Hordeum murinum aspiration revealed by a pneumopleurocutaneous fistula in a 15-month-old infant

Background Hordeum murinum is a specie of grass rarely reported among the aspirated foreign body. It has high tissue penetration power and may cause lung damages. Case presentation We report the case of a 15-month-old girl who choke while playing in the grass without any evident cause. This episode was immediately followed by vomiting and coughing with traces of blood. While she was fine during the following week, she relapsed at day (D) 7 with fever. At D10, she was finally hospitalized for signs of respiratory distress. The chest CT-scan revealed a voluminous right sub pleural empyema with an aerial component, responsible for the collapse of the right lower lobe, and complicated by a pneumopleurocutaneous fistula to the right paravertebral muscles. Intravenous antibiotics were prescribed, but no invasive procedure was performed. At D18, the spikelet of a false barley spontaneously externalized through the fistula. Evolution was favorable thereafter with disappearance of the fever and progressive decrease of the biological inflammatory syndrome. The follow-up at 4 months was reassuring, with normal clinical evaluation, and complete regression of the empyema on the chest X-rays. Conclusions Hordeum murinum is a rare type of foreign body, and the aspiration often goes unnoticed. In these peculiar cases, CT-scans can be as informative as bronchoscopies, and the evolution is usually favorable after fistulization.

Epigenetic responses of hare barley (Hordeum murinum subsp. leporinum) to climate change: an experimental, trait-based approach

The impact of reduced rainfall and increased temperatures forecasted by climate change models on plant communities will depend on the capacity of plant species to acclimate and adapt to new environmental conditions. The acclimation process is mainly driven by epigenetic regulation, including structural and chemical modifications on the genome that do not affect the nucleotide sequence. In plants, one of the best-known epigenetic mechanisms is cytosine-methylation. We evaluated the impact of 30% reduced rainfall (hereafter “drought” treatment; D), 3 °C increased air temperature (“warming”; W), and the combination of D and W (WD) on the phenotypic and epigenetic variability of Hordeum murinum subsp. leporinum L., a grass species of high relevance in Mediterranean agroforestry systems. A full factorial experiment was set up in a savannah-like ecosystem located in southwestern Spain. H. murinum exhibited a large phenotypic plasticity in response to climatic conditions. Plants subjected to warmer conditions (i.e., W and WD treatments) flowered earlier, and those subjected to combined stress (WD) showed a higher investment in leaf area per unit of leaf mass (i.e., higher SLA) and produced heavier seeds. Our results also indicated that both the level and patterns of methylation varied substantially with the climatic treatments, with the combination of D and W inducing a clearly different epigenetic response compared to that promoted by D and W separately. The main conclusion achieved in this work suggests a potential role of epigenetic regulation of gene expression for the maintenance of homoeostasis and functional stability under future climate change scenarios.

Mumetopia interfeles sp. nov., a new species of Anthomyzidae (Diptera) occurring en masse in an urban grassy habitat in Chile: its taxonomy, phylogeny and biology

A new species of Anthomyzidae (Diptera), viz., Mumetopia interfeles Roháček sp. nov. (both sexes), is described from Chile, based on a large series collected from a small grassy area (consisting of a non-native species, Hordeum murinum L.) among houses in the city of Valparaíso. Its systematic affiliation, phylogenetic relationships, and biology are discussed. Cases of mass occurrence of adult Anthomyzidae, particularly those in anthropogenic habitats, are reviewed and general features of them discussed. A phylogenetic hypothesis is proposed for the relationships of the new species and the Chamaebosca group of genera within Anthomyzidae (64 species in dataset), based on Bayesian inference and maximum likelihood analyses of seven DNA markers (12S, 16S, 28S, COI, COII, CytB, ITS2). Taxonomic limits of the genus Mumetopia Melander, 1913 are discussed. Based on a new molecular hypothesis and a previous cladistic analysis of morphological data (Roháček & Barber 2009), a broadened, better-supported concept of Mumetopia (s. str.) is proposed to include M. interfeles sp. nov. (and its unnamed relatives) and externally aberrant, undescribed species endemic to the Juan Fernández Islands. Apart from Anthomyzidae (M. interfeles sp. nov. only), the community of Diptera associated with H. murinum was dominated by phytophagous Chloropidae: Ceratobarys sacculicornis (Enderlein, 1911) occurred in extremely high numbers similar to those of M. interfeles sp. nov., while the less abundant Opetiophora sp. represents the first record of the genus from South America.

Resistance Evolution to EPSPS Inhibiting Herbicides in False Barley (Hordeum murinum) Harvested in Southern Spain

A failure of the EPSPS-inhibiting herbicide glyphosate to control several populations of Hordeum murinum subsp. leporinum (or H. murinum) occurred in southern Spain after more than fifteen applications in both crop (olive, orchards, and citrus) and non-crop (dry areas, roadsides and ditches) areas. Eight out of 18 populations studied were resistant (R) to glyphosate with R factors higher than four based on GR50. These populations also had the highest values of LD50 and the lowest levels of shikimic acid accumulation. Two adjuvants tested increased glyphosate efficacy in both susceptible (S) and R populations thanks to better spray foliar retention. Moreover, PS I-, PS II-, and ACCase-inhibiting herbicides, in pre- or post-emergence, proved to be the best chemical alternatives with different sites of action (SoA) to control both S and glyphosate-R populations. This study represents the first report worldwide of glyphosate resistance in H. murinum found in very different crop and non-crop areas from southern Spain. To design chemical strategies to implement integrated weed management programs for glyphosate-R H. murinum, both adjuvants and herbicides with alternative SoA as well as application timings should be considered.

The Impact of Herbicide Application and Defoliation on Barley Grass (Hordeum murinum subsp. glaucum) Management in Mixed Pasture Legumes

Barley grass (Hordeum murinum subsp. glaucum.) is an annual weed associated with grain revenue loss and sheep carcass damage in southern Australia. Increasing herbicide resistance led to a recent investigation into effective integrated weed management strategies for barley grass in southern Australia. Field studies in Wagga Wagga, New South Wales (NSW) during 2016 and 2017 examined the effect of post-emergent herbicide applications and strategic defoliation by mowing on barley grass survival and seed production in a mixed legume pasture. Statistically significant differences between herbicide-only treatments in both years showed propaquizafop to be more than 98% effective in reducing barley grass survival and seed production. Paraquat was not effective in controlling barley grass (58% efficacy), but led to a 36% and 63.5% decrease in clover and other weed biomass, respectively, after 12 months and increased lucerne biomass by over three-fold after 24 months. A single repeated mowing treatment resulted in a 46% decline in barley grass seedling emergence after 12 months and, when integrated with herbicide applications, reduced other weed biomass after 24 months by 95%. Resistance to acetyl-CoA carboxylase (ACCase)-inhibiting herbicides observed in local barley grass populations led to additional and more focused investigation comparing the efficacy of other pre- and post-emergent herbicides for barley grass management in legume pastures. Haloxyfop-R + simazine or paraquat, applied at early tillering stage, were most efficacious in reducing barley grass survival and fecundity. Impact of defoliation timing and frequency on barley grass seedlings was also evaluated at various population densities, highlighting the efficacy of repeated post-inflorescence defoliations in reducing plant survival and seed production. Results highlight the importance of optimal environmental conditions and application timing in achieving efficacious control of barley grass and improving pasture growth and biomass accumulation.