Delivery of E. coli Nissle to the mouse gut by mucoadhesive microcontainers does not improve its competitive ability against strains linked to ulcerative colitis.

For patients with ulcerative colitis (UC), administration of the probiotic E. coli Nissle (EcN) holds promise for alleviation of disease symptoms. The mechanisms are unclear, but it has been hypothesised that a capacity of the probiotic to outcompete potentially detrimental UC-associated E. coli strains plays an important role. However, this could previously not be confirmed in a mouse model of competition between EcN and two UC-associated strains, as reported by Petersen et al. 2011. In the present study, we re-evaluated the idea, hypothesising that delivery of EcN by a micro device dosing system (microcontainers), designed for delivery into the intestinal mucus, could support colonisation and confer a competition advantage compared to classical oral dosing. Six groups of mice were pre-colonised with one of two UC-associated E. coli strains followed by oral delivery of EcN, either in capsules containing microcontainers with freeze-dried EcN powder, capsules containing freeze-dried EcN powder, or as a fresh sucrose suspension. Co-colonisation between the probiotic and the disease-associated strains was observed regardless of dosing method, and no competition advantages linked to microcontainer delivery were identified within this setup. Other approaches are thus needed if the competitive capacity of EcN in the gut should be improved.

Local Delivery of Streptomycin in Microcontainers Facilitates Colonization of Streptomycin-Resistant Escherichia coli in the Rat Colon.

Oral antibiotic treatment is often applied in animal studies in order to allow establishment of an introduced antibiotic-resistant bacterium in the gut. Here, we compared the application of streptomycin dosed orally in microcontainers to dosage through drinking water. The selective effect on a resistant bacterial strain, as well as the effects on fecal, luminal, and mucosal microbiota composition, were investigated. Three groups of rats (n = 10 per group) were orally dosed with microcontainers daily for 3 days. One of these groups (STR-M) received streptomycin-loaded microcontainers designed for release in the distal ileum, while the other two groups (controls [CTR] and STR-W) received empty microcontainers. The STR-W group was additionally dosed with streptomycin through the drinking water. A streptomycin-resistant Escherichia coli strain was orally inoculated into all animals. Three days after inoculation, the resistant E. coli was found only in the cecum and colon of animals receiving streptomycin in microcontainers but in all intestinal compartments of animals receiving streptomycin in the drinking water. 16S rRNA amplicon sequencing revealed significant changes in the fecal microbiota of both groups of streptomycin-treated animals. Investigation of the inner colonic mucus layer by confocal laser scanning microscopy and laser capture microdissection revealed no significant effect of streptomycin treatment on the mucus-inhabiting microbiota or on E. coli encroachment into the inner mucus. Streptomycin-loaded microcontainers thus enhanced proliferation of an introduced streptomycin-resistant E. coli in the cecum and colon without affecting the small intestine environment. While improvements of the drug delivery system are needed to facilitate optimal local concentration and release of streptomycin, the application of microcontainers provides new prospects for antibiotic treatment. IMPORTANCE Delivery of antibiotics in microcontainer devices designed for release at specific sites of the gut represents a novel approach which might reduce the amount of antibiotic needed to obtain a local selective effect. We propose that the application of microcontainers may have the potential to open novel opportunities for antibiotic treatment of humans and animals with fewer side effects on nontarget bacterial populations. In the current study, we therefore elucidated the effects of streptomycin, delivered in microcontainers coated with pH-sensitive lids, on the selective effect on a resistant bacterium, as well as on the surrounding intestinal microbiota in rats.

Fluidic resistance control enables high-throughput establishment of mixed-species biofilms.

Bacteria often live in communities of mixed species embedded in a self-produced extracellular matrix of polysaccharides, proteins and DNA, termed biofilms. The BioFlux microfluidic flow system is useful for studying biofilm formation in different media under flow. However, analyzing the architecture and maturation of biofilms under flow requires a proper seeding, which can prove difficult when working with bacteria of different sizes, motile bacteria or aiming for a high number of replicates. Here we developed an efficient protocol that exploits viscosity tuning and seeding indicator dyes to improve seeding and allow for high-throughput examination and visualization of consistent mono- and mixed-species biofilm developments under flow.

Consolidative Radiotherapy to Residual Masses After Chemotherapy Is Associated With Improved Outcome in Diffuse Large B-Cell Lymphoma. A Retrospective, Population-Based Study.

BACKGROUND: The role of consolidative radiotherapy (RT) in advanced diffuse large B-cell lymphoma (DLBCL) is not established. PATIENTS AND METHODS: In a population-based retrospective analysis of patients with DLBCL in Western Norway during 2003 to 2008, 170 consecutive patients admitted to Haukeland University Hospital (HUS) and 94 to Stavanger University Hospital (SUS) were included. The mean age was 64 years (range, 17-95 years), 147 patients (56%) were male, 80 patients (30%) had stage I/II, 126 patients (48%) stage III/IV, and 57 patients (22%) had primary extranodal disease. RESULTS: There were no differences between hospitals in patient characteristics, use of rituximab, number of chemotherapy courses or cumulative doses, or in distribution of response categories after chemotherapy. The use of RT was significantly different: 17 patients (23%) received RT at SUS and 92 patients (65%) at HUS (P < .001). For 219 patients with International Prognostic Index (IPI) score of 0 to 3, 5-year cancer-specific survival (CSS) was 67% at SUS and 81% at HUS (P = .012). For 73 patients with complete response after chemotherapy there were no differences in survival between patients with and without RT. For 138 patients with any residual mass after chemotherapy, there were highly significant differences in favor of receiving RT (n = 81) versus no RT (n = 57): 5-year CSS 89% versus 69% (P < .001), and 5-year overall survival 82% versus 59% (P = .005). The effect of RT on residual mass was evident in most subgroups, mainly in low to intermediate risk, but not in high-risk (IPI 4-5) patients. CONCLUSION: With the limitations of a retrospective study, these data suggest that consolidative RT might improve survival in DLBCL patients with a residual mass after chemotherapy, also in advanced disease.

An automated bladder volume measurement algorithm by pixel classification using random forests.

Residual bladder volume measurement is a very important marker for patients with urinary retention problems. To be able to monitor patients with these conditions at the bedside by nurses or in an out patient setting by general physicians, hand held ultrasound devices will be extremely useful. However to increase the usage of these devices by non traditional users, automated tools that can aid them in the scanning and measurement process will be of great help. In our paper, we have developed a robust segmentation algorithm to automatically measure bladder volume by segmenting bladder contours from sagittal and transverse ultrasound views using a combination of machine learning and active contour algorithms. The algorithm is tested on 50 unseen images and 23 transverse and longitudinal image pairs and the performance is reported.