Diversity analysis of Tomato leaf curl New Delhi virus-[potato], causing apical leaf curl disease of potato in India

The complete coat protein (cp) gene sequence of eighty Tomato leaf curl New Delhi virus-[potato] (ToLCNDV-[potato]) isolates collected from eleven states were determined. Phylogenetic analysis based on cp gene grouped the isolates into two major clades (I & II) and they shared 95.9–100.0% identity. The DNA A and DNA B of eight representative isolates (six from clade I and two from clade II) were 2739–2740 and 2692–2694 nts long and shared 94.6–99.4% and 97.2–99.5% homology within the isolates, respectively. Among the eight isolates, the DNA A of two isolates (Clade II), GWA-5 and FAI-19 had 94.6–95.3% sequence identity to other six isolates and formed a sub-clade within the ToLCNDV-[potato] isolates. Similar grouping was also revealed with AC1 and AC4 genes of these eight isolates. The DNA A components shared more than 90.0% identity with the DNA A of ToLCNDV isolates from cucurbitaceous crops, tomato, bhendi, 89.0–90.0% with ToLCNDV-papaya isolates and 70.4–74.0% with other tomato leaf curl viruses. Hence, the begomovirus infecting potatoes are the ToLCNDV isolates, designated as ToLCNDV-[potato]. Whereas, the DNA B components shared 86.6–91.7% identity with ToLCNDV isolates from cucurbits, tomato and bhendi. Evidence for intra-species recombination was detected only in DNA A with a maximum of three events in GWA-5 and FAI-19 isolates. Analysis of cp gene, DNA A, iterons and recombination events clearly indicate that two groups of ToLCNDV-[potato] infects potato in India.     

Bioaccessibility of pro-vitamin A carotenoids is minimally affected by non pro-vitamin a xanthophylls in maize (Zea mays sp.)

The absorption of some carotenoids has been reported to be decreased by coingestion of relatively high concentrations of other carotenoids. It is unclear if such interactions occur among carotenoids during the digestion of plant foods. Current varieties of maize contain limited amounts of the pro-vitamin A (pro-VA) carotenoids beta-carotene (BC) and beta-cryptoxanthin (BCX) and relatively higher levels of their oxygenated metabolites lutein (LUT) and zeaxanthin (ZEA). Here, we examined if LUT and ZEA attenuate the bioaccessibility of pro-VA carotenoids at amounts and ratios present in maize. BC incorporation into bile salt mixed micelles during chemical preparation and during simulated small intestinal digestion of carotenoid-enriched oil was slightly increased when the concentration of LUT was sixfold or more greater than BC. Likewise, the efficiency of BC micellarization was slightly increased during simulated small intestinal digestion of white maize porridge supplemented with oil containing ninefold molar excess of LUT to BC. Mean efficiencies of micellarization of BC, BCX, LUT, and ZEA were 16.7, 27.7, 30.3, and 27.9%, respectively, and independent of the ratio of LUT plus ZEA to pro-VA carotenoids during simulated digestion of maize porridge prepared from flours containing 0.4-11.3 microg/g endogenous pro-VA carotenoids. LUT attenuated uptake of BC by differentiated cultures of Caco-2 human cells from medium-containing micelles in a dose-dependent manner with inhibition reaching 35% when the molar ratio of LUT to BC was 13. Taken together, these results suggest that the bioaccessibility of pro-VA carotenoids in maize is likely to be minimally affected by the relative levels of xanthophylls lacking pro-VA activity present in cultivars of maize.     

Seroprevalence of avian pneumovirus in Minnesota turkeys

Avian pneumovirus (APV) causes respiratory tract infection in turkeys and was first seen in the United States in Colorado in late 1996. In early 1997, the disease was recognized in Minnesota and caused estimated losses of up to 15 million dollars per year. This virus has not been reported in the other turkey producing states. We here report the seroprevalence of APV in Minnesota from August 1998 to July 2002. The average rate of seroprevalence has been 36.3% (range = 14.2%-64.8%). A seasonal bias was observed, with peak incidences in the fall and spring. A higher rate of seropositivity was observed in counties with the highest concentration of turkeys.     

