Protection Against Infectious Bronchitis Virus Vaccine Recombinants and Chicken-Selected Vaccine Subpopulations.

Outbreaks of infectious bronchitis (IB) continue to occur from novel variants of IB virus (IBV) emerging from selection of vaccine subpopulations and/or naturally occurring recombination events. S1 sequencing of Arkansas (Ark) -type viruses obtained from clinical cases in Alabama broilers and backyard chickens shows both Ark Delmarva Poultry Industry (ArkDPI) vaccine subpopulations as well as Ark vaccine viruses showing recombination with other IB vaccine viruses. IB Ark-type isolates AL5, most similar to an ArkDPI vaccine subpopulation selected in chickens, AL4, showing a cluster of three nonsynonymous changes from ArkDPI subpopulations selected in chickens, and AL9, showing recombination with Massachusetts (Mass) -type IBV, were examined for pathogenicity and ability to break through immunity elicited by vaccination with a commercial ArkDPI vaccine. Analysis of predicted S1 protein structures indicated the changes were in regions previously shown to comprise neutralizing epitopes. Thus, they were expected to contribute to immune escape and possibly virulence. Based on clinical signs, viral load, and histopathology, all three isolates caused disease in naïve chickens, although AL9 and AL5 viral loads in trachea were statistically significantly higher (30- and 40-fold) than AL4. S1 gene sequencing confirmed the stability of the relevant changes in the inoculated viruses in the chickens, although virus in some individual chickens exhibited additional S1 changes. A single amino acid deletion in the S1 NTD was identified in some individual chickens. The location of this deletion in the predicted structure of S1 suggested the possibility that it was a compensatory change for the reduced ability of AL4 to replicate in the trachea of naïve chickens. Chickens vaccinated with a commercial ArkDPI vaccine at day of hatch and challenged at 21 days of age showed that vaccination provided incomplete protection against challenge with these viruses. Moreover, based on viral RNA copy numbers in trachea, differences were detected in the ability of the vaccine to protect against these IBV isolates, with the vaccine protecting the most poorly against AL4. These results provide additional evidence supporting that IBV attenuated vaccines, especially ArkDPI vaccines, contribute to perpetuating the problem of IB in commercial chickens.

Protección contra los virus de la bronquitis infecciosa vacunales recombinantes y las subpoblaciones de vacunas seleccionadas en pollos. Los brotes de la bronquitis infecciosa aviar continúan presentándose a partir de nuevas variantes de dicho virus, que surgen de la selección de subpoblaciones de vacunas y/o eventos de recombinación que ocurren naturalmente. La secuenciación del gene S1 de virus tipo Arkansas (Ark) obtenidos de casos clínicos en pollos de engorde y de traspatio de Alabama muestra que tanto las subpoblaciones de la cepa vacunal Arkansas Delmarva Poultry Industry (ArkDPI) así como los virus de la vacuna Arkansas muestran recombinación con otros virus vacunales de la bronquitis infecciosa. Los aislamientos del virus de la bronquitis infecciosa Arkansas tipo "AL5", más similares a una subpoblación de vacuna ArkDPI seleccionada en pollos, "AL4", que muestra un grupo de tres cambios no sinónimos de subpoblaciones de ArkDPI seleccionadas en pollos y el tipo "AL9", que muestra recombinación con el serotipo Massachusetts, se examinaron para determinar su patogenicidad y capacidad para traspasar la inmunidad generada por la vacunación con una vacuna comercial ArkDPI. El análisis de las estructuras predichas de la proteína S1 indicó que los cambios se produjeron en regiones que previamente se había demostrado comprendían epítopos neutralizantes. Por lo tanto, se esperaba que contribuyeran al escape inmunológico y posiblemente a la virulencia. Con base en los signos clínicos, la carga viral y la histopatología, los tres aislados causaron enfermedad en pollos sin exposición previa, aunque las cargas virales de AL9 y AL5 en la tráquea fueron estadísticamente significativamente mayores (30 y 40 veces) en comparación con AL4. La secuenciación del gene S1 confirmó la estabilidad de los cambios relevantes en los virus inoculados en los pollos, aunque el virus en algunos pollos individuales exhibió cambios adicionales en el gene S1. Se identificó una deleción de un solo aminoácido en el dominio terminal N del gene S1 (NTD S1) en algunos pollos individuales. La ubicación de esta eliminación en la estructura predicha del gene S1 sugirió la posibilidad de que se tratara de un cambio compensatorio por la capacidad reducida de AL4 para replicarse en la tráquea de pollos sin exposición previa. Los pollos vacunados con una vacuna comercial ArkDPI el día de la eclosión y desafiados a los 21 días de edad mostraron que la vacunación proporcionó una protección incompleta contra el desafío con estos virus. Además, basándose en el número de copias del ARN viral en la tráquea, se detectaron diferencias en la capacidad de la vacuna para proteger contra estos aislados del virus de la bronquitis infecciosa, siendo la vacuna con la protección más deficiente contra AL4. Estos resultados proporcionan evidencia adicional que respalda que las vacunas atenuadas contra el virus de la bronquitis infecciosa, especialmente las vacunas ArkDPI, contribuyen a perpetuar esta enfermedad en los pollos comerciales.

