Demographic and environmental risk factors for infection by Theileria equi in 590 horses in Israel

The prevalence of Theileria equi infection as well as the environmental and demographic risk factors for infection was studied in 590 healthy horses from 46 farms in Israel. The prevalence of T. equi DNA was assessed using a polymerase chain reaction for a segment of the Theileria 18S rRNA gene. The overall prevalence was 26.4% (156/590). There was a significant geographical variation in the prevalence of T. equi infection, ranging from 9.3% (25/270) in the central lowlands to 81.7% (49/60) in the Golan Heights. The prevalence of T. equi infection was found to be significantly associated with management types with more horses with access to pasture being positive. Breed was identified as a risk factor for T. equi infection in a univariate analysis with relatively high infection rates in the Quarter horse and local breeds (41.1% and 36.3% respectively), while ponies and Arabian horses had a relatively low prevalence (10% and 9.1%, respectively). However, since a correlation between geographic location and breed was found, it is difficult to draw definite conclusions regarding this risk factor. Age and gender were not found as risk factors for T. equi infection in this study. The environmental variables that were significantly associated with positivity were relative humidity and minimum land surface temperature at day which both showed negative correlation with T. equi prevalence. In conclusion, Israel was found to be enzootic for T. equi infection, as indicated by the high sub-clinical infection rate, which differed between geographical areas.     

The prevalence of Middle East respiratory syndrome coronavirus (MERS‐CoV) antibodies in dromedary camels in Israel

Middle East respiratory syndrome coronavirus, MERS‐CoV, was identified in Saudi Arabia in 2012, and as of January 29, 2018, there were 2,123 laboratory‐confirmed MERS‐CoV cases reported to WHO (WHO, 2018, https://www.who.int/emergencies/mers-cov/en/ ). Multiple studies suggest that dromedary camels are a source for human MERS‐CoV infection. MERS‐CoV‐specific antibodies have been detected in the serum of dromedary camels across Northern Africa and across the Arabian Peninsula. Israel's geographic location places Israel at risk for MERS‐CoV infection. To date, MERS‐CoV‐related illness has not been reported and the burden of MERS‐CoV infection in the Israeli population is unknown. The seroprevalence of MERS‐CoV‐specific antibodies in Israeli dromedary camels is unknown. The objective of this study was to determine the prevalence of MERS‐CoV seropositivity in dromedary camels in Israel. The prevalence of MERS‐CoV antibodies in Israeli camels was examined in 71 camel sera collected from four farms across Israel by MERS‐CoV‐specific microneutralization (Mnt) assay and confirmed by MERS‐CoV‐specific immunofluorescence assay (IFA). Although this study cannot rule out potential antibody cross‐reactivity by IFA, the presence of bovine coronavirus‐specific antibodies do not appear to impact detection of MERS‐CoV antibodies by Mnt. MERS‐CoV neutralizing antibodies were detectable in 51 (71.8%) camel sera, and no association was observed between the presence of neutralizing antibodies and camel age or gender. These findings extend the known range of MERS‐CoV circulation in Middle Eastern camels. The high rate of MERS‐CoV‐specific antibody seropositivity in dromedary camels in the absence of any reported human MERS cases suggests that there is still much to be learned about the dynamics of camel‐to‐human transmission of MERS‐CoV.     

Circulation of bovine ephemeral fever in the Middle East--strong evidence for transmission by winds and animal transport

Bovine ephemeral fever virus (BEFV) is an economically important arbovirus of cattle. The main routes of its transmission between countries and continents are not completely elucidated. This study aimed to explore BEFV transmission in the Middle-East. A phylogenetic analysis was performed on the gene encoding the G protein of BEFV isolates from Israel from 2000 and 2008 with isolates from Turkey (2008), Egypt (2005), Australia (1968-1998) and East Asia (1966-2004). Calf sera collected during the years 2006-2007 were tested by serum neutralization in order to explore for recent exposure to BEFV before 2008. These were followed by a meteorological analysis, aimed to reveal movement of air parcels into Israel in the two weeks preceding the first case of BEF in Israel in 2008. The 2008 Israeli and Turkish isolates showed 99% identity and formed a new cluster with the 2000 Israeli isolate. The serological survey showed no new exposure to BEFV during 2006 and 2007. These results coincided with the meteorological analysis, which revealed that air parcels originating in Southern Turkey had reached the location of outbreak onset in Israel nine days before the discovery of the index case. The Egyptian isolate clustered phylogenetically with the Taiwanese isolates, coinciding with data on importation of cattle from China to the Middle East in the year preceding the isolation of the Egyptian isolates. These results suggest that both winds and animal transport may have an important role in trans-boundary transmission of BEFV.     

