Antimicrobial resistance in Escherichia coli and Salmonella spp. isolates from fresh produce and the impact to food safety

Foodborne diseases associated with fresh produce consumption have escalated worldwide, causing microbial safety of produce of critical importance. Bacteria that have increasingly been detected in fresh produce are Escherichia coli and Salmonella spp., both of which have been shown to progressively display antimicrobial resistance. The study focused on the assessment of antimicrobial resistance of these enteric bacteria from different kinds of fresh produce from various open air markets and supermarkets in the Philippines. Using the disk diffusion assay on a total of 50 bacterial isolates obtained from 410 fresh produce surveyed, monoresistance to tetracycline was observed to be the most prevalent (38%), followed by multidrug resistance to tetracycline, chloramphenicol, ciprofloxacin, and nalidixic acid (4%), and lastly by dual resistance to tetracycline and chloramphenicol (2%). Using multiplex and simplex polymerase chain reaction (PCR) assays, tetA (75%) and tetB (9%) were found in tetracycline resistant isolates, whereas catI (67%) and catIII (33%) were detected in chloramphenicol resistant isolates. Sequence analysis of gyr and par genes from the ciprofloxacin and nalidixic acid resistant isolates revealed different mutations. Based on the results, fresh produce act as a reservoir of these antibiotic resistant bacteria which may pose health threat to consumers.     

Effects and success factors of sustainable consumption policy instruments: a comparative assessment across Europe

Important knowledge gaps exist regarding the effects of policy instruments for sustainable consumption (SC) and success factors of such instruments. This article compares and summarizes the results of six case studies on the effects and success factors of SC instruments in the need areas of housing and food. While analysing different instrument types from four different European countries, all case studies were guided by the same analytical framework and mixed-methods approach. This synthesis article particularly emphasizes factors fostering the generation of instrument effects (outcomes and impacts) or hampering the creation of such effects, respectively. These factors include instrument goals and design, the accommodation of consumer needs, and the simultaneous addressing of framework conditions, as well as market context, policy interaction, and stakeholder involvement. The findings and conclusions can contribute to a better understanding of the conditions under which policy instruments can steer consumer behaviour towards sustainability.     

垃圾土上植物的生长与生态毒性试验

研究了粮食作物、蔬菜、牧草、草坪草与观赏花卉等植物在垃圾土上的生长状况,结果表明各种植物在垃圾土上均可成活,且大部分植物生长快,有效成分含量高,但作物种子和苜宿可食部分的重金属含量超标。      

二氧化硫对植物新陈代谢的影响(Ⅱ)——对光合、呼吸与物质代谢的影响

从光合作用,呼吸作用和物质代谢三方面综述了二氧化硫对植物新陈代谢的影响;阐述了二氧化硫对植物光合作用和呼吸作用的影响;分析了二氧化硫引起植物光合作用变化的原因与途径;综述了二氧化硫对糖、蛋白质和氨基酸等物质代谢的影响。      

石灰对土壤吸附镉行为及有效性的影响

酸性红壤上添加石灰显著增加土壤对镉的吸附量并降低吸附态镉的解吸量。但石灰用量较低时,镉的解吸率反而比未施石灰时增加。盆栽试验亦表明,在石灰用量较低时,土壤pH虽有所升高,但小麦和黑麦草植株镉含量降低不明显甚至有所升高;只有较高的石灰用量使土壤pH得以明显升高,植株吸镉量才能明显降低。对这一现象的原因进行了讨论。      

Estimating the potential of wild foods for nutrition and food security planning in tropical areas: Experimentation with a method in Northwestern Colombia

Wild foods contribute to the food security of multiple communities in tropical areas of Africa, Asia and Latin America. However, wild foods are not regularly considered in the planning of strategies for food and nutrition security mainly due to the lack of technical and/or scientific knowledge so that they can be considered suitable for human consumption. This paper proposes a multidisciplinary method that estimates the potential of wild foods as alternative resources when planning interventions in favour of food and nutrition security in tropical forest territories. When designing the method, four dimensions were identified in science, technology and innovation (STI) that define this potential as well as ten assessment criteria. The wild foods chosen for applying the method were Alibertia patinoi (a fruit commonly known as Borojó) and Proechimys semispinosus (Mouse of thorns), which are two of the main wild foods traditionally used by human communities in a tropical forest territory in the northwest of Colombia. In both cases, although there are significant advances in STI, compliance with some criteria is still required to regard them as viable alternatives for nutrition and food security within this territory. This research is useful for promoting the inclusion of wild food in food security programmes for communities where this food is already included in their traditional pattern of consumption and identifies the progress needed in STI to achieve this purpose. It may also promote the early recognition of possible traditional and cultural practices with high risk of transmission of pathogenic elements by the handling and/or inadequate consumption of wild foods. This early recognition could contribute to the prevention of diseases of wild animal origin, including those of rapid global spread.     

