DOES LOW MAGNESIUM IN CYSTIC FIBROSIS CONTRIBUTE TO BACTERIAL PATHOGENICITY?

poster abstractCystic fibrosis (CF) is a genetic disease for which there is currently no cure. Individuals with CF are plagued by myriad symptoms, including chronic pneumonia, which diminishes quality of life and reduces life expectancy to 40 years. The most common bacterium in CF patients’ lungs is Pseudomonas aeruginosa, a highly adaptable organism capable of surviving robust antibi-otic treatment. At the heart of developing improved treatments for CF pa-tients is the need to better understand P. aeruginosa pathogenicity. To this end, we have been studying the role of magnesium, which is often found at below normal levels in CF patients. Magnesium is an essential element in numerous cellular functions in both bacteria and humans. In previous re-search, we developed a P. aeruginosa strain with a deletion of the magnesi-um transport protein MgtE, as well as 16 plasmids carrying different muta-tions of the mgtE gene. Experiments with these constructs demonstrated a relationship between magnesium transport and bacterial toxin production. In the research presented here, we hypothesize that lower levels of magnesium may trigger a bacterial response, causing a change in P. aeruginosa patho-genicity. Changes may include differential growth, toxin release, and for-mation of biofilms, which are surface-adhered, antibiotic tolerant bacterial communities in a protective polysaccharide matrix. Using various magnesi-um levels, we have measured P. aeruginosa growth rates, motility, biofilm formation, and cytotoxicity toward cultured cells derived from the CF bron-chial epithelium. Preliminary results suggest that lower magnesium contrib-utes to changes in the bacterium that favor persistence in the CF lung. On-going studies include the effect of long-term growth of P. aeruginosa in low magnesium and how this impacts a number of virulence factors. We antici-pate that our research will elucidate the relationship between magnesium and P. aeruginosa pathogenicity and potentially lead to improved treatments for CF patients

Development of a New in vitro System for Cystic Fibrosis Research

poster abstractIndividuals with cystic fibrosis (CF) have a life expectancy of 40 years and require daily treatments to mitigate the effects of the disease. CF impacts organs throughout the body, especially the lungs, where thick mucus builds up, impairs breathing, and provides an environment for bacterial growth. Chronic lung infection is the leading cause of mortality in CF. The majority of CF lung infections are caused by Pseudomonas aeruginosa, a common bacterium which typically does not cause disease in healthy individuals. In the CF lung, however, P. aeruginosa burrows into the thick mucus layer, evades the immune system, and resists antibiotic therapy by encasing itself in a protective matrix called a biofilm. Laboratory methods for studying biofilm are not true replicas of the CF lung environment, leaving a knowledge gap between how bacteria grow in a test tube (in vitro) and how they grow in the lungs of a person with CF. The focus of this work is to develop an improved laboratory model which combines artificial sputum (as a surrogate for mucus in the CF lung) and cultured CF airway epithelial cells. To assess the potential of this model, we have performed experiments to compare P. aeruginosa in artificial sputum versus standard laboratory media. Results demonstrate that P. aeruginosa in artificial sputum exhibits differences in growth, biofilm formation, toxin production, cytotoxicity, and protein expression, compared to results in standard media. These data suggest that our model system can contribute new information to the understanding of CF airway infection. The aim of future studies is to use this system to identify sputum components and bacterial proteins which have not been recognized previously by standard methods. It is our ultimate goal to contribute knowledge leading to improved longevity and quality of life for people with CF

Deposits and Cutoff Ages of Horseshoe and Marion Oxbow Lakes, Red River, Manitoba