Effect of the nitrification inhibitor nitrapyrin on the fate of nitrogen applied to a soil incubated under laboratory conditions

The aim of this study was to examine the effect of the nitrification inhibitor nitrapyrin on the fate and recovery of fertilizer nitrogen (N) and on N mineralization from soil organic sources. Intact soil cores were collected from a grassland field. Diammonium phosphate (DAP) and urea were applied as N sources. Cores were equilibrated at –5 kPa matric potential and incubated at 20 °C for 42 to 56 days. Changes in NH₄⁺‐N, accumulation of NO₃^–‐N, apparent recovery of applied N, and emission of N₂O (acetylene was used to block N₂O reductase) were examined during the study. A significant increase in NH₄⁺‐N released through mineralization was recorded when nitrapyrin was added to the control soil without N fertilizer application. In the soils to which N was added either as urea or DAP, 50–90 % of the applied N disappeared from the NH₄⁺‐N pool. Some of this N (8–16 %) accumulated as NO₃^–‐N, while a small proportion of N (1 %) escaped as N₂O. Addition of nitrapyrin resulted in a decrease and delay of NH₄⁺‐N disappearance, accumulation of much lower soil NO₃^–‐N contents, a substantial reduction in N₂O emissions, and a 30–40 % increase in the apparent recovery of added N. The study indicates that N recovery can be increased by using the nitrification inhibitor nitrapyrin in grassland soils at moisture condition close to field capacity.     

Stability of isoflavones in soy milk stored at elevated and ambient temperatures

Soy isoflavones are widely recognized for their potential health benefits. The increased use of traditional and new food products calls for the assessment of their stability during processing and storage. The present study examines the stability of genistein and daidzein derivatives in soy milk. Soy milk was stored at ambient and elevated temperatures, and the change in isoflavone concentration was monitored with time. Genistin loss in time showed typical first-order kinetics, with rate constants ranging from 0.437-3.871 to 61-109 days(-1) in the temperature ranges of 15-37 and 70-90 degrees C, respectively. The temperature dependence of genistin loss followed the Arrhenius relation with activation energies of 7.2 kcal/mol at ambient temperatures and 17.6 kcal/mol at elevated temperatures. At early stages of soy milk storage at 80 and 90 degrees C, the 6' '-O-acetyldaidzin concentration increased, followed by a slow decrease. The results obtained in this study can serve as a basis for estimating the shelf life of soy milk as related to its genistin content.     

Performance of Pseudomonas spp. containing ACC-deaminase for improving growth and yield of maize (Zea mays L.) in the presence of nitrogenous fertilizer

Some plant-growth-promoting rhizobacteria (PGPR) promote plant growth by lowering the endogenous ethylene synthesis in the roots through their 1-aminocylopropane-1-carboxylate (ACC)-deaminase activity. However, in the vicinity of the roots may decrease the efficiency of these PGPR by stimulating ACC-oxidase activity resulting in greater ethylene production by the roots. This study was designed to assess the performance of PGPR containing ACC-deaminase for improving growth and yield of maize grown in N-amended soil. Several strains of rhizobacteria containing ACC-deaminase were screened for their growth-promoting activity in maize roots under gnotobiotic conditions. Six strains were selected and their effectiveness in soil amended with N at a concentration of 175 kg ha⁻¹ (1050 mg pot⁻¹) was investigated by conducting a pot trial on maize. Significant increases in plant height, root weight and total biomass were observed in response to inoculation. Based upon the results of pot trials, the three most efficient strains were selected and tested in the field for their effectiveness in the presence and absence of N fertilizer. Results of the field trial revealed that the inoculum performed relatively better in the absence of N-fertilizer application. Pseudomonas fluorescens biotype G (N₃) was the most effective strain both in the presence and absence of N fertilizer. Results may imply that even in the presence of optimum levels of nitrogenous fertilizers, inoculation with rhizobacteria containing ACC-deaminase activity could be effective to improve the growth and yield of inoculated plants.     

