Molecular structure of endotoxins from Gram-negative marine bacteria: an update

Marine bacteria are microrganisms that have adapted, through millions of years, to survival in environments often characterized by one or more extreme physical or chemical parameters, namely pressure, temperature and salinity. The main interest in the research on marine bacteria is due to their ability to produce several biologically active molecules, such as antibiotics, toxins and antitoxins, antitumor and antimicrobial agents. Nonetheless, lipopolysaccharides (LPSs), or their portions, from Gram-negative marine bacteria, have often shown low virulence, and represent potential candidates in the development of drugs to prevent septic shock. Besides, the molecular architecture of such molecules is related to the possibility of thriving in marine habitats, shielding the cell from the disrupting action of natural stress factors. Over the last few years, the depiction of a variety of structures of lipids A, core oligosaccharides and O-specific polysaccharides from LPSs of marine microrganisms has been given. In particular, here we will examine the most recently encountered structures for bacteria belonging to the genera Shewanella, Pseudoalteromonas and Alteromonas, of the γ-Proteobacteria phylum, and to the genera Flavobacterium, Cellulophaga, Arenibacter and Chryseobacterium, of the Cytophaga-Flavobacterium-Bacteroides phylum. Particular attention will be paid to the chemical features expressed by these structures (characteristic monosaccharides, non-glycidic appendages, phosphate groups), to the typifying traits of LPSs from marine bacteria and to the possible correlation existing between such features and the adaptation, over years, of bacteria to marine environments.     

黄羽肉种鸡营养需要量与饲料研究进展

为促进我国黄羽肉鸡种业高效、健康发展,解决目前存在的饲粮浪费、环境污染以及繁殖效能低下等问题尤为关键。总结了关于黄羽肉种鸡营养需要量和饲料研究方面的国内外相关文献,从其代谢能、粗蛋白质、主要必需氨基酸（蛋氨酸、赖氨酸、苏氨酸、色氨酸、精氨酸和异亮氨酸）、维生素（VA、VD、VE）和矿物元素（钙、磷、铁、铜、锌、锰和硒）的需要量,饲料资源评价与利用,生物活性添加剂益生素与益生菌,植物提取物和中草药制剂,抗应激剂应用等方面研究现状进行较全面的综述,对存在问题和未来研发趋势进行分析。总体来看,近年来在黄羽肉种鸡营养需要量和饲料添加剂的应用研究越来越多,但主要集中在产蛋期,研发亮点在于开展黄羽肉鸡代谢能每天需要量与代谢体重、平均日增重和产蛋量的相关性分析,以代谢体重、平均日增重和产蛋量为变量,建立了重型、中型和轻型 3 种类型黄羽肉种母鸡日粮氮校正代谢能需要量析因法预测模型。目前黄羽肉种鸡育雏期、育成期营养及限饲技术研究报道较少,饲料资源评价与安全高效利用技术、繁殖性能提升关键技术等仍需进一步突破。     

天然雌核发育普安鲫(A型)细胞遗传学和血清电泳的初步研究

本文对贵州省普安县青山一带天然水体中的普安鲫(A型)作了细胞遗传学观察和血清电泳分析,发现它是天然雌核发育的鲫鱼,既不同于普通野鲫,也与已知的天然雌核发育方正银鲫和滇池高背鲫不是同一来源。     

Hemophilia A in a Belgian Shepherd Malinois dog: case report

This case report presents a Belgian Shepherd Malinois dog affected by hemophilia A recognized at the age of seven months. The clinical follow-up including all the diagnostic procedures leading to the final diagnosis and the course of this disorder are presented.     