Vectorial capacities for malaria in eastern Amazonian Brazil depend on village, vector species, season, and parasite species.

BACKGROUND: The vector species in the Amazon River Basin are regionally and locally diverse, which makes it imperative to understand and compare their roles in malaria transmission to help select appropriate methods of intervention and evaluation. The major aim of this study was to measure the vectorial capacity of five Anopheles species in three neighbouring villages, for two Plasmodium parasite species affecting humans. METHODS: From 32 consecutive months of sampling in three villages, 1.5-7.0 km apart, on the Matapi River, Amapá State, Brazil, vectorial capacities (C) were estimated as time series for An. darlingi, An. marajoara, An. nuneztovari, An. triannulatus, and An. intermedius. Monthly parity measurements for each vector species were used to estimate daily survivorship and compared to estimates of survivorship from mark-release-recapture experiments. Gonotrophic cycle lengths were estimated through a time-series analysis of parity data, and durations of sporogony at study site temperatures for the two malaria parasite species were estimated from previous literature. RESULTS: The absolute abundances of five vector species were strongly tracked by the spatial variation in C among villages. Temporally, C varied between wet and dry seasons, with An. darlingi, An. marajoara and An. triannulatus exhibiting higher C in the dry season from August to December, and An. nuneztovari its highest C early in the rainy season in January and February. Anopheles intermedius exhibited higher C in the rainy season from April to June than in the dry season. Significant differences in overall survival for each independent variable, and a significant difference in C between wet and dry seasons, among villages, and among vector species for both Plasmodium falciparum and Plasmodium vivax. A generalized linear mixed model (GLMM) analysis by village showed significant effects of vector species on C in only one village, but significant effects of parasite species in all three. Although the GLMM analysis detected no significant parasite x vector species interaction effects on C, effects on C of spline regressions of C dynamics x vector species interactions were significant in all villages. CONCLUSIONS: These detailed analyses of entomological and parasitological variables revealed hidden complexities of malaria epidemiology at local scales in neighbouring riverine villages of the Amazon Region.

Supplemental Fumigant Placement Improves Root Knot and Fusarium Wilt Management for Tomatoes Produced on a Raised-Bed Plasticulture System in Florida's Myakka Fine Sand.

Fresh-market tomatoes are produced on a raised-bed plasticulture system that relies heavily on soil-applied preplant fumigants for the management of soilborne pathogens, nematodes, and weeds. Since the transition from methyl bromide to alternative fumigants, growers have experienced a resurgence of several soilborne pests and pathogens, including root-knot nematode caused by Meloidogyne spp. and Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici race 3. This resurgence is attributed to the inability of the alternative fumigants to effectively disperse through the soil in the same manner as methyl bromide. Two supplemental fumigation strategies, the application of chloropicrin (PIC) below bed edges (herein "supplemental PIC") and broadcast deep-shank applications of 1,3-dichloropropene (1,3-D), were evaluated in conjunction with standard raised-bed applications of Pic-Clor 60, Pic-Clor 80, and Pic 100 covered with a virtually impermeable film or a totally impermeable film. Large-plot replicated studies were conducted in two separate commercial tomato fields with a history of production losses caused by root-knot nematode and Fusarium wilt. Deep-shank 1,3-D applications significantly reduced the recovery of root-knot and total parasitic nematodes across field sites before the preparation of raised beds. Both supplemental PIC and deep-shank 1,3-D reduced root-knot galling and Fusarium wilt incidence, but the latter supplemental treatment statistically had the greatest impact. Fumigant applied within raised beds or plastic film had no significant effect on root-knot galling or Fusarium wilt. Although both supplemental fumigation strategies had a significant effect on pest and disease pressure, neither statistically improved tomato yields based on small subplot harvests. Controlled laboratory experiments confirmed the fungicidal activity of 1,3-D against F. oxysporum f. sp. lycopersici, with 75, 90, 95, and 99% lethal doses corresponding to estimated field application rates of 56.1, 93.5, 121.6, and 184.7 liters/ha, respectively. The results demonstrate how fumigant placement can improve pest and disease control activity with current fumigant alternatives to methyl bromide and further support the broader pesticidal activity of some chemical fumigants.

