Prevalence and antibiotic susceptibility of AmpC and ESBLs producing clinical isolates at a tertiary health care center in Kano, north-west Nigeria

The increase in production of Extended Spectrum Beta Lactamase (ESBL) and Amp C beta lactamase among clinical isolates in our hospitals is of utmost importance. Failure to detect these enzymes in many of our hospitals has greatly led to treatment failure and uncontrolled spread of multi drug resistant pathogens. It was for this purpose that the present study was conducted to determine the prevalence, distribution and susceptibility pattern of Gram negative bacteria producing ESBLs and Amp C beta lactamases in the largest tertiary health care provider in Kano, North-West Nigeria. A total of 75 ESBL and 10 AmpC producing bacteria were involved in the study which were obtained from a study involving 500 Gram negative clinical bacterial isolates from various hospital wards over a period of 9 months from Aminu Kano Teaching Hospital (AKTH), Kano, Nigeria. Isolates were screened for ESBLs and AmpC using Double Disc Diffusion Method and Amp C Disc test respectively. All confirmed ESBL and Amp C producing isolates were tested for susceptibility to sixteen (16) different antibiotics by the Disc Diffusion Method (DDM). The prevalence of ESBLs was high in Shigella spp. (1/2 or 50%), followed by Klebsiella pneumoniae (10/50 or /20%), and E. coli (47/247 or 19.3%) while Amp C producers were detected more in Klebsiella pneumoniae (4%) and E. coli (2.8%). Of the specimens screened, distribution varies between ESBL and AmpC producers, but more prevalent in urinary tract pathogens in both. Highest prevalence of ESBLs and AmpC producers was recorded in intensive care units and surgical wards. ESBL and AmpC production in the hospital is not sex dependent statistically, thought higher in males (52 and 60%) than in females (48 and 40%) for ESBL and AmpC respectively. ESBL and AmpC producers were both sensitive to Imipenem, Nitrofurantoin and Levofloxacin and resistance to Amoxycillin, Ceftazidime and Tetracycline. The study indicates the occurrence of ESBL and AmpC producers in our tertiary health provider, widely distributed in various clinical samples, wardsand sexes and are multi drug resistant posing serious threat in managing life threatening infections.Key words: prevalence, distribution, ESBL producers, Amp C producers, antibiotic susceptibilit

Mineralogical and Geochemical Assessment of Clay Properties of Edda, Afikpo Sub Basin Nigeria for Possible Use in the Ceramics Industry

Clay samples from selected part of Edda were analyzed to identify the clay mineral types present, their chemical and physical properties with a view to appraising their industrial suitability as ceramic materials. The mineralogical and geochemical analyses were done using the principles of X-Ray diffraction and X-ray fluorescence respectively. A total of seven clay samples were used for the study, other tests such as plasticity, bulk density, shrinkage, loss on ignition (LOI) and water absorption capacity was carried out to determine the amount of water absorbed under specified conditions. The basic industrial properties assessment showed that more than 70% of the clays are fine-grained. The clays exhibited low to moderate plasticity, moderate shrinkage and bulk density, low to moderate values of both loss on ignition and water absorption capacity. The clays are buff to yellowish in colour. The results of x-ray fluorescence revealed that the mean concentration of major oxide in the clays is shown as follows: SiO2 (62.78%), Al2O3 (20.25%), total Fe (6.09%), CaO (0.56%), MgO (3.21%),Na2O (0.47%), K2O, (1.44%) and TiO2 (0.52%).The samples have high silica content, low alumina and low oxide content. The results of x-ray diffraction revealed that kaolinite is the dominant clay mineral with illite and montmorillonite occurring in subordinate amounts, while quartz and feldspar are the non-clay components present. The characteristics of the clays for each parameter were compared with industrial standards.These properties are appropriate for the Afikpo clays to be useful in the manufacturing of ceramics. However, since the silica content of the clays is high further beneficiation is recommended

