Search results for "bakteeri"
showing 10 items of 168 documents
Small things matter : of phages and antibiotic resistance conferring plasmids
2016
Viruses and plasmids are small units of genetic material dependent on cells either transiently or continuously. Intriguingly, stories of these small entities intertwine in antibiotic resistance crisis. Horizontal gene transfer enables bacteria to respond rapidly to chances in their environment. Anthropogenic consumption of antibiotics induces the travel of resistance encoding genes mainly as passengers of conjugative plasmids. In this thesis, I demonstrate that clinically important resistance plasmids could evolutionarily rescue susceptible bacteria under lethal antibiotic concentrations. If mobile resistance genes are available in surrounding community, administration of high doses of anti…
Counteracting the horizontal spread of bacterial antibiotic resistance with conjugative plasmid-dependent bacteriophages
2016
Microencapsulation of Enteric Bacteriophages in a pH-Responsive Solid Oral Dosage Formulation Using a Scalable Membrane Emulsification Process
2019
A scalable low-shear membrane emulsification process was used to produce microencapsulated Escherichia coli-phages in a solid oral dosage form. Uniform pH-responsive composite microparticles (mean size ~100 µ
The “Seili-index” For The Prediction of Chlorophyll-α Levels In The Archipelago Sea of The Northern Baltic Sea, Southwest Finland
2021
AbstractTo build a forecasting tool for the state of eutrophication in the Archipelago Sea, we fitted a Generalized Additive Mixed Model (GAMM) to marine environmental monitoring data, which were collected over the years 2011–2019 by an automated profiling buoy at the Seili ODAS-station. The resulting “Seili-index” can be used to predict the chlorophyll-α (chl-a) concentration in the seawater a number of days ahead by using the temperature forecast as a covariate. An array of test predictions with two separate models on the 2019 data set showed that the index is adept at predicting the amount of chl-a especially in the upper water layer. The visualization with 10 days of chl-a level predict…
Bacteriophage Adherence to Mucus Mediates Preventive Protection against Pathogenic Bacteria
2019
The mucosal surfaces of animals are habitat for microbes, including viruses. Bacteriophages—viruses that infect bacteria—were shown to be able to bind to mucus. This may result in a symbiotic relationship in which phages find bacterial hosts to infect, protecting the mucus-producing animal from bacterial infections in the process. Here, we studied phage binding on mucus and the effect of mucin on phage-bacterium interactions. The significance of our research is in showing that phage adhesion to mucus results in preventive protection against bacterial infections, which will serve as basis for the development of prophylactic phage therapy approaches. Besides, we also reveal that exposure to m…
Urban forest soils harbour distinct and more diverse communities of bacteria and fungi compared to less disturbed forest soils.
2022
Anthropogenic changes to land use drive concomitant changes in biodiversity, including that of the soil microbiota. However, it is not clear how increasing intensity of human disturbance is reflected in the soil microbial communities. To address this issue, we used amplicon sequencing to quantify the microbiota (bacteria and fungi) in the soil of forests (n=312) experiencing four different land uses, national parks (set aside for nature conservation), managed (for forestry purposes), suburban (on the border of an urban area) and urban (fully within a town or city), which broadly represent a gradient of anthropogenic disturbance. Alpha diversity of bacteria and fungi increased with increasin…
Microencapsulation of Salmonella-Specific Bacteriophage Felix O1 Using Spray-Drying in a pH-Responsive Formulation and Direct Compression Tableting o…
2019
The treatment of enteric bacterial infections using oral bacteriophage therapy can be challenging since the harsh acidic stomach environment renders phages inactive during transit through the gastrointestinal tract. Solid oral dosage forms allowing site-specific gastrointestinal delivery of high doses of phages, e.g., using a pH or enzymatic trigger, would be a game changer for the nascent industry trying to demonstrate the efficacy of phages, including engineered phages for gut microbiome modulation in expensive clinical trials. Spray-drying is a scalable, low-cost process for producing pharmaceutical agents in dry powder form. Encapsulation of a model Salmonella-specific phage (Myoviridae…
Aquaculture as a source of empirical evidence for coevolution between CRISPR-Cas and phage
2019
So far, studies on the bacterial immune system CRISPR-Cas and its ecological and evolutionary effects have been largely limited to laboratory conditions. While providing crucial information on the constituents of CRISPR-Cas, such studies may overlook fundamental components that affect bacterial immunity in natural habitats. Translating laboratory-derived predictions to nature is not a trivial task, owing partly to the instability of natural communities and difficulties in repeated sampling. To this end, we review how aquaculture, the farming of fishes and other aquatic species, may provide suitable semi-natural laboratories for examining the role of CRISPR-Cas in phage/bacterium coevolution…
Characterization of dry-film photolithography for the study of B. burgdorferi motility
2017
Kuivafilmilitografian karakterisointi Borrelia burgdorferi:n liikkuvuuden tutkimiselle. Borrelia burgdorferi on puutiaisten kantama spirokeettabakteeri, joka voi tarttua useisiin eläinlajeihin. Ihmisillä B. burgdorferi aiheuttaa borrelioosia. Tauti on laajalle levinnyt monissa pohjois- ja länsimaissa ja leviää entisestään ilmastonmuutoksen laajentaessa punkkien elinaluetta. Monet tekijät vaikeuttavat borrelioosin hoitoa. B. burgdorferin kyky välttää ihmisen luontaista immuunijärjestelmää ovat tässä suhteessa merkittävä. Bakteerien liikkuvuus on olennainen tämän kyvyn kannalta, mutta sen tarkka rooli bakteerien kyvyssä liikkua verisuonistossa on osittain tuntematon. Mikrofluidistiikka hyödyn…