Efficient nitrogen-fixing <Emphasis Type="Italic">Rhizobium</Emphasis> strains isolated from amazonian soils are highly tolerant to acidity and aluminium

One of the most cultivated and consumed vegetables in Brazil is the common bean, Phaseolus vulgaris L. The symbiosis of this plant species with nitrogen-fixing bacteria that are adapted to the stresses commonly found in tropical soils can increase production. The aim of this study was to evaluate the symbiotic effectiveness of bacterial strains from soils under different land uses in the Amazon region. Further, rhizobia tolerance to acidity and aluminium and the involvement of some possible physiological mechanisms of such tolerance were also investigated. In assessing the efficiency of biological nitrogen fixation, inoculation with strains UFLA04-195, UFLA04-173 and UFLA04-202, belonging to the genus Rhizobium, resulted in greater plant growth, higher shoot nitrogen content and good nodulation compared to the inoculation with the strain CIAT 899 (R. tropici), and to the mineral nitrogen control or Burkholderia fungorum strains that nodulated or not bean plants. These efficient strains grew better at pH 5.0 than at pH 6.0 or pH 6.9; they also tolerated up to 1 mmol l⁻¹ of Al³⁺ and showed an increased production of exopolysaccharides where the growing rates were less (pH 6.0 and pH 6.9). With respect to aluminium, the highest production of EPS produced greater tolerance to this element. Taken together, these results indicate that the strains evaluated in this study were tolerant to acidity and aluminium; they appeared to have developed resistance mechanisms such as EPS production and a resistant cell outer membrane (indicated by resistance to polymyxin and methyl violet). As these strains also gave increased yields of the host species, further studies on whether to recommend these strains as inoculants are already underway.     

Oxoquinoline acyclonucleoside phosphonate analogues as a new class of specific inhibitors of human immunodeficiency virus type 1

The emergence of a multidrug-resistant HIV-1 strain and the toxicity of anti-HIV-1 compounds approved for clinical use are the most significant problems facing antiretroviral therapies. Therefore, it is crucial to find new agents to overcome these issues. In this study, we synthesized a series of new oxoquinoline acyclonucleoside phosphonate analogues (ethyl 1-[(diisopropoxyphosphoryl)methyl]-4-oxo-1,4-dihydroquinoline-3-carboxylates 3a-3k), which contained different substituents at the C6 or C7 positions of the oxoquinoline nucleus and an N1-bonded phosphonate group. We subsequently investigated these compounds' in vitro inhibitory effects against HIV-1-infected peripheral blood mononuclear cells (PBMCs). The most active compounds were the fluoro-substituted derivatives 3f and 3g, which presented excellent EC(50) values of 0.4±0.2 μM (3f) and 0.2±0.005 μM (3g) and selectivity index values (SI) of 6240 and 14675, respectively.     

Technetium-99m-labeled ceftizoxime loaded long-circulating and pH-sensitive liposomes used to identify osteomyelitis

Osteomyelitis is an infectious disease located in the bone or bone marrow. Long-circulating and pH-sensitive liposomes containing a technetium-99m-labeled antibiotic, ceftizoxime, (SpHL-(99m)Tc-CF) were developed to identify osteomyelitis foci. Biodistribution studies and scintigraphic images of bone infection or non infection-bearing rats that had been treated with these liposomes were performed. A high accumulation in infectious foci and high values in the target-non target ratio could be observed. These results indicate the potential of SpHL-(99m)Tc-CF as a potential agent for the diagnosis of bone infections.     

Central pharmacological activity of a new piperazine derivative: 4-(1-phenyl-1h-pyrazol-4-ylmethyl)-piperazine-1-carboxylic acid ethyl ester

AimsOur study focuses on the design and synthesis of a new piperazinic derivate, 4-(1-phenyl-1h-Pyrazol-4-Ylmethyl)-Piperazine-1-Carboxylic Acid Ethyl ester (LQFM008), and evaluation of its anxiolytic-like profile in Swiss mice.Main methodsLQFM008 was evaluated in a screening test of the central nervous system including the rota-rod, sodium pentobarbital-induced sleep, open field, elevated plus maze and light–dark box tests.Key findingsLQFM008 induced convulsions at the dose of 1.1 mmol/kg (i.p., s.c. or p.o.). LQFM008 up to 400 μmol/kg had no effect in the rota rod test. In the open field test, LQFM008 increased the number of crossings and the time spent at the central area as well as the sleeping time in sodium pentobarbital-induced sleep. In the elevated plus maze and light–dark box tests, this compound showed an anxiolytic-like activity. This anxiolytic-like activity was antagonized by NAN-190 (5-HT_1A antagonist) but not by flumazenil (benzodiazepine antagonist).SignificanceThe compound LQFM008 showed anxiolytic-like activity which may involve serotonergic pathway.     

