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Browsing by Subject "yhteisvaikutukset"

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  • Silén, Heidi (2021)
    Antimicrobial resistance is a growing problem worldwide. It has been shown that more than 70% of the bacteria that cause nosocomial infections are resistant to at least one antibiotic commonly used to treat them. Two concomitant phenomena that aggravate the diarrheal disease situation, especially in developing countries, are general contamination (spread of pathogens due to unclean water, poor sanitation, and malnutrition) and resistant bacterial strains (the adverse consequences of infections increase as infections prolong). According to the WHO, foodborne diseases (FBDs) were estimated to have caused approximately 91 million people to become ill and 137,000 deaths in Africa in 2010. The number is about a third of the deaths caused by FBD worldwide. Diarrhea caused about 70% of the FBD burden. Bacteria that cause food poisoning include Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Cronobacter sakazakii, Esherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., Staphylococccus aureus and Yersinia enterocolitica, some of which are discussed in more detail in this master’s thesis; antibiotics against which resistance has developed, how bacteria resist antibiotics, and the emergence of resistance in Africa. The antibiotic resistance of bacteria and the mechanisms of resistance against antimicrobial drugs are also discussed shortly. In addition to food poisoning, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus can cause difficult-to-treat infections such as wounds. In addition, this work has first dealt with antimicrobial plant derived compounds in general and their modes of action, and then focused on compounds, fractions and extracts of species of the genera Combretum, Terminalia, Pteleopsis and Anogeissus, as well as their antibacterial effects and uses in traditional medicine. In addition, the antibacterial mechanisms of action of different groups of compounds have been discussed in more detail. This work also deals with the combination studies of some plant extracts, fractions and compounds with antibiotics. Combination studies with antibiotics have generally been studied less than the antibacterial effects alone or the effects of combinations of many plant extracts, as used in African traditional medicine. The experimental part covers, among other things, the preparation and yield determination of crude extracts (water and methanol) as well as the agar diffusion method, the microdilution method, the Time kill tests and the checkerboard method in interaction tests to determine MIC, MBC and FIC values. Due to the Covid 19 pandemic, study results were obtained only by the agar diffusion method against Bacillus cereus. The most antimicrobial extracts were extracts of species of the genus Terminalia.