Expression of MPB83 from Mycobacterium bovis in Brucella abortus S19 induces specific cellular immune response against the recombinant antigen in BALB/c mice

Immunodominant MPB83 antigen from Mycobacterium bovis was expressed as a chimeric protein fused to either β-galactosidase, outer membrane lipoprotein OMP19 or periplasmic protein BP26 in gram-negative Brucella abortus S19, in all cases driven by each gene's own promoter. All fusion proteins were successfully expressed and localized in the expected subcellular fraction. Moreover, OMP19-MPB83 was processed as a lipoprotein when expressed in B. abortus. Splenocytes from BALB/c mice immunized with the recombinant S19 strains carrying the genes coding for the heterologous antigens in replicative plasmids, showed equally specific INF-γ production in response to MPB83 stimulation. Association to the lipid moiety of OMP19 presented no advantage in terms of immunogenicity for MPB83. In contrast, fusion to BP26, which was encoded by an integrative plasmid, resulted in a weaker immune response. None of the constructions affected the survival rate or the infection pattern of Brucella. We concluded that B. abortus S19 is an appropriate candidate for the expression of M. bovis antigens both associated to the membrane or cytosolic fraction and may provide the basis for a future combined vaccine for bovine brucellosis and tuberculosis.     

A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

In situ analysis of native microbial communities in complex samples with high particulate loads

In the present study a procedure combining a cell extraction method and Fluorescence In Situ Hybridization (FISH) for molecular monitoring and quantification of bacteria in soil and aquifer samples is presented. FISH was applied to bacterial cells extracted from the matrix by density gradient centrifugation. This separation method was applied to soil and aquifer samples and produced high cell recovery of 76.5%+/-4.4 and 78.0%+/-3.2, respectively. FISH, performed on the harvested cells, permitted a perfect visualization and quantification of bacteria. This approach is therefore promising for in situ detection of indigenous bacterial communities in complex samples.     

Development of an optical immunosensor based on the fluorescence of Cyanine-5 for veterinarian diagnostics

A model optical immunosensor was developed to quantify an antibody present in a sample by measuring the fluorescence of Cyanine-5 conjugated with the antibody, using a competitive and a sandwich immunoreaction configuration, with the antigen immobilised in controlled pore glass beads. At pH 2, 94% of the antigen-antibody complex was dissociated, allowing reutilisation. Photobleaching had no effect on the fluorescence. This model system was used to detect Brucella sp. infection and could quantify anti-Brucella sp. antibodies in ovine serum samples in the range from 0.005 to 0.11 mg ml(-1).     

Advantages of the division of labour for the long-term population dynamics of cyanobacteria at different latitudes

A fundamental advancement in the evolution of complexity is division of labour. This implies a partition of tasks among cells, either spatially through cellular differentiation, or temporally via a circadian rhythm. Cyanobacteria often employ either spatial differentiation or a circadian rhythm in order to separate the chemically incompatible processes of nitrogen fixation and photosynthesis. We present a theoretical framework to assess the advantages in terms of biomass production and population size for three species types: terminally differentiated (heterocystous), circadian, and an idealized species in which nitrogen and carbon fixation occur without biochemical constraints. On the basis of real solar irradiance data at different latitudes, we simulate population dynamics in isolation and in competition for light over a period of 40 years. Our results show that in isolation and regardless of latitude, the biomass of heterocystous cyanobacteria that optimally invest resources is comparable to that of the idealized unconstrained species. Hence, spatial division of labour overcomes biochemical constraints and enhances biomass production. In the circadian case, the strict temporal task separation modelled here hinders high biomass production in comparison with the heterocystous species. However, circadian species are found to be successful in competition for light whenever their resource investment prevents a waste of fixed nitrogen more effectively than do heterocystous species. In addition, we show the existence of a trade-off between population size and biomass accumulation, whereby each species can optimally invest resources to be proficient in biomass production or population growth, but not necessarily both. Finally, the model produces chaotic dynamics for population size, which is relevant to the study of cyanobacterial blooms.     

The Amusic Brain: Lost in Music,but Not in Space

Congenital amusia is a neurogenetic disorder of music processing that is currently ascribed to a deficit in pitch processing. A recent study challenges this view and claims the disorder might arise as a consequence of a general spatial-processing deficit. Here, we assessed spatial processing abilities in two independent samples of individuals with congenital amusia by using line bisection tasks (Experiment 1) and a mental rotation task (Experiment 2). Both amusics and controls showed the classical spatial effects on bisection performance and on mental rotation performance, and amusics and controls did not differ from each other. These results indicate that the neurocognitive impairment of congenital amusia does not affect the processing of space.     

Animal xenodiversity in Italian inland waters: distribution, modes of arrival, and pathways

The paper provides a list of the non-indigenous animal species occurring today in Italian inland waters. Xenodiversity was found to amount to 112 species (64 invertebrates and 48 vertebrates), which contribute for about 2% to the inland-water fauna in Italy. Northern and central regions are most affected, and Asia, North America, and the rest of Europe are the main donor continents. The large majority of non-indigenous species entered Italy as a direct or indirect effect of human intervention. A difference between invertebrates and vertebrates was found for their mode of arrival (unintentional for invertebrates and intentional for vertebrates). Accidental transport, in association with both fish (for aquaculture or stock enhancement) and crops, has been the main vector of invertebrate introductions, whereas vertebrates were mostly released for stocking purposes. Overall stock enhancement (47.92%) and culture (37.5%) prevailed over the other pathways. Seventeen and 7 species of our list are included among the 100 worst invasive species of Europe (DAISIE) and of the world (IUCN), respectively. For some (but not all) non-indigenous species recorded in Italy the multilevel impact exerted on the recipient communities and ecosystems is known, even if rarely quantified, but knowledge on their chronic impact is still missing. Additional research is needed to provide criteria for prioritizing intervention against well established invaders and identify which new potential invader should be targeted as “unwanted”.     

Biological Aspects of Medorippe lanata (Linnaeus, 1767) (Brachyura: Dorippidae) from the Eastern Ligurian Sea (Western Mediterranean)

The aim of the present study is to investigate the demographic structure and to identify some aspects of the biology of an exploited population of Medorippe lanata (Brachyura: Dorippidae) in the eastern Ligurian Sea, western Mediterranean. 1364 specimens (639 males and 725 females) of M. lanata were collected on a monthly basis from January to December 2001, in a wide area of the eastern Ligurian Sea usually exploited by the Viareggio ‘rapido’ trawl fleet. M. lanata represented an important fraction of the discard, both in weight and in number of individuals. Maximum abundance of this species occurred in late summer-early autumn (up to 3369 ind. km⁻² and 50.6 kg km⁻² in August). The overall females:males sex-ratio was 1.13:1, while the monthly sex-ratio did not differ statistically from 1:1 in all months, except in September and October, when females significantly outnumbered males. The sampled population was composed of two cohorts from November to April. Sizes ranged from 10 to 29 mm carapace length (CL) for females and from 9 to 29 mm CL for males. The von Bertalanffy growth curve, computed for both sexes, gave a higher growth rate in males than in females. Recently moulted males and females were observed throughout the year, except in summer, when the highest number of ovigerous females was present. Females with external eggs were collected from March to November, with peaks in August and September. The monthly evolution of the ovarian maturity stages showed no clear temporal trend. At 21 mm CL, 50% of females were ovigerous or showed macroscopically mature ovaries. According to the dimorphism in chelae size, the presence of adult males (post-puberty stage) was observed all year round, from 18 to 29 mm CL, without evident temporal trends.