In vitro antibiotic resistance profiles of Ornithobacterium rhinotracheale strains from Minnesota turkeys during 1996-2002

Antimicrobial resistance in nearly all human and animal pathogens is on the increase. In poultry, Ornithobacterium rhinotracheale has been identified as a newly emerging respiratory bacterial pathogen that has caused significant economic losses to the poultry industry. In this study, we examined in vitro antibiotic resistance profiles of 125 isolates of O. rhinotracheale isolated from turkeys in Minnesota during 1996-2002. A majority of isolates was sensitive to clindamycin, erythromycin, spectinomycin, and ampicillin. Resistance against sulfachloropyridiazine decreased from 1996 to 2002, but an increase in resistance was seen against gentamicin, ampicillin, trimethoprim sulfa, and tetracycline. The annual trend slopes for these antibiotics were 7.36%, 3.02%, 2.43%, and 1.95%, respectively. The resistance against penicillin remained constant from year to year with a trend slope of only 0.54% per year. These results emphasize the need for continued monitoring of O. rhinotracheale isolates for antibiotic resistance and establishment of baseline resistance pattern data for this organism. These data can then be used to design and evaluate local epidemiological interventions.     

Evaluation of five different antigens in enzyme-linked immunosorbent assay for the detection of avian pneumovirus antibodies.

Five different antigens were evaluated in enzyme-linked immunosorbent assay (ELISA) tests for the detection of avian pneumovirus (APV) antibodies. Two of the 5 antigens were prepared from recent APV isolates from Minnesota. The 2 older isolates were passage 63 of a strain currently used as a live, attenuated vaccine and a Colorado strain isolated for the first time in the United States and currently used in an ELISA test. The fifth antigen is based on an APV recombinant N-protein. Basic parameters and positive-negative threshold of the assays were established for all 5 antigens on the basis of data obtained by testing 46 known negative and 46 known positive serum samples. Subsequently, 449 field samples were tested by all 5 ELISAs. The optical density difference (ODD) was calculated by subtracting optical density of the sample in the negative antigen well from that in the positive antigen well. In the current ELISA test based on the Colorado strain, an ODD of 0.2 is considered to be the cutoff value to classify samples as negative or positive. In this study, however, use of different cutoffs, based on ODD of negative control plus 3 SD or values estimated from Receiver operating characteristic analysis, was considered to be more appropriate for the various antigens used. Overall person-to-person and day-to-day variability was found to be large for all tests using either ODD or sample to positive ratio to report results. In addition, results suggest that antigenicity of the APV isolates in the United States has not changed between 1997 and 2000.     

Action of praziquantel on calcium transport in Hymenolepis diminuta

Effect of praziquantel on inward and outward Ca++ fluxes was investigated in Hymenolepis diminuta in glucose supplemented balanced electrolyte solution and under conditions of glucose/Mg++ deficiency. The 45Ca++ uptake in freshly isolated worms presented, generally, a biphasic kinetics. This comprised of an initial fast uptake phase, followed by a continued slower influx. The initial fast kinetics showed insensitivity to or slight stimulation by praziquantel depending on its concentration, and such stimulatory action was particularly prominent under Mg++ deficient condition (P less than 0.01). The subsequent slower 45Ca++ uptake was, however, markedly inhibited by the drug under both these conditions (P less than 0.01). Glucose starvation of the worms resulted in abolition of the fast 45Ca++ influx phase and uniform inhibition by the praziquantel without any indication of initial stimulatory effect (P less than 0.01). The extrusion of 45Ca++ from the label preloaded worms was stimulated by praziquantel under all the conditions investigated (P less than 0.01).     

Growth and digestive enzymes of Macrobrachium rosenbergii juveniles: effect of different stocktypes and dietary protein levels under a similar culture environment

