Transposon Tn1721 distribution among strains of Xylella fastidiosa

Transposons are mobile genetic elements found within the genomes of various organisms including bacteria, fungi, plants and animals. Fragments of the transposon Tn1721 were found included in the genome of Xylella fastidiosa strain 9a5c. Regions from such fragments were PCR-amplified using specially designed primers (TNP1 and TNP2). In order to detect insertions of the Tn1721 element, both primers were used and one of them included a region of the transposon (TNP1) and the other one had the right repeat and part of the bacterial chromosome (TNP2). The PCR products obtained from strain 9a5c were used as a pattern for fragment size comparisons when DNA samples from other X. fastidiosa strains were used as template for the PCR assays. Differences were observed concerning the PCR products of such amplifications when some X. fastidiosa strains isolated from grapevine and plum were used. For the citrus-derived strains only the strains U187d and GP920b produced fragments with different sizes or weak band intensity. Such variations in the X. fastidiosa genome related to disrupted Tn1721 copies are probably due to the possibility of such a transposon element being still able to duplicate even after deletion events might have taken place and also because the bacterial strains in which the main differences were detected are derived from different host plants cultivated under different climate conditions from the one used as reference. © 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

Comparison of a multiplex-PCR assay with mycolic acids analysis and conventional methods for the identification of Mycobacteria

A fast, sensitive and cost-effective multiplex-PCR assay for Mycobacterium tuberculosis complex (MTC) and Mycobacterium avium (M. avium) identification for routine diagnosis was evaluated. A total of 158 isolates of mycobacteria from 448 clinical specimens from patients with symptoms of mycobacterial disease were analyzed. By conventional biochemical methods 151 isolates were identified as M. tuberculosis, five as M. avium and two as Mycobacterium chelonae (M. chelonae). Mycolic acid patterns confirmed these results. Multiplex-PCR detected only IS6110 in isolates identified as MTC, and IS1245 was found only in the M. avium isolates. The method applied to isolates from two patients, identified by conventional methods and mycolic acid analysis, one as M. avium and other as M. chelonae, resulted positive for IS6110, suggesting co-infection with M. tuberculosis. These patients were successfully submitted to tuberculosis treatment. The multiplex-PCR method may offer expeditious identification of MTC and M. avium, which may minimize risks for active transmission of these organisms and provide useful treatment information.

Genetic conservation of Brazilian fishes - Present state and perspectives

Natural environments have been worldwide affected by the growing impact of anthropogenic actions that promote the reduction or the extinction of several vertebrate species. Aquatic ecosystems represent one of the most affected environments and many fish species and/or populations have been increasingly fragmented distributed due to habitat degradation, predatory fishing, introduction of exotic species, river sedimentation, deforestation, pollution, reduction of food resource, and construction of hydroelectric dams. Actually, more than 150 Brazilian fish species, including freshwater, estuary and coastal species, can be considered threatened. Information on the diversity, conservation biology and population analysis on threatened species or populations, with several DNA markers, can be extremely useful for the success of fish species-recovery and maintenance programs. Although DNA analysis in Neotropical fish species are just beginning, they tend to increase with the widespread attention to the use of molecular approaches to minimize problems related to the risk of extinction. The accumulation of information on biology and pattern of genetic variation of fish species, associated with ecological and demographic data, and also education and respect to the nature, constitutes a crucial task to develop efficient conservation strategies in order to preserve the genetic diversity in aquatic environments.

Alternative interpretations of some earliest ediacaran fossils from China

In a letter to Nature (February, 2011), Xunlai Yuan and collaborators recorded carbon compression fossils from black shales of the Lantian Formation (Ediacaran), southern Anhui Province, South China. The new fossils, described under five morphological types (Types A to E), exhibit degrees of morphological differentiation suggesting that they were multicellular eukaryotes. Some of the Lantian macrofossils were interpreted as algae, but others are of unknown affinities. For reasons noted in this discussion, Type A fossils attracted our particular attention, and we suggest an alternative interpretation of their affinities. According to our view, some of them (at least those with three faces and no globose holdfast at their base) may represent conulariid cnidarians or close medusozoan relatives. The undistorted organism probably was a three-sided cone in life. We believe that our suggested alternative interpretations of the anatomy and affinities of the fossils in question can be useful in guiding future research on the oldest currently known fossil assemblage of multicellular organisms. Copyright © 2012.