Different stressors elicit different responses in the salivary biomarkers cortisol,haptoglobin, and chromogranin A in pigs

Most commonly, salivary cortisol is used in pig stress assessment, alternative salivary biomarkers are scarcely studied. Here, salivary cortisol and two alternative salivary biomarkers, haptoglobin and chromogranin A were measured in a pig stress study. Treatment pigs (n = 24) were exposed to mixing and feed deprivation, in two trials, and compared to untreated controls (n = 24). Haptoglobin differed for feed deprivation vs control. Other differences were only found within treatment. Treatment pigs had higher salivary cortisol concentrations on the mixing day (P < 0.05). Chromogranin A concentrations were increased on the day of refeeding (P < 0.05). Haptoglobin showed a similar pattern to chromogranin A. Overall correlations between the salivary biomarkers were positive. Cortisol and chromogranin A were moderately correlated (r = 0.49, P < 0.0001), correlations between other markers were weaker. The present results indicate that different types of stressors elicited different physiological stress responses in the pigs, and therefore including various salivary biomarkers in stress evaluation seems useful.     

Genomic analysis of influenza A virus from captive wild boars in Brazil reveals a human-like H1N2 influenza virus

Influenza is a viral disease that affects human and several animal species. In Brazil, H1N1, H3N2 and 2009 pandemic H1N1 A(H1N1)pdm09 influenza A viruses (IAV) circulate in domestic swine herds. Wild boars are also susceptible to IAV infection but in Brazil until this moment there are no reports of IAV infection in wild boars or in captive wild boars populations. Herein the occurrence of IAV in captive wild boars with the presence of lung consolidation lesions during slaughter was investigated. Lung samples were screened by RT-PCR for IAV detection. IAV positive samples were further analyzed by quantitative real-time PCR (qRRT-PCR), virus isolation, genomic sequencing, histopathology and immunohistochemistry (IHC). Eleven out of 60 lungs (18.3%) were positive for IAV by RT-PCR and seven out of the eleven were also positive for A(H1N1)pdm09 by qRRT-PCR. Chronic diffuse bronchopneumonia was observed in all samples and IHC analysis was negative for influenza A antigen. Full genes segments of H1N2 IAV were sequenced using Illumina's genome analyzer platform (MiSeq). The genomic analysis revealed that the HA and NA genes clustered with IAVs of the human lineage and the six internal genes were derived from the H1N1pdm09 IAV. This is the first report of a reassortant human-like H1N2 influenza virus infection in captive wild boars in Brazil and indicates the need to monitor IAV evolution in Suidae populations.     

Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt

Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n = 1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n = 1242) and wild birds (n = 807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n = 306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p < 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F = 29.5, p < 0.0001).     

Establishment of a Conditional Transgenic System Using the 2A Peptide in the Female Mouse Germline

Transgenic mice are essential research tools in developmental biology studies. The 2A peptide allows multiple genes to be expressed simultaneously at comparable levels in somatic cells, but there are no reports of it being used successfully in germ cells. We constructed a Cre/loxP-based conditional vector containing the 2A peptide to significantly enhance the expression of a reporter and target gene from a constitutive promoter in oocytes. Mice with a transgene insertion containing the chicken β-actin promoter, floxed EGFP-polyA cassette, mCherry reporter, 2A peptide and target gene DNA methyltransferase 3A2 (Dnmt3a2) were crossed with TNAP- or Vasa-Cre mice to produce offspring, in which mCherry and DNMT3A2 proteins were highly expressed in oocytes upon Cre-mediated removal of EGFP-polyA. This novel transgenic mouse line based on the 2A expression system can serve as a useful tool for examining gene function during oogenesis.     

检测水貂出血性肺炎绿脓杆菌的比色LAMP法的建立与应用

为了快速有效检测水貂出血性肺炎病原绿脓杆菌,本研究结合金属指示剂HNB特性建立了快速检测绿脓杆菌比色LAMP法。根据绿脓杆菌外毒素A基因设计引物,建立了检测LAMP法;并且对该方法进行了特异性、灵敏性分析;同时进行了初步应用。结果显示,该方法特异性强,灵敏性好,可检测167CFU/mL的菌体,对病貂肺脏检出率高。结果表明,该比色LAMP法可以有效地检测水貂出血性肺炎绿脓杆菌。