (HBV) infection is a global problem with Asia and sub-Saharan Africa mostly affected. Unfortunately, residual risk of transfusion associated HBV (TAHBV) is greater in low- and middle-income countries where virus prevalence is higher and implementation of Nucleic Acid Testing (NAT) and/or anti-HBc testing remain high-priced due to cost and loss of donors/blood products. There is therefore the need for cheaper and practical alternatives to reducing TAHBV. For this study, blood samples were collected from 273 consenting blood donors, aged 18-60 years. Five HBV serological markers: HBV surface and envelope antigens (HBsAg, HBeAg), and HBV core, surface and envelope antibodies (anti-HBc,anti-HBs, HBeAb) were detected using Enzyme Linked Immunosorbent Assays. A high anti-HBs prevalence of 37.7% was detected among the donors while HBsAg prevalence was 5.1%, a rate lower than 8% value for high endemic regions to which Nigeria is classified. Among the donors HBcIgM prevalence was 4.8% (13/273), with twelve donors (4.4%; 12/13) having anti-HBc IgM as the only detectable marker of HBV infection. Anti-HBs presence of 200 mIU/mL or more has been reported safe as a transfusion component in anti-HBc-positive blood. A high anti-HBs observed among blood donors in this study could be explored in routine HBV screening of anti-HBc-positive blood donors. Including anti-HBs screening and anti-HBc IgM found as the only HBV infection marker in 12 (4.4%) donors could reduce TAHBV in Nigeria where HBV NAT screening is not affordable and discarding anti-HBc IgG-positive blood not feasible because blood transfusion is critical to treatment of diverse pathologies.Item Serological markers of HBV infection: A community-based study of urban dwellers in Southwest Nigeria(African Society for Clinical and Experimental Microbiology, 2020) Akere, A.; Omoruyi, E. C.; Adewumi, M. O.; Faleye, T. O. C.; Ifeorah, I. M.; Bakarey, A. S.; Ogunwale, A. O.; Dafikpaku, I. N.; Oni, O. E.; Tomo, O. V.; Akinola, A. O.; Onyenucheya, A. G.; Adeniji, J. A.Background and Aim: Globally, hepatitis B virus (HBV) infection has been a major public health issue. In sub-Saharan Africa, about 10–20% of the general population are chronic carriers of HBV infection, making it a high endemic region. This study was designed to evaluate the pattern of distribution of markers of HBV among asymptomatic subjects in an urban community in southwest Nigeria. Methodology: The study was carried out among apparently healthy subjects without prior knowledge of their HBV status. A structured questionnaire was used to collect demographic and relevant information, while ELISA kits were used to detect HBsAg/Ab, HBeAg/Ab, Total anti-HBc, and anti-HBc IgM using the participants’ sera. Results: The results of 438 subjects comprising 133 (30.4%) males and 305 (69.6%) females were analysed, age ranged 1.5–70 years (35.7 ± 15.7 years). Overall, 31 (7.1%) of the participants had detectable HBsAg, 2 (6.5%) and 7 (1.6%) subjects had detectable HBeAg and anti-HBc IgM respectively. Anti-HBs was detected in 83 (18.9%) subjects, while 39 (8.9%) had anti-HBe. Of the HBsAg positive participants, 13 (3.2%) were also positive for both anti-HBc IgM and HBeAg, 25 (80.6%) had anti-HBe, while 3 (9.7%) had only anti-HBc IgM. None of them had anti-HBs. Among those who were HBsAg negative, 83 (20.4%) had anti-HBs as the only serological marker, while 313 (76.9%) had no serological markers of HBV infection. Only 145 of the total population were tested for anti-HBc Total, of whom 65 (44.8%) were positive. Conclusion: This study has highlighted the burden of HBV infection in the population studied. There is therefore the need for more awareness through information programmes to the public and for preventive measures through vaccination programmes.Item Detection of Non-Cytopathic Enteroviruses in Supernatant of RD and L20B Cell Cultures(ResearchersLinks Ltd., 2020-08-29) Adewumi, M. O.; Ogunsakin, T. R.; Ogunrombi, S. B.; Ojeamiren, I.; Olawole, A. S.; Faleye, T. O. C.; Adeniji, J. A.We investigated the likely presence of enteroviruses in supernatants of cytopathic effect (CPE) negative RD and L20B cell culture tubes in which faecal suspension from acute flaccid paralysis (AFP) cases were cultured. Samples analyzed were collected in 2017 as part of the AFP surveillance program in Nigeria and declared negative for enteroviruses because they did not produce CPE in RD and L20B cell lines. In all, 120 cell culture supernatants (60 each on RD and L20B cell lines) that emanated from 30 stool suspensions (2 samples per case) were analyzed as 60 pools (pooled per case by cell line). Pools were subjected to RNA extraction, RT-snPCR, amplicon sequencing and phylogenetic analysis. Eleven and one of the 30 pools of RD and L20B cell culture supernatants, respectively, were positive for the RT-snPCR. Nine of the 11 amplicons from RD and the only from L20B were sequenced and identified as seven EV types; Coxsackievirus A4 (CVA4), CV-A6, CV-A13, CV-A17 (both RD and L20B), CV-B2, Echovirus 9 (E9) and Enterovirus A76 (EVA76). Our findings suggest some enteroviruses are present in and might be replicating in RD cell line without producing CPE. We also report the existence of CV-A6 genotype E (possibly sub-Saharan Africa restricted).Item Isolation and Complete Capsid Sequence of Enterovirus D111 from Faeces of a Child