Tracing the Fate of Pollen Substitute Patties in Western Honey Bee (Hymenoptera: Apidae) Colonies.

Commercial beekeepers need healthy, productive honey bee (Apis mellifera L.) colonies, even when the landscape lacks adequate pollen forage to sustain the colonies. As a result, many commercial beekeepers spend significant money and labor on the use of pollen substitutes in their colonies. However, there is little consensus in the literature about the benefits and drawbacks of pollen substitute use on honey bee colony health. In order to understand this critically, it is important to know first how honey bees distribute pollen substitute patties throughout their colonies. We traced the fate of three commercially available pollen substitute patties (MegaBee, UltraBee, AP23) dyed with a nontoxic food coloring (Brilliant Blue FCF) and undyed as negative controls, a dyed positive control (fondant), and a dyed consumption control (Crayola Model Magic Clay) in 44 honey bee colonies. Using spectrophotometry and visual inspection, we analyzed adult bee guts, larval guts, bee bread stores and colony debris underneath the hive for presence of the dye. Our data suggest that (1) a proportion of adult bees ingest the patty, (2) adult bees likely do not feed patty directly to larvae, (3) adult bees do not store patty like bee bread, and (4) only a very small proportion of patty is lost as debris. Collectively our data suggest that honey bee colonies use pollen substitute patties. However, patties likely do not replace the function of natural pollen entirely in terms of larval provisioning and long-term storage as bee bread.

Losses of selected pesticides in drainage water from containerized ornamental plants.

Limited research has focused on factors affecting pesticide losses from ornamental plant production nurseries. This project evaluated the effects of overhead irrigation or simulated rainfall intensity and formulation and application methods on the losses of acephate, bifenthrin, and imidacloprid in drainage water. The liquid formulation of each respective pesticide was applied to individual replicates (potted Ilex cornuta Lindl. & Paxton plant on a drainage collection saucer) as substrate-applied drenches or foliar sprays (acephate and bifenthrin only). Granular formulations of acephate and imidacloprid were spread across the tops of media in pots. After application of treatments, irrigation or simulated rainfall was applied daily for 19 consecutive days at rates of 42.3 ± 4.57, 56.7 ± 7.92, and 95.4 ± 19.47 ml min-1 , and drainage water from individual replicates was collected for analysis. Irrigation or simulated rainfall intensity had no effects on losses of the pesticides under the conditions tested. Concentrations in drainage of all three pesticides were highest from the drench applications, whereas respective foliar spray applications resulted in the lowest active ingredient concentrations in drainage. The percentage of active ingredient lost in drainage water ranged from a minimum of 0.2 ± 0.05% (mean ± SE) for granular acephate to a maximum of 19.5 ± 3.14% (mean ± SE) for the imidacloprid drench. Most pesticide losses occurred within the first 2 d after application of drenches or sprays. Granular formulations had a longer period of release, indicating a risk of loss from overirrigation during an extended period. Results emphasize the need for careful water management after applications.

Radiographic tracheal dimensions in brachycephalic breeds before and after surgical treatment for brachycephalic airway syndrome.

The objective of this retrospective study was to compare preoperative and postoperative tracheal measurements in brachycephalic dogs undergoing surgical treatment of brachycephalic airway syndrome (BAS) using 2 radiographic methods (TD:TI and TT:3R). Medical records of 24 brachycephalic dogs with surgically corrected BAS were reviewed. Represented breeds included English bulldogs (n = 9), French bulldogs (n = 9), pugs (n = 5), and a Japanese chin (n = 1). Dogs with BAS that had postoperative thoracic radiographs ≤ 1 week after surgery showed no significant difference in the mean TD:TI ratios (P = 0.06) or mean TT:3R ratios (P = 0.19) when comparing preoperative to postoperative ratios. Dogs that had postoperative thoracic radiographs > 1 week after surgery showed no significant difference in the mean TD:TI ratios (P = 0.06) or mean TT:3R ratios (P = 0.32) when comparing preoperative to postoperative ratios. According to these findings, surgical correction for BAS does not resolve or improve tracheal hypoplasia in brachycephalic breeds.

