Pathology of experimentally induced quail bronchitis

Bobwhite quails (Colinus virginianus) were inoculated with 10(6) mean tissue-culture infective dose of quail bronchitis virus at 1, 3, 6, or 9 weeks of age by intratracheal, intraperitoneal, or subcutaneous routes. Quails developed necrotizing tracheitis, proliferative and necrotizing bronchitis and pneumonia; multifocal necrotizing hepatitis; necrotizing splenitis, with or without hyperplasia of splenic mononuclear phagocytes; bursal lymphoid necrosis; and bursal atrophy. Lesions were more extensive and severe in quails inoculated at 1 or 3 weeks of age than in older quails. Large intranuclear inclusions, characteristic of adenovirus infection, were identified in trachea, lung, liver, and bursa of Fabricius. This is the first report of the histopathology of experimentally induced quail bronchitis.     

Internet sales of plants for planting – an increasing trend and threat?1

The sale of plants for planting on the Internet and by other direct marketing methods (e.g. newspaper offers) has increased dramatically in recent years. Some companies are specialist suppliers in this area and typically with this trade small quantities of plants are sent by mail to a very large number of amateur growers scattered throughout the UK. It is often difficult for the NPPO to keep track of this activity especially when the supplier is located outside its jurisdiction. Also if problems arise with plants sold in this way, taking effective official eradicatory action can be problematic. To demonstrate the issues and problems involved, two examples that occurred in the UK in 2008 are described.     

Mycobacterium infection in a gray-cheeked parakeet

A gray-cheeked parakeet, approximately 3 years of age, was submitted for necropsy. Clinical signs included diarrhea, decreased feed consumption, fluffing of feathers, shivering, weight loss, and limping. Necropsy revealed enlargement and pale discoloration of the spleen and intestines. The liver contained multifocal pale foci. Granulomas, some of which had necrotic centers, were present along the subserosa of the intestinal tract. Microscopic examination revealed diffuse granulomatous splenitis, enteritis, and multifocal granulomatous hepatitis. Numerous acid-fast bacteria were demonstrated in the spleen, liver, and intestine.     

Effects of white-tailed deer on vegetation structure and woody seedling composition in three forest types on the Piedmont Plateau

White-tailed deer (Ododcoileus virginiana) can substantially affect the structure and species composition of a forest. The tolerance of a forest community to browsing may vary by type as a result of varying biotic and abiotic factors of the environment. To date, no studies have compared the effects of browsing among forest communities within a physiographic region. We investigated the effects of browsing on vegetation structure and woody seedling composition in three forest types (oak–hickory, Virginia pine–eastern red cedar, bottomland hardwood) in Manassas National Battlefield Park (MNBP), Virginia, USA. We compared forb cover, vertical plant cover (0–1.5 m tall), and survival of tagged seedlings in 10 exclosed (2 m × 6 m) and 10 unexclosed plots in each forest type during a 5-year period. No differential effects of browsing were found among forest types. In all forest types, deer (67 deer/km²) suppressed forb and vertical plant cover to levels less than would be expected in the absence of deer. Seedling survival rates of most species were significantly reduced by browsing. By the 4th year of the study, box elder (Acer negundo), hickory (Carya spp.), and red maple (Acer rubrum) had been eliminated from unexclosed plots, and red and white oaks (Quercus spp.) dramatically reduced. Ash (Fraxinus spp.), black cherry (Prunus serotina), and hackberry (Celtis occidentalis), although significantly impacted, remained the most abundant species throughout the study. These findings suggest that white-tailed deer may be modifying the structure of the forest interior to the extent that it adversely affects wildlife species dependent on a dense understory to thrive. We predict that the future composition of forests in MNBP will shift towards stands with fewer species and a greater dominance of ash, black cherry, and hackberry, particularly in the oak–hickory and bottomland hardwood forests, where the majority of current dominants are most affected.     

Insoluble fraction of buckwheat (Fagopyrum esculentum Moench) protein possessing cholesterol-binding properties that reduce micelle cholesterol solubility and uptake by Caco-2 cells

Buckwheat (Fagopyrum esculentum Moench) protein (BWP) exhibits hypocholesterolemic activity in several animal models by increasing fecal excretion of neutral and acidic sterols. In the current study, the ability of BWP to disrupt micelle cholesterol solubility by sequestration of cholesterol was investigated. When BWP (0.2%) was incubated with cholesterol and micelle lipid components prior to micelle formation, cholesterol solubility was reduced 40%. In contrast, cholesterol solubility was not decreased when BWP (0.2%) was incubated after micelle formation and incorporation of soluble cholesterol. Buckwheat flour, from which BWP was derived, had no significant effect on cholesterol solubility. Cholesterol uptake in Caco-2 cells from micelles made in the presence of BWP (0.2%) was reduced by 47, 36, 35, and 33% when compared with buckwheat flour, bovine serum albumin, casein, and gelatin, respectively. Reduction in cholesterol uptake in Caco-2 cells was dose-dependent, with maximum reductions at 0.1-0.4% BWP. In cholesterol-binding experiments, 83% of the cholesterol was associated with an insoluble BWP fraction, indicating strong cholesterol-binding capacity that disrupts solubility and uptake by Caco-2 cells.     

