Association of Plasmid Bearing Multi Drug Resistant Bacteria with High Mortalities in Nigerian Poultry

Bacteriological investigations were carried out on reported cases of low and high mortalities in commercial poultry in the year 2007-2009 in commercial flocks of breeders, layers, broilers, chicks and growers. Pure bacterial isolates obtained from dead birds, mainly Gram negative,  were tested for their biochemical and antibiotic susceptibility profiles using Microscan® Dried Gram-negative Breakpoint Combo Pannels. The microscan panel analysis bacterial isolates for 24 biochemical tests and up to 25 antimicrobial agents following 16-20 hours of incubation at 35-37oC. Bacteria isolated were Escherichia coli, Salmonella Enteritidis, Salmonella Pullorum, Salmonella Gallinarum, Citrobacter youngae, Klebsiella ozaneae, Klebsiella variicola, Enterobacter cloaceae, Hafnia alvei, Pasteurella gallinarum and Pasteurella multocida. The bacterial isolates showed resistance to 6-23 of the 25 antibiotics tested. Tetracycline and ampicilllin were found as the least potent drugs, with 90 and 90.91% resistance respectively. Resistance was obtained against antibacterial agents that are not in use in Nigerian poultry industry, such as the cephalosporins, carbapenems, piperacillin, tircacillin, amikacin, tobramcycin and levofloxacin suggesting possible genetic contribution to resistance. Thirty-four (85%) of the 40 pathogenic bacteria isolates treated for plasmid profile were found to be carrying plasmids. Plasmid DNA size 11.50 kbp was commonly observed (about 65%) among all the plasmid borne mdr bacteria, plasmid DNA size 10kbp (incidence of about 22% in plasmid borne bacteria) as well as a 26.3 kbp plasmid DNA and a 6.6 kbp plasmid DNA. The susceptibility of the plasmid bearing bacteria to antibiotics was enhanced following plasmid curing with sodium deodecyl sulphate.  Antibiotic susceptibility testing should guide treatment in all infections where organism can be cultured in veterinary medicine practice Keywords: Antibiotics, high mortalities, multi-drug resistant bacteria, plasmid, poultry

Evaluation of Volumetric Properties of Cassava Peel Ash Modified Asphalt Mixtures

In continuance to providing a reliable and cost-efficient road construction material that would aid the development of sustainable pavements while also eradicating agricultural wastes to protect the environment, Cassava Peel Ash (CPA) modified asphalt mixture is seen to be one of the most viable options. This study aimed to determine the suitability of Cassava Peel Ash (CPA) in hot mix asphalt for improved pavement performance. Using response surface methodology, a central composite design was employed for the mix design parameters, namely coarse aggregate (CA), fine aggregate (FA), mineral filler (MF), bitumen content (BC), and cassava peel ash (CPA). CPA was used as a partial replacement for filler and varied between 0% and 20%. The BC varied between 4% and 8%, the MF varied between 15% and 20%, the FA varied between 10% and 14%, and the CA varied between 46% and 52%. The interactive effect between the mix design parameters on the volumetric properties of the asphalt mixtures was evaluated. The results obtained showed the Marshall stability, flow, density, volume of the void, and void in mineral aggregates of the asphalt mixtures at 1.8037–8.045 kN, 2.7-8.22 mm, 2.0426–2.3909%, 1.094–7.966% and 55.5105–93.1393% respectively. These results indicate that the interaction of CA, FA, MF, BC, and CPA influences the volumetric properties of asphalt mixtures. From the RSM analysis, a prediction model and an optimal condition of 4.018% asphalt content, 20% cassava peel ash, 46% coarse aggregate, 10% fine aggregate, and 15% mineral filler were achieved for the asphalt mixtures. Doi: 10.28991/CEJ-2022-08-10-07 Full Text: PD

Author Correction: Dimensional stability and mechanical properties of extruded-compression biopolymer composites made from selected Nigerian grown wood species at varying proportions

250 µm particle size of wood and polyethylene (PE) materials were compounded at mixing proportions of 60/40, 70/30, and 80/20 (with an increase in polymer to decrease in wood content) and extruded using a single screw extruder at a temperature range of 110–135 °C. The particles of Gmelina Arborea, Tectona grandis, Cordia milleni, and Nauclea diderichii with recycled Polyethylene were compounded and compressed at 175 N/mm to produce biopolymer composites. The biopolymer composites were subjected to dimensional stability test at 24 h of the water soak method and the ability to withstand load-bearing capacity was investigated. The outcome of the results shows that extruded-compressive biopolymer composites had values ranging from 0.06–1.43 g/cm(3), 0.38–3.41%, and 0.82–6.85% for observed density, water absorption, and thickness swelling at 24 h of a water soak test. The mechanical properties values ranged from 0.28 Nmm(−2)–21.35 Nmm(−2) and 0.44–550.06 Nmm(−2) for flexural modulus and strength; and 191.43 Nmm(−2)–1857.24 Nmm(−2) and 0.35 Nmm(−2)–243.75 Nmm(−2) for tensile modulus and strength respectively. It was observed that moisture uptake and strength displayed by the composites vary accordingly in values obtained for wood species at different mixing proportions. As observed that the more polyethylene content is compounded to wood, the better its dimensional stability, and flexural and tensile properties. The wood particles of Cordia milleni compounded at a proportion of 60 to 40 (polyethylene/wood) performed best in dimensional stability and load-bearing capacity. This study confirmed the effect of methods on wood species and recycled PE for manufacturing wood polymer-based composite for both indoor and outdoor applications