L'objectif de cette étude rétrospective était de comparer les mesures trachéales préopératoire et postopératoire chez des chiens brachycéphales soumis à un traitement chirurgical pour le syndrome des voies respiratoires brachycéphales (BAS) en utilisant deux méthodes radiographiques (TD:TI et TT:3R). Les dossiers médicaux de 24 chiens brachycéphales avec un BAS corrigé chirurgicalement furent examinés. Les races représentées incluaient les bulldogs anglais (n = 9), les bulldogs français (n = 9), les carlins (n = 5) et l'épagneul japonais (n = 1). Les chiens avec BAS qui ont eu des radiographies thoraciques postopératoires ≤ 1 semaine après la chirurgie ne montraient aucune différence significative dans les ratios moyens TD:TI (P = 0,06) ou ratios moyens TT:3R (P = 0,19) lors de la comparaison des ratios préopératoire et postopératoire. Les chiens avec BAS qui ont eu des radiographies thoraciques postopératoires > 1 semaine après la chirurgie ne montraient aucune différence significative dans les ratios moyens TD:TI (P = 0,06) ou ratios moyens TT:3R (P = 0,32) lors de la comparaison des ratios préopératoire et postopératoire. En fonction de ces trouvailles, la correction chirurgicale pour le BAS ne résout pas ou n'améliore pas l'hypoplasie trachéale chez les races brachycéphales.(Traduit par Dr Serge Messier).

Comparing four methods of rearing Varroa destructor in vitro.

The parasitic mite Varroa destructor Anderson and Trueman continues to devastate western honey bee (Apis mellifera L.) colonies throughout most of the world where they are managed. The development of a method to rear Varroa in vitro would allow for year-round Varroa research, rapidly advancing our progress towards controlling the mite. We created two separate experiments to address this objective. First, we determined which of four in vitro rearing methods yields the greatest number of Varroa offspring. Second, we attempted to improve the rearing rates achieved with that method. The four methods tested included (1) rearing Varroa on honey bee pupae in gelatin capsules, (2) rearing Varroa on in vitro-reared honey bees, (3) group rearing Varroa on honey bee pupae in Petri dishes, and (4) providing Varroa a bee-derived diet. The number of reproducing females and the number of fully mature offspring were significantly higher in the gelatin capsules maintained at 75% RH than in any other method. A 2 × 3 full factorial design was used to test combinations of gelatin capsule size (6 and 7 mm diameter) and relative humidity (65, 75, or 85%) on Varroa rearing success. Varroa reproduction and survival were significantly higher in 7-mm-diameter gelatin capsules maintained at 75% RH than in those maintained in 6-mm capsules and at the other humidities. By identifying factors that influence Varroa reproductive success in vitro, this work provides an important foundation for the development of future rearing protocols.

Evaluating the Efficacy of Oxalic Acid Vaporization and Brood Interruption in Controlling the Honey Bee Pest Varroa destructor (Acari: Varroidae).

A successful Integrated Pest Management approach to Varroa destructor Anderson and Trueman control in managed colonies of western honey bees Apis mellifera Linnaeus (Hymenoptera: Apidae) must be an improvement over conventional control methods and include cost-effective treatments that can be readily employed by beekeepers. Herein, we tested the efficacy of oxalic acid (OA) vaporization and brood interruption as Varroa controls. Sixty experimental colonies were randomly assigned to one of six treatment groups with 10 colonies per group. The six treatments were: 1) OA applied once, 2) OA applied three times, 3) brood interruption, 4) OA applied once + brood interruption, 5) OA applied three times + brood interruption, and 6) no OA or brood interruption. The OA was applied via vaporization, with each application being 1 g OA applied through the hive entrance (label rate), on the bottom board. Brood interruption was accomplished by caging a colony's queen in a queen cage for a period of 24 d. An additional 10 colonies were treated with amitraz (Apivar - positive control). Varroa levels were estimated before, during, and after treatment applications using sticky boards left in colonies for 3 d. Our data suggest that queen caging to achieve brood interruption during the fall season can negatively impact colony strength and survival. We observed high colony mortality in some treatments, despite diligent colony management to alleviate the side effects of the treatments. Colonies treated with amitraz were healthier and had better survival than those treated with OA vaporization. In conclusion, OA and/or brood interruption did not provide sufficient Varroa control.

Resistance to pH decline and slower calpain-1 autolysis are associated with higher energy availability early postmortem in Bos taurus indicus cattle.

