Metabolic and physiological adaptations of microalgal growth-promoting bacterium Azospirillum brasilense growing under biogas atmosphere: a microarray-based transcriptome analysis.

Using microalgal growth-promoting bacteria (MGPB) to improve the cultured microalga metabolism during biotechnological processes is one of the most promising strategies to enhance their benefits. Nonetheless, the culture condition effect used during the biotechnological process on MGPB growth and metabolism is key to ensure the expected positive bacterium growth and metabolism of microalgae. In this sense, the present research study investigated the effect of the synthetic biogas atmosphere (75% CH4-25% CO2) on metabolic and physiological adaptations of the MGPB Azospirillum brasilense by a microarray-based transcriptome approach. A total of 394 A. brasilense differentially expressed genes (DEGs) were found: 201 DEGs (34 upregulated and 167 downregulated) at 24 h and 193 DEGs (140 upregulated and 53 downregulated) under the same conditions at 72 h. The results showed a series of A. brasilense genes regulating processes that could be essential for its adaptation to the early stressful condition generated by biogas. Evidence of energy production is shown by nitrate/nitrite reduction and activation of the hypothetical first steps of hydrogenotrophic methanogenesis; signal molecule modulation is observed: indole-3-acetic acid (IAA), riboflavin, and vitamin B6, activation of Type VI secretion system responding to IAA exposure, as well as polyhydroxybutyrate (PHB) biosynthesis and accumulation. Moreover, an overexpression of ipdC, ribB, and phaC genes, encoding the key enzymes for the production of the signal molecule IAA, vitamin riboflavin, and PHB production of 2, 1.5 and 11 folds, respectively, was observed at the first 24 h of incubation under biogas atmosphere Overall, the ability of A. brasilense to metabolically adapt to a biogas atmosphere is demonstrated, which allows its implementation for generating biogas with high calorific values and the use of renewable energies through microalga biotechnologies.

Endogenous viral elements in mosquito genomes: current knowledge and outstanding questions.

Integrations from non-retroviral RNA viruses (nrEVEs) have been identified across several taxa, including mosquitoes. Amongst all Culicinae species, the viral vectors Aedes aegypti and Aedes albopictus stand out for their high number of nrEVEs. In addition, Aedes nrEVEs are enriched in piRNA clusters and generate piRNAs that can silence incoming viral genomes. As such, nrEVEs represent a new form of inherited antiviral immunity. To propel this discovery into novel transmission-blocking vector control strategies, a deeper understanding of nrEVE biology and evolution is essential because differences in the landscape of nrEVEs have been identified in wild-caught mosquitoes, the piRNA profile of nrEVEs is not homogeneous and nrEVEs outside piRNA clusters exist and are expressed at the mRNA level. Here we summarise current knowledge on nrEVEs in mosquitoes and we point out the many unanswered questions and potentials of these genomic elements.

[Use of non-occupational HIV post-exposure prophylaxis in Spain (2001-2005)]. / Demanda y prescripción de la profilaxis postexposición no ocupacional al VIH en España (2001-2005).

BACKGROUND: Non-occupational post-exposure prophylaxis for human immunodeficiency virus (HIV) infection is widely used, although there is little available scientific evidence to support its effectiveness. The aim of this study is to describe the characteristics of the persons exposed, types of exposures, antiretroviral treatment prescribed, and outcome of HIV infection in cases of non-occupational exposure in Spain. METHOD: The data used included all cases of accidental HIV exposure notified to the Non-occupational Post-exposure Prophylaxis Information System between January 2001 and December 2005. Non-occupational exposure to HIV was defined as accidental contact with blood and/or other biological fluids outside the healthcare setting. RESULTS: A total of 993 cases of exposure were notified (569 men [57.3%]); median age was 30 years (range: 1-87). Exposure was sexual in 53.1%, parenteral in 39.8%, and other types in 7.2%. The source person was identified in 82.7% of cases. Antiretroviral treatment (ART) was prescribed in 528 cases (53.2%), with triple therapy in 68.2%. A total of 54.2% returned for the 6-month visit among patients receiving ART and 61.1% among those without this therapy (P < 0.05). One or more side effects developed in 135 (32.4%) cases, and there were 18 treatment interruptions (4.3%). Three seroconversions to HIV were notified (0.3%). CONCLUSIONS: A national registry for monitoring non-occupational post-exposure prophylaxis to HIV is needed because of the high number of cases notified, the considerable incidence of side effects, and the difficulties of follow-up.