Successful Biodegradation of a Refractory Pharmaceutical Compound by an Indigenous Phenol-Tolerant <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> Strain

This study provides an alternative solution for the bioremediation of a recalcitrant pharmaceutical micropollutant. Clofibric acid (CLA) was chosen as target molecule, because of its environmental persistence and resistance to wastewater treatment technologies. The aim of this study was to investigate the potential of a phenol-resistant Pseudomonas aeruginosa strain isolated from the activated sludge to degrade CLA. In order to evaluate the effect of acclimation process with glucose as carbon co-substrate, two protocols were performed, in which the transfer of the inoculum is carried out either in the exponential growth phase or in the decline phase. The results showed a removal efficiency of CLA of 35% when cells in the decline phase were used for inoculation. In contrast, a very low removal yield (10%) was achieved when cells harvested in the exponential phase were used as inoculum. This work is the first one reporting on the capability of this bacterium to remove this drug. The obtained data showed that the isolated strain is able to degrade target molecule and might be a promising agent for the elimination of this refractory compound.     

Soil moisture index improves models of forage production in central Iran

This study is focused on the relative importance of bioclimatic variables and soil moisture index (SMI) for predicting forage production in Central Iran rangelands. We used a dataset of 93 forage production collected from 16 rangeland sites during 8 years in Isfahan province. Climatic and topographic variables were obtained using a digital elevation model and geographical information system. SMI is derived using a triangle space concept between the land surface temperature and normalized difference vegetation index from MODIS satellite data over Isfahan province. Using Nonparametric Multiplicative Regression model, we produced two distinct models to predict forage production, the first model with climatic and topographic variables (reduced model) and the second model with climatic, topographic and SMI variables (complete model). The inclusion of SMI significantly improved the quality of forage production predictions within the study area. The forage production is predicted to vary from 41.4 to 474 kg ha^?1 in first model and 20.5 to 485 kg ha^?1 in second model. We anticipated that using SMI would improve standing crop estimates relative to using bioclimatic variables. The cross-validated R² (×R²) increased from 57% to 63% when SMI is added to NPMR model.     

Antimicrobial and cellular activity of poly(L-lactide)/chitosan/Imipenem antibiotic composite nanofibers

Synthesis of biocompatible polymer nanofibers is valuable, due to their use as a cover for burns and as a replacement for bandage because of their antimicrobial properties. In this study, electrospinning of chitosan(Ch) and nanofibers synthesis with antibacterial properties was investigated. Nanofibers with antibacterial properties were synthesized by electrospun of Ch/poly(L-lactide)(PLA)/Imipenem(Imi) polymer solution. The results showed that the optimized ratio of Ch/PLA polymer solution was ratio of 50:50 and Ch 2 wt% and PLA 10 wt% polymer solution was the best weight percentage for nanofiber preparation. Also, the average diameter of Ch/PLA/Imi nanofibers was 143 nm and measured with ImageJ software. Afterwards, the antibacterial properties of Imi as additives (with different percentages) was studied in the polymer solution. The scanning electron microscopy (SEM) images and antibacterial tests were showed that the electrospun of Ch/PLA/Imi polymeric nanofibers were effective against Gram negative bacteria Escherichia coli (E. coli) and inhibited growth of E. coli. The growth and viability percentage of fibroblast cells with nanofibers in αMEM culture are at desirable levels after 6 days.     

Isolation and characterisation of equine influenza viruses (H3N8) from Europe and North America from 2008 to 2009

Like other influenza A viruses, equine influenza virus undergoes antigenic drift. It is therefore essential that surveillance is carried out to ensure that recommended strains for inclusion in vaccines are kept up to date. Here we report antigenic and genetic characterisation carried out on equine influenza virus strains isolated in North America and Europe over a 2-year period from 2008 to 2009. Nasopharyngeal swabs were taken from equines showing acute clinical signs and submitted to diagnostic laboratories for testing and virus isolation in eggs. The sequence of the HA1 portion of the viral haemagglutinin was determined for each strain. Where possible, sequence was determined directly from swab material as well as from virus isolated in eggs. In Europe, 20 viruses were isolated from 15 sporadic outbreaks and 5 viruses were isolated from North America. All of the European and North American viruses were characterised as members of the Florida sublineage, with similarity to A/eq/Lincolnshire/1/07 (clade 1) or A/eq/Richmond/1/07 (clade 2). Antigenic characterisation by haemagglutination inhibition assay indicated that the two clades could be readily distinguished and there were also at least seven amino acid differences between them. The selection of vaccine strains for 2010 by the expert surveillance panel have taken these differences into account and it is now recommended that representatives of both Florida clade 1 and clade 2 are included in vaccines.     

