Evaluation of modified vaccinia virus Ankara expressing VP2 protein of infectious bursal disease virus as an immunogen in chickens

A recombinant modified vaccinia Ankara (MVA) virus expressing mature viral protein 2 (VP2) of the infectious bursal disease virus (IBDV) was constructed to develop MVA-based vaccines for poultry. We demonstrated that this recombinant virus was able to induce a specific immune response by observing the production of anti-IBDV-seroneutralizing antibodies in specific pathogen-free chickens. Besides, as the epitopes of VP2 responsible to induce IBDV-neutralizing antibodies are discontinuous, our results suggest that VP2 protein expressed from MVA-VP2 maintained the correct conformational structure. To our knowledge, this is the first report on the usefulness of MVA-based vectors for developing recombinant vaccines for poultry.     

Conservation value of tropical secondary forest: A herpetofaunal perspective

In some areas of the tropics forests are recovering on abandoned cattle pastures. These secondary forests may be important habitats for conserving biodiversity, but we know little about their species composition over the long term. We studied herpetofaunal community changes in a 40 years chronosequence of forest succession on abandoned pastures in Puerto Rico. Twelve submontane sites (100-250 masl) represented four forest recovery stages: pasture, young (1-5 years after abandonment), intermediate (10-20 years), and advanced (40 years). Among these stages we analyzed the relationship of forest structure, microclimate, and herpetofaunal community structure. During succession total forest height increased, new strata of vegetation appeared in the understory, and the forest gained heterogeneity and complexity. Microclimate changed with changes in the physiognomy and structure of the vegetation. Microclimatic shifts were more dramatic in forest <20 years since abandonment. During 1 year we observed 7991 individuals of thirteen reptilian species (60% of observations) and six anuran species. Herpetofaunal richness was similar among stages, but the total abundance increased through succession. Relative abundance of anurans and reptiles was similar between stages, but species dominance changed with succession. Forest >20 years old resembles mature forest in some structural characteristics important to herpetofauna and can provide habitat for forest herpetofauna in disturbed areas.     

Diversity among agrobacteria isolated from diseased plants of blueberry (Vaccinium corymbosum) in Argentina

The aim of this study was to isolate, identify and analyze the diversity of the causative agents of crown galls and hairy roots from symptomatic plants of Vaccinium corymbossum by means of biological, biochemical and molecular tools. All the bacteria isolated from blueberries (n?=?78) were found to be Agrobacterium since they grew on three differential media, provoked cell and/or root proliferation on Kalanchoe, and contained a 730?bp partial sequence that codes for virulence genes within the virC operon found on Ti and/or Ri plasmids. Isolates were highly variable considering the ERIC-PCR patterns as well as biochemical reactions and were all represented by 7 different restriction patterns of the 16SrDNA. While most of the isolates belonged to Agrobacterium bv. 1 (n?=?33) or Agrobacterium bv. 2 (n?=?31) only fourteen were Agrobacterium rubi. A representative isolate of each of these three groups was further identified by sequencing the approximately 400?bp 16SrDNA. We concluded that Vaccinium plants are particularly susceptible to Agrobacterium bv. 1, Agrobacterium bv. 2, and also to Agrobacterium rubi. To our knowledge this is the first survey of Agrobacterium affecting blueberries in Argentina.     

Elevated α-esterase levels associated with permethrin tolerance in Aedes aegypti (L.) from Baja California, Mexico

A discriminating dose for permethrin for Aedes aegypti from Baja California, Mexico was determined, and was used to select individuals. Mosquitoes were collected from four different municipalities located in the north and south end of the Baja California Peninsula. Individuals were chosen for further study based on their similar response to the insecticide. We exposed 10 groups of 90 Ae. aegypti females to the discriminating dose (172 μg/ml) and after producing 50% mortality, individuals were divided into two categories: killed and survivors. Each of these groups was dissected to separate the head, thorax, and abdomen. Biochemical tests were performed on the head and thorax to determine resistance-related enzyme activities including: α- and β-esterases, glutathione S-transferase, acetyl cholinesterase, insensitive acetyl cholinesterase, and mixed-function oxidases. The results were compared with those for the susceptible New Orleans strain of Ae. aegypti. All the populations studied showed the consistent presence of α-esterases, with elevated levels in permethrin-selected populations. Although β-esterases and GST levels were present in high proportions, they did not reveal a clear pattern in relation to resistance.     

Characterization of langerhans cells in epidermal sheets along the body of Armadillo (Dasypus novemcinctus)

Armadillos are apparently important reservoirs of Mycobacterium leprae and an animal model for human leprosy, whose immune system has been poorly studied. We aimed at characterizing the armadillo's langerhans cells (LC) using epidermal sheets instead of tissue sections, since the latter restrict analysis only to cut-traversed cells. Epidermal sheets by providing an en face view, are particularly convenient to evaluate dendritic morphology (cells are complete), spatial distribution (regular vs. clustered), and frequency (cell number/tissue area). Lack of anti-armadillo antibodies was overcome using LC-restricted ATPase staining, allowing assessment of cell frequency, cell size, and dendrites extension. Average LC frequency in four animals was 528 LC/mm(2), showing a rather uniform non-clustered distribution, which increased towards the animal's head, while cell size increased towards the tail; without overt differences between sexes. The screening of antibodies to human DC (MHC-II, CD 1a, langerin, CD86) in armadillo epidermal sheets, revealed positive cells with prominent dendritic morphology only with MHC-II and CD86. This allowed us to test DC mobilization from epidermis into dermis under topical oxazolone stimulation, a finding that was corroborated using whole skin conventional sections. We hope that the characterization of armadillo's LC will incite studies of leprosy and immunity in this animal model.     