In situ infiltration as influenced by cover crop and tillage management

Water is usually the most limiting factor in agricultural grain crop production. Various agricultural management practices such as tillage and use of cover crops have the potential to influence water infiltration into soil. This study was conducted on a Waldron silt loam (fine, smectictic, calcareous, mesic Aeric Fluvaquents) soil to evaluate the influence of cover crop and tillage management on in situ infiltration. The field site included three replicate blocks in a randomized complete block design with each plot measuring 21.3 m (69.9 ft) length and 12.2 m (40.0 ft) width. The two treatment factors included cover crop at two levels (cereal rye [Secale cereale] cover crop [CC] versus no cover crop [NC]) and tillage at two levels (moldboard plow tillage [Till] versus no-tillage [NT]). Continuous corn (Zea mays L.) was grown. Infiltration rates were measured in all the treatments using a Mariotte system with single ring infiltrometers during the 2014 and 2015 growing seasons. Water infiltration parameters were estimated using the Parlange and Green-Ampt infiltration equations. Parlange and Green-Ampt models appeared to fit measured data well with coefficient of variation ranging from 0.92 to 0.99. In 2014, the saturated hydraulic conductivity (KS) parameter value determined from the Parlange model was 30.4 mm h-1 for NT, about 42% greater than Till. The KS parameter value determined from the Green-Ampt model was 25.9 mm h-1 for NT, about 54% greater than Till. In 2015, the sorptivity (S) parameter value determined from the Parlange model was 38.6 mm h-0.5 for CC, about 82% greater than NC. The S parameter value determined from the Green-Ampt model was 34.0 mm h-0.5 for CC, about 90% greater than NC. Cover crop management can increase water infiltration, which can improve soil quality and enhance the sustainability of crop production systems

Detection of metallo betalactamases among gram negative bacterial isolates from Murtala Muhammad Specialist Hospital, Kano and Almadina Hospital Kaduna, Nigeria

Over the last few years, the increase in the number of multi-resistant (MR) enterobacteria has become a major clinical problem. This study detects the occurrence and prevalence of Metallo betalactamase production among some clinical bacterial isolates in Murtala Muhammad SpecialistHospital, Kano and Al-Madina Specialist Hospital Kaduna, Nigeria. A total of 200 clinical isolates comprising of E. coli (83), Klebsiella pneumoniae (52), Pseusomonas aeruginosa (28) and Proteus mirabilis (37) were screened phenotypically for carbapenemase and specifically for Metallo betalactamase using Modified Hodges Test and EDTA Disc Synergy Test respectively. The result showed that 67(33.5%) of the isolates were found to produce carbapenemase. High production occurred in 24(35.8%) and low production occurred in 43(64.2%) of the isolates. Highest prevalence of carbapenemase was found in Pseudomonas aeruginosa (38.55%) followed by E. coli (34.8%), Proteus mirabilis. (29.1%) and least prevalence in Klebsiella pneumoniae (25.0%). The prevalence of MBLs in the study was 24.5% with highest prevalence in E. coli (31.32%) followed by Proteus mirabilis. (21.6%), Pseudomonas aeruginosa (21.2%) and least among Klebsiella pneumoniae. (14.3%). Most of carbapenemase producers produce MBL type. Urine samples were found to be with the highest prevalence of 38.3% when compared with ear swab (12.0%). Prevalence of 67.9% and 76.9% were recorded for Murtala Muhammad specialist hospital Kano and Al-madina hospital Kaduna respectively. This showed that carbapenemase-mediated resistance occurred in the selected hospitals and uncontrolled spread may lead to treatment failure and frustration.Keywords: Metallobetalactamase, Carbapenemase, Enterobacteriaceae, prevalence, Hospita

Statistical Modeling and Optimization of Biodiesel Production from Azadirachta Indica (Neem) Using Co-Solvent Technique