Horseshoe Lake and the Marion Lake scar, along the Red River, southern Manitoba, were cored to investigate the timing of the meander cutoffs and the sedimentology of the channel in-fill deposits. The Horseshoe Lake core, 10.75 m long, consists of 9.73 m of silt-rich deposits inferred to be lacustrine from 0 to 4 m deep, transitional from 4 to 5 m deep and alluvial below 5 m deep. Four wood and charcoal specimens sampled from the core yielded radiocarbon ages of 310 ± 40, 1730 ± 50, 2040 ± 50 and 2240 ± 50 BP. The Marion Lake core, 16.77 m long, consists of 14.73 m of silt-rich deposits inferred to be lacustrine from 0 to 5 m deep and alluvial below 8.5 m deep; the transition is indistinct and falls between 5 to 8.5 m deep. Four wood samples from the fluvial deposits yielded radiocarbon ages of 1600 ± 40, 1700 ± 40, 1660 ± 40 and 1620 ± 40 BP. The cutoffs that led to the formation of Horseshoe and Marion lakes are interpreted to have occurred at ~1990 and ~1520 cal BP or shortly thereafter, respectively. The silt-rich, alluvial-lacustrine deposits in the lakes lack structural and textural characteristics that can be readily recognized in core to distinguish the depositional environments. The absence of coarse sediments at the base of the fluvial units at both sites implies that minor to negligible amounts of sand were transported along the thalwegs of the channels prior to the meanders being cutoff. The dominance of silt within the oxbow deposits reflects sediment supply as the geomorphic setting of the river is within an extensive glaciolacustrine clay plain.Le lac Horseshoe et l'ancien lac Marion ont fait l'objet de carottages dans le but d'établir le moment du recoupement de leur méandre et la sédimentologie des dépôts accumulés dans leur chenal. La carotte du lac Horseshoe (10,75 m) est constituée de 9,73 m de dépôts riches en limon, probablement lacustres entre 0 et 4 m de profondeur, de transition entre 4 et 5 m et alluviaux sous les 5 m. Quatre échantillons de bois et de charbon ont donné des âges au radiocarbone de 310 ± 40, 1730 ± 50, 2040 ± 50 et 2240 ± 50 BP. La carotte du lac Marion (16,77 m) est constituée de 14,73 m de dépôts riches en limon, apparemment lacustres entre 0 et 5 m et alluviaux sous les 8,5 m ; la transition, mal définie, se situe entre 5 et 8,5 m de profondeur. Quatre échantillons de bois provenant des dépôts fluviatiles ont donné des âges au radiocarbone de 1600 ± 40, 1700 ± 40, 1660 ± 40 et 1620 ± 40 BP. On estime que les recoupements qui ont donné naissance aux deux lacs se sont produits il y a environ 1990 (Horseshoe) et 1520 cal. BP (Marion), ou peu après. Les dépôts alluvio-lacustres riches en limon des lacs ne comportent pas de structures et de textures assez nettes pour permettre d’identifier leur milieux de sédimentation. L'absence, dans les deux cas, de sédiments grossiers à la base de l'unité fluviatile laisse supposer que des quantités minimes, voire négligeables, de sable ont été transportées le long des thalwegs avant que les recoupements ne surviennent. La prédominance du limon dans les dépôts des lacs en croissant reflète la provenance des sédiments, le cadre géomorphologique de la rivière étant celui d’une vaste plaine d'argile glaciolacustre.Los sedimentos de los lagos Horseshoe y Marion situados a lo largo del río Red al sur de Manitoba fueron estudiados para establecer la fecha de formación de meandros y la sedimentología de los depósitos de los canales. El núcleo testigo de sondeo proveniente del lago Horseshoe, de 10,75 m de largo, está compuestos de depósitos ricos en limo de hasta 9,73 m. Dichos depósitos son considerados como de origen lacustre en una región de 0 a 4 m de profundidad, de tipo de transición entre 4 y 5 m de profundidad y de origen aluvial por debajo de 5 m de profundidad. Cuatro especímenes de madera y de carbón obtenidos de dicho núcleo testigo fueron datados con radiocarbono proporcionando un edad cercana a los 310 ± 40, 1730 ± 50, 2040 ± 50 y 2240 ± 50 años BP. El núcleo testigo de sondeo de 16,77 m de largo proveniente del lago Marion, esta compuesto de una zona que abarca 14.73 m de depósitos arcillosos de origen lacustre entre 0-5 m de profundidad y de origen aluvial por debajo de los 8.5 m de profundidad; la zona de transición se sitúa entre 5 y 8.5 m de profundidad pero no se encuentra bien definida. La datación con radiocarbono de cuatro muestras de depósitos fluviales proporciono una edad que las sitúa hace unos 1600 ± 40, 1660 ± 40 y 1620 ± 40 años BP. Se cree que el corte de terreno que dio origen a la formación de los lagos Horseshoe y Marion ocurrió hace unos 19 900 a 15 200 años o poco tiempo después, respectivamente. Los depósitos ricos en limo de origen lacustre-aluvial de los lagos carecen de las características estructurales y de textura que pueden ser reconocidos fácilmente en el núcleo testigo para distinguir los ambientes de depósito. La ausencia de sedimentos de tipo grueso en la base de la unidad fluvial en ambos sitios indica que un aporte pequeño o insignificante de arena fue transportado a lo largo de la vaguada de los canales antes de que ocurriera la formación de los meandros. La predominancia de limos entre los depósitos del brazo muerto refleja el origen de los sedimentos y concuerda con el cuadro geomorfológico de un rió situado dentro de una planicie arcillosa glaciolacustre muy extensa

Case–Control Research Study of Auto-Brewery Syndrome

Background: Auto-brewery syndrome (ABS), also known as Gut Fermentation Syndrome and Endogenous Ethanol Fermentation, is afflicting people worldwide, but little is known about ABS patients’ demographics, health history, lifestyle factors, and diet. Method: We conducted a broad-based case–control survey study on 52 patients known to have a diagnosis of ABS and their household members. The research compares the symptomatic group (N ¼ 28) to the asymptomatic group (N ¼ 18) regarding lifestyle and health, diet, and medical history. Results: With a response rate of 88% and using rank-sum tests, the data demonstrate that patients with ABS have significant differences compared to people without ABS in lower quality bowel movements (P ¼.048), more frequent bowel movements (P ¼.038), more reports of malodorous breath (P ¼.0001), and self-classify as having poorer health (P ¼.009). Furthermore, participants with ABS consume more water (P ¼.038), consume less tea and coffee (P ¼.033), eat fewer dairy products (P ¼.0185), eat less candy (P ¼.032), eat out less and rely on food prepared at home (P ¼.043), have more aversion to starch (P ¼.008), and have more food sensitivities (P ¼.043) than the group without ABS. The ABS group also reports more diarrhea (P ¼.048), higher amounts of yeast in their gastrointestinal tract (P ¼.015), and using acne medication for a longer time (P ¼.037) than the control group. Conclusion: Patients with ABS have significant differences in their lifestyle and health, diet, and medical history compared to non-ABS participants and these differences warrant further research