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Aortic infections are rare, life-threatening and constitute a major challenge in surgical management. This thesis aims to evaluate short – and long-term outcome of endovascular aortic repair (EVAR) for mycotic aortic aneurysms (MAA) and the subsequent risk of recurrent infections, changes in surgical practice over time for abdominal MAAs in Sweden and outcome for different treatment modalities, as well as the risk of secondary vascular infection after treatment with Open abdomen after aortic surgery. Paper I, a retrospective single centre study of patients with MAA treated with EVAR, demonstrated a good short-term outcome, 91% survival at 30-days, and acceptable mid-term survival, 73% at 1-year. Paper II, a retrospective international multicentre study of patients treated with EVAR for MAA, confirmed the results in paper I, and showed that EVAR is feasible and for most MAA patients a durable treatment option, 5-year survival was 55% and 10-year 41%. A total of 19% died from an infection-related complication, mostly during the first postoperative year. Non-Salmonella-positive culture was a predictor for late infection–related death. Paper III, a population-based cohort study on all abdominal MAAs operated on between 1994-2014 in Sweden. Overall survival was 86% at 3-months, 79% at 1-year and 59% at 5-years. The survival was significantly better after endovascular compared to open repair up to 1-year without increasing recurrence of infection or reoperation, thereafter there was no difference. After 2001 EVAR constituted 60 % of all repairs, thus indicating a paradigm shift in treatment for abdominal MAAs in Sweden. Paper IV, a prospective multicentre study of patients treated with open abdomen after aortic surgery. Infectious complications, such as graft infections, occurred after intestinal ischaemia and prolonged OA-treatment, and were often fatal.

Ubiquitous in agro-environments, Fusarium species infect and damage economically important crops and contaminate food commodities with harmful secondary metabolites called mycotoxins. In addition, human infection by pathogenic Fusarium strains has now emerged as a major problem particularly among individuals with suppressed immunity. Trichothecenes, deoxynivalenol, nivalenol, rnoniliforme and fumonisins are potent toxins produced by Fusorium species including F. poae, F. nygami, F. oxysporum, F. proilferatum and F. verticillioides. The last three, together with F. solani and F. chlamydosporum are presently recognised as major role players in the occurrence of fusarioses in individuals with compromised immunity. In subsistence situations in rural areas of South Africa, a variety of traditional leafy vegetables, collectively known as morogo, supplement maize-based staple diets with minerals and vitamins. The utilisations of these traditional vegetables are generally based on indigenous knowledge pertaining to production and processing. Morogo plants are not natural hosts to mycotoxigenic and mycotic Fusarium species that are mainly associated with pathogeneses of grain crops such as maize. However, morogo growing in close proximity of maize in typical subsistence agricultural situations might be at risk of Fusarium contamination from maize. The study was conducted in the Dikgale Demographic Surveillance Site (DDSS), a rural area in the Limpopo Province characterised by the production of maize and different types of traditional morogo for household subsistence. HIVIAIDS is prevalent in the Limpopo Province. Chronic dietary exposure to Fusarium toxins and disseminated fusarioses might enhance disease outcomes associated with AIDS in affected individuals, thus adding to the burden of disease in DDSS communities. The aim of the study was to investigate the occurrence of mycotic and mycotoxigenic Fusarium species in traditional morogo and ago-environments in DDSS. Questionnaires were employed to obtain relevant information and indigenous knowledge from communities of Sefateng. Madiga, Mantheding and Moduane related to the utilisation of raditional morogo. At each village thepe (amaranth) and lerotho (African cabbage) were sampled on two occasions, namely before maize planting (M-) and when maize was fully grown (M+). Maize, soil and air were sampled at the same time. Botanical species identification was carried out on specimens of lerotho and thepe from each village. Lerotho. thepe, maize, soil and air samples were subjected to mycological analysis to determine the average fungal levels and Fusarium species that occurred. Samples of fresh and traditionally sun-dried samples of thepe and lerotho were analysed by HPLC for