Model organic compounds differ in their effects on pH changes of two soils differing in initial pH

The mechanisms by which organic materials affect soil pH are not fully understood. This study for the first time compared the short-term effect of various model organic compounds on pH change of two soils differing in initial pH (Podosol of pH 4.4 and Tenosol of pH 6.1). Eight organic compounds, representing common compounds in plant residues, were selected based on the number and type of chemical functional groups. The addition of organic acids (acetic, malic, citric, and benzoic acid) reduced soil pH immediately due to H⁺ dissociation. The magnitude of pH decrease depended on the rate of application, degree of dissociation of the acids, and initial soil pH. During a subsequent incubation, pH was slowly restored as these compounds were decomposed. The degree to which pH was restored was reduced with increasing addition rate. The production of H⁺ ions was increased with increasing rate of acid addition and decreased over time. When potassium citrate (organic anion) was added, soil pH increased due to H⁺ consumption upon decomposition. Compounds with amine groups (glucosamine hydrochloride) and less easily decomposable compounds (phenol) did not significantly alter pH during 16-day shaking. Changes in pH after glucose addition were relatively small compared with other compounds and were not expected because hydroxyl chemical groups of glucose are neutral. The present study demonstrated that the addition of model organic compounds to soil caused soil pH to increase, decrease, or remains unaffected. The extent and direction of pH change was dependent on the chemical functional group, addition rate, decomposition, and the initial soil pH.     

In situ quantification of CH<Subscript>4</Subscript> bubbling events from a peat soil using a new infrared laser spectrometer

Purpose  

CH₄ emissions from peatlands are space and time dependent. The variety of efflux routes contributes to these variabilities. CH₄ bubbling remains difficult to investigate since it occurs on a timescale of seconds. The aims of this study were to use for the first time the recently built infrared high-resolution spectrometer, SPectrometre Infra-Rouge In situ Troposphérique to (1) measure in situ CH₄ fluxes in natural and artificial peatland plot and (2) observe online bubbling events with quantification of CH₄ emission fluxes corresponding to this very sudden degassing event.     

Synthesis of a combinatorial library of amides and its evaluation against the fall armyworm, Spodoptera frugiperda

The fall armyworm Spodoptera frugiperda is a polyphagous pest that causes important damage in different regions of America and mainly affects corn crops in both tropical and subtropical areas. Currently, control relies on both transgenic plants and/or chemical pesticides. In this work we describe the preparation of an indexed combinatorial library of amides and its toxic effect by contact against S. frugiperda . (E)-1-(1-Piperidinyl)-3-[4-(trifluoromethoxy)phenyl]-2-propen-1-one was the most active compound with an LD(50) = 0.793 μg mg(-1) of larva. This amide was also evaluated by ingestion and at the lowest concentration (1 mg kg(-1)) achieved 83.3% mortality.     

Animal rabies situation in Sultanate of Oman (2017–2019)

Successful preventive and control measures of zoonotic diseases require updated epidemiological data. Sylvatic rabies is endemic in Oman since 1990. Studying of the prevalence of animal rabies in Oman (2017–2019) was the goal of the current study besides the clinical–histopathological investigations of rabies in different animal species. A total of 117 whole brains of different animal species from different regions of Oman were examined by fluorescent antibody test (FAT) and histopathology for rabies during 2017–2019. Sixty-four samples (54.7%) were positive for rabies by FAT. The most affected species were goat (53.1%) followed by camel (18.8%), which pose a great risk to farmers and veterinarians. Positive fox cases were (10.9%). Most confirmed cases of animal rabies were submitted from Northern regions of Oman. Rabies was reported recently in Al Wusta among wild ruminants, Central Oman. The seasonal cycle of animal rabies in Oman was year-round with the peak from December to April. The clinical signs and neuropathological findings were nearly similar in different animal species. Histopathology-positive cases had Negri bodies in pyramidal and purkinje neurons, non-suppurative encephalitis features, and neuronal degeneration and necrosis. The sensitivity and specificity of histopathological diagnosis of rabies in different animals were 76.47% and 100.00%, respectively. Finally, sylvatic rabies remains a major challenge to the public and animal health in Oman. Although of the value of histopathological diagnosis of rabies if no other technique is available, other complementary tests must be employed to confirm negative results.