Beef from Bos taurus indicus is associated with toughness compared to Bos taurus taurus, suggesting there is antagonism between adaptability to heat and beef quality. Resistance to cellular stress in muscle may be protective postmortem, thereby delaying its conversion to meat. Therefore, our objective was to determine pH decline, calpain-1 and caspase 3 activation, and proteolysis in different biological cattle types. Angus, Brangus, and Brahman steers (n = 18) were harvested, and Longissimus lumborum were assessed postmortem for pH decline, ATP content, protease activation, and calpastatin content; and myofibrillar protein degradation was evaluated in beef aged to 14d. Brahman Longissimus lumborum exhibited resistance to pH decline, greater ATP content at 1 h, and delayed calpain-1 autolysis. Although content of caspase-3 zymogen was lower in Brahman, there was no evidence of caspase-3 mediated proteolysis. Greater resistance to energetic and pH changes early postmortem in Brahman Longissimus lumborum are associated with calpain-1 autolysis but not mitochondria mediated apoptosis.

Comparing Host Plant Resistance, Repellent Mulches, and At-Plant Insecticides for Management of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) and Tomato Yellow Leaf Curl Virus.

Bemisia tabaci MEAM1 (Gennadius), the sweetpotato whitefly, transmits Tomato yellow leaf curl virus (TYLCV), which causes significant yield losses annually in Florida and other tomato-producing regions. Field trials were carried out at the University of Florida's Gulf Coast Research and Education Center to evaluate integration of plastic mulch type, at-plant insecticide, and tomato variety for management of the sweetpotato whitefly and TYLCV. The tomato varieties Charger, Rally, and Tygress had significantly lower season-long densities of whitefly eggs and nymphs than Florida-47 in one or more trials. Aggressive chemical control measures failed to reduce virus incidence in two of the three trials and did not improve yield. In 2013, when virus pressure was extremely high, yield in the susceptible variety was decimated, but virus-tolerant varieties produced a crop. Egg and nymph densities tended to be lowest on TYLCV-tolerant varieties and on tomato grown on metalized mulch. Differences in yield were primarily due to tomato variety and TYLCV incidence. Intensive insecticide use common in Florida tomato production may reduce losses when viral pressure is moderate, but not when migration of viruliferous whiteflies into the field is constant. Without significant winter freezes or a coordinated host-free period to reduce whitefly populations, insecticidal control and repellent-metalized mulches will offer limited protection compared with genetic tolerance to the virus, which may also be overcome under high virus pressure.

Use of three-dimensional accelerometers to evaluate behavioral changes in cattle experimentally infected with bovine viral diarrhea virus.

OBJECTIVE To assess the use of 3-D accelerometers to evaluate behavioral changes in cattle experimentally infected with a low-virulent strain of bovine viral diarrhea virus (BVDV). ANIMALS 20 beef steers (mean weight, 238 kg). PROCEDURES Calves were allocated to a BVDV (n = 10) or control (10) group. On day 0, calves in the BVDV group were inoculated with a low-virulent strain of BVDV (4 × 10(6) TCID50, intranasally), and calves in the control group were sham inoculated with BVDV-free medium (4 mL; intranasally). An accelerometer was affixed to the right hind limb of each calf on day -7 to record activity (lying, walking, and standing) continuously until 35 days after inoculation. Baseline was defined as days -7 to -1. Blood samples were collected at predetermined times for CBC, serum biochemical analysis, virus isolation, and determination of anti-BVDV antibody titers. RESULTS All calves in the BVDV group developed viremia and anti-BVDV antibodies but developed only subclinical or mild disease. Calves in the control group did not develop viremia or anti-BVDV antibodies. Mean time allocated to each activity did not differ significantly between the BVDV and control groups on any day except day 8, when calves in the BVDV group spent less time standing than the calves in the control group. Following inoculation, calves in both groups tended to spend more time lying and less time walking and standing than they did during baseline. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that behavioral data obtained by accelerometers could not distinguish calves subclinically infected with BVDV from healthy control calves. However, subtle changes in the behavior of the BVDV-infected calves were detected and warrant further investigation.

Efficacy of multivalent, modified- live virus (MLV) vaccines administered to early weaned beef calves subsequently challenged with virulent Bovine viral diarrhea virus type 2.