In this work, statistical modeling and optimization of biodiesel production from Azadirachta Indica(neem) using co-solvent technique via a two-step transesterification process was carried out. Neem oil was extracted from neem seeds and properties such as moisture content, specific gravity, acid value, saponification value and iodine value were determined. The experimental design used was Central Composite Design. The range of factor levels used for the Central Composite Design were reaction temperature (30°C to 46°C), catalyst amount (0.8% to 1.2%, w/w), reaction time (20 to 40min) and methanol-to-oil molar ratio (5:1 to 9:1). The co-solvents used were methanol and diethyl ether. The co-solvent-to-methanol volume ratio for all the experimental runs was kept constant at 1:1. Also the biodiesel produced was characterized for some important properties including acid value, specific gravity, saponification value, iodine value, cetane number, ester value, kinematic viscosity, flash point, pour point and cloud point. Optimized biodiesel yield of 84.77% was obtained for reaction time of 35 min, catalyst amount of 1.10g, reaction temperature of 34°C, and oil-to-methanol molar ratio of 6:1. The cetane number (51.733), specific gravity (0.8881g/cm3), flash point (134oC) and kinematic viscosity (5.86mm2/s) of the produced biodiesel met the ASTM specifications. The results of characterization of the biodiesel revealed that biodiesel can be produced at lower reaction conditions and with comparable fuel property with biodiesel produced using conventional methods

Soil hydraulic properties: influence of tillage and cover crops

Understanding the effects of cover crops and tillage on soil physical properties is important for determining soil productivity. This study was conducted at Lincoln University's Freeman Center, USA to evaluate the effects of tillage and cover crop management on soil hydraulic properties. The field site included three replicate blocks in a randomized complete block design with each plot measuring 21.3 m in length and 12.2 m in width. Treatment factors were tillage at two levels (moldboard plow tillage vs. no tillage) and cover crop at two levels (cereal rye (Secale cereal) cover crop vs. no cover crop). Soil samples were collected in late spring/early summer from each treatment at 10-cm depth increments from the soil surface to a depth of 40 cm using cores (76.2-mm diameter and 76.2-mm length). Soil bulk density was 13% lower with tillage compared with no-tillage. Volumetric water content was significantly higher at 0.0 and −0.4 kPa pressures with tillage compared with no tillage. Tillage increased the proportion of coarse mesopores by 32% compared with no tillage, resulting in 87% higher saturated hydraulic conductivity (Ksat). Cover crop increased the proportion of macropores by 24% compared with no cover crop; this can potentially increase water infiltration and reduce runoff. As a result of higher macroporosity, Ksat was higher under cover crop compared with no cover crop. This study demonstrated that tillage can benefit soil hydraulic properties in the short term, but these effects may not persist over time. Cover crops may slightly improve soil hydraulic properties, but longer term studies are needed to evaluate the long-term effects

Soil thermal properties affected by topsoil thickness in switchgrass and row crop management systems

Perennial systems, such as switchgrass have been shown to improve soil hydraulic properties on degraded soils relative to annual cropping systems; however, studies of the effects on thermal properties are limited. Therefore, the objectives of this study were to determine the effects of topsoil thickness on soil thermal properties under switchgrass (Panicum virgatum L.) and row crop production systems. The experiment was carried out at the University of Missouri South Farm Research Center (38°54′ N, 92°16′ W). Research plots were re-established in 2009 with selected topsoil thickness categorized into two treatments (shallow [4 cm] and deep [36 cm]) on a Mexico silt loam (Vertic Epiaqualfs). Plots were planted to either switchgrass or a corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation with four replicates. Undisturbed soil cores (7.6 by 7.6 cm) and bulk soil were collected from two depths (10 cm increments) to determine thermal properties. Thermal conductivity (λ), vo-lumetric heat capacity (C v), and thermal diffusivity (D) were measured at 0, −33, −100 and − 300 kPa soil water pressures. In addition, soil organic carbon (SOC), bulk density (D b) and water content (θ) were also determined. The results showed that the switchgrass treatment had 23% higher SOC, 5-8% greater θ, and 11% lower D b than the row crop treatment. In turn, switchgrass plot exhibited a 5-7% reduction in λ, an 8-9% reduction in D, and a 2-3% increase in C v. Shallow topsoil thickness demonstrated increased thermal properties (λ, D and C v) relative to the deep topsoil thickness, likely due to higher clay content in the surface soil horizon and associated higher θ. This study contributes to a better understanding of the impact of topsoil loss and perennial vegetation on the thermal properties of soils in degraded landscapes

Soil thermal properties influenced by perennial biofuel and cover crop management