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Edge-interior differences in the species richness and abundance of drosophilids in a semideciduous forest fragment

Habitat fragmentation is the main cause of biodiversity loss, as remnant fragments are exposed to negative influences that include edge effects, prevention of migration, declines in effective population sizes, loss of genetic variability and invasion of exotic species. The Drosophilidae (Diptera), especially species of the genus Drosophila, which are highly sensitive to environmental variation, have been used as bioindicators. A twelve-month field study was conducted to evaluate the abundance and richness of drosophilids in an edge-interior transect in a fragment of semideciduous forest in São Paulo State, Brazil. One objective of the study was to evaluate the applied methodology with respect to its potential use in future studies addressing the monitoring and conservation of threatened areas. The species abundance along the transect showed a clear gradient, with species associated with disturbed environments, such as Drosophila simulans, Scaptodrosophila latifasciaeformis and Zaprionus indianus, being collected at the fragment edge and the species D. willistoni and D. mediostriata being found in the fragment's interior. Replacement of these species occurred at approximately 60 meters from the edge, which may be a reflection of edge effects on species abundance and richness because the species found within the habitat fragment are more sensitive to variations in temperature and humidity than those sampled near the edge. The results support the use of this methodology in studies on environmental impacts. © 2013 Penariol and Madi-Ravazzi; licensee Springer.

Euselasia hygenius Occulta (Riodininae): First report of feeding on Psidium guajava (Myrtaceae) in Minas Gerais State, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sustainable production of biologically active molecules of marine based origin

The marine environment offers both economic and scientific potential which are relatively untapped from a biotechnological point of view. These environments whilst harsh are ironically fragile and dependent on a harmonious life form balance. Exploitation of natural resources by exhaustive wild harvesting has obvious negative environmental consequences. From a European industry perspective marine organisms are a largely underutilised resource. This is not due to lack of interest but due to a lack of choice the industry faces for cost competitive, sustainable and environmentally conscientious product alternatives. Knowledge of the biotechnological potential of marine organisms together with the development of sustainable systems for their cultivation, processing and utilisation are essential. In 2010, the European Commission recognised this need and funded a collaborative RTD/SME project under the Framework 7-Knowledge Based Bio-Economy (KBBE) Theme 2 Programme 'Sustainable culture of marine microorganisms, algae and/or invertebrates for high value added products'. The scope of that project entitled 'Sustainable Production of Biologically Active Molecules of Marine Based Origin' (BAMMBO) is outlined. Although the Union is a global leader in many technologies, it faces increasing competition from traditional rivals and emerging economies alike and must therefore improve its innovation performance. For this reason innovation is placed at the heart of a European Horizon 2020 Strategy wherein the challenge is to connect economic performance to eco performance. This article provides a synopsis of the research activities of the BAMMBO project as they fit within the wider scope of sustainable environmentally conscientious marine resource exploitation for high-value biomolecules. © 2013 Elsevier B.V.

Tratamento de efluentes de piscicultura utilizando sistema tipo wetland povoado com espécies de macrófitas aquáticas de três tipos ecológicos diferentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The status of biodiversity and bioprospecting efforts in the Caribbean subregion

Includes bibliography

Frequency of antibodies to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burdgorferi in cattle from the northeastern region of the state of Pará, Brazil

A babesiose, a anaplasmose e a tripanossomose são enfermidades relevantes, potencialmente causadoras de morbidade em bovinos, levando a perdas econômicas. A borreliose assume importância como zoonose potencial. O objetivo desse estudo foi determinar, por meio do ensaio de imunoadsorção enzimática (ELISA), a freqüência de anticorpos para Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax e Borrelia burgdorferi em bovinos da região nordeste do Estado do Pará, Brasil. Amostras de soro de 246 vacas dos municípios de Castanhal e São Miguel do Guamá foram usadas. ELISAs com antígeno bruto foram utilizados para detector anticorpos contra todos os agentes, exceto para A. marginale, para o qual um ELISA indireto com proteína principal de superfície 1a (MSP1a) foi usado. As freqüências de bovinos soropositivos foram: B. bigemina - 99,2%; B. bovis - 98,8%; A. marginale - 68,3%; T. vivax - 93,1% and B. burgdorferi -54,9% As freqüências de bovinos soropositivos para B. bovis e B. bigemina sugerem uma alta taxa de transmissão desses organismos por carrapatos, na região estudada, a qual pode ser classificada com sendo de estabilidade enzoótica para os hemoparasitos. A baixa freqüência de bovinos soropositivos para A. marginale pode ser atribuída a uma menor sensibilidade do ELISA com antígeno recombinante, ou uma menor taxa de inoculação da riquétsia pelos carrapatos, quando comparada àquelas observadas para Babesia sp. A alta freqüência de bovinos soropositivos para T. vivax indica que esse hemoprotozoário é prevalente em rebanhos do nordeste do Estado do Pará. O percentual de animais com anticorpos homólogos para B. burgdorferi indica a presenças deste espiroquetídeo transmitido por carrapatos na população de bovinos da região estudada.

