Contribution of midgut bacteria to blood digestion and egg production in aedes aegypti (diptera: culicidae) (L.)

<p>Abstract</p> <p>Background</p> <p>The insect gut harbors a variety of microorganisms that probably exceed the number of cells in insects themselves. These microorganisms can live and multiply in the insect, contributing to digestion, nutrition, and development of their host.</p> <p>Recent studies have shown that midgut bacteria appear to strengthen the mosquito's immune system and indirectly enhance protection from invading pathogens. Nevertheless, the physiological significance of these bacteria for mosquitoes has not been established to date. In this study, oral administration of antibiotics was employed in order to examine the contribution of gut bacteria to blood digestion and fecundity in <it>Aedes aegypti</it>.</p> <p>Results</p> <p>The antibiotics carbenicillin, tetracycline, spectinomycin, gentamycin and kanamycin, were individually offered to female mosquitoes. Treatment of female mosquitoes with antibiotics affected the lysis of red blood cells (RBCs), retarded the digestion of blood proteins and reduced egg production. In addition, antibiotics did not affect the survival of mosquitoes. Mosquito fertility was restored in the second gonotrophic cycle after suspension of the antibiotic treatment, showing that the negative effects of antibiotics in blood digestion and egg production in the first gonotrophic cycle were reversible.</p> <p>Conclusions</p> <p>The reduction of bacteria affected RBC lysis, subsequently retarded protein digestion, deprived mosquito from essential nutrients and, finally, oocyte maturation was affected, resulting in the production of fewer viable eggs. These results indicate that <it>Ae. aegypti </it>and its midgut bacteria work in synergism to digest a blood meal.</p> <p>Our findings open new possibilities to investigate <it>Ae. aegypti</it>-associated bacteria as targets for mosquito control strategies.</p

A rationally identified marine GH1 β‐glucosidase has distinguishing functional features for simultaneous saccharification and fermentation

The classical route for second‐generation ethanol from lignocellulosic biomass is hampered by high process costs, fostering the development of alternative strategies such as simultaneous saccharification and fermentation (SSF). However, the lack of compatible enzyme cocktails poses a challenge. In this study, the enzyme EmBgl from the marine bacterium Exiguobacterium marinum was rationally identified based on structural and phylogenetic analyses, known desirable properties of close orthologs, and the ecological niche of its organism source. EmBgl is a multifunctional and glucose‐tolerant enzyme that efficiently hydrolyzes cello‐oligosaccharides due to a positive‐subsite region that can accommodate long cello‐oligosaccharides without imposing steric impediments. The efficacy of EmBgl in an SSF process was demonstrated using pretreated sugarcane bagasse as feedstock, yielding 28 g L−1 of ethanol in 30 h. The distinguishing functional properties of EmBgl and its successful utilization in an SSF process highlight its potential in biotechnological applications in which lignocellulose deconstruction is desirable under milder temperatures14611631179FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP17/14253‐9; 16/19995‐0; 16/06509‐0; 19/08855‐1; 15/26982‐0; 18/02865‐2; 16/06509‐0; 16/19995‐0; 17/14253‐9; 18/02865‐2; 15/26982‐0; 19/08855‐

Child maltreatment: a survey of dentists in southern Brazil

Child abuse is a serious public health problem and affects the victims&#39 physical and mental health and development. The aims of this study were two-fold: to assess the attitudes and perceptions of dentists regarding child abuse, and to investigate professional characteristics associated with the identification of suspected child abuse. A questionnaire was sent to the 276 dentists of Pelotas, RS, Brazil , and 187 (68.0%) were returned. Demographic characteristics and profiles of the dentists, and information about their knowledge and attitudes regarding child abuse were collected. Descriptive analysis was performed, and associations were tested by chi-square and Fisher&#39;s exact tests. From all dentists surveyed, 123 (71.9%) reported providing treatment for children. Most dentists believed they could detect cases of child abuse (78.7%), but 85.7% had never suspected it. Among those who did suspect, 76.0% did not report the cases to authorities. No differences were observed between sexes, years of graduation, types of licenses, and the frequency at which children were treated. A higher proportion of dentists working at university had suspected child abuse. Even though dentists considered themselves able to identify suspicious cases, only a small percentage reported those suspicions, indicating a lack of awareness by these professionals in the adoption of protective measures for victims of aggression. It is necessary that dental professionals receive interdisciplinary training to enhance their ability to care for and protect children