Frequent human‐poultry interactions and low prevalence of Salmonella in backyard chicken flocks in Massachusetts

The backyard chicken (BYC) movement in the USA has increased human contact with poultry and subsequently, human contact with the pathogen Salmonella. However, to date, there have been few studies assessing prevalence of Salmonella in backyard flocks, despite the known public health risk this zoonotic bacterium poses. The objective of this study was to characterize human‐BYC interactions and assess the prevalence of Salmonella among BYC flocks. We interviewed 50 BYC owners using a structured questionnaire to determine flock and household characteristics that facilitate contact with BYC and that may be associated with Salmonella in the BYC environment. Composite faecal material, cloacal swabs and dust samples from 53 flocks housed on 50 residential properties in the Greater Boston, Massachusetts area were tested for Salmonella using standard culture techniques and confirmed using Matrix‐Assisted Laser Desorption/Ionization‐Time of Flight Mass Spectrometer. Microbroth dilution and whole genome sequencing were used to determine phenotypic and genotypic resistance profiles, respectively, and sequence results were used to determine multilocus sequencing type. No owners self‐reported a diagnosis of salmonellosis in the household. Over 75% of a subset of owners reported that they and their children consider BYC pets. This perception is evident in how owners reported interacting with their birds. Salmonella enterica subspecies enterica serotype Kentucky ST152 (serogroup C)—a strain not commonly associated with human infection—was confirmed in one flock, or 2% of tested flocks, and demonstrated resistance to tetracycline and streptomycin. We detected Salmonella at low prevalence in BYC. Further study of the health effects of exposure to zoonotic gastrointestinal pathogens such as Salmonella among families with BYC is warranted.     

马驽巴贝斯虫新疆伊犁株Bc48基因克隆、表达及其多克隆抗体的制备

为表达马驽巴贝斯虫新疆伊犁株Bc48基因,制备多克隆抗体,试验根据GenBank中马驽巴贝斯虫Bc48基因序列,设计合成1对特异性引物,以提取的新疆株Bc48基因组DNA为模板进行PCR扩增,将扩增产物克隆至原核表达载体pET-28a（+）中,阳性质粒转化至大肠杆菌BL21（DE3）感受态细胞中,经IPTG诱导后表达产物进行SDS-PAGE分析,切胶纯化蛋白后免疫6周龄雌性BALB/c小鼠,制备多克隆抗体;同时把该基因克隆至真核表达载体pCMV-N-flag中,将阳性质粒转化至大肠杆菌DH5α感受态细胞中,提取pCMV-N-flag-Bc48质粒转染到293T细胞中进行真核表达。结果显示,获得了大小约为15 ku的融合蛋白,与预期目的蛋白大小相一致;免疫BALB/c小鼠制备的多克隆抗体经ELISA和Western blotting检测、验证,能特异地识别相应抗原,其抗体效价可达1：128 000,说明该多克隆抗体有较高的抗体效价和特异性;真核表达质粒在293T细胞中表达Bc48蛋白。本试验可为进一步研究马驽巴贝斯虫功能基因及建立快速的检测方法奠定基础,在虫株的分类学研究及候选疫苗的研制中有重要意义。     

重金属铬及盐胁迫对小香蒲种子萌发的影响

小香蒲是湿地生态系统中重要的植物种。以小香蒲为材料,探讨不同浓度的铬(Cr6+)及盐胁迫(NaCl与NaNO3)对小香蒲种子萌发的影响。结果表明,当Cr6+浓度为5 mg/L时,Cr6+对小香蒲种子萌发率略微有促进作用,而浓度为10、50、100 mg/L依次递增时,Cr6+不利于小香蒲种子的萌发和生长,即Cr6+对小香蒲种子的抑制作用逐渐增大。盐胁迫下,随着盐浓度的不断增大,小香蒲种子的发芽势、发芽率均呈下降趋势。     

Nasal vascular hamartoma in a Domestic Shorthair cat

A nasal mass in a Domestic Shorthair cat was causing facial deformity, sneezing and intermittent epistaxis. Biopsy samples obtained previously had been non-diagnostic. Computed tomography images revealed an irregular, contrast-enhancing mass occupying a large portion of the righthand side of the nasal cavity. Previously described criteria for malignancy were not present. A ventral surgical approach combined with temporary, ipsilateral, common carotid arterial occlusion provided excellent access for debulking the lesion and collecting samples for histopathology. A nasal vascular hamartoma was diagnosed and clinical signs resolved postoperatively. This is the first documentation of this abnormality in the cat. Hamartomatous abnormalities should be included on the list of differential diagnoses for feline nasal mass lesions. The prognosis for hamartomatous lesions postoperatively is good, in keeping with their limited propensity for growth after maturity.     

Organic and conventional agriculture: Materializing discourse and agro-ecological managerialism

This introduction situates key themesfound in papers given at a recent workshop on thechanging material practices, meanings, and regulationof US organic food production. The context is theemergence of an international bio-politics ofagriculture and food and, more particularly in the US,the contradictions of sustainable agriculturemovements catalyzed by the rapid scaling up of organicagriculture from a niche activity to nascentindustry.     

Detecting fish parvalbumin with commercial mouse monoclonal anti-frog parvalbumin IgG

Parvalbumin is a calcium-binding muscle protein that is highly conserved across fish species and amphibians. It is the major cross-reactive allergen associated with both fish and frog allergy. We used two-dimensional electrophoretic and immunoblotting techniques to investigate the utility of a commercial monoclonal anti-frog parvalbumin IgG for detecting parvalbumin present in some commonly consumed fish species. The 2D electrophoresis and immunoblots revealed species-specific differences in proteins that appear to represent various numbers of isoforms of parvalbumin in carp (5), catfish (3), cod (1) and tilapia (2). No parvalbumin was detected in yellowfin tuna. Based on minor differences in relative intensities of protein staining and immunodetection, parvalbumin isoforms may have slight differences in the epitope region recognized by the anti-frog parvalbumin antibody. These results suggest that the frog anti-parvalbumin antibody can be used as a valuable tool to detect parvalbumins from the fish tested in this study, except yellowfin tuna.     

哈尔滨城市绿地土壤肥力调查与评价

对采集于哈尔滨城市广场绿地、高校附属绿地和苗圃生产绿地0～20 cm土壤的pH值和速效氮、速效磷、速效钾等各项土壤肥力指标进行了测试分析.结果表明:测试绿地的土壤pH呈碱性,土壤速效氮、速效磷、速效钾含量明显高于苗圃生产绿地,肥力处于中等或以上水平.     

羊踯躅嫩茎离体培养和植株再生

本研究以羊踯躅嫩茎为外植体,应用均匀设计法筛选其最适合的嫩茎基部直接再生芽苗和生根培养基.结果表明,最适合羊踯躅嫩茎基部直接再生芽苗的诱导培养基为:1/4DR+ 2ip3.75 mg/L+IAA 0.03 mg/L+KT 1.30 mg/L,诱导率为99.8％;生根培养基为:1/4DR+ZT 0.06 mg/L+ NAA 0.02 mg/L,生根率达99.0％以上.以再生植株茎节为材料进行快繁的结果表明,在28 d的培养周期内,每段增殖倍数平均达5以上.成功建立了羊踯躅的离体培养和植株再生体系,所建立的植株再生体系可以满足羊踯躅工厂化育苗的需要.