Surveillance for highly pathogenic avian influenza in migratory shorebirds at the terminus of the East Asian-Australasian Flyway

AIM: To determine if migratory birds arriving in New Zealand in the Southern Hemisphere spring of 2004 were infected with the highly pathogenic avian influenza (AI) virus, H5N1.

METHODS: Cloacal and faecal samples were collected from migratory red knots following their arrival in New Zealand in October 2004. Two species of resident sympatric birds, wrybill and mallard duck, were sampled prior to, and following, the arrival of migratory birds.

RESULTS: No AI viruses were isolated from migratory or resident shorebirds. Non-pathogenic AI viruses were isolated from six resident mallard ducks, comprising the endemic subtypes H4 (n=2), H7 (non-pathogenic), H10, and H11 (n=2).

CONCLUSIONS: Highly pathogenic AI H5N1 virus was not detected in migratory shorebirds or sympatric water birds in the Firth of Thames, New Zealand, in 2004-2005, despite the possible proximity of migratory birds to outbreaks of the disease in East Asia in 2004.     

Poor maternal nutrition inhibits muscle development in ovine offspring

Background

Maternal over and restricted nutrition has negative consequences on the muscle of offspring by reducing muscle fiber number and altering regulators of muscle growth. To determine if over and restricted maternal nutrition affected muscle growth and gene and protein expression in offspring, 36 pregnant ewes were fed 60%, 100% or 140% of National Research Council requirements from d 31 ± 1.3 of gestation until parturition. Lambs from control-fed (CON), restricted-fed (RES) or over-fed (OVER) ewes were necropsied within 1 d of birth (n = 18) or maintained on a control diet for 3 mo (n = 15). Semitendinosus muscle was collected for immunohistochemistry, and protein and gene expression analysis.

Results

Compared with CON, muscle fiber cross-sectional area (CSA) increased in RES (58%) and OVER (47%) lambs at 1 d of age (P < 0.01); however at 3 mo, CSA decreased 15% and 17% compared with CON, respectively (P < 0.01). Compared with CON, muscle lipid content was increased in OVER (212.4%) and RES (92.5%) at d 1 (P < 0.0001). Muscle lipid content was increased 36.1% in OVER and decreased 23.6% in RES compared with CON at 3 mo (P < 0.0001). At d 1, myostatin mRNA abundance in whole muscle tended to be greater in OVER (P = 0.07) than CON. Follistatin mRNA abundance increased in OVER (P = 0.04) and tended to increase in RES (P = 0.06) compared with CON at d 1. However, there was no difference in myostatin or follistatin protein expression (P > 0.3). Phosphorylated Akt (ser473) was increased in RES at 3 mo compared with CON (P = 0.006).

Conclusions

In conclusion, maternal over and restricted nutrient intake alters muscle lipid content and growth of offspring, possibly through altered gene and protein expression.     

Molecular characterization of reticuloendotheliosis virus insertions in the genome of field and vaccine strains of fowl poxvirus

Evidence of the widespread occurrence of reticuloendotheliosis virus (REV) sequence insertions in fowl poxvirus (FPV) genome of field isolates and vaccine strains has increased in recent years. However, only those strains carrying a near intact REV provirus are more likely to cause problems in the field. Detection of the intact provirus or REV protein expression from FPV stocks has proven to be technically difficult. The objective of the present study was to evaluate current and newly developed REV and FPV polymerase chain reaction (PCR) assays to detect the presence of REV provirus in FPV samples. The second objective was to characterize REV insertions among recent "variant" FPV field isolates and vaccine strains. With REV, FPV, and heterologous REV-FPV primers, five FPV field isolates and four commercial vaccines were analyzed by PCR and nucleotide sequence analysis. Intact and truncated REV 5' long terminal repeat (LTR) sequences were detected in all FPV field isolates and vaccine strains, indicating heterogeneous REV genome populations. However only truncated 3' LTR and envelope sequences were detected among field isolates and in one vaccine strain. Amplifications of the REV envelope and 3' LTR provided strong evidence to indicate that these isolates carry a near intact REV genome. Three of the four FPV vaccine strains analyzed carried a solo complete or truncated 5' LTR sequence, indicating that intact REV provirus was not present. Comparison of PCR assays indicated that assays amplifying REV envelope and REV 3' LTR sequences provided a more accurate assessment of REV provirus than PCR assays that amplify the REV 5' LTR region. Therefore, to differentiate FPV strains that carry intact REV provirus from those that carry solo 5' LTR sequences, positive PCR results with primers that amplify the 5' LTR should be confirmed with more specific PCR assays, such as the envelope, or the REV 3' LTR PCR.