Background: Mastitis in dairy cattle is a common ailment worldwide. A cause of mastitis can be bacteria such as Escherichia coli. Mastitis is not a deadly ailment and sometimes the dairy cows show no symptoms but if certain virulence genes are present in the bacteria that cause the mastitis, the bacteria can be transmitted to humans and cause severe diseases. The potential presence of enterohemorrhagic Escherichia coli (EHEC) in particular would be a major concern for human health.Aim: The aim for this study was to analyze the presence of virulence genes known to be present in E.coli strains isolated from dairy cows with mastitis in Sweden.Method: A Qiagen BIO ROBOT EZ1 was used to purify DNA from 90 bacterial cultures. A panel of virulence genes were amplified and biotinylated from the purified DNA by PCR and an E.coli based DNA microarray was used to detect presumed virulence genes in E.coli.Result: There were no samples that had all the genes traditionally used to classify E.coli as EHEC or potential EHEC.

Escherichia (E) coli is one of the most common udder pathogens associated with acute clinical mastitis in Swedish dairy cows. The aim of this study is to review some of the existing literature on E coli mastitis from a Swedish perspective. The bacteria, its most important characteristics, and diagnostics under field conditions is covered, as well as what happens during infection, how E coli affects the cow and which consequences this have. Clinical symptoms associated with E coli mastitis are described and information on when these cases of mastitis usually occurs is given. Risk factors in the cow?s enviroment are described as well as the importance of the cow?s immune defence.

In this study the hygienic quality of minced moose meat was examined with regard to the prevalence of different bacteria. The methods used are described in NMKL, "Nordic Method Committee for Food". The results show that the levels of Escherichia coli and coagulase positive staphylococci in the meat are too high. The reason for this might be environmental factors, such as high temperature and humidity during the time when the carcasses are hanging and when the meat is cut up..

The purpose of this study was to investigate the occurrence of Verotoxin-encoding bacteriophages in mussels, cultured downstream the sewage treatment plant in Lysekil.Mussels were collected in three growing areas from April 2008 to March 2009. Real-time PCR was performed for detection of vtx1 and vtx2 genes and enrichment of bacteriophages on non Verotoxin-producing Escherichia coli O157: H7 was carried out. All samples in real-time PCR analysis were negative; no presence of Verotoxin-encoding phages was shown. No plaque was formed on blood agar base plates, indicating that no bacteriophages had been taken up by E. coli bacteriaThe levels of Verotoxin-encoding phages and E.coli outside the sewage treatment plant in Lysekil were not high enough to be able to form VTEC in mussels, indicating that the faecal contamination was low.

Stafylococcus aureus, Stafylococcus epidermidis, Escherichia coli, Streptococcuspyogenes och Bacillus sp. är bakterier som förekommer i vår normalflora eller runt om ivår omgivning. De är i de allra flesta fall harmlösa men kan orsaka sjukdom ifall dehamnar i t.ex. sår eller kontaminerar mat. Vissa av dessa bakterier har även en tendens attutveckla resistens mot antibiotika, infektioner orsakade av resistenta bakterier kan bliallvarliga och väldigt svåra att behandla.

The study evaluated the Mutant Prevention Concentration (MPC) of Pradofloxacin on three Escherichia coli (E.coli) strains, 2 wildtypes and one first-step gyrA resistant mutant. We also measured the value of AUC (Under the Concentration)/MPC that prevents growth of resistant mutants. It is of importance to reach a concentration above MPC that prevent E.coli from developing resistance against the antibiotic.We used an in vitro kinetic model where we added bacteria? and antibiotic. The culture flask was attached to a pump with an adjustable pump-speed.

Flera stora utbrott med kontaminerade grönsaker har skett under de senaste åren, många människor har blivit sjuka och till och med dött efter att ha ätit färska grönsaker. Denna studie undersöker bevattningsvattnet som en faktor till dessa utbrott. Det finns olika bakterier som kan förekomma i bevattningsvattnet Campylobacter, Salmonella spp, Shigella spp, Escherichia coli (E.coli) och Listeria är exempel som behandlas i detta arbete. Litteraturundersökningen fokuserar på hur bakterier kan spridas, olika kontamineringsrisker, rekommenderade gränsvärden för hur mycket bakterier det får finnas i bevattningsvattnet samt produkter som kan vara särskilt utsatta för en kontamination. I den experimentella delen undersöks hur mängden E.coli förändras med tiden på spenat.

Färdigsallader är en produktgrupp som blir allt mer populär. Dessvärre har det på senare år förekommit ett antal utbrott där människor har smittats av tarmbakterier som Salmonella och verotoxinproducerande Escherichia coli i olika ouppvärmda produkter som till exempel böngroddar från Tyskland. I denna litteraturstudie undersöks vilka patotyper av E. coli och Salmonella som kan infektera människor och hur detta kan gå till. Det ges förslag för att minska smittspridningen. Särskilt fokus ges E.

