Effects of trophic 2,2′, 4,4′-tetrabromodiphenyl ether (BDE-47) exposure in Oreochromis niloticus: A multiple biomarkers analysis

Polybrominated diphenyl esters are emerging environmental contaminants with few toxicological data, being a concern for the scientific community. This study evaluated the effects of BDE-47 on the health of Oreochromis niloticus fish. The animals were exposed to three doses of BDE-47 (0, 0.253, 2.53, 25.3 ng g⁻¹) every 10 days, for 80 days. The BDE-47 affected the hepatosomatic and gonadosomatic index in female and the condition factor by intermediate dose in both sexes. The levels of estradiol decreased and the T4 are increased, but the vitellogenin production was not modulated in male individuals. Changes in AChE, GST, LPO and histopathology were observed while the integrated biomarker response index suggests that the lowest dose of BDE-47 compromised the activity of antioxidant enzymes. The oral exposure to BDE-47 in environmental concentrations is toxic to O. niloticus and the use of multiple biomarkers is an attribution in ecotoxicology studies and biomonitoring programs.     

Vaxvec: The first web-based recombinant vaccine vector database and its data analysis

A recombinant vector vaccine uses an attenuated virus, bacterium, or parasite as the carrier to express a heterologous antigen(s). Many recombinant vaccine vectors and related vaccines have been developed and extensively investigated. To compare and better understand recombinant vectors and vaccines, we have generated Vaxvec (http://www.violinet.org/vaxvec), the first web-based database that stores various recombinant vaccine vectors and those experimentally verified vaccines that use these vectors. Vaxvec has now included 59 vaccine vectors that have been used in 196 recombinant vector vaccines against 66 pathogens and cancers. These vectors are classified to 41 viral vectors, 15 bacterial vectors, 1 parasitic vector, and 1 fungal vector. The most commonly used viral vaccine vectors are double-stranded DNA viruses, including herpesviruses, adenoviruses, and poxviruses. For example, Vaxvec includes 63 poxvirus-based recombinant vaccines for over 20 pathogens and cancers. Vaxvec collects 30 recombinant vector influenza vaccines that use 17 recombinant vectors and were experimentally tested in 7 animal models. In addition, over 60 protective antigens used in recombinant vector vaccines are annotated and analyzed. User-friendly web-interfaces are available for querying various data in Vaxvec. To support data exchange, the information of vaccine vectors, vaccines, and related information is stored in the Vaccine Ontology (VO). Vaxvec is a timely and vital source of vaccine vector database and facilitates efficient vaccine vector research and development.     

Comparative proteomics reveals essential mechanisms for osmotolerance in Gluconacetobacter diazotrophicus

Plant growth-promoting bacteria are a promising alternative to improve agricultural sustainability. Gluconacetobacter diazotrophicus is an osmotolerant bacterium able to colonize several plant species, including sugarcane, coffee, and rice. Despite its biotechnological potential, the mechanisms controlling such osmotolerance remain unclear. The present study investigated the key mechanisms of resistance to osmotic stress in G. diazotrophicus. The molecular pathways regulated by the stress were investigated by comparative proteomics, and proteins essential for resistance were identified by knock-out mutagenesis. Proteomics analysis led to identify regulatory pathways for osmotic adjustment, de novo saturated fatty acids biosynthesis, and uptake of nutrients. The mutagenesis analysis showed that the lack of AccC protein, an essential component of de novo fatty acid biosynthesis, severely affected G. diazotrophicus resistance to osmotic stress. Additionally, knock-out mutants for nutrients uptake (Δtbdr and ΔoprB) and compatible solutes synthesis (ΔmtlK and ΔotsA) became more sensitive to osmotic stress. Together, our results identified specific genes and mechanisms regulated by osmotic stress in an osmotolerant bacterium, shedding light on the essential role of cell envelope and extracytoplasmic proteins for osmotolerance.     

