Search results for "antibiootit"

Degradation of Antibiotic Vancomycin by UV Photolysis and Pulsed Corona Discharge Combined with Extrinsic Oxidants

2023

Antibiotics are the most frequently detected pharmaceuticals in the environment creating conditions for the development of resistant genes in bacteria. Degradation and mineralization of glycopeptide antibiotic vancomycin (VMN) were examined by UV photolysis, pulsed corona discharge (PCD), and their combinations with extrinsic oxidants, hydrogen peroxide (HP), peroxydisulfate (PDS), and peroxymonosulfate (PMS). Both combinations were effective in VMN degradation and faster at pH 11 than in acidic or neutral media. Combined with the UV photolysis, HP showed a higher oxidation rate than other oxidants, whereas PMS and PDS proved to be more efficient in combinations with PCD. In contrast to low…

Occurrence and control of selected antibiotics and antiretroviral drugs in urban hydrological cycles

2018

A multiresidue analytical method for trace level determination of antibiotics and antiretroviral drugs in wastewater and surface water using SPE-LC-M…

2016

An analytical method for simultaneous determination of seven commonly used antibiotics and three antiretrovirals in surface water and urban wastewater at the ng L−1 level has been developed. The method involves concentration and clean-up by solid phase extraction (SPE) followed by identification and quantification by liquid chromatography tandem mass spectrometry (LC-ESI-MS/MS). The use of matrix-matched calibration curves constructed by spiking surface water was evaluated for quantification and compared with the internal standard method using isotopically labelled compounds. The method gave absolute recoveries of 41–116% with most of the compounds having recoveries >50%. The LOQs ranged fr…

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

Simultaneous determination of five antibiotics in urban wastewater using SPE-HPLC-MS/MS

2015

Antibioottien havaitseminen jätevesistä on haastavaa johtuen matalista pitoisuuksista ja monimutkaisesta matriisista. Tässä työssä kehiteltiin kiinteäfaasiuuttoa, nestekromatografia ja tandem massaspektrometriä hyväksi käyttävä menetelmä, jolla voitiin analysoida viittä antibioottia yhtäaikaisesti matalina pitoisuuksina jätevesistä, ja sitä testattiin käytännössä kolmen keskisuuren suomalaisen jätevedenpuhdistamon jätevesiin. Monimutkainen matriisi heikentää usein antibioottien signaalia massaspektrometrissä ja tässä työssä käytettiin matriisi-korjattua ulkoista standardia huomioimaan efektiä. Mene-telmä oli yksinkertainen, nopea ja toistettava. Määritysrajat vaihtelivat <10–150 ng/l välill…

Environmental remediation using nanomaterial as adsorbents for emerging micropollutants

2023

Water shortage and scarcity are issues of global concern. Water pollution caused by organic micropollutants further aggravates the problem, by rendering an already scarce resource unfit for human consumption. The existing conventional wastewater treatment methods and infrastructure were not designed to eliminate micropollutants. Therefore, their inefficiencies call for modern methods for removing emerging micropollutant residues such as Active Pharmaceutical Ingredients (APIs), Endocrine Disrupting Compounds (EDCs), personal care products and pesticides. The use of nanomaterials, for the abatement of micropollutants in water is gaining traction in recent years, due to the abundance of susta…

Multispecies coinfections and presence of antibiotics shape resistance and fitness costs in a pathogenic bacterium

2023

Increasing antimicrobial resistance (AMR) poses a challenge for treatment of bacterial diseases. In real life, bacterial infections are typically embedded within complex multispecies communities and influenced by the environment, which can shape costs and benefits of AMR. However, knowledge of such interactions and their implications for AMR in vivo is limited. To address this knowledge gap, we investigated fitness-related traits of a pathogenic bacterium (Flavobacterium columnare) in its fish host, capturing the effects of bacterial antibiotic resistance, coinfections between bacterial strains and metazoan parasites (fluke Diplostomum pseudospathaceum) and antibiotic exposure. We quantifie…

Rearing background and exposure environment together explain higher survival of aquaculture fish during a bacterial outbreak

2019

1.Parasitic diseases represent one of the greatest challenges for aquaculture worldwide and there is an increasing emphasis on ecological solutions to prevent infections. One proposed solution is enriched rearing, where traditional stimulus‐poor rearing tanks are equipped with different types of structures to increase habitat complexity. Such spatial enrichment is known to increase survival of fish during parasite epidemics, but the underlying mechanisms are still unclear. 2.We studied whether enriched rearing affected infection of an important fish pathogen Flavobacterium columnare in young Atlantic salmon (Salmo salar) and sea‐migrating brown trout (Salmo trutta). First, we used natural b…