Activity of species-specific antibiotics against Crohnʼs disease–associated adherent-invasive Escherichia coli

Background: Crohn's disease (CD) is associated with bacterial dysbiosis that frequently includes colonization by adherent-invasive Escherichia coli (AIEC). AIEC are adept at forming biofilms and are able to invade host cells and stimulate the production of proinflammatory cytokines. The use of traditional antibiotics for the treatment of CD shows limited efficacy. In this study, we investigate the use of species-specific antibiotics termed colicins for treatment of CD-associated AIEC. Methods: Colicin activity was tested against a range of AIEC isolates growing in the planktonic and biofilm mode of growth. Colicins were also tested against AIEC bacteria associated with T84 intestinal epithelial cells and surviving inside RAW264.7 macrophages using adhesion assays and gentamicin protection assay, respectively. Uptake of colicins into eukaryotic cells was visualized using confocal microscopy. The effect of colicin treatment on the production of proinflammatory cytokine tumor necrosis factor alpha by macrophages was assessed by an enzyme-linked immunosorbent assay. Results: Colicins show potent activity against AIEC bacteria growing as biofilms when delivered either as a purified protein or through a colicin-producing bacterial strain. In addition, colicins E1 and E9 are able to kill cell-associated and intracellular AIEC, but do not show toxicity toward macrophage cells or stimulate the production of proinflammatory cytokines. Colicin killing of intracellular bacteria occurs after entry of colicin protein into AIEC-infected macrophage compartments by actin-mediated endocytosis. Conclusions: Our results demonstrate the potential of colicins as highly selective probiotic therapeutics for the eradication of E. coli from the gastrointestinal tract of patients with CD

Measuring Bonds in Equine-Facilitated Psychotherapy

Equine-facilitated psychotherapy is a type of animal-assisted intervention that has potential to be an effective therapeutic modality in the treatment of psychiatric disorders. It is theorized that a meaningful relationship is formed between client and horse; this relationship is thought to inspire meaningful change in the client. The current study found evidence of human-equine bonds and determined they can be measured quantitatively using adapted bonding scales. This study also explored variables that may impact bonds formed between clients and horse co-therapists. Finally, a potential correlation between the strength of the bond and the severity of symptoms over the course of therapy was investigated

The development of colicins as novel antimicrobials against Crohn’s disease associated adherent-invasive Escherichia coli

Crohn’s Disease (CD) is an incurable form of inflammatory bowel disease (IBD) of complex etiology that is associated with gut dysbiosis that frequently includes colonisation by adherent-invasive E. coli (AIEC). AIEC are adept at forming biofilms and are able to invade host cells and stimulate the production of pro-inflammatory cytokines. A number of antibiotics have been tested in the treatment of CD but at best show limited efficacy. Additionally, broad spectrum antibiotics are themselves strong drivers of dysbiosis and a number of studies have linked the administration of antibiotics with an increased risk of the development of CD. An alternative approach to the eradication of pathogenic bacteria in a complex community is to use species-specific antibiotics such as the colicin-like bacteriocins. Alongside their narrow spectrum killing, colicins also demonstrate extreme potency, are active against bacterial biofilms and can be readily isolated from clinical isolates. The aim of this work was to investigate the efficacy of these E. coli targeted antibiotics against AIEC. To achieve this, colicin activity against ileal CD-mucosa associated AIEC strain LF82, was tested in vitro and also in vivo using a murine model of persistent AIEC colonisation. Colicins showed good efficacy against LF82 associated with intestinal epithelial cells and growing intracellularly within macrophages. In addition, colicins do not show toxicity towards a macrophage cell line or stimulate the production of pro-inflammatory cytokines. To test the efficacy of colicins in an in vivo model of AIEC colonisation, methods were developed to formulate purified protein for delivery to the GI tract. However, this formulation showed only minimal efficacy in a mouse model of AIEC colonisation. In addition to investigating the efficacy of colicins, this thesis also attempts to further elucidate the role of the target pathogen, AIEC in the development of intestinal inflammation. Interestingly, we show here that AIEC associated phenotypes can be detected in commensal E. coli strains, undermining the current definition and classification of the AIEC pathotype

Effect of Text Messaging and Cellphone Use on a Multi-sensory Tracking Task

This experiment studied subjects’ performance on a continuous multisensory tracking task. Different theories suggest that there is a decrease in performance due to attentional capacity; furthermore, talking or texting on a mobile phone will negatively affect task performance. Twenty-four college-age students were recruited to be tested on the Biodex Balance System SD with the texting condition, talking on a mobile phone condition, and control condition. Results showed that text messaging while performing a continuous multisensory tracking task negatively affected performance. There was no significant difference, however, between the control condition and talking on a mobile phone while completing the task. Results suggest that talking on a mobile phone has become second-nature to this sub-set of the population, thus not exceeding the resource capacity. However, the text messaging condition proved to be a more challenging secondary task, causing the amount of attention needed for this task to be increased. Attention was diverted from the primary task, causing a decrease in performance. It can be concluded that texting while performing a multi-sensory tracking task can have deleterious effects on attention. These findings have a direct application to texting while driving; it is not possible to safely communicate via text message while operating a motor vehicle

Automated Quantification of Mitochondrial Fragmentation in an In Vitro Parkinson's Disease Model

Neuronal mitochondrial fragmentation is a phenotype exhibited in models of neurodegeneration such as Parkinson's disease. Delineating the dysfunction in mitochondrial dynamics found in diseased states can aid our understanding of underlying mechanisms of disease progression and possibly identify novel therapeutic approaches. Advances in microscopy and the availability of intuitive open‐access software have accelerated the rate of image acquisition and analysis, respectively. These developments allow routine biology researchers to rapidly turn hypotheses into results. In this protocol, we describe the utilization of cell culture techniques, high‐content imaging (HCI), and the subsequent open‐source image analysis pipeline for the quantification of mitochondrial fragmentation in the context of a rotenone‐based in vitro Parkinson's disease model

The intermediate-age open cluster NGC 2112

We report on $BVI$ CCD photometry of a field centered on the region of the intermediate-age open cluster NGC 2112 down to V=21. Due to the smaller field coverage, we are able to limit the effect of field star contamination which hampered in the past precise determinations of the cluster age and distance. This way, we provide updated estimates of NGC 2112 fundamental parameters. Having extended the photometry to the $I$ pass-band, we are able to construct a colour-colour diagram, from which we infer a reddening $E_{B-V}= 0.63\pm0.14$ mag. The comparison of the Colour-Magnitude Diagram (CMD) with theoretical isochrones leads to a distance of $850 \pm 100$ pc, and an age of $2.0 \pm 0.3$ Gyr. While the distance is in agreement with previous determinations, the age turns out to be much better constrained and significantly lower than previous estimates.Comment: 7 pages, 7 eps figures, in press in MNRA