Molecular diversity of Brazilian strains of porcine circovirus type 2 (PCV-2)

Porcine circovirus 2 (PCV-2) is associated with a broad range of syndromes. In this study, eight pig tissue samples from two Brazilian states were analyzed using six PCR primer pairs amplifying a 1705-bp fragment of the PCV-2 genome. The NJ distance-based method was used for the phylogenetic analysis with the eight field strains herein, 15 GenBank sequences and using PCV-1 as an out-group. This yielded two major clusters (A and B) for this viral species, with the Brazilian strains segregating with European and Asian sequences. Nucleotide identity was 99.7 to 100% among the sequences. This information can be used in further studies of pathogenesis related to PCV-2 in Brazil.     

Circulating β-endorphin,adrenocorticotrophic hormone and cortisol levels of stallions before and after short road transport: stress effect of different distances

Background

Since transport evokes physiological adjustments that include endocrine responses, the objective of this study was to examine the responses of circulating β-endorphin, adrenocorticotrophic hormone (ACTH) and cortisol levels to transport stress in stallions.

Methods

Forty-two healthy Thoroughbred and crossbred stallions were studied before and after road transport over distances of 100, 200 and 300 km. Blood samples were collected from the jugular vein: first in a single box immediately before loading (pre-samples), then immediately after transport and unloading on arrival at the breeding stations (post-samples).

Results

An increase in circulating β-endorphin levels after transport of 100 km (P < 0.01), compared to basal values was observed. Circulating ACTH levels showed significant increases after transport of 100 km (P < 0.001) and 200 km (P < 0.001). Circulating cortisol levels showed significant increases after road transport over distances of 100, 200 and 300 km (P < 0.001). An effect of transport on β-endorphin, ACTH and cortisol variations was therefore evident for the different distances studied. No significant differences (P > 0.05) between horses of different ages and different breeds were observed for β-endorphin, ACTH and cortisol levels.

Conclusion

The results obtained for short term transportation of stallions showed a very strong reaction of the adrenocortical system. The lack of response of β-endorphin after transport of 200–300 km and of ACTH after transport of 300 km seems to suggest a soothing effect of negative feedback of ACTH and cortisol levels.     

Interactions between fisheries and cetaceans in the Thracian sea (Greece) and management proposals

Greek fisheries (purse seine, trawling and small‐scale coastal, by order of importance) mostly operate in the Thracian Sea, which despite its relatively small size relative to the Aegean Sea (≈4.4%) is the most productive region in Greek waters due to its elevated nutrient concentration. The Thracian Sea is also vital to several species of cetaceans, mainly bottlenose dolphin, Tursiops truncatus (Montagu), and common dolphin, Delphinus delphis L. The area has been proposed as a potential cetacean conservation hotspot. For this reason, the interactions between fishing activities and local cetacean populations have been investigated through reports of stranded dolphins, interviews with fishers, surveys and detailed dolphin stomach content analysis. Reports of stranded cetaceans and interviews with fishers revealed cases of cetacean entanglement in fishing nets, as well as frequent dolphin damage to fishing nets. Necropsy stomach analysis of stranded dolphins revealed a preference for fish and cephalopods of low commercial value, indicating a low trophic overlap between cetaceans and commercial fisheries. Recommendations for the management of fisheries–cetacean interactions in the Thracian Sea are provided.     

Survival and growth of hatchery-produced postlarvae and spat of the Caribbean scallops Argopecten nucleus and Nodipecten nodosus

A study was made of the growth and survival of postlarvae and spat of Argopecten nucleus and Nodipecten nodosus produced in the laboratory and exposed to different conditions of settlement and culture. An evaluation was made of the different types of collection substrates (onion-bags, artificial-grass, fibreglass-plates), two types of settlement inducers (epinephrine, low temperature), and two culture environments (sea, laboratory). The results showed that larger numbers of postlarvae were obtained in artificial-grass collectors than on fibreglass-plates or in the onion-bags. The growth of the A. nucleus postlarvae was not affected by the collector type, while that of N. nodosus was higher on fibreglass-plates, and lesser in the onion-bags. Both thermal and chemical stimulation of the competent larvae resulted in recovery of a greater percentage of postlarvae. The growth of postlarvae of A. nucleus was better in groups exposed to the two methods of settlement induction, while those of N. nodosus remained unaffected by this treatment. The survival of the postlarvae and spat was greater in the laboratory than at sea except in the case of A. nucleus postlarvae attached to collectors, whose survival was similar in both environments. The growth of postlarvae and spat was greater in the sea than in the laboratory.     

Influence of the type of collector and collector preparation periods on the settling rate of the scallop Nodipecten nodosus L. in the laboratory

We analysed the settling rate of Nodipecten nodosus L. scallop spats during winter and spring, testing different types of collectors and collector preparation periods. Larval rearing was conducted with water exchange every 48 h, density at 2 larvae mL⁻¹ and feeding between 0.5 and 2 × 10⁴ microalgae cellsmL⁻¹. The recovery larvae based on D-larvae produced were 31.6% (Winter Trial) and 47.2% (Spring Trial), without any antibacterial additives. The mean settling rates obtained in Winter Trial were from 0.04% to 0.79% withstand in Spring Trial were 24.99–48.65%. In the Winter Trial, there was no statistical difference between the settling rate of collectors prepared for 6 or 12 days. The settling rates of the netlon collectors with pine leaves were up to 19 times higher than those of the other types of collectors. In the Spring Trial, there was no statistical difference between the settling rates of the netlon and plastic net fruit collectors. Collectors with pine leaves produced a yield of spats up to 48.65%, more than those without pine leaves ( P <0.01). The efficiency of larval rearing and settling obtained in spring, pine leaves and low-cost local material indicate the feasibility to improve and facilitate regular production of N. nodosus spats for promotion of the growth of scallop culture in Brazil.