Zoonotic enterohemorrhagic Escherichia coli: A One Health perspective

Escherichia coli O157 and other enterohemorrhagic E. coli (EHEC) are food- and waterborne zoonotic pathogens that cause diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome in humans but little or no discernible disease in their animal reservoirs. Like other zoonotic infections, EHEC are illustrative of the One Health concept as they embody the complex ecology of agricultural animals, wildlife, and the environment in zoonotic transmission of EHEC O157. But compared to the detailed epidemiological and clinical information available for EHEC infection in humans, there is an incomplete understanding of the ecology of EHEC infection in animals and the persistence of EHEC bacteria in the environment. Significant aspects of the microbiology, epidemiology, and host-pathogen interactions of EHEC in animals remain undefined. This review highlights the nature of EHEC infection in humans, provides a One Health perspective on what is known about EHEC in animal and environmental reservoirs, and proposes interventions targeted at pathways of transmission to optimize effective prevention and control measures.     

A veterinary perspective on One Health in the Arctic

Exposure to long-range transported industrial chemicals, climate change and diseases is posing a risk to the overall health and populations of Arctic wildlife. Since local communities are relying on the same marine food web as marine mammals in the Arctic, it requires a One Health approach to understand the holistic ecosystem health including that of humans. Here we collect and identify gaps in the current knowledge of health in the Arctic and present the veterinary perspective of One Health and ecosystem dynamics. The review shows that exposure to persistent organic pollutants (POPs) is having multiple organ-system effects across taxa, including impacts on neuroendocrine disruption, immune suppression and decreased bone density among others. Furthermore, the warming Arctic climate is suspected to influence abiotic and biotic long-range transport and exposure pathways of contaminants to the Arctic resulting in increases in POP exposure of both wildlife and human populations. Exposure to vector-borne diseases and zoonoses may increase as well through range expansion and introduction of invasive species. It will be important in the future to investigate the effects of these multiple stressors on wildlife and local people to better predict the individual-level health risks. It is within this framework that One Health approaches offer promising opportunities to survey and pinpoint environmental changes that have effects on wildlife and human health.     

Clostridioides difficile infection and One Health: an equine perspective

Clostridioides (Clostridium) difficile presents a significant health risk to humans and animals. The complexity of the bacterial–host interaction affecting pathogenesis and disease development creates an ongoing challenge for epidemiological studies, control strategies and prevention planning. The recent emergence of human disease caused by strains of C. difficile found in animals adds to mounting evidence that C. difficile infection (CDI) may be a zoonosis. In equine populations, C. difficile is a known cause of diarrhoea and gastrointestinal inflammation, with considerable mortality and morbidity. This has a significant impact on both the well-being of the animal and, in the case of performance and production animals, it may have an adverse economic impact on relevant industries. While C. difficile is regularly isolated from horses, many questions remain regarding the impact of asymptomatic carriage as well as optimization of diagnosis, testing and treatment. This review provides an overview of our understanding of equine CDI while also identifying knowledge gaps and the need for a holistic One Health approach to a complicated issue.     

Natural product antifoulants: One perspective on the challenges related to coatings development

Fouling of surfaces by abiotic and biotic substances has molecular, microbial, and macro-organismal levels of organization. Fouling involves molecular bonding and biological adhesives. Existing commercial solutions to fouling are antifouling or foul-release. Antifouling uses broad-spectrum biocides which kill foulers by virtue of oxidation or toxic metal ions. Foul-release coatings are dimethyl silicone polymers that foul, but clean easily. The best foul-release coatings also contain additives that kill organisms. Environmentally unacceptable consequences of toxic antifouling coatings, especially those based on organotins, have prompted interest in antifoulants found in living organisms. Laboratories worldwide now use bioassays with target fouling organisms to direct purification and identification of antifoulant compounds. Natural antifoulants are common and include toxins, anesthetics, surface-active agents, attachment and/or metamorphosis inhibitors and repellents. Development of commercial coatings using natural products is blocked by cost, the time horizon to meet government regulations and performance standards based upon coatings with unacceptable environmental impacts. If blocks are removed, the potential for environmentally acceptable solutions that combine natural products with organic biocides is high.     