BACKGROUND: Vaccination of young calves against Bovine viral diarrhea virus (BVDV) is desirable in dairy and beef operations to reduce clinical disease and prevent spread of the virus among cattle. Although protection from clinical disease by multivalent, modified-live virus (MLV) vaccines has been demonstrated, the ability of MLV vaccines to prevent viremia and viral shedding in young calves possessing passive immunity is not known. The purpose of this study was to compare the ability of three different MLV vaccines to prevent clinical disease, viremia, and virus shedding in early weaned beef calves possessing maternal immunity that were vaccinated once at 45 days prior to challenge with virulent BVDV 2. RESULTS: At 45 days following vaccination, calves that received vaccines B and C had significantly higher BVDV 1 and BVDV 2 serum antibody titers compared with control calves. Serum antibody titers for BVDV 1 and BVDV 2 were not significantly different between control calves and calves that received vaccine D. Following BVDV 2 challenge, a higher proportion of control calves and calves that received vaccine D presented viremia and shed virus compared with calves that received vaccines B and C. Rectal temperatures and clinical scores were not significantly different between groups at any time period. Calves that received vaccines B and C had significantly higher mean body weights at BVDV 2 challenge and at the end of the study compared with control calves. CONCLUSIONS: Moderate to low maternally-derived BVDV antibody levels protected all calves against severe clinical disease after challenge with virulent BVDV 2. Vaccines B and C induced a greater antibody response to BVDV 1 and BVDV 2, and resulted in reduced viremia and virus shedding in vaccinated calves after challenge indicating a greater efficacy in preventing virus transmission and reducing negative effects of viremia.

Effect of exercise and environmental terrain on development of the digital cushion and bony structures of the bovine foot.

OBJECTIVE: To determine whether exercise on alternative terrain affects the development of the digital cushion and bony structures of the bovine foot. ANIMALS: 20 weaned bull calves. PROCEDURES: Two-month-old calves were randomly allocated to an exercise or control group. For 4 months, the control group was maintained in grass paddocks, and the exercise group was maintained in a 0.8-km lane with a mixed terrain of dirt, stones (0.32- to 0.95-cm pea gravel and 5-cm crusher run), and grass. Water and food for the exercise group were located at opposite ends of the lane; calves were fed twice daily, which ensured they walked 3.2 km/d. Pedometers were applied to all calves to measure distance traveled. All calves were slaughtered at 6 months of age. The right forefeet and hind feet were harvested for MRI and CT evaluation. RESULTS: Control calves walked a mean of 1.1 km daily, whereas the exercised calves walked a mean of 3.2 km daily. Mean digital cushion volume and surface area were 25,335 mm(3) and 15,647 mm(2), respectively, for the exercised calves and 17,026 mm(3) and 12,745 mm(2), respectively, for the control calves. When weight was controlled, mean digital cushion volume and surface area for the exercise group were increased by 37.10% and 18.25%, respectively, from those for the control group. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that exercise on alternative terrain increased the volume and surface area of the digital cushion of the feet of dairy calves, which should make them less susceptible to lameness.

Varied Growth Response of Cogongrass Ecotypes to Elevated CO2.

Cogongrass [Imperata cylindrica (L.) P. Beauv] is an invasive C4 perennial grass which is listed as one of the top ten worst weeds in the world and is a major problem in the Southeast US. Five cogongrass ecotypes [Florida (FL), Hybrid (HY), Louisiana (LA), Mobile (MB), and North Alabama (NA)] collected across the Southeast and a red-tip (RT) ornamental variety were container grown for 6 months in open top chambers under ambient and elevated (ambient plus 200 ppm) atmospheric CO2. Elevated CO2 increased average dry weight (13%) which is typical for grasses. Elevated CO2 increased height growth and both nitrogen and water use efficiencies, but lowered tissue nitrogen concentration; again, these are typical plant responses to elevated CO2. The HY ecotype tended to exhibit the greatest growth (followed by LA, NA, and FL ecotypes) whiles the RT and MB ecotypes were smallest. Interactions of CO2 with ecotype generally showed that the HY, LA, FL, and/or NA ecotypes showed a positive response to CO2 while the MB and RT ecotypes did not. Cogongrass is a problematic invasive weed in the southeastern U.S. and some ecotypes may become more so as atmospheric CO2 continues to rise.

The bacterial pathogen Xylella fastidiosa affects the leaf ionome of plant hosts during infection.

Xylella fastidiosa is a plant pathogenic bacterium that lives inside the host xylem vessels, where it forms biofilm believed to be responsible for disrupting the passage of water and nutrients. Here, Nicotiana tabacum was infected with X. fastidiosa, and the spatial and temporal changes in the whole-leaf ionome (i.e. the mineral and trace element composition) were measured as the host plant transitioned from healthy to diseased physiological status. The elemental composition of leaves was used as an indicator of the physiological changes in the host at a specific time and relative position during plant development. Bacterial infection was found to cause significant increases in concentrations of calcium prior to the appearance of symptoms and decreases in concentrations of phosphorous after symptoms appeared. Field-collected leaves from multiple varieties of grape, blueberry, and pecan plants grown in different locations over a four-year period in the Southeastern US showed the same alterations in Ca and P. This descriptive ionomics approach characterizes the existence of a mineral element-based response to X. fastidiosa using a model system suitable for further manipulation to uncover additional details of the role of mineral elements during plant-pathogen interactions. This is the first report on the dynamics of changes in the ionome of the host plant throughout the process of infection by a pathogen.