A feeding trial was conducted to study the effect of dietary protein (DP) levels on the growth and digestive enzyme activities of different wild stocks of Macrobrachium rosenbergii juveniles. Wild juveniles of M. rosenbergii were collected from the west coast of India, Gujarat (G), Maharashtra (M) and from the east coast of India, Andhra Pradesh (A), and raised in culture ponds of 200 m² at 1 juvenile m^?2. All the animals were tagged individually with Elastomer tags of a particular colour assigned to their respective stock and acclimatized for 7 days before being released into the pond at a ratio of 70:65:65 (A:M:G). Each of the two feeds, the first with 27% DP, termed the suboptimum level (S), and the second 32% DP, termed the optimum level (O), was fed in duplicate ponds at 6% of the body mass for the first 30 days and 4% for the last 30 days. The average weight of stocked prawn, respectively, in O DP and S DP fed ponds was 0.90 ± 0.04 and 1.06 ± 0.08 g for the G stock, 0.80 ± 0.07 and 1.01 ± 0.1 g for the M stock and 3.06 ± 0.13 and 3.10 ± 0.23 g for the A stock. Both the protein level and the stock type had a significant (P<0.05) effect on the weight gain% of the prawn. There was an approximate 95% change in weight gain with a DP change. Similarly, G and M stocks exhibited significantly higher (P<0.05) growth rates of approximately 90% than the A stock, although no difference was noted between the G and the M stocks. However, for protein × stock (interaction) levels, there was no significant difference (P>0.05) among the groups. Although insignificant, the survival rates among the different stocks varied from 56% to 77%. Optimum protein level showed a significant increase (P<0.05) in the specific growth rate (SGR). Feed conversion ratio, feed efficiency ratio, protein efficiency ratio and net protein utilization were not affected either due to DP, stock type or their interaction. The O × A group exhibited the maximum variation in body weight. Digestive enzyme activities were similar in all the groups, but enzymes for phospho‐monoesterase were significantly higher (P<0.05) at O DP. Both the G and the M stock showed a significantly higher (P<0.05) alkaline phosphatase activity while acid phosphatase activity was significantly higher (P<0.05) in the M stock only. Overall, the G and M stocks showed higher growth responses compared with the A stock.     

Fertilization management affects the alkaline phosphatase bacterial community in barley rhizosphere soil

There is increasing interest in good agriculture practices that address the issues of sustainability, reduction in inputs such as fertilizers and pesticides while maintaining crop yield and soil fertility. It is important that soil microbial diversity and function are not impaired by altered agricultural practice. In this study, as indicators of soil quality, the bacterial community structure was evaluated from a long-term field trial managed with conventional and low-input fertilization/pesticide regimes. The low-input plots under study received approximately one fifth less N fertilizer than the conventional-input plots, a maximum of half the recommended application rates of fungicides and pesticides and no externally added P source. A non-culturable approach was taken using polymerase chain reaction–denaturing gradient gel electrophoresis analysis of 16S rRNA and alkaline phosphomonoesterase [phosphatase] (ALP) genes in an attempt to relate bacterial community structure to respective field management regimes. To identify the ALP bacteria in these plots, randomly selected ALP clones were sequenced. The results based on Shannon diversity indices and community structure analysis of ALP genes suggest differences in community diversity and structure under conventional and low-input barley sites in most sampling seasons. We conclude that soil fertilization management affects the ALP bacteria in the barley rhizosphere, while the overall changes in bacterial community in these sites are prominently due to seasonal variation compared to crop or input regimes. The randomly selected ALP sequences identified from these sites were mostly from the Alpha and Gamma classes of Proteobacteria.     

Simulating Runoff from Small Grazed Pasture Watersheds Located at North Appalachian Experimental Watershed in Ohio

Runoff from grazing pasture lands can impact water quality in receiving streams if not well managed. Management consists of conservation practices to reduce runoff and pollutants transport. Simulation models have been effectively used to design and implement these conservation practices. The Agricultural Policy Environmental Extender (APEX), a process-based hydrologic model, was used in this study to simulate the management impacts on surface runoff from three small grazed pasture watersheds located at the North Appalachian Experimental Watersheds near Coshocton, Ohio. Specific objectives of this study were to 1) calibrate the APEX model and test runoff predictions against measured runoff and 2) simulate the long-term impacts of different management scenarios on surface runoff. Results show that the APEX model simulated surface runoff reasonably well with the coefficient of determination (R²) and Nash-Sutcliffe efficiency values varying from 0.49 to 0.72 and from 0.25 to 0.60 for calibration and validation, respectively. After validation, the APEX model was run for 37 yr (1975 ? 2011) for long-term scenarios to analyze the impacts of soil properties and management on surface runoff. Data from this study indicated that keeping the watershed land use as a hay meadow instead of grazing significantly reduced cumulative runoff by 58 ? 67%. Buffer strips of perennial grasses resulted in decreased simulated runoff. To simulate the impacts of soils on runoff, the surface (0 ? 5 cm) soil properties of the toe position were applied to the entire grazed watershed. Subsequently, the increase in soil richness resulted in reduction (≤ 5%) in surface runoff. The simulation results from the present study demonstrate the benefits of hayed meadow over grazed pasture and further predict the decreased trend of runoff due to soil properties change and buffer strips.