fumonisins. Average fungal plate counts of morogo from all four villages were notably higher in lerotho compared to thepe. Lerotho sampled from M- fields of Madiga, Mantheding and Moduane exhibited higher average fungal levels than those from the M+ fields. However, in lerotho sampled from the M+ field of Sefateng average fungal levels were significantly higher than that of the M- field. Fungal levels in maize growing close to morogo were lowest in Sefateng and highest in Moduane. The highest fungal counts in soil were reported for Sefateng's M- field and the lowest for Sefateng M+ field. Fungal levels were high in air samples of M+ fields of all four villages and the lowest in M- field of Sefateng. The majority Fusarium isolates retrieved from morogo and environmental samples belonged to known mycotoxigenic and/or mycotic species, though predominant species and levels thereof varied in samples from M- and M+ fields of the four villages. Fusarium levels in thepe from both M- and M+ fields were shown to be lower as in lerotho. In samples of the Sefateng M- field, F. poae occurred predominantly in lerotho, thepe, soil as well as air, while F. subglutinans was the predominant species in lerotho and air samples of Mantheding. In Sefateng samples from M+ field, F. chlamydosporum predominated among isolates retrieved from lerotho, F. prolifiratum and F. gramenearum among those from maize and F. solani among those from soil and air. F. proliferatum dominated among isolates from lerotho, maize, soil and air of M+ sites of Madiga and F. chlamydosporum in soil and air samples of Mantheding. HPLC analysis detected fumonisin B1 in traditionally sun-dried as well as fresh samples of lerorho as well as thepe. The occurrence of mycotoxigenic and rnycotic Fusarium species in traditional morogo and agro-environments might be an aggravating health risk factor for DDSS communities. / Thesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007.

Ubiquitous in agro-environments, Fusarium species infect and damage economically important crops and contaminate food commodities with harmful secondary metabolites called mycotoxins. In addition, human infection by pathogenic Fusarium strains has now emerged as a major problem particularly among individuals with suppressed immunity. Trichothecenes, deoxynivalenol, nivalenol, rnoniliforme and fumonisins are potent toxins produced by Fusorium species including F. poae, F. nygami, F. oxysporum, F. proilferatum and F. verticillioides. The last three, together with F. solani and F. chlamydosporum are presently recognised as major role players in the occurrence of fusarioses in individuals with compromised immunity. In subsistence situations in rural areas of South Africa, a variety of traditional leafy vegetables, collectively known as morogo, supplement maize-based staple diets with minerals and vitamins. The utilisations of these traditional vegetables are generally based on indigenous knowledge pertaining to production and processing. Morogo plants are not natural hosts to mycotoxigenic and mycotic Fusarium species that are mainly associated with pathogeneses of grain crops such as maize. However, morogo growing in close proximity of maize in typical subsistence agricultural situations might be at risk of Fusarium contamination from maize. The study was conducted in the Dikgale Demographic Surveillance Site (DDSS), a rural area in the Limpopo Province characterised by the production of maize and different types of traditional morogo for household subsistence. HIVIAIDS is prevalent in the Limpopo Province. Chronic dietary exposure to Fusarium toxins and disseminated fusarioses might enhance disease outcomes associated with AIDS in affected individuals, thus adding to the burden of disease in DDSS communities. The aim of the study was to investigate the occurrence of mycotic and mycotoxigenic Fusarium species in traditional morogo and ago-environments in DDSS. Questionnaires were employed to obtain relevant information and indigenous knowledge from communities of Sefateng. Madiga, Mantheding and Moduane related to the utilisation of raditional morogo. At each village thepe (amaranth) and lerotho (African cabbage) were sampled on two occasions, namely before maize planting (M-) and when maize was fully grown (M+). Maize, soil and air were sampled at the same time. Botanical species identification was carried out on specimens of lerotho and thepe from each village. Lerotho. thepe, maize, soil and air samples were subjected to mycological analysis to determine the average fungal levels and Fusarium species that occurred. Samples of fresh and traditionally sun-dried samples of thepe and lerotho