Browsing by Author "Femi Ayoade"

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    A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa
    (Science, 2021-10-23) Femi Ayoade
    The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants.
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    BACTERIOLOGICAL ASSESSMENT OF FRIED-READY-TO EAT (RTE) VENDED FOODS SOLD IN OSOGBO, OSUN STATE, NIGERIA
    (Journal of Faculty of Food Engineering, Ştefan cel Mare University of Suceava, Romania, 2023-12-29) Femi Ayoade
    The purpose of this paper is to investigate the bacteriological profile of Enterobacteriaceae from ready-to-eat (RTE) fried foods and to also screen for the presence of shiga-toxins, intimin and haemolysin genes which are indicator genes for food-borne infections and diseases. The morphological and biochemical characterizations were carried out using standard isolation techniques while enumeration was done using a colony counter. To study the resistance and susceptibility pattern of the isolated Enterobacteriaceae, the characterized isolates were subjected to antibiotics susceptibility test using the Kirby-Bauer disk diffusion method. The presence of stx 1 and 2 (shiga toxin genes), eaeA (intimin gene) and hylA (haemolysin gene) were screened for in the multi- drug resistant (MDR) isolates. Six (6) species of bacteria were isolated from the RTE food samples namely: Proteus spp (20%), Escherichia coli (60%), Salmonella spp (30%), Klebsiella spp (30%), Staphylococcus spp (20%) and Shigella spp (50%) while the colonial count ranged from 60×105- 299×103. The phenotypic antibiotics profile result showed that 60% of the multi-drug resistant organisms harboured stx1 and 2 while 40% harboured hylA. However, none of the MDR isolates were positive for eaeA. In conclusion, commercially vended RTE food handlers should be continuously educated on the importance of basic food hygiene and sanitation.
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    Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria
    (Nature communications, 2023-02-13) Femi Ayoade
    Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeo- graphic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates.
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    First report of Wolbachia from field populations of Culex mosquitoes in south-western Nigeria
    (2019-10-16) Femi Ayoade
    Recent reports on finding Wolbachia-strain infections in field mosquito species in some West African countries and the potential for developing these as disease vector biocontrol tools have prompted a search for Wolbachia in mosquitoes within the study area. Using a completely randomised design, mosquito traps were set at different locations in a rural and an urbanised community. One hundred and eighty (180) mosquitoes were trapped and pooled on the basis of genus, sex and site of collection, because there have been no earlier reports of Wolbachia isolated from Nigeria. Twenty pools, made up of not more than ten mosquitoes per pool, were homogenised and analysed for Wolbachia-specific DNA. Mosquitoes were trapped within Ede (urbanised community) and Akoda (rural community). Genomic DNA was extracted from trapped mosquito samples and used as a template in a PCR reaction. The Wolbachia sp. specific 16S rRNA gene was amplified, sequence analysis of PCR products was performed and a chromatogram of the sequence was subjected to Basic Local Alignment Search Tool analysis to identify the Wolbachia sp. This sequence was subsequently submitted to GenBank with accession number MK127541. The first evidence of the presence of the endosymbiont, Wolbachia in field-caught mosquitoes is hereby documented. The homology of this strain of Wolbachia bears similarities to those reported recently from other parts of West Africa and forms a single clade with a Wolbachia sp. from Mali, with a strong bootstrap support of 99%. This finding of a Wolbachia strain in mosquitoes at Ede could form the basis for more searches for diverse strains of Wolbachia in Nigeria.
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    Hand Hygiene Practices and the Effectiveness of Hand Sanitizers at Controlling Enteropathogens among the Residents of a University Community in Osun State Nigeria
    (2019-04) Femi Ayoade
    To explore perceptions, attitudes and hand washing practices in relation to the effectiveness of hand sanitizers in controlling enteropathogens amongst residents of a Nigerian University with the purpose of creating awareness on the importance of hand hygiene to control the spread of communicable diseases. Study Design: A simple random cluster sampling technique was used. A questionnaire designed to relate demographic and hand hygiene practices to the effectiveness of the practices to the control of enteropathogens was applied to the respondents.Place and Duration of Study: The study was carried out between January and May, 2018 at the Redeemer’s University, Ede, Osun State, Nigeria. Methodology: Sterile swabs moistened with sterile normal saline were used in sampling the palms of 50 respondents and the normal transient flora was established, samples were again taken to determine effectiveness of hand washing at reducing the bacterial load and the diversity of organisms isolated from the samples after hand washing and application of hand sanitizers. Using standard microbiological methods, serial dilutions of the swabs in normal saline were plated on Eosin Methylene Blue agar in order to isolate members of the bacterial family Enterobacteriacae. Identification was done using cultural, morphological and relevant biochemical tests. Subsequently, the results for the different treatments were compared using the Duncan’s multiple range test at p<0.05. Results: The results showed that at least 60% of the respondents were unaware of the WHO recommended way to wash hands and 72% of these do not wash their hands before eating food or after taking care of sick people. The predominant transient hand flora in the tested population were determined to be constituted by the following bacterial species, namely, Enterobacter spp, Enterobacter aerogenes, Staphylococcus aureus, Yersinia pestis, Erwinia cactida, Klebsiella pneumonia, Enterobacter cloacae and Klebsiella oxytoca. Hand washing with soap was found to be more effective at reducing these on the hands of the respondents at a degree similar to treatment with the hand sanitizer were PL® with a label claim of 70% alcohol contentand more effective than hand sanitizers CS® and GC® with 62% and 60% alcohol content respectively. Conclusion: Hand washing with soap and water when done properly remains the most reliable means of breaking the cycle and spread of preventable enteropathogens in the community setting and it is perhaps more reliable than the use of alcohol-based hand sanitizers.
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    Impact of an Acylanilide Herbicide Propanil on Biochemical Indices in Kidney of Diabetic Rats
    (Asian Journal of Biological Sciences, 2019-03-14) Femi Ayoade
    Background and Objective: Propanil (PRO) is an acylanilide herbicide used to control barnyard grass and broad leaf weeds. This study evaluated the impact of PRO in streptozotocin (STZ)-induced diabetic rats. Materials and Methods: Diabetes was induced in rats by a single injection of STZ (60 mg kgG1 intraperitoneal, i.p.). The PRO was administered at the dose of 200 mg kgG1 (i.p. for 7 days), to both normal and diabetic rats. Results: The plasma levels of triglyceride, aspartate aminotransferase, creatinine and renal malondialdehyde level (an index of lipid peroxidation) were significantly increased in diabetic rats. In addition, the levels of high density lipoprotein-cholesterol, superoxide dismutase were depressed in the STZ-treated rats compared to the control group. The co-exposure of PRO increased absolute organ weight, catalase, glutathione peroxidase and malondialdehyde levels. Conclusion: Taken together, exposure to PRO exacerbated oxidative stress in renal tissue of diabetic rats.
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    Molecular surveillance of non-O157 Shiga toxigenic Escherichia coli in selected chicken abattoirs and retail outlets in Osogbo, Osun State, Nigeria
    (Journal of Food Safety and Hygiene, 2021-12-10) Femi Ayoade
    Three selected chicken abattoirs and two retail locations were studied to determine the frequency of occurrence and profile for Shiga toxin-producing Escherichia coli (STEC) strain present in abattoirs and retail (frozen) chicken carcasses in Osun state, Nigeria. Samples were plated on Eosin Methylene Blue agar for the presence of E. coli. Furthermore, the isolates were confirmed serologically as non-O157 STEC using a latex agglutination serotyping kit. Multiplex PCR was used to check for specific virulence factors in the isolated E. coli strains. The mean colony count results showed that effluent water samples from the Ikirun slaughter slab type abattoir were the highest at 25 cfu/ml. A post hoc comparison showed that this value was significantly higher than that of the slaughtering table at Oluode-1 (P = 0.04) and retail chicken meat samples at Igbona (P = 0.01). The results show that chicken abattoirs are poor reservoirs of STEC. Moreover, the results from this study showing that the stx2-producing strains that are more prone to cause hemolytic uremic syndrome are the predominant strain in the study area are worrisome. These results underscore the improper hygiene practices of the abattoir workers combined with inadequate waste management and biological waste disposal systems. It is recommended that regulatory bodies in this locality should focus on ensuring the upgrade of biological waste disposal from these abattoirs in order to limit the spread of potentially virulent pathogens into the runoff and groundwater.
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    Molecular surveillance of shiga toxigenic Escherichia coli in selected beef abattoirs in Osun State Nigeria
    (nature.com/scientificreports, 2021-07-07) Femi Ayoade
    Shiga toxigenic strains of E. coli (STEC) known to be etiological agents for diarrhea were screened for their incidence/occurrence in selected abattoirs sources in Osogbo metropolis of Osun State, Nigeria using a randomized block design. Samples were plated directly on selective and differential media and E. coli isolates. Multiplex PCR analysis was used to screen for the presence of specific virulence factors. These were confirmed serologically as non-O157 STEC using latex agglutination serotyping kit. Sequence analysis of PCR products was performed on a representative isolate showing the highest combination of virulence genes using the 16S gene for identification purposes only. Results showed that the average cfu/cm2 was significantly lower in the samples collected at Sekona-2 slaughter slab compared with those collected at Al-maleek batch abattoir and Sekona-1 slaughter slab in ascending order at P = 0.03. Moreover, the average cfu/cm2 E. coli in samples collected from butchering knife was significantly lower when compared with that of the workers’ hand (P = 0.047) and slaughtering floor (P = 0.047) but not with the slaughter table (P = 0.98) and effluent water from the abattoir house (P = 0.39). These data suggest that the abattoir type may not be as important in the prevalence and spread of STEC as the hygiene practices of the workers. Sequence analysis of a representative isolate showed 100% coverage and 96.46% percentage identity with Escherichia coli O113:H21 (GenBank Accession number: CP031892.1) strain from Canada. This sequence was subsequently submitted to GenBank with accession number MW463885. From evolutionary analyses, the strain from Nigeria, sequenced in this study, is evolutionarily distant when compared with the publicly available sequences from Nigeria. Although no case of E. coli O157 was found within the study area, percent occurrence of non-O157 STEC as high as 46.3% at some of the sampled sites is worrisome and requires regulatory interventions in ensuring hygienic practices at the abattoirs within the study area.
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    Resourcefulness of propylprodigiosin isolated from Brevundimonas olei strain RUN-D1
    (AMB Express, 2023-07-09) Femi Ayoade
    A novel red-pigmented bacterium was isolated from a water sample collected at Osun River, Ede. Morphological and 16 S rRNA gene sequencing revealed that the bacterium is a strain of Brevundimonas olei, while its red pigment was identified using UV-visible, FTIR and GCMS as a derivative of propylprodigiosin. The maximum absorbance of 534 nm, the FTIR’s 1344 cm− 1 peak of prodigiosin’s methoxyl C-O interaction, and the molecular ions from GCMS confirmed the pigment’s identity. The pigments production was temperature-sensitive (25 °C), lost at > 28 °C, and in the presence of urea and humus. In addition, the pigment turned pink in the presence of hydrocarbons, while its red colour was retained with KCN and Fe2SO4, and enhanced by methylparaben. Furthermore, the pigment is stable in high temperature, salt, and acidic conditions, but changed to yellow in alkaline solution. The pigment, identified as propylprodigiosin (m/z 297), demonstrated broad-spectrum antibacterial activities against clini- cally important strains of Staphylococcus aureus (ATCC25923), Pseudomonas aeruginosa (ATCC9077), Bacillus cereus (ATCC10876), Salmonella typhi (ATCC13311), and Escherichia coli (DSM10974). The ethanol extract has the highest zones of inhibition of 29 ± 3.0, 26 ± 1.2, 22 ± 3.0, 22 ± 1.5, and 20 ± 2.0 mm, respectively. Furthermore, the acetone pig- ments interacted with cellulose and glucose such that increasing glucose concentrations showed linearity at 425 nm. Finally, the fastness of the pigments to fabrics was excellent, with percentage fadedness of 0 and − 43% light and washing tests, respectively, in the presence of Fe2SO4 as the mordant. The antibacterial nature of prodigiosin solu- tions and their good textile fastness to fabrics could be essential in manufacturing antiseptic materials such as band- ages, hospital clothing and agricultural applications such as tubers preservation. Key points Key points a. Propylprodigiosin-producing Brevundimonas olei was isolated from freshwater. b. Pigmentation was possible on agar at room temperature and induced in broth with parabens. iii. The propylprodigiosin has potential for pharmaceutical, biotechnological and textile applications.
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    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
    (Science, 2022-09-15) Femi Ayoade
    Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscores the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.