with Acute Flaccid Paralysis in Nigeria(ResearchersLinks Ltd, 2019) Faleye, T. O. C.; Adewumi, M. O.; Olayinka, O. T.; Adeniji, J. A.The WHO recommended cell-culture-based algorithm requires enterovirus (EV) isolates to produce reproducible cytopathic effect (R-CPE) in RD and/or L20b cell lines. Samples with non-reproducible CPE (NR-CPE) are considered negative for EVs. We investigated whether there could be EVs lurking in samples with NR-CPE. Fifty-nine cell culture supernatants (CCS) (collected between 2016 and 2017) from RD and L20b cell-culture-tubes with NR-CPE, were analyzed. The tubes had been previously inoculated with stool suspension from children (<15 years) in Nigeria with acute flaccid paralysis (AFP). All CCS were screened for Enteric Adenoviruses (EAVs) and group A Rotavirus (GARV) using a rapid immunochromatographic test kit. Subsequently, they were passaged in HEp-2 cell line. All isolates were subjected to RNA extraction, cDNA synthesis, three (5l-UTR, VP1 and EV Species C [EV-C]) different PCR assays and sequencing of amplicons. EVs were further subjected to [‘]Illumina sequencing. All CCS were negative for EAVs and GARVs. Four CCS produced R-CPE in HEp-2 cell line, three of which were positive for the 5l-UTR assay. Of the three isolates, two and none were positive for the VP1 and EV-C assays, respectively. One of the two VP1 amplicons was successfully sequenced and identified as Echovirus 1. Illumina sequencing of the three 5l-UTR positive isolates confirmed the E1 isolate and typed the remaining two as EV-Ds (94 and 111). We describe the first EV-D isolates of Nigerian origin and the first complete capsid sequence of the virus globally. We also show that NR-CPE could sometimes be caused by EVs that do not produce R-CPE in specific cell lines.Item Rapid HIV Antigen–Antibody Assays and detection of acute HIV infection in sub-saharan Africa(American Society of Tropical Medicine and Hygiene, 2019) Adetunji, A. A.; Adewumi, M. O.; Michael, O. S.; Fayemiwo, S. A.; Ogunniyi, A.; Taiwo, B. O.Detection of acute HIV infection is a unique problem that fourth-generation HIV assays were expected to alleviate. In this commentary, we draw attention to the limitations and challenges with use of currently available rapid antigen–antibody (Ag/Ab) combination tests for detection of acute HIV infection in sub-Saharan Africa. Laboratory-based HIV-1 Ag/Ab immunoassays are complex, requiring specialized equipment and handling that are currently not affordable in many settings in Africa. The point-of-care Ag/Ab platform on the other hand is easier to deploy and potentially more accessible in resource-limited settings. However, available fourth-generation HIV-1 rapid diagnostic tests have demonstrated poor performance characteristics in field studies where non-B subtypes of HIV-1 dominate. The potential for point-of-care HIV-1 Ag/Ab diagnostics to significantly improve detection of acute HIV infection remains yet to be realized in sub-Saharan Africa. Assay platforms need to be optimized to identify local circulating subtypes, and optimal algorithms need to be determinedItem Recovery of nonpolio enteroviruses from l20b cell line with non-reproducible cytopathic effect(BioMed Central, 2018) Adeniji, J. A.; Ibok, U. I.; Ayinde,O. T.; Oragwa, A. O.; George, U. E.; Faleye. T. O. C.; Adewumi, M. O.Background and Aim of the Study: Samples showing cytopathic effect (CPE) on initial inoculation into L20B cell line but with no observed or reproducible CPE on passage in L20B or RD are considered negative for both poliovirus and nonpolio enteroviruses (NPEVs). The phenomenon is termed ‘non-reproducible CPE’. Its occurrence is usually ascribed to the likely presence of reoviruses, adenoviruses and other non-enteroviruses. This study aimed to investigate the likelihood that NPEVs are also present in cases with non-reproducible CPE. Place and Duration of Study: This study was carried out in the Department of Virology, College of Medicine, University of Ibadan using twenty-six (26) cell culture suspensions collected from the WHO National Polio Laboratory, Department of Virology, College of Medicine, University of Ibadan. The suspensions emanated from 13 L20B cell culture tubes that showed cytopathology within 5 days of inoculation with faecal suspension from AFP cases. However, on passage into one each of RD and L20B cell lines, the CPE was not reproducible. The study lasted for three (3) months from samples collection to report writing. Methodology: All samples were subjected to RNA extraction, cDNA synthesis, the WHO recommended VP1 RT-seminested PCR assay, species resolution PCR assay, sequencing andphylogenetic analysis. Results: Six (6) samples were positive for the VP1 RT-seminested PCR assay. Only four of which were positive by the species resolution PCR assay. The four amplicons were sequenced, however, only three (3) were successfully identified as Coxsackievirus A20 (2 isolates) and Echovirus 29 (1isolate). Conclusion: The results of this study unambiguously showed the presence of NPEVs (particularly CVA20 and E29) in cell culture supernatants of samples with CPE on initial inoculation into L20B cell line but with no observed or reproducible CPE on passage in RD cell line. Therefore, like reoviruses, adenoviruses and other non-enteroviruses, NPEVs can also be recovered in cases with non-reproducible CPE.