One ancestor for two codes viewed from the perspective of two complementary modes of tRNA aminoacylation

Background  

The genetic code is brought into action by 20 aminoacyl-tRNA synthetases. These enzymes are evenly divided into two classes (I and II) that recognize tRNAs from the minor and major groove sides of the acceptor stem, respectively. We have reported recently that: (1) ribozymic precursors of the synthetases seem to have used the same two sterically mirror modes of tRNA recognition, (2) having these two modes might have helped in preventing erroneous aminoacylation of ancestral tRNAs with complementary anticodons, yet (3) the risk of confusion for the presumably earliest pairs of complementarily encoded amino acids had little to do with anticodons. Accordingly, in this communication we focus on the acceptor stem.     

Seroepidemiology of Crimean-Congo Haemorrhagic Fever among cattle in Cameroon: Implications from a One Health perspective

BackgroundCrimean-Congo Haemorrhagic Fever (CCHF) is a tick-borne viral zoonotic disease distributed across several continents and recognized as an ongoing health threat. In humans, the infection can progress to a severe disease with high fatality, raising public health concerns due to the limited prophylactic and therapeutic options available. Animal species, clinically unaffected by the virus, serve as viral reservoirs and amplifier hosts, and can be a valuable tool for surveillance. Little is known about the occurrence and prevalence of Crimean-Congo Haemorrhagic Fever Virus (CCHFV) in Cameroon. Knowledge on CCHFV exposure and the factors associated with its presence in sentinel species are a valuable resource to better understand transmission dynamics and assess local risks for zoonotic disease emergence.Methods and findingsWe conducted a CCHFV serological survey and risk factor analysis for animal level seropositivity in pastoral and dairy cattle in the North West Region (NWR) and the Vina Division (VD) of the Adamawa Region in Cameroon. Seroprevalence estimates were adjusted for sampling design-effects and test performance. In addition, explanatory multivariable logistic regression mixed-effects models were fit to estimate the effect of animal characteristics, husbandry practices, risk contacts and ecological features on the serological status of pastoral cattle. The overall seroprevalence was 56.0% (95% CI 53.5–58.6) and 6.7% (95% CI 2.6–16.1) among pastoral and dairy cattle, respectively. Animals going on transhumance had twice the odds of being seropositive (OR 2.0, 95% CI 1.1–3.8), indicating that animal movements could be implicated in disease expansion. From an ecological perspective, absolute humidity (OR 0.6, 95% CI 0.4–0.9) and shrub density (OR 2.1, 95% CI 1.4–3.2) were associated with seropositivity, which suggests an underlying viral dynamic connecting vertebrate host and ticks in a complex transmission network.ConclusionsThis study demonstrated high seroprevalence levels of CCHFV antibodies in cattle in Cameroon indicating a potential risk to human populations. However, current understanding of the underlying dynamics of CCHFV locally and the real risk for human populations is incomplete. Further studies designed using a One Health approach are required to improve local knowledge of the disease, host interactions and environmental risk factors. This information is crucial to better project the risks for human populations located in CCHFV-suitable ecological niches.     

One oxidant,many pathways: a theoretical perspective of monooxygenation mechanisms by cytochrome P450 enzymes

Density functional theoretical studies of monooxygenation reactivity of the high-valent oxoiron(IV) porphyrin cation-radical compound of cytochrome P450, the so-called Compound I, and of its precursor, the ferric(III)-hydroperoxide species, are described. The degeneracy of the spin states of Compound I, its electron deficiency, and dense orbital manifold lead to two-state and multi-state reactivity scenarios and may thereby create reactivity patterns as though belonging to two or more different oxidants. Most of the controversies in the experimental data are reconciled using Compound I as the sole competent oxidant. Theory finds ferric(III)-hydroperoxide to be a very sluggish oxidant, noncompetitive with Compound I. If and when Compound I is absent, P450 oxidation will logically proceed by another form, but this has to be more reactive than ferric(III)-hydroperoxide. Theoretical studies are conducted to pinpoint such an oxidant for P450.

