Search

Zymoseptoria tritici is the causal agent of Septoria tritici blotch, the most important disease affecting wheat crops and responsible for up to 50% loss in yield. Azoles and SDHIs are the main groups of fungicides used to control the disease. The efficacy of these fungicides has decreased in recent years due to resistance development. Fungicide resistance can be a result of mutations in the target genes, mutations in upstream regulatory elements that result in over-expression of target proteins and the overexpression of transporters that remove toxic compounds from cells. In the current study nanopore sequencing was used to analyse isolates, mock communities and field samples to determine the pathogen population composition related to azole resistance. Despite the presence of sequencing errors, the method was able to effectively differentiate the sequences of different haplotypes present in both mock and field populations for haplotypes that were relatively common in the overall population. However, haplotypes present at a frequency lower than 5% of the total population, could not be accurately distinguished from haplotypes generated through background sequencing errors. The nanopore protocols are rapid and inexpensive, enabling the routine profiling of haplotypes within pathogen populations at the start of the season or between sprays, facilitating the selection of the most appropriate fungicide to control them, yet limit further selection for azole resistance.

The gastrointestinal tract microbiota interacts with the host to modulate metabolic phenotype. This interaction could provide insights into why some low birthweight pigs can exhibit compensatory growth whilst others remain stunted. This study aimed to identify microbiota markers associated with birthweight [low birthweight (n = 13) or normal birthweight pigs (n = 13)] and performance [“good” or “poor” average daily gain (ADG) class]. Furthermore, the study determined whether the taxonomic markers were longitudinal, or time point specific in their ability to identify low birthweight pigs who could exhibit compensatory growth. Faecal samples were collected and liveweight recorded at 10 different time points from birth to 56 days of age. No consistent associations between birthweight, performance and gut microbiota were found across all time points. However, there was a significant (P < 0.05) effect of birthweight on microbiota richness at 21, 27, 32 and 56 days of age. Significant differences (P < 0.05) in genera abundance according to birthweight and performance were also identified. Low birthweight pigs had a significantly (P < 0.05) lower abundance of Ruminococcaceae UCG-005, but a significantly (P < 0.05) higher abundance of Ruminococcaceae UCG-014 on days 21 and 32, respectively. Piglets classified as having a “good” ADG class had a significantly (P < 0.05) higher abundance of Lactobacillus, unclassified Prevotellaceae and Ruminococcaceae UCG-005 on days 4, 8 and 14, respectively. Furthermore, Ruminococcaceae UCG-005 was significantly more abundant at 14 days of age in normal birthweight pigs with a “good” ADG class compared to those classified as “poor.” The results of this study indicate that there are time point-specific differences in the microbiota associated with birthweight and performance, corresponding to the period in which solid feed intake first occurs. Identifying early-life microbiota markers associated with performance emphasises the importance of the neonatal phase when considering intervention strategies aimed at promoting performance.

The mucus layer is an important physical niche within the gut which harbours a distinct microbial community. Here the authors show that specific carbohydrate-binding modules associated with bacterial carbohydrate-active enzymes are mucus adhesins that target regions of the distal colon rich in sialomucins.

Clostridium botulinum produces botulinum neurotoxins (BoNTs), highly potent substances responsible for botulism. Currently, mathematical models of C. botulinum growth and toxigenesis are largely aimed at risk assessment and do not include explicit genetic information beyond group level but integrate many component processes, such as signalling, membrane permeability and metabolic activity. In this paper we present a scheme for modelling neurotoxin production in C. botulinum Group I type A1, based on the integration of diverse information coming from experimental results available in the literature. Experiments show that production of BoNTs depends on the growth-phase and is under the control of positive and negative regulatory elements at the intracellular level. Toxins are released as large protein complexes and are associated with non-toxic components. Here, we systematically review and integrate those regulatory elements previously described in the literature for C. botulinum Group I type A1 into a population dynamics model, to build the very first computational model of toxin production at the molecular level. We conduct a validation of our model against several items of published experimental data for different wild type and mutant strains of C. botulinum Group I type A1. The result of this process underscores the potential of mathematical modelling at the cellular level, as a means of creating opportunities in developing new strategies that could be used to prevent botulism; and potentially contribute to improved methods for the production of toxin that is used for therapeutics.

The multicellular nature of plants requires that cells should communicate in order to coordinate essential functions. This is achieved in part by molecular flux through pores in the cell wall, called plasmodesmata. We describe the proteomic analysis of plasmodesmata purified from the walls of Arabidopsis suspension cells. Isolated plasmodesmata were seen as membrane-rich structures largely devoid of immunoreactive markers for the plasma membrane, endoplasmic reticulum and cytoplasmic components. Using nano-liquid chromatography and an Orbitrap ion-trap tandem mass spectrometer, 1341 proteins were identified. We refer to this list as the plasmodesmata- or PD-proteome. Relative to other cell wall proteomes, the PD-proteome is depleted in wall proteins and enriched for membrane proteins, but still has a significant number (35%) of putative cytoplasmic contaminants, probably reflecting the sensitivity of the proteomic detection system. To validate the PD-proteome we searched for known plasmodesmal proteins and used molecular and cell biological techniques to identify novel putative plasmodesmal proteins from a small subset of candidates. The PD-proteome contained known plasmodesmal proteins and some inferred plasmodesmal proteins, based upon sequence or functional homology with examples identified in different plant systems. Many of these had a membrane association reflecting the membranous nature of isolated structures. Exploiting this connection we analysed a sample of the abundant receptor-like class of membrane proteins and a small random selection of other membrane proteins for their ability to target plasmodesmata as fluorescently-tagged fusion proteins. From 15 candidates we identified three receptor-like kinases, a tetraspanin and a protein of unknown function as novel potential plasmodesmal proteins. Together with published work, these data suggest that the membranous elements in plasmodesmata may be rich in receptor-like functions, and they validate the content of the PD-proteome as a valuable resource for the further uncovering of the structure and function of plasmodesmata as key components in cell-to-cell communication in plants.

Pneumothorax is a common complication in cystic fibrosis and is associated with worsening of lung function. However, bilateral simultaneous pneumothorax in cystic fibrosis is a rare condition. We describe the case of a 17-year-old female with cystic fibrosis who presented with spontaneous pneumothorax. Clinically, she presented right-sided chest pain and progressive breathlessness. The pneumothorax failed to resolve after the initial treatment (chest drainage). However, the patient was later successfully treated with additional chest drainage and talc pleurodesis. We also discuss the etiology and management of pneumothorax in patients with cystic fibrosis, since pneumothorax is associated with increased morbidity and mortality among such patients.O pneumotórax é uma complicação comum na fibrose cística e está associado com a piora da função pulmonar. Entretanto, o pneumotórax simultâneo bilateral na fibrose cística é um achado raro. Nesse artigo é descrito o caso de uma paciente de 17 anos com fibrose cística que cursou com pneumotórax espontâneo simultâneo bilateral. Clinicamente ela apresentou dor torácica à direita e dificuldade respiratória progressiva. Embora o pneumotórax não tenha respondido bem ao tratamento inicial (drenagem torácica), ela foi posteriormente tratada com drenagem e pleurodese com talco, com sucesso. São discutidos também a etiologia e a conduta nesta condição, que está associada com o aumento da morbidade e mortalidade.