DNA damage profiles induced by sunlight at different latitudes

Despite growing knowledge on the biological effects of ultraviolet (UV) radiation on human health and ecosystems, it is still difficult to predict the negative impacts of the increasing incidence of solar UV radiation in a scenario of global warming and climate changes. Hence, the development and application of DNA-based biological sensors to monitor the solar UV radiation under different environmental conditions is of increasing importance. With a mind to rendering a molecular view-point of the genotoxic impact of sunlight, field experiments were undertaken with a DNA-dosimeter system in parallel with physical photometry of solar UVB/UVA radiation, at various latitudes in South America. Onapplying biochemical and immunological approaches based on specific DNA-repair enzymes and antibodies, for evaluating sunlight-induced DNA damage profiles, it became clear that the genotoxic potential of sunlight does indeed vary according to latitude. Notwithstanding, while induction of oxidized DNA bases is directly dependent on an increase in latitude, the generation of 6-4PPs is inversely so, whereby the latter can be regarded as a biomolecular marker of UVB incidence. This molecular DNA lesion-pattern largely reflects the relative incidence of UVA and UVB energy at any specific latitude. Hereby is demonstrated the applicability of this DNA-based biosensor for additional, continuous field experiments, as a means of registering variations in the genotoxic impact of solar UV radiation. Environ. Mol. Mutagen. 2012. (c) 2012 Wiley Periodicals, Inc.FAPESP (Sao Paulo, Brazil)FAPESP (Sao Paulo, Brazil)CNPq (Brasilia, Brazil)CNPq (Brasilia, Brazil)Ministry of Education, Culture, Sports, Science, and Technology (Japan)Ministry of Education, Culture, Sports, Science, and Technology of JapanLaboratory of Science and Engineering, Takushoku University, JapanLaboratory of Science and Engineering, Takushoku University, Japa

MBSP1: a biosurfactant protein derived from a metagenomic library with activity in oil degradation

Microorganisms represent the most abundant biomass on the planet; however, because of several cultivation technique limitations, most of this genetic patrimony has been inaccessible. Due to the advent of metagenomic methodologies, such limitations have been overcome. Prevailing over these limitations enabled the genetic pool of non-cultivable microorganisms to be exploited for improvements in the development of biotechnological products. By utilising a metagenomic approach, we identifed a new gene related to biosurfactant production and hydrocarbon degradation. Environmental DNA was extracted from soil samples collected on the banks of the Jundiaí River (Natal, Brazil), and a metagenomic library was constructed. Functional screening identifed the clone 3C6, which was positive for the biosurfactant protein and revealed an open reading frame (ORF) with high similarity to sequences encoding a hypothetical protein from species of the family Halobacteriaceae. This protein was purifed and exhibited biosurfactant activity. Due to these properties, this protein was named metagenomic biosurfactant protein 1 (MBSP1). In addition, E. coli RosettaTM (DE3) strain cells transformed with the MBSP1 clone showed an increase in aliphatic hydrocarbon degradation. In this study, we described a single gene encoding a protein with marked tensoactive properties that can be produced in a host cell, such as Escherichia coli, without substrate dependence. Furthermore, MBSP1 has been demonstrated as the frst protein with these characteristics described in the Archaea or Bacteria domains

Microbial culture in minimal medium with oil favors enrichment of biosurfactant producing genes

The waste produced by petrochemical industries has a significant environmental impact. Biotechnological approaches offer promising alternatives for waste treatment in a sustainable and environment-friendly manner. Microbial consortia potentially clean up the wastes through degradation of hydrocarbons using biosurfactants as adjuvants. In this work, microbial consortia were obtained from a production water (PW) sample from a Brazilian oil reservoir using enrichment and selection approaches in the presence of oil as carbon source. A consortium was obtained using Bushnell-Haas (BH) mineral medium with petroleum. In parallel, another consortium was obtained in yeast extract peptone dextrose (YPD)-rich medium and was subsequently compared to the BH mineral medium with petroleum. Metagenomic sequencing of these microbial communities showed that the BH consortium was less diverse and predominantly composed of Brevibacillus genus members, while the YPD consortium was taxonomically more diverse. Functional annotation revealed that the BH consortium was enriched with genes involved in biosurfactant synthesis, while the YPD consortium presented higher abundance of hydrocarbon degradation genes. The comparison of these two consortia against consortia available in public databases confirmed the enrichment of biosurfactant genes in the BH consortium Functional assays showed that the BH consortium exhibits high cellular hydrophobicity and formation of stable emulsions, suggesting that oil uptake by microorganisms might be favored by biosurfactants. In contrast, the YPD consortium was more efficient than the BH consortium in reducing interfacial tension. Despite the genetic differences between the consortia, analysis by a gas chromatography-flame ionization detector showed few significant differences regarding the hydrocarbon degradation rates. Specifically, the YPD consortium presented higher degradation rates of C12 to C14 alkanes, while the BH consortium showed a significant increase in the degradation of some polycyclic aromatic hydrocarbons (PAHs). These data suggest that the enrichment of biosurfactant genes in the BH consortium could promote efficient hydrocarbon degradation, despite its lower taxonomical diversity compared to the consortium enriched in YPD medium. Together, these results showed that cultivation in a minimal medium supplemented with oil was an efficient strategy in selecting biosurfactant-producing microorganisms and highlighted the biotechnological potential of these bacterial consortia in waste treatment and bioremediation of impacted areas