Species composition and abundance of the benthic community of Axiidea

ABSTRACT: The thalassinideans (Axiidea and Gebiidea) encompasses approximately 615 species with reclusive habits, generally confined to extensive galleries burrowed into the sand or mud and, more rarely, in openings in reefs or the cavities of sessile animals such as sponges and coral. These species use the galleries for shelter, feeding and breeding, except during the pelagic larval stage. They inhabit estuaries, bays, lagoons, beaches, seas and both tropical and temperate oceanic areas throughout the world, distributed predominantly in the intertidal zone (mid-littoral and infralittoral zones). The aim of the present study was to assess the species composition and abundance of thalassinideans, comparing two micro-habitats (consolidated and non-consolidated substrates), and determine whether there is a correlation between abundance of the organisms and time of the year, collection sites or salinity. Twelve monthly samplings were carried out between August 2006 and July 2007 over consolidated and non-consolidated bottoms of the upper and lower portions of the mid-littoral zones, with three sub-samplings, totaling 48 monthly samples and 576 in all. A total of 651 individuals were collected – 114 Lepidophthalmus siriboia Felder & Rodrigues, 1993 and 537 Upogebia vasquezi Ngoc-Ho, 1989. There was correlation between the abundance of both species and salinity, but U. vasquezi was more abundant in the rainy season. Lepidophthalmus siriboia appears to prefer non-consolidated substrates, whereas U. vasquezi prefers consolidated substrates. The recruitment period for the callianassid L. siriboia appears to occur in just two periods of the year and is more intense in the dry season, whereas U. vasquezi is more frequent throughout the year. The smallest and largest sizes (carapace length – CL) recorded for L. siriboia were smaller than those recorded for the species in northeastern region of Brazil. CL values for ovigerous females suggest that U. vasquezi reaches sexual maturity at a smaller size than L. siriboia.

Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region - North of Brazil)

A distribuição espacial e temporal da densidade e biomassa dos copépodos planctônicos Pseudodiaptomus richardi e P. acutus, ao longo de um gradiente de salinidade, foi estudada no Estuário do Rio Caeté (Norte do Brasil) durante os meses de junho e dezembro de 1998 (estação seca) e fevereiro e maio de 1999 (estação chuvosa). A biomassa dos copépodos foi estimada a partir de parâmetros da regressão baseada na relação entre o peso seco e o comprimento do corpo (prossoma) de organismos adultos. O Estuário do Rio Caeté caracterizou-se por uma grande variação espacial e sazonal na salinidade (0,8-37,2). A relação peso-comprimento para ambas as espécies de Pseudodiaptomus foi do tipo exponencial. Os valores de densidade e biomassa oscilaram entre 0,28-46,18 ind. m^-3 e 0,0022-0,3507 mg DW. m^-3 para P. richardi; e entre 0,01-17,02 ind. m^-3 e 0,0005-0,7181 mg DW. m^-3 para P. acutus. Os resultados revelaram que a contribuição de P. richardi para a produção secundária no Estuário do Rio Caeté é mais importante na zona liminética que em outras zonas onde foram dominantes os regimes eurihalino-polihalino. Contudo, para P. acutus não foi possível observar de forma clara um padrão de distribuição espacial e temporal para a área estudada.

Chemical composition of phytoplankton from the estuaries of Eastern Amazonia

O fitoplancton é de grande importância para os estudos das interações solo-água, como indicadores de modificações químicas e biológicas nos ecossistemas naturais. O objetivo desse estudo foi determinar a composição química total do fitoplâncton nos estuários do rio Pará e Mocajuba (Pará, Brasil). As análises químicas foram realizadas na água superficial, sedimento de fundo (amostra total e fração biodisponível) e no fitoplancton, por espectrometria óptica e de massa com plasma indutivamente acoplado. A composição química elementar do fitoplancton é composta por elevadas concentrações de Ca, P, Mn, Fe, Zn, Al, Ba e Pb. O fitoplancton do estuário do rio Mocajuba é rico em Fe (2.967 a 84.750 µg g^-1) e do rio Pará rico em Al (1.216 a 15.389 µg g^-1), provavelmente com contribuição antropogênica. O material fitoplanctonico apresentou elevado fator de bioconcentração proveniente tanto da água quanto da fração biodisponível, e reflete a eficiência desses organismos em concentrar metais.

Exposure to an extremely low-frequency electromagnetic field only slightly modifies the proteome of Chromobacterium violaceum ATCC 12472

Several studies of the physiological responses of different organisms exposed to extremely low-frequency electromagnetic fields (ELF-EMF) have been described. In this work, we report the minimal effects of in situ exposure to ELF-EMF on the global protein expression of Chromobacterium violaceum using a gel-based proteomic approach. The protein expression profile was only slightly altered, with five differentially expressed proteins detected in the exposed cultures; two of these proteins (DNA-binding stress protein, Dps, and alcohol dehydrogenase) were identified by MS/MS. The enhanced expression of Dps possibly helped to prevent physical damage to DNA. Although small, the changes in protein expression observed here were probably beneficial in helping the bacteria to adapt to the stress generated by the electromagnetic field.