Application of the Apn2/MAT locus to improve the systematics of the Colletotrichum gloeosporioides complex: an example from coffee (Coffea spp.) hosts

To improve phylogenetic resolution of the Colletotrichum gloeosporioides species complex we developed and tested the performance of a new set of primers for the Apn2/MAT locus with a case study of 22 isolates. These were isolated mainly from coffee plants and represent six divergent and well characterized species within the C. gloeosporioides complex. Following previous studies on this locus, we have generated sequence data from an expanded region (> 4600 bp), revealing increased phylogenetic informativeness when compared to other commonly used markers such as ITS, β-tub2 and GS. Within the Apn2/MAT locus the ApMAT marker alone was almost as informative in terms of phylogenetic resolution as a seven-gene concatenated dataset. Our results further revealed that gene-tree discordance may come to be a common issue in resolving evolutionary relationships in the C. gloeosporioides complex, highlighting the importance of multilocus approaches. The use of state-of-the-art data analysis techniques and a highly informative dataset as employed here may abate this issue and hopefully assist in disentangling the C. gloeosporioides complex.     

Use of the advanced backcross-QTL method to transfer seed mineral accumulation nutrition traits from wild to Andean cultivated common beans

Iron deficiency anemia and zinc deficiency are major health concerns across the world and can be addressed by biofortification breeding of higher mineral concentration in staple crops, such as common bean. Wild common beans have for the most part had higher average seed mineral concentration than cultivars of this species but have small un-commercial seeds. A logical approach for the transfer of the seed mineral trait from wild beans to cultivated beans is through the advanced backcross breeding approach. The goal of this study was to analyze a population of 138 BC(2)F(3:5) introgression lines derived from the very high iron wild genotype G10022 backcrossed into the genetic background of the commercial-type variety 'Cerinza', a large-red seeded bush bean cultivar of the Andean genepool. In addition to measuring seed mineral accumulation traits and the quantitative trait loci (QTL) controlling these traits we were interested in simultaneously testing the adaptation of the introgression lines in two replicated yield trials. We found the cross to have high polymorphism and constructed an anchored microsatellite map for the population that was 1,554-cM long and covered all 11 linkage groups of the common bean genome. Through composite interval mapping (CIM) and single point analysis (SPA), we identified associations of markers and mineral traits on b01, b06, b07, b08, b10 and b11 for seed iron concentration, and markers on b01, b04 and b10 for seed zinc concentration. The b07 and b08 QTL aligned with previous QTL for iron concentration. A large number of QTL were found for seed weight (9 with CIM and 36 with SPA analysis) and correlations between seed size and mineral content affected the identification of iron and zinc contents' QTL on many linkage groups. Segregation distortion around domestication genes made some areas difficult to introgress. However, in conclusion, the advanced backcross program produced some introgression lines with high mineral accumulation traits using a wild donor parent.     

Numts help to reconstruct the demographic history of the ocellated lizard (Lacerta lepida) in a secondary contact zone

In northwestern Iberia, two largely allopatric Lacerta lepida mitochondrial lineages occur, L5 occurring to the south of Douro River and L3 to the north, with a zone of putative secondary contact in the region of the Douro River valley. Cytochrome b sequence chromatograms with polymorphisms at nucleotide sites diagnostic for the two lineages were detected in individuals in the region of the Douro River and further north within the range of L3. We show that these polymorphisms are caused by the presence of four different numts (I-IV) co-occurring with the L3 genome, together with low levels of heteroplasmy. Two of the numts (I and II) are similar to the mitochondrial genome of L5 but are quite divergent from the mitochondrial genome of L3 where they occur. We show that these numts are derived from the mitochondrial genome of L5 and were incorporated in L3 through hybridization at the time of secondary contact between the lineages. The additional incidence of these numts to the north of the putative contact zone is consistent with an earlier postglacial northward range expansion of L5, preceding that of L3. We show that genetic exchange between the lineages responsible for the origin of these numts in L3 after secondary contact occurred prior to, or coincident with, the northward expansion of L3. This study shows that, in the context of phylogeographic analysis, numts can provide evidence for past demographic events and can be useful tools for the reconstruction of complex evolutionary histories.     

Group B streptococcus GAPDH is released upon cell lysis, associates with bacterial surface, and induces apoptosis in murine macrophages

Glyceraldehyde 3-phosphate dehydrogenases (GAPDH) are cytoplasmic glycolytic enzymes that, despite lacking identifiable secretion signals, have been detected at the surface of several prokaryotic and eukaryotic organisms where they exhibit non-glycolytic functions including adhesion to host components. Group B Streptococcus (GBS) is a human commensal bacterium that has the capacity to cause life-threatening meningitis and septicemia in newborns. Electron microscopy and fluorescence-activated cell sorter (FACS) analysis demonstrated the surface localization of GAPDH in GBS. By addressing the question of GAPDH export to the cell surface of GBS strain NEM316 and isogenic mutant derivatives of our collection, we found that impaired GAPDH presence in the surface and supernatant of GBS was associated with a lower level of bacterial lysis. We also found that following GBS lysis, GAPDH can associate to the surface of many living bacteria. Finally, we provide evidence for a novel function of the secreted GAPDH as an inducer of apoptosis of murine macrophages.