同一个世界 同一个健康

随着工业化和城镇化水平的持续提高,人类的生活方式发生了翻天覆地的变化,在传统因素依然制约人类健康的同时,食源性疾病与营养结构不合理、畜禽养殖方式转变与宠物快速发展带来人与动物关系深刻变化、生态环境与居住环境变化等非传统因素,对人类健康的制约凸显。面对这些人类健康的新挑战,我们必须因应时代变化,在大力发展医疗卫生事业的同时,树立营养健康、动物健康、环境健康三位一体的现代健康新理念。努力提高营养健康水平,以宠物健康为新的关注点高度重视动物健康,以人居、社区环境为重点营造健康生态环境,建立起现代健康新模式。     

One World,One Health

正时光悄悄飞逝而去,我们迎来了2016年。在变化万千和动荡的世界里,2015年医学微生物学与感染病学的进展令人瞩目,给世界带来了深刻的影响。新发和突发传染病如埃博拉病毒病、登革热、流感及近期出现的Zika(目前译为寨卡)病毒病仍是最受关注的事件。据世界卫生组织(World Health Organization,WHO)报道,迄今已有约28 000人感     

One Bacterial Cell,One Complete Genome

While the bulk of the finished microbial genomes sequenced to date are derived from cultured bacterial and archaeal representatives, the vast majority of microorganisms elude current culturing attempts, severely limiting the ability to recover complete or even partial genomes from these environmental species. Single cell genomics is a novel culture-independent approach, which enables access to the genetic material of an individual cell. No single cell genome has to our knowledge been closed and finished to date. Here we report the completed genome from an uncultured single cell of Candidatus Sulcia muelleri DMIN. Digital PCR on single symbiont cells isolated from the bacteriome of the green sharpshooter Draeculacephala minerva bacteriome allowed us to assess that this bacteria is polyploid with genome copies ranging from approximately 200–900 per cell, making it a most suitable target for single cell finishing efforts. For single cell shotgun sequencing, an individual Sulcia cell was isolated and whole genome amplified by multiple displacement amplification (MDA). Sanger-based finishing methods allowed us to close the genome. To verify the correctness of our single cell genome and exclude MDA-derived artifacts, we independently shotgun sequenced and assembled the Sulcia genome from pooled bacteriomes using a metagenomic approach, yielding a nearly identical genome. Four variations we detected appear to be genuine biological differences between the two samples. Comparison of the single cell genome with bacteriome metagenomic sequence data detected two single nucleotide polymorphisms (SNPs), indicating extremely low genetic diversity within a Sulcia population. This study demonstrates the power of single cell genomics to generate a complete, high quality, non-composite reference genome within an environmental sample, which can be used for population genetic analyzes.     

Therapeutic perspective

Unless proper perspective is maintained in medical therapeutics, a physician in his earnest desire to cure disease may often use measures which may ultimately cause more damage than the disease being treated.In order to avoid loss of perspective, it is necessary to balance the known consequences of the disease against the expected benefits of the treatment minus the known hazards of the treatment.     

Patent perspective

Patent Update is a regular column dedicated to the complex issues that affect patents in the genomics and proteomics field. In each issue, there are two sections compiled by patent attorneys. The first section, Patents – a Practical Perspective, is a commentary on current issues, landmark patents, useful patent resources and how to search them, and legislative changes that impact the pharma and biotech industries. The second section, Patent News, provides brief synopses of recently issued patents and other patent events, and their significance to drug discovery R&D.     

Biosensors-a perspective

Biosensors have been under development for over 35 years and research in this field has become very popular for 15 years. Electrochemical biosensors are the oldest of the breed, yet sensors for only one analyte (glucose) have achieved widespread commercial success at the retail level. This perspective provides some cautions related to expectations for biosensors, the funding of science, and the wide gap between academic and commercial achievements for sensor research. The goal of this commentary is not to arrive at any particular truth, but rather to stimulate lively discussion.