Spatial spread and demographic expansion of Lyme borreliosis spirochaetes in Eurasia

The Lyme borreliosis (LB) group of spirochaetes currently comprises 18 named species that vary in their geographic distribution, host specificity and ability to cause disease in humans. In Europe three species are most abundant, Borrelia afzelii, Borrelia garinii and Borrelia valaisiana but only two of these (B. garinii and B. afzelii) are regularly found in Asia as well. A recently published study has shown that Borrelia species associated with birds, such as B. garinii, showed limited geographic structuring between European countries while, the rodent associated species, B. afzelii, showed extensive spatial structuring in Europe. Here, we use multilocus sequence analysis to show that when the wider, inter-continental, distribution is considered, there is evidence of spatial structuring even in the bird-associated species B. garinii. Furthermore, our investigations into historical LB populations provided evidence for range expansions of B. garinii and B. afzelii populations in Europe in the distant past. We propose that the expansion of B. afzelii in Europe may be linked to rodent population expansions after the last glacial maximum.     

Bacterial associates of Hyalesthes obsoletus (Hemiptera: Cixiidae), the insect vector of bois noir disease,with a focus on cultivable bacteria

The planthopper Hyalesthes obsoletus (Hemiptera: Cixiidae) is an important vector of phytoplasma diseases in grapevine. In the current study, the bacterial community compositions of symbionts of this insect were examined. Two dominant bacterial lineages were identified by mass sequencing: the obligate symbiont Candidatus Sulcia, and a facultative symbiont that is closely related to Pectobacterium sp. and to BEV, a cultivable symbiont of another phytoplasma vector, the leafhopper Euscelidius variegatus. In addition, one bacterium was successfully isolated in this study – a member of the family Xanthomonadaceae that is most closely related to the genus Dyella. This Dyella-like bacterium (DLB) was detected by FISH analysis in H. obsoletus guts but not ovaries, and its prevalence in H. obsoletus increased during the fall, suggesting that it was acquired by the host through feeding. We found that DLB inhibits Spiroplasma melliferum, a cultivable relative of phytoplasma, suggesting that it is a potential candidate for biological control against phytoplasma in grapevines.     

Lymphopenic community-acquired pneumonia is associated with a dysregulated immune response and increased severity and mortality

ObjectivesLymphopenic (<724 lymphocytes/µL) community-acquired pneumonia (L-CAP) is an immunophenotype with an increased risk of mortality. We aimed to characterize the l-CAP immunophenotype though lymphocyte subsets and the inflammatory response and its relationship with severity at presentation and outcome.MethodsProspective study of 217 immunocompetent patients hospitalized for CAP. Lymphocyte subsets (CD4⁺, CD8⁺, CD19⁺, and natural killer [NK] cells) and inflammatory cytokines were analyzed on days 1 and 4, and immunoglobulin subclasses were analyzed on day 1 in a nested group.Results39% of patients showed l-CAP, with decreased levels of all lymphocyte subsets with a partial recovery of CD4⁺ and CD8⁺ cells by day 4. l-CAP patients exhibited higher initial severity and systemic levels of interleukin (IL)-8, IL-10, granulocyte colony-stimulating factor, and monocyte chemoattractant protein-1. Initial IgG2 levels were lower in patients with <724 lymphocytes/µL and positively correlated with ALC, CD4⁺, and CD19⁺ cell counts. Low CD4⁺ counts (<129 cells/µL) also independently predicted 30-day mortality after adjusting for age, gender, and the CURB-65 score.Conclusionsl-CAP is characterized by CD4⁺ depletion, a higher inflammatory response, and low IgG2 levels that correlated with greater severity at presentation and worse prognosis. l-CAP is an immunophenotype useful for rapidly recognizing severity.     

非新生儿破伤风诊疗规范

破伤风分为新生儿破伤风和非新生儿破伤风。我国已于2012年消除了新生儿破伤风,但非新生儿破伤风仍是一个严重的公共卫生问题。非新生儿破伤风重症患者在无医疗干预的情况下,病死率接近100%,即使经过积极的综合治疗,全球范围病死率仍为30%~50%,是一种极为严重的潜在致命性疾病。为规范我国非新生儿破伤风诊疗行为,提高医疗质量,保障医疗安全,特制定本规范。本规范包括了非新生儿破伤风的病原学、流行病学、发病机制、临床表现及实验室检查、诊断、鉴别诊断、分级、治疗等方面内容。