This study was performed to investigate the bacteriological quality of French cheeses made from raw milk. Fifty cheeses of this type were purchased from Swedish retail premises. The methods described by the Nordic Committee on Food Analysis (NMKL) were used to determine the number of Enterobacteriaceae, presumptive Escherichia coli, coagulase positive staphylococci and Listeria monocytogenes. In 32 cheeses (64%) the number of bacteria mentioned above exceeded the determined maximum value. Thirty samples (60%) showed high counts of Enterobacteriaceae.

PSI-N is one of the subunits in eukaryotic Photosystem I (PSI) and is located on the lumenal side of the thylakoid membrane. It is known to interact in the electron transport chain between plastocyanin and PSI, but the mechanism behind the interaction is still unclear. To achieve a better understanding of PSI-N´s role in the photosynthesis it is necessary to develop a method for purification of PSI-N. The goal with this project was to design a plasmid that encodes a fusion protein containing PSI-N. With use of proteases the fusion protein can be cleaved into purified PSI-N.

PSI-N is one of the subunits in eukaryotic Photosystem I (PSI) and is located on the lumenal side of the thylakoid membrane. It is known to interact in the electron transport chain between plastocyanin and PSI, but the mechanism behind the interaction is still unclear. To achieve a better understanding of PSI-N´s role in the photosynthesis it is necessary to develop a method for purification of PSI-N. The goal with this project was to design a plasmid that encodes a fusion protein containing PSI-N. With use of proteases the fusion protein can be cleaved into purified PSI-N.

In the country of Jordan, egg production is very important economically, but several bacte-ria are involved in food borne diseases transmitted from eggs or other poultry products. The most important are Salmonella spp., Campylobacter jejuni and Escherichia coli. In Jordan two different housing systems are used for hens in large scale egg production; con-ventional cages and litter floor systems. Eggs from four different farms were analysed and compared to see if a difference could be found regarding the presence of pathogenic bacte-ria on the egg surfaces between these two systems. Total number of aerobic bacteria was analysed, the presence of Salmonella spp., C.

Förekomsten av Extended Spectrum ?-Lactamases (ESBL) och Vancomycinresistenta enterokocker (VRE) har ökat hos gramnegativa bakterier under de senaste åren. Måsfåglar kan användas som biologiska indikatorer för att se prevalensen av antibiotikaresistens i naturen, vilken sedan kan jämföras med den hos humana populationer.Syftet var att med odling av fekalprover på selekterande och differentierande agarplattor analysera det allmänna resistensläget hos Escherichia coli samt analysera förekomst av Extended Spectrum ?-Lactamases hos enterobakterier och Vancomycinresistenta enterokocker i 300 prover från måsar på Irland. För att artbestämma bakterierna utfördes även biokemiska analyser.Den allmänna resistensen analyserades med diskdiffusionstest på Muller-Hintonagarplattor.

Oxochlorates are anions with a partially naturally occurrence in nature but are also spread by human activities, including the paper industry. These compounds are harmful to both nature and humans, which makes it necessary to find a good way for their degradation. There are two different kinds of bacteria that can use oxochlorates as electron acceptors in their metabolism, bacteria that break down perchlorate and bacteria that break down both perchlorate and chlorate. A bacterium that can break down chlorate under anaerobic conditions is Ideonella dechloratans which holds the genes for chlorite dismutase and chlorate reductase which are enzymes for the degradation of chlorate. Gene expression and enzyme activity of chlorite dismutase are induced under anaerobic conditions, which makes it interesting to find out how this regulation functions in order to better exploit these bacteria in biological wastewater treatment.

Utveckling av antibiotikaresistens är ett problem som innebär ett stort hot mot folk- och djurhälsa. Resistensläget i Sverige övervakas kontinuerligt genom ett samarbete mellan Smittskyddsinstitutet, SMI och Statens Veterinärmedicinska Anstalt, SVA. I Sverige har vi idag ett gott läge när det gäller resistens, men en oroande ökning av vissa fruktade multiresistenta bakterier ses även här. I flera studier, från olika länder, har man sett att förekomsten av antibiotikaresistens är högre hos unga individer för att sedan minska med åldern. När det gäller nötkreatur ser man en hög resistensförekomst i tarmfloran hos kalvar framför allt under perioden då de utfodras med mjölk. Syftet med denna studie var att ytterligare öka förståelsen om hur den unga kalven träffar på, och koloniseras av, de resistenta bakterierna.