Brucella causes undulant fever in humans and uterine and systemic infection leading to abortions in domestic animals and wild life. For the acquisition of iron in mammalian hosts, species of Brucella are known to produce two siderophores, 2, 3-dihydroxy benzoic acid (2, 3-DHBA) and brucebactin. Inability to synthesize of 2, 3-DHBA affects the ability of pathogen to metabolize erythritol, replicate in trophoblast cells and cause abortion in pregnant ruminant host. The entF gene has been implicated in the unresolved pathway allowing brucebactin biosynthesis in Brucella. The research effort presented in this thesis tries to relate the role of entF in iron acquisition and potential relation with erythritol metabolism by wild type B. abortus 2308. An entF deletion mutant (BAN1) of B. abortus 2308, generated using cre-lox methodology was found to be growth inhibited in iron minimal media compared to wild type strain. Growth inhibition was further enhanced with the addition of an iron chelator or 0.1% erythritol. Compared to wild type strain, no growth inhibition of BAN1 mutant was found in murine J774A.1 macrophages, which suggests that Brucella could acquire iron inside mammalian cells. The entF gene complemented mutant strains of BAN1 (BAN2A and BAN2B) were found to be intermediate in their ability to grow in iron minimal media supplemented with 0.0.05% erythritol, when compared to wild type and BAN1 strain. The results from the present thesis demonstrate that entF gene plays an important role in iron acquisition and erythritol metabolism by B. abortus 2308 under iron limiting conditions. / Master of Science

Yes / In the study of microbial keratitis, in vivo animal models often require a large number of animals, and in vitro monolayer cell culture does not maintain the three-dimensional structure of the tissues or cell-to-cell communication of in vivo models. Here, we propose reproducible ex vivo models of single- and dual-infection keratitis as an alternative to in vivo and in vitro models. / Wellcome Trust

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Thesis (Ph.D. in Pharmaceutical Sciences) -- University of Colorado, 2006. / Typescript. Includes bibliographical references (leaves 191-216). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

This thesