Browsing by Author "Obafemi Yemisi Dorcas"

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    Antibacterial activities of plant leaf extracts against multi-antibiotic resistant Staphylococcus aureus associated with skin and soft tissue infections.
    (BMC Complementary Medicine and Therapies, 2022) Banjo Temitope Temitayo; Akinduti Akinniyi Paul; Emoh‑Robinson Victoria; Obamoh‑Triumphant H. F.; Obafemi Yemisi Dorcas
    Background: The antibacterial activities of aqueous leaf extracts of Moringa oleifera, Vernonia amygdalina, Azadirachta indica and Acalypha wilkesiana against multidrug resistance (MDR) Staphylococcus aureus associated with skin and soft tissue infections were investigated. Methods: Staphylococcus aureus (n = 183) from the skin and soft tissue infections with evidence of purulent pus, effusions from aspirates, wounds, and otorrhea were biotyped, and evaluated for biofilm production. The phenotypic antibiotic resistance and MDR strains susceptibility to plant leaves extract were determined using disc diffusion and micro-broth dilution assays respectively. The correlation of plant extract bioactive components with inhibitory activities was determined. Results: High occurrence rate of S. aureus were recorded among infant and adult age groups and 13.2% mild biofilm producers from the wound (p < 0.05). Of 60.2% MDR strains with overall significant MARI of more than 0.85 (p < 0.05), high resistant rates to linozidine (92.7%; 95% CI:7.27–10.52), ofloxacin (94.2%; 95% CI:6.09–8.15), chloramphenicol (91.2%; 95% CI:6.11–8.32), gentamicin (97.3%; 95% CI:6.20–8.22), ciprofloxacin (92.7%; 95% CI: 5.28–7.99) and vancomycin (86.6%; 95% CI:6.81–9.59) were observed. Vernonia amygdalina and Azadirachta indica showed significant antimicrobial activity at 100 mg/ml and 75 mg/ml, with low susceptibility of less than 10% to 25 mg/ml, 50 mg/ml, and 75 mg/ml Moringa oleifera. Alkaloids, saponin and terpenoids were significant in Moringa oleifera, Acalypha wilkesiana, Azadirachta indica and Vernonia amygdalina leaves extracts (p < 0.05). High inhibitory concentrations at IC50; 3.23, 3.75 and 4.80 mg/ml (p = 0.02, CI: − 0.08 – 11.52) and IC90; 12.9, 7.5, and 9.6 mg/ml (p = 0.028, CI: 2.72–23.38) were shown by Acalypha wilkesiana, Vernonia amygdalina and Moringa oleifera respectively. Comparative outcome of the plant extracts showed Acalypha wilkesiana, Vernonia amygdalina and Moringa oleifera to exhibit significant inhibition activities (p < 0.05) compared to other extracts. Significant median inhibitory concentration (15.3 mg/ml) of Azadirachta indica were observed (p < 0.01) and strong associations of phytochemical compounds of Azadirachta indica (eta = 0.527,p = 0.017), Vernonia amygdalina (eta = 0.123,p = 0.032) and Acalypha wilkesiana (eta = 0.492,p = 0.012) with their respective inhibitory values. Conclusion: Observed high occurrence rate of skin and soft tissue infections caused by biofilm-producing MDR S. aureus requires alternative novel herbal formulations with rich bioactive compounds from Moringa oleifera, Acalypha wilkesiana, Azadirachta indica and Vernonia amygdalina as skin therapeutic agents.
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    Clonal diversity and spatial dissemination of multi-antibiotics resistant Staphylococcus aureus pathotypes in Southwest Nigeria
    (Plos one, 2021) Banjo Temitope Temitayo; Akinduti Akinniyi Paul; Osiyemi Joshua Adekunle; Ejilude Oluwaseun; El-Ashker Maged; Adeyemi Adewale Gideon; Obafemi Yemisi Dorcas; Isibor Patrick Omoregie
    Spread of genetically diverse Staphylococcus aureus characterized with multi-antibiotic resistance and regulated by high level agr functionalities in several communities in southwest Nigeria was investigated and evaluated for infection control. Staphylococcus aureus pathotypes recovered from 256 cases including purulent pus from skin infections, soft tissue aspirates, wounds, otorrhea, eye, throat and endocervical infections were assayed for biofilm and antibiogram. Further genotyped with micro-array, mapped for geospatial distribution and evaluated for clonal diversity and functional accessory gene regulators (agr). Significant Staphylococci infection among the ages (OR:0.021, CI:0.545–1.914) and female gender with prevalence rate of MSSA (53.0%) and MRSA (1.5%) (OR:1.021, CI:0.374–1.785) were observed. More than 52.5% resistance rates to tetracycline and amoxicillin with significant median resistance were observed in all the infection cases (p = 0.001). Resistance rate of 78.8% at MIC50 32μg/ml and MIC90 128μg/ml to amoxicillin-clavulanate, and more than 40% resistance to ceftazidime, ciprofloxacin and tetracycline of MIC90 and MIC50 at 32 μg/ ml were observed. Strains with multi-antibiotic resistance index above 0.83, high beta lactamase and strong biofilm clustered into separate phylo-group. Heterogeneous t442 (wound and pus), t657 (wound), t091 (ear) and t657 (ear and wound) revealed high phylogenetic diversity. Only 4.6% pvl+ MSSA-CC1 agrI, pvl+ MSSA-CC5 (13.6%) and pvl+ MRSA-CC7 agrII (4.6%), expressed enterotoxin, leukocidins, proteases and resistance gene determinants. Livestock clonal types clustered with identified community-associated strains. Clonal dissemination of resistant pvl+ MSSA-CC1 and MRSA-CC5 encoding agr were predominant in several peri-urban communities where adequate geno-surveillance, population target antimicrobial stewardship, extensive community structured infection control programs are needed to prevent further focal dissemination.