High specific activity in low microbial biomass soils across a no-till evapotranspiration gradient in Colorado

The need to identify microbial community parameters that predict microbial activity is becoming more urgent, due to the desire to manage microbial communities for ecosystem services as well as the desire to incorporate microbial community parameters within ecosystem models. In dryland agroecosystems, microbial biomass C (MBC) can be increased by adopting alternative management strategies that increase crop residue retention, nutrient reserves, improve soil structure and result in greater water retention. Changes in MBC could subsequently affect microbial activities related to decomposition, C stabilization and sequestration. We hypothesized that MBC and potential microbial activities that broadly relate to decomposition (basal and substrate-induced respiration, N mineralization, and β-glucosidase and arylsulfatase enzyme activities) would be similarly affected by no-till, dryland winter wheat rotations distributed along a potential evapotranspiration (PET) gradient in eastern Colorado. Microbial biomass was smaller in March 2004 than in November 2003 (417 vs. 231 μg g⁻¹ soil), and consistently smaller in soils from the high PET soil (191 μg g⁻¹) than in the medium and low PET soils (379 and 398 μg g⁻¹, respectively). Among treatments, MBC was largest under perennial grass (398 μg g⁻¹). Potential microbial activities did not consistently follow the same trends as MBC, and the only activities significantly correlated with MBC were β-glucosidase (r = 0.61) and substrate-induced respiration (r = 0.27). In contrast to MBC, specific microbial activities (expressed on a per MBC basis) were greatest in the high PET soils. Specific but not total activities were correlated with microbial community structure, which was determined in a previous study. High specific activity in low biomass, high PET soils may be due to higher microbial maintenance requirements, as well as to the unique microbial community structure (lower bacterial-to-fungal fatty acid ratio and lower 17:0 cy-to-16:1ω7c stress ratio) associated with these soils. In conclusion, microbial biomass should not be utilized as the sole predictor of microbial activity when comparing soils with different community structures and levels of physiological stress, due to the influence of these factors on specific activity.     

Plant density and nitrogen effects on growth dynamics,light interception and yield of maize

Maize (Zea mays L.) growth and yield are most sensitive to variations in plant density and nitrogen (N) in north-western Pakistan. This study was conducted on the Agricultural Research Farm of NWFP (North West Frontier Province) Agricultural University, Peshawar, from 2002–2004 to establish an accurate plant density and N management system aimed at high yield of maize. The 2 × 3 × 6 factorial experiment was designed having two plant densities (P1 = 60,000 and P2 = 100,000 plants ha^?1) and three nitrogen rates (N1 = 60, N2 = 120 and N3 = 180 kg N ha^?1) applied to the main plots, while six split application for N in different proportions were applied to subplots at different growth stages of maize in two equal (S1), three equal (S2), three unequal (S3), four equal (S4), five equal (S5) and five unequal splits (S6) at sowing and with 1st, 2nd, 3rd and 4th irrigation at two-week intervals. Growth rate and yield increased with elevated dose and number of N split applications. Improved endurance to high stands allowed maize to intercept and use solar radiation more efficiently, contributing to the remarkable increase in the crop growth rate and yield.     

Comparative effectiveness of Pseudomonas and Serratia sp. containing ACC-deaminase for coinoculation with Rhizobium leguminosarum to improve growth, nodulation, and yield of lentil

Three plant growth-promoting rhizobacteria strains containing ACC-deaminase (Pseudomonas jessenii, Pseudomonas fragi, and Serratia fonticola) and Rhizobium leguminosarum were selected and characterized by conducting some experiments under axenic condition. The selected isolates had the potential to improve the growth of lentil seedlings under axenic conditions. Pot and field experiments were conducted to evaluate the potential of these selected strains for improving growth and yield of lentil under natural conditions. A classical triple response (reduction of stem elongation, swelling of hypocotyle, and change in the direction of growth) bioassay was also conducted to evaluate the effect of high ethylene concentration on the growth of etiolated lentil seedlings, and the performance of coinoculation was evaluated to reduce the classical triple response in comparison with cobalt (Co²⁺), a chemical inhibitor of ethylene. Results showed that coinoculation of Pseudomonas and Serratia sp. with R. leguminosarum significantly increased the growth and yield of lentil. However, synergistic/coinoculation effect of P. jessenii with R. leguminosarum was more pronounced compared to that with P. fragi and S. fonticola. It increased the number of pods per plant, number of nodules per plant, dry nodule weight, grain yield, and straw yield up to 76%, 196%, 109%, 150%, and 164% under pot and up to 98%, 98%, 100%, 82%, and 78%, respectively, under field conditions as compared to uninoculated control. Similarly, combined inoculation significantly increased N concentration of grains under both pot and field conditions. The results from classical triple response assay showed that the effects of classical triple response decreased due to coinoculation in etiolated lentil seedlings and due to a decrease in the ethylene concentration. It is suggested that the strategy adopted by Pseudomonas sp. containing ACC-deaminase with Rhizobium to promote nodulation and yield by adjusting ethylene levels could be exploited as an effective tool for improving growth, nodulation, and yield of lentil.