Heat transport is an important factor that can influence the soil environment. The objective of this study was to determine if perennial biofuel and cover crops could alter soil thermal properties. Experimental treatments included two levels of cover crops (cover crops [CC] vs. no cover crops) [NC], collectively called row crops (RC), and two biofuel crop treatments. Cover crops used included cereal rye (Secale cereale L.), hairy vetch (Vicia villosa subsp. villosa), and Austrian winter pea [Pisum sativum subsp. arvense (L.) Asch. & Graebn]. The two biofuel treatments included perennial biofuel crops (PB): giant miscanthus (Miscanthus × giganteus J.M. Greef & Deuter ex Hodkinson & Renvoize) and switchgrass (Panicum virgatum L.). Soil samples were collected at 10-cm depth increments from the soil surface to a depth of 30 cm. Soil thermal properties (thermal conductivity [λ], volumetric heat capacity [CV], thermal diffusivity [D]), and volumetric water content (θ) were determined at 0, -33, -100 and -300 kPa soil water matric potentials. Additionally, bulk density and soil organic C (SOC) were determined. Results showed that PB had 11% higher CV at saturation, probably because they had significantly higher θ and SOC than RC management. Cover crops had 13% higher CV at saturation probably because they had significantly higher θ and SOC than no cover crop management. Row crops had significantly higher λ and D than PB. The results from the current study imply that CC and PB can change soil thermal properties by reducing λ and D and increasing CV under laboratory conditions

Soil water infiltration affected by topsoil thickness in row crop and switchgrass production systems

Conversion of annual grain crop systems to biofuel production systems can restore soil hydrologic function; however, information on these effects is limited. Hence, the objective of this study was to evaluate the influence of topsoil thickness on water infiltration in claypan soils for grain and switchgrass (Panicum virgatum L.) production systems. The experiment was performed at the University of Missouri South Farm (38°54′N, 92°16′W) on a Mexico silt loam (Vertic Luvisols) soil. Since 2009, plots were planted with either switchgrass or a corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation. Infiltration rates were measured using ponded infiltrometers during two years (2014 and 2015) under switchgrass and grain crop management each with two levels of topsoil thickness (0 and 37.5 cm). Physically-based Parlange and Green-Ampt infiltration models were used to estimate saturated hydraulic conductivity (Ks) and sorptivity (S) parameters. Switchgrass planted on degraded soil (shallow topsoil treatment) resulted in greater Ks, S, qs (quasi-steady infiltration rate) and Kfs (field-saturated hydraulic conductivity) values than with row crop management for both 2014 and 2015 measurement years. Results for selected 24-hour mean frequency (11.8, 14.2, and 16.2 cm) storms showed that switchgrass production systems enhanced estimated water infiltration, reduced estimated runoff, and decreased estimated time from water ponding to end of ponding compared with row crop management. Switchgrass is recommended to be planted on degraded soils especially in claypan landscapes for improved water use

DNA Aptamers against the Lup an 1 Food Allergen

Using in vitro selection, high affinity DNA aptamers to the food allergen Lup an 1, ß-conglutin, were selected from a pool of DNA, 93 bases in length, containing a randomised sequence of 49 bases. ß-conglutin was purified from lupin flour and chemically crosslinked to carboxylated magnetic beads. Peptide mass fingerprinting was used to confirm the presence of the ß-conglutin. Single stranded DNA was generated from the randomised pool using T7 Gene 6 Exonuclease and was subsequently incubated with the magnetic beads and the captured DNA was released and amplified prior to a further round of Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Evolution was monitored using enzyme linked oligonucleotide assay and surface plasmon resonance. Once a plateau in evolution was reached, the isolated DNA sequences were cloned and sequenced. The consensus motif was identified via alignment of the sequences and the affinities of these sequences for immobilised ß-conglutin were determined using surface plasmon resonance. The selected aptamer was demonstrated to be highly specific, showing no cross-reactivity with other flour ingredients or with other conglutin fractions of lupin. The secondary structures of the selected aptamers were predicted using m-fold. Finally, the functionality of the selected aptamers was demonstrated using a competitive assay for the quantitative detection of ß-conglutin. . Future work will focus on structure elucidation and truncation of the selected sequences to generate a smaller aptamer for application to the analysis of the Lup an 1 allergen in foodstuffs