中国厨余垃圾处理技术及资源化方案选择

介绍了中国厨余垃圾的产量及特征,分析了厨余垃圾粉碎直排、填埋、焚烧、饲料、昆虫养殖、堆肥、转换能源和高值化利用处理技术的现状及优缺点,表明厨余垃圾资源化处理是未来的发展趋势,其中饲料化应是未来值得提倡的资源化技术之一.此外,对比了厌氧消化和好氧堆肥两大主流资源化模式的特点,厌氧消化和好氧堆肥分别适用于集中大规模处理和分...     

Effects of ozone on inter- and intra-species competition and photosynthesis in mesocosms of Lolium perenne and Trifolium repens

Trifolium repens and Lolium perenne were exposed as both monocultures and two-species mixtures to an episodic rural ozone regime in large, well-watered containers within solardomes for 12 weeks. There were reductions in biomass for T. repens, but not L. perenne, and the proportion of T. repens decreased in ozone-exposed mixtures compared to the control. In addition, leaf biomass of T. repens was maintained at the expense of biomass partitioning to the stolons. The decreased growth corresponded with decreased photosynthetic capacity for T. repens, however, by the end of the exposure there was also decreased photosynthetic capacity of L. perenne, a species previously considered insensitive to ozone. The observed decreases in photosynthetic efficiency and capacity in elevated ozone indicate that the ability of such ubiquitous vegetation to act as a sink for atmospheric carbon may be reduced in future climates.     

不同来源污泥接种餐厨垃圾厌氧发酵产氢效果研究

在相同接种配比(接种污泥占餐厨垃圾的质量分数为30%)条件下,研究了4种不同来源污泥(压滤污泥、厌氧污泥、曝气污泥和河底淤泥)添加或不添加缓冲剂时对餐厨垃圾厌氧发酵产氢效果的影响.结果发现,在不添加缓冲剂时.4种污泥接种餐厨垃圾厌氧发酵平均产氢量依次为厌氧污泥>河底淤泥>压滤污泥>曝气污泥,接种厌氧污泥的餐厨垃圾平均产氢量最高,达10.11mL(以每克挥发性固体(VS)计,下同);而添加缓冲剂时.4种污泥接种餐厨垃圾厌氧发酵平均产氢量依次为厌氧污泥>曝气污泥>压滤污泥>河底淤泥,接种厌氧污泥的餐厨垃圾平均产氢量也最高,为33.72 mL,且体系pH得以缓冲.     

Oxidative stress is an early symptom triggered by aluminum in Al-sensitive potato plantlets

The objective of this study was to evaluate whether the oxidative stress caused by aluminum (Al) toxicity is an early symptom that can trigger root growth inhibition in Macaca (Al-sensitive) and SMIC148-A (Al-tolerant) potato clones. Plantlets were grown in a nutrient solution (pH 4.00) with 0, 100 and 200 mg Al L⁻¹. At 24, 72, 120 and 168 h after Al addition, root length and biochemical parameters were determined. Regardless of exposure time, root length of the Macaca clone was significantly lower at 200 mg Al L⁻¹. For the SMIC148-A clone, root length did not decrease with any Al treatments. Al supply caused lipid peroxidation only in Macaca, in both roots (at 24, 72, 120 and 168 h) and shoot (at 120 and 168 h). In roots of the Macaca, catalase (CAT) and ascorbate peroxidase (APX) activity decreased at 72 and 120 h, and at 24, 72 and 120 h, respectively. At 168 h, both activities increased upon addition of Al. In roots of the SMIC148-A, CAT activity increased at 72 and 168 h, whereas APX activity decreased at 72 h and increased at 24, 12 and 168 h. The Macaca showed lower root non-protein thiol group (NPSH) concentration at 200 mg Al L⁻¹ in all evaluations, but the SMIC148-A either did not demonstrate any alterations at 24 and 72 h or presented higher levels at 120 h. This pattern was also observed in root ascorbic acid (AsA) concentration at 24 and 120 h. The cellular redox status of these potato clones seems to be affected by Al. Therefore, oxidative stress may be an important mechanism for Al toxicity, mainly in the Al-sensitive Macaca clone.