were analysed by HPLC for fumonisins. Average fungal plate counts of morogo from all four villages were notably higher in lerotho compared to thepe. Lerotho sampled from M- fields of Madiga, Mantheding and Moduane exhibited higher average fungal levels than those from the M+ fields. However, in lerotho sampled from the M+ field of Sefateng average fungal levels were significantly higher than that of the M- field. Fungal levels in maize growing close to morogo were lowest in Sefateng and highest in Moduane. The highest fungal counts in soil were reported for Sefateng's M- field and the lowest for Sefateng M+ field. Fungal levels were high in air samples of M+ fields of all four villages and the lowest in M- field of Sefateng. The majority Fusarium isolates retrieved from morogo and environmental samples belonged to known mycotoxigenic and/or mycotic species, though predominant species and levels thereof varied in samples from M- and M+ fields of the four villages. Fusarium levels in thepe from both M- and M+ fields were shown to be lower as in lerotho. In samples of the Sefateng M- field, F. poae occurred predominantly in lerotho, thepe, soil as well as air, while F. subglutinans was the predominant species in lerotho and air samples of Mantheding. In Sefateng samples from M+ field, F. chlamydosporum predominated among isolates retrieved from lerotho, F. prolifiratum and F. gramenearum among those from maize and F. solani among those from soil and air. F. proliferatum dominated among isolates from lerotho, maize, soil and air of M+ sites of Madiga and F. chlamydosporum in soil and air samples of Mantheding. HPLC analysis detected fumonisin B1 in traditionally sun-dried as well as fresh samples of lerorho as well as thepe. The occurrence of mycotoxigenic and rnycotic Fusarium species in traditional morogo and agro-environments might be an aggravating health risk factor for DDSS communities. / Thesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007.

Infektionen im Bereich der Aorta stellen heute noch eine der gravierendsten Komplikationen der rekonstruktiven Gefäßchirurgie dar. Ziel der vorliegenden Arbeit war es, die Effektivität von kryokonservierten Aortenallografts bei der in situ-Behandlung einer manifesten Infektion im Bereich der Aorta tierexperimentell zu evaluieren. Dessweiteren sollte die Rolle der im Rahmen der Kryokonservierung zum Zwecke der Dekontamination eingesetzten Antibiotika untersucht werden. Zu diesem Zwecke erfolgte im in-vitro Experiment die Untersuchung der Antibiotikakonzentration im Gewebe sowie die der Freisetzungskinetik. Am Modell einer durch Staphylococcus epidermidis RP-62 verursachten Protheseninfektion der infrarenalen Bauchaorta des Hundes konnte eine intrinsische Infektionsresistenz der kryokonservierten Aortenallografts nachgewiesen werden. Jedoch scheint die Antibiotikabehandlung der Allografts für die Optimierung des therapeutischen Effektes essentiell zu sein. Die Ergebnisse der in vivo-Experimente werden durch die in vitro-Untersuchungen, ebenso wie durch die Analyse der eigenen klinischen Ergebnisse und der in der Literatur publizierten Daten belegt. Die vorliegende Arbeit kommt zu dem Schluß, daß die Verwendung von kryokonservierten Allografts das Therapiekonzept der Wahl zur Behandlung von Infektionen im Bereich der Aorta darstellt. / Infections of the aorta remain one of the most dreaded complications in reconstructive vascular surgery. The purposes of this study were to evaluate the efficacy of a cryopreserved aortic allograft to treat an established vascular graft infection by the surgical in situ replacement of the infected segment in an animal model, and to investigate the role of antibiotics to decontaminate the allograft during the cryopreservation process. Furthermore, the tissue concentrations of the antibiotic and the kinetics of desorption were investigated in in vitro experiments. A model of prosthetic graft infection by Staphylococcus epidermidis RP-62 (inserted in the infrarenal aorta) in dogs was developed. By in situ replacement of the infected prosthetic graft with a cryopreserved aortic allograft, this study demonstrated an intrinsic resistance to infection of cryopreserved aortic allografts. However, antibiotic loading of the cryopreserved aortic allografts appeared to be essential to obtain optimal therapeutic effects. The results of these in vivo experiments were supported by the findings of our in vitro studies, as well by analysis of our own clinical results and by clinical data published in the medical literature. We conclude that in situ replacement with a cryopreserved allograft is currently the therapy of choice for an aortic infection.