Avian influenza in ovo vaccination with replication defective recombinant adenovirus in chickens: vaccine potency, antibody persistence, and maternal antibody transfer.

Protective immunity against avian influenza (AI) can be elicited in chickens in a single-dose regimen by in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad)-vector encoding the AI virus (AIV) hemagglutinin (HA). We evaluated vaccine potency, antibody persistence, transfer of maternal antibodies (MtAb), and interference between MtAb and active in ovo or mucosal immunization with RCA-free recombinant Ad expressing a codon-optimized AIV H5 HA gene from A/turkey/WI/68 (AdTW68.H5(ck)). Vaccine coverage and intrapotency test repeatability were based on anti-H5 hemagglutination inhibition (HI) antibody levels detected in in ovo vaccinated chickens. Even though egg inoculation of each replicate was performed by individuals with varying expertise and with different vaccine batches, the average vaccine coverage of three replicates was 85%. The intrapotency test repeatability, which considers both positive as well as negative values, varied between 0.69 and 0.71, indicating effective vaccination. Highly pathogenic (HP) AIV challenge of chicken groups vaccinated with increasing vaccine doses showed 90% protection in chickens receiving > or = 10(8) ifu (infectious units)/bird. The protective dose 50% (PD50) was determined to be 10(6.5) ifu. Even vaccinated chickens that did not develop detectable antibody levels were effectively protected against HP AIV challenge. This result is consistent with previous findings ofAd-vector eliciting T lymphocyte responses. Higher vaccine doses significantly reduced viral shedding as determined by AIV RNA concentration in oropharyngeal swabs. Assessment of antibody persistence showed that antibody levels of in ovo immunized chickens continued to increase until 12 wk and started to decline after 18 wk of age. Intramuscular (IM) booster vaccination with the same vaccine at 16 wk of age significantly increased the antibody responses in breeder hens, and these responses were maintained at high levels throughout the experimental period (34 wk of age). AdTW68.H5(ch)-immunized breeder hens effectively transferred MtAb to progeny chickens. The level of MtAb in the progenies was consistent with the levels detected in the breeders, i.e., intramuscularly boosted breeders transferred higher concentrations of antibodies to the offspring. Maternal antibodies declined with time in the progenies and achieved marginal levels by 34 days of age. Chickens with high maternal antibody levels that were vaccinated either in ovo or via mucosal routes (ocular or spray) did not seroconvert. In contrast, chickens without MtAb successfully developed specific antibody levels after either in ovo or mucosal vaccination. These results indicate that high levels of MtAb interfered with active Ad-vectored vaccination.

Natural Migration of Rotylenchulus reniformis In a No-Till Cotton System.

Rotylenchulus reniformis is the most damaging nematode pathogen of cotton in Alabama. It is easily introduced into cotton fields via contaminated equipment and, when present, is difficult and costly to control. A trial to monitor the natural migration of R. reniformis from an initial point of origin was established in 2007 and studied over two growing seasons in both irrigated and non-irrigated no-till cotton production systems. Vermiform females, juveniles and males reached a horizontal distance of 200 cm from the initial inoculation point, and a depth of 91 cm in the first season in both systems. Irrigation had no effect on the migration of vermiform females and juveniles, but males migrated faster in the irrigated trial than in the non-irrigated trial. Population density increased steadily in the irrigated trial during both years, exceeding the economic threshold of 1,000 per 150 cm(3), but was highly correlated with rainfall in the non-irrigated trial. The average speed of migration ranged from 0- to 3.3-cm per day over 150 days. R. reniformis was able to establish in both the irrigated and non-irrigated trials in one season and to increase population density significantly.

Synergistic interactions between Cry1Ac and natural cotton defenses limit survival of Cry1Ac-resistant Helicoverpa zea (Lepidoptera: Noctuidae) on Bt cotton.

Larvae of the bollworm Helicoverpa zea (Boddie) show some tolerance to Bacillus thuringiensis (Bt) Cry1Ac, and can survive on Cry1Ac-expressing Bt cotton, which should increase resistance development concerns. However, field-evolved resistance has not yet been observed. In a previous study, a population of H. zea was selected for stable resistance to Cry1Ac toxin. In the present study, we determined in laboratory bioassays if larvae of the Cry1Ac toxin-resistant H. zea population show higher survival rates on field-cultivated Bt cotton squares (= flower buds) collected prebloom-bloom than susceptible H. zea. Our results show that Cry1Ac toxin-resistant H. zea cannot complete larval development on Cry1Ac-expressing Bt cotton, despite being more than 150-fold resistant to Cry1Ac toxin and able to survive until pupation on Cry1Ac toxin concentrations greater than present in Bt cotton squares. Since mortality observed for Cry1Ac-resistant H. zea on Bt cotton was higher than expected, we investigated whether Cry1Ac interacts with gossypol and or other compounds offered with cotton powder in artificial diet. Diet incorporation bioassays were conducted with Cry1Ac toxin alone, and with gossypol and 4% cotton powder in the presence and absence of Cry1Ac. Cry1Ac toxin was significantly more lethal to susceptible H. zea than to resistant H. zea, but no difference in susceptibility to gossypol was observed between strains. However, combinations of Cry1Ac with gossypol or cotton powder were synergistic against resistant, but not against susceptible H. zea. Gossypol concentrations in individual larvae showed no significant differences between insect strains, or between larvae fed gossypol alone vs. those fed gossypol plus Cry1Ac. These results may help explain the inability of Cry1Ac-resistant H. zea to complete development on Bt cotton, and the absence of field-evolved resistance to Bt cotton by this pest.

Using FAME analysis to compare, differentiate, and identify multiple nematode species.

We have adapted the Sherlock(®) Microbial Identification system for identification of plant parasitic nematodes based on their fatty acid profiles. Fatty acid profiles of 12 separate plant parasitic nematode species have been determined using this system. Additionally, separate profiles have been developed for Rotylenchulus reniformis and Meloidogyne incognita based on their host plant, four species and three races within the Meloidogyne genus, and three life stages of Heterodera glycines. Statistically, 85% of these profiles can be delimited from one another; the specific comparisons between the cyst and vermiform stages of H. glycines, M. hapla and M. arenaria, and M. arenaria and M. javanica cannot be segregated using canonical analysis. By incorporating each of these fatty acid profiles into the Sherlock(®) Analysis Software, 20 library entries were created. While there was some similarity among profiles, all entries correctly identified the proper organism to genus, species, race, life stage, and host at greater than 86% accuracy. The remaining 14% were correctly identified to genus, although species and race may not be correct due to the underlying variables of host or life stage. These results are promising and indicate that this library could be used for diagnostics labs to increase response time.

Serum concentrations of adiponectin and characterization of adiponectin protein complexes in dogs.

OBJECTIVE: To assess serum concentrations of adiponectin and characterize adiponectin protein complexes in healthy dogs. ANIMALS: 11 healthy dogs. PROCEDURES: Sera collected from 10 dogs were evaluated via velocity sedimentation and ultracentrifugation, SDS-PAGE, western immunoblotting, and radioimmunoassay. Visceral adipose tissue (approx 90 g) was collected from the falciform ligament of a healthy dog undergoing elective ovariohysterectomy, and adiponectin gene expression was assessed via a real-time PCR procedure. RESULTS: Adiponectin gene expression was detected in visceral adipose tissue. Serum adiponectin concentrations ranged from 0.85 to 1.5 microg/mL (mean concentration, 1.22 microg/mL). In canine serum, adiponectin was present as a multimer, consisting of a low-molecular-weight complex (180 kd); as 3 (180-, 90-, and 60-kd) complexes under denaturing conditions; as 2 (90- and 60-kd) complexes under reducing conditions; and as a dimer, a monomer, and globular head region (60, 30, and 28 kd, respectively) under reducing-denaturing conditions. It is likely that adiponectin also circulates as a high-molecular-weight (360- to 540-kd) complex in canine serum, but resolution of this complex was not possible via SDS-PAGE. CONCLUSIONS AND CLINICAL RELEVANCE: After exposure to identical experimental conditions, adiponectin protein complexes in canine serum were similar to those detected in human and rodent sera. Circulating adiponectin concentrations in canine serum were slightly lower than concentrations in human serum. Adiponectin gene expression was identified in canine visceral adipose tissue. Results suggest that adiponectin could be used as an early clinical marker for metabolic derangements, including obesity, insulin resistance, and diabetes mellitus in dogs.