Food animals as reservoirs and potential sources of multidrug-resistant diarrheagenic E. coli pathotypes: Focus on intensive pig farming in South Africa

BackgroundDiarrheagenic E. coli (DEC) strains are a major cause of diarrheal diseases in both developed and developing countries. Healthy asymptomatic animals may be reservoirs of zoonotic DEC, which may enter the food chain via the weak points in hygiene practices.AimWe investigated the prevalence of DEC along the pig production continuum from farm-to-fork.MethodsA total of 417 samples were collected from specific points along the pig production system, that is, farm, transport, abattoir and food. E. coli was isolated and enumerated using Colilert. Ten isolates from each Quanti-tray were selected randomly and phenotypically identified using eosin methylene blue agar selective media. Real-time polymerase chain reaction (PCR) was used to confirm the species and to classify them into the various diarrheagenic pathotypes. Antimicrobial susceptibility was determined against a panel of 20 antibiotics using the Kirby-Bauer disk diffusion method and EUCAST guideline.ResultsThe final sample size consisted of 1044 isolates, of which 45.40% (474/1044) were DEC and 73% (762/1044) were multidrug-resistant. Enteroinvasive E. coli (EIEC) was the most predominant DEC at all the sampling sites.ConclusionThe presence of DEC in food animal production environments and food of animal origin could serve as reservoirs for transmitting these bacteria to humans, especially in occupationally exposed workers and via food. Adherence to good hygienic practices along the pig production continuum is essential for mitigating the risk of transmission and infection, and ensuring food safety.     

Metabolic Status during Germination of Nano Silica Primed Zea mays Seeds under Salinity Stress

Journal of Crop Science and Biotechnology - Priming is a safe, easy, and effective way to increase plant tolerance against stress. This research aims to study the metabolic status of the...     

Nitrous oxide fluxes and denitrification sensitivity to temperature in Irish pasture soils

Nitrous oxide (N₂O) emissions from grazed pastures constitute approximately 28% of total global anthropogenic N₂O emissions. The aims of this study were to investigate the effect of inorganic N fertilizer application on fluxes of N₂O, quantify the emission factors (EFs) for a sandy loam soil which is typical of large areas in Ireland and to investigate denitrification sensitivity to temperature. Nitrous oxide flux measurements from a cut and grazed pasture field for 1 year and denitrification laboratory incubation were carried out. The soil pH was 7.3 and had a mean organic C and N content at 0–20 cm of 44.1 and 4.4 g/kg dry weight, respectively. The highest observed peaks of N₂O fluxes of 67 and 38.7 g N₂O‐N per hectare per day were associated with times of application of inorganic N fertilizer. Annual fluxes of N₂O from control and fertilized treatments were 1 and 2.4 kg N₂O‐N per hectare, respectively. Approximately 63% of the annual flux was associated with N fertilizer application. Multiple regression analysis revealed that soil nitrate and the interaction between soil nitrate and soil water content were the main factors controlling N₂O flux from the soil. The derived EF of 0.83% was approximately 66% of the IPCC default EF value of 1.25% as used by the Irish EPA to estimate greenhouse gases (GHGs) in Ireland. The IPCC‐revised EF value is 0.9%. A highly significant exponential regression (r² = 0.98) was found between denitrification and incubation temperature. The calculated Q₁₀ ranged from 4.4 to 6.2 for a temperature range of 10–25 °C and the activation energy was 47 kJ/mol. Our results show that denitrification is very sensitive to increasing temperature, suggesting that future global warming could lead to a significant increase in soil denitrification and consequently N₂O fluxes from soils.     

Veneer strand flanged I-beam with MDF or particleboard as web material II: effect of resin type,application rate,strand dimension,and pressing time on the basic properties

Optimization of the manufacturing conditions of the veneer strand flanged I-beam invented in the previous study was investigated using different combinations of strand dimensions, resin types between web and flange, different pressing times, and different wood–resin moisture contents under conventional hot pressing conditions. The main results revealed that the strand dimensions have no effect on the bending properties of the flange part and the dimensional stability of the I-beam. Increasing the resin application rate between strands was found to improve the dimensional stability of the I-beams. The use of isocyanate (MDI) resin between web and flange significantly improved the bond strength between web and flange, the modulus of rupture of the I-beam, and the modulus of rupture of the flange part. Dimensional stability was also improved. Shortening the pressing time from 20 to 12min was found to be feasible. Using low wood-resin moisture content was found to interfere with the curing of the phenol–formaldehyde (PF) resin at the flange part resulting in poor quality beams. Of the three moisture content levels tested, 12% was found to be the optimal level for producing I-beams with balanced mechanical properties and dimensional stability.Part of this work was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003     

The Effect of Season on Spermatozoa Motility,Plasma Membrane and Acrosome Integrity in Fresh and Frozen–Thawed Semen from Xinong Saanen Bucks

The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.     

Selection in Faba Bean for Tolerance to Broomrape, Orobanche crenata Forsk.

Six populations of faba bean (Vicia faba L.) were developed through various selection schemes to examine the influence of selection In improving tolerance to Orobanche crenata (Forsk.) in local faba bean stocks. All populations trace their origin to 209 farmers’ seed lots that were collected from Egypt. The entries of each population were grown during the 1982/1983 season in the Orobanche nursery located at Giza in Egypt. Comparison among means of the selected, populations showed that more progress in improving Orobanche tolerance could be achieved from combined selection between and within lots. Between-lots selection was less efficient than single-plant selection. Results, of this study show that considerable progress could be achieved from selection for Orobanche tolerance in local faba bean germplasm. There was sufficient residual genetic variation in the selected populations to expect substantial progress from further selection for most tolerance traits.     

The Poll Glands of the Dromedary (Camelus dromedarius): Ultrastructural Characteristics

The poll glands of the camel are tubuloalveolar glands. They consist of lobules separated by interlobular connective tissue. Adrenergic axons and blood vessels including fenestrated capillaries are present in the intralobular connective tissue in close proximity to the secretory cells. The prominent features of the secretory cell cytoplasm are many mitochondria, smooth endoplasmic reticulum, and many vesicles in various secretory stages.
It is concluded that the secretory cells have apocrine as well as merocrine modes of secretion. The glands may have the ability to uptake hormones and concentrate them. Additional work is needed before considering these glands as steroid-secreting glands.