Genetic polymorphisms associated with the inflammatory response in bacterial meningitis

BACKGROUND Bacterial meningitis (BM) is an infectious disease that results in high mortality and morbidity. Despite efficacious antibiotic therapy, neurological sequelae are often observed in patients after disease. Currently, the main challenge in BM treatment is to develop adjuvant therapies that reduce the occurrence of sequelae. In recent papers published by our group, we described the associations between the single nucleotide polymorphisms (SNPs) AADAT +401C > T, APEX1 Asn148Glu, OGG1 Ser326Cys and PARP1 Val762Ala and BM. In this study, we analyzed the associations between the SNPs TNF -308G > A, TNF -857C > T, IL-8 -251A > T and BM and investigated gene-gene interactions, including the SNPs that we published previously. METHODS The study was conducted with 54 BM patients and 110 healthy volunteers (as the control group). The genotypes were investigated via primer-introduced restriction analysis-polymerase chain reaction (PIRA-PCR) or polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) analysis. Allelic and genotypic frequencies were also associated with cytokine and chemokine levels, as measured with the x-MAP method, and cell counts. We analyzed gene-gene interactions among SNPs using the generalized multifactor dimensionality reduction (GMDR) method. RESULTS We did not find significant association between the SNPs TNF -857C > T and IL-8 -251A > T and the disease. However, a higher frequency of the variant allele TNF -308A was observed in the control group, associated with changes in cytokine levels compared to individuals with wild type genotypes, suggesting a possible protective role. In addition, combined inter-gene interaction analysis indicated a significant association between certain genotypes and BM, mainly involving the alleles APEX1 148Glu, IL8 -251 T and AADAT +401 T. These genotypic combinations were shown to affect cyto/chemokine levels and cell counts in CSF samples from BM patients. CONCLUSIONS In conclusion, this study revealed a significant association between genetic variability and altered inflammatory responses, involving important pathways that are activated during BM. This knowledge may be useful for a better understanding of BM pathogenesis and the development of new therapeutic approaches

The Genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles- darlingi. © 2013 The Author(s)

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Epidemiological profile of acute bacterial meningitis in the state of Rio Grande do Norte, Brazil

INTRODUCTION: Acute bacterial meningitis (ABM) remains a public health problem in Brazil. To evaluate the epidemiology of ABM cases at Giselda Trigueiro Hospital, Rio Grande do Norte, a descriptive retrospective survey was conducted covering 2005 to 2008. METHODS: Clinical and laboratory data were collected from the epidemiology department of the hospital and analyzed. RESULTS: Out of 168 ABM cases, 24.4%, 10.7%, and 2.4% were, respectively, caused by Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenza b, and 5.4% by other bacteria. The mean age was 22.48 ± 18.7 years old. CONCLUSIONS: Streptococcus pneumoniae was the main causative pathogen in the young urban population

Obesity and Nutrigenetics Testing: New Insights

Background: Obesity results from interactions between environmental factors, lifestyle, and genetics. In this scenario, nutritional genomics and nutrigenetic tests stand out, with the promise of helping patients avoid or treat obesity. This narrative review investigates whether nutrigenetic tests may help to prevent or treat obesity. Scientific studies in PubMed Science Direct were reviewed, focusing on using nutrigenetic tests in obesity. The work showed that few studies address the use of tools in obesity. However, most of the studies listed reported their beneficial effects in weight loss. Ethical conflicts were also discussed, as in most countries, there are no regulations to standardize these tools, and there needs to be more scientific knowledge for health professionals who interpret them. International Societies, such as the Academy of Nutrition and Dietetics and the Brazilian Association for the Study of Obesity and Metabolic Syndrome, do not recommend nutrigenetic tests to prevent or treat obesity, especially in isolation. Advancing nutrigenetics depends on strengthening three pillars: regulation between countries, scientific evidence with clinical validity, and professional training