Ladoke Akintola University of Technology

About: Ladoke Akintola University of Technology is a education organization based out in Ogbomoso, Nigeria. It is known for research contribution in the topics: Population & Adsorption. The organization has 2786 authors who have published 3066 publications receiving 36850 citations. The organization is also known as: Oyo State University of Technology & LAUTECH.

Biomedical Applications of Cocoa Bean Extract-Mediated Silver Nanoparticles as Antimicrobial, Larvicidal and Anticoagulant Agents

Abstract: In this work, cocoa bean extract (CBE) was used to synthesize silver nanoparticles (AgNPs) under ambient conditions. The fairly polydispersed spherical CBE-AgNPs had size range of 8.96–54.22 nm with λmax occurring at 438.5 nm. The prominent peaks at 3275.13 and 1635.54 cm−1 from FTIR data laid credence to the involvement of phenolics and proteins in the biofabrication and stabilization of CBE-AgNPs. Energy dispersive X-ray and selected area electron diffraction studies showed the conspicuous presence of silver in colloidal solution with distinctive crystalline face-centered cubic phase of AgNPs. CBE-AgNPs showed appreciable activities against multi-drug resistant bacteria, producing zones of inhibition of 10–14 mm, and also enhanced activities of ampicillin, cefuroxime, cefixime and erythromycin by 42.9–100 % in synergistic studies. It produced pronounced antimicrobial activities against several bacteria and fungi, when incorporated into emulsion paint. Furthermore CBE-AgNPs showed good larvicidal activities against Anopheles gambiae mosquito larvae with LC50 of 44.37 µg/ml, while it also prevented the coagulation of human blood. This study established synthesis of AgNPs using CBE as a viable green route approach, with remarkable antimicrobial, larvicidal and anticoagulant activities. As far as we know, this is the first report of the use of CBE to synthesize AgNPs.

Biogenic synthesis of silver nanoparticles using cell-free extract of Bacillus safensis LAU 13: antimicrobial, free radical scavenging and larvicidal activities

Abstract: The cell-free extract of Bacillus safensis LAU 13 strain (GenBank accession No: KJ461434) was used for green biosynthesis of silver nanoparticles (Ag-NPs). Characterization of Ag-NPs was carried out using UV-VIS spectroscopy, Fourier-transform infrared spectroscopy, and transmission electron microscopy. Evaluation of synthesized Ag-NPs as antimicrobial agents was done using multi-drug resistant clinical isolates as well as their synergistic effects when combined with some selected antibiotics. Furthermore, potential of Ag-NPs as antimicrobial additives in paint was demonstrated. The Ag-NPs have maximum absorbance at 419 nm, with peaks at 3308, 2359, 1636, and 422 cm-1, indicating that proteins were the capping and stabilisation molecules in the synthesis of Ag-NPs. The particles were spherical shaped having size of 5–95 nm, with silver as the prominent metal from the energy dispersive X-ray analysis, while selected area electron diffraction pattern agrees well with the crystalline nature and face-centred cubic phase of Ag-NPs. Inhibition of Staphylococcus aureus, Escherichia coli, Klebsiella granulomatis and Pseudomonas aeruginosa was achieved at 100 μg/mL. Improvement of activities of augmentin, ofloxacin and cefixime to the tune of 7.4-142.9% was achieved in synergistic study, while total inhibitions of P. aeruginosa, S. aureus, Aspergillus flavus and Aspergillus fumigatus were achieved in Ag-NPs-paint admixture. The Ag-NPs showed potent antioxidant and larvicidal activities with IC50 and LC50 of 15.99 and 42.19 μg/mL, respectively. The present study demonstrated that the biosynthesized Ag-NPs have potent biological activities, which can find applications in diverse areas. The report adds to the growing biotechnological relevance of B. safensis.

Characterization of methicillin-susceptible and -resistant staphylococci in the clinical setting: a multicentre study in Nigeria

Abstract: The staphylococci are implicated in a variety of human infections; however, many clinical microbiology laboratories in Nigeria do not identify staphylococci (in particular coagulase negative staphylococci - CNS) to the species level. Moreover, data from multi-centre assessment on antibiotic resistance and epidemiology of the staphylococci are not available in Nigeria. This study investigated 91 non-duplicate staphylococcal isolates obtained from the microbiology laboratories of eight hospitals in Nigeria during the period January to April 2010. Identification and antibiotic susceptibility testing was performed using the VITEK 2 system, detection of resistance genes by PCR, and molecular characterization was determined by SCCmec typing, spa and multilocus sequence typing (MLST). All the isolates were susceptible to mupirocin, tigecycline, vancomycin and linezolid, but 72.5% of CNS and 82.3% of Staphylococcus aureus were resistant to cotrimoxazole, while multiresistance was observed in 37 of the 40 CNS isolates. Untypeable SCCmec types (ccrC/Class A mec and ccr-negative/Class C2 mec gene complex) in two methicillin-resistant S. aureus (MRSA) were identified. Additionally, ccr-negative/Class A mec and ccr type 4/Class C2 mec gene complex was detected in one isolate each of S. sciuri and S. haemolyticus, respectively. The S. aureus isolates were classified into 21 spa types including two new types (t8987, t9008) among the methicillin-susceptible S. aureus (MSSA) isolates. Two (CC8-SCCmecnon-typeable and CC88-SCCmec IV) and four (CC8-SCCmec III/IV/V; CC30-SCCmec II/III; CC88-SCCmec IV; and ST152-SCCmecnon-typeable) MRSA clones were identified in Maiduguri (North-East Nigeria) and South-West Nigeria, respectively. The proportion of Panton-Valentine leukocidin (PVL)-positive MSSA was high (44.4%) and 56.3% of these strains were associated with sequence type (ST) 152. The identification of multiresistant mecA positive S. haemolyticus and S. sciuri from clinical samples indicates that characterization of CNS is important in providing information on their diversity and importance in Nigeria. There is the need to develop new SCCmec classification methods for non-typeable methicillin-resistant staphylococci, and to curtail the spread and establishment of the S. aureus ST152 clone in Nigeria. The study presents the first report of a PVL-positive ST152-SCCmecnontypeable MRSA and SCCmec typing of methicillin-resistant CNS in Nigeria.

Adsorptive features of banana (Musa paradisiaca) stalk-based activated carbon for malachite green dye removal

Abstract: Chemically prepared activated carbon derived from banana stalk (BSAC) was used as an adsorbent to remove malachite green (MG) dye from aqueous solution. BSAC was characterised using thermogravimetric analyser, Brunauer Emmett Teller, Fourier transform infrared spectrometry, scanning electron microscopy, pHpzc, elemental analysis and Boehm titration. The effectiveness of BSAC in adsorbing MG dye was studied as a function of pH, contact time, temperature, initial dye concentration and repeated desorption–adsorption processes. pHpzc of BSAC was 4.5 and maximum dye adsorption occurred at pH 8.0. The rate of dye adsorption by BSAC was very fast initially, attaining equilibrium within 120 min following a pseudo-second-order kinetic model. Experimental data were analysed by Langmuir, Freundlich and Dubinin–Raduschevich isotherms. Equilibrium data fitted best into the Langmuir model, with a maximum adsorption capacity of 141.76 mg·g−1. Δ G 0 values were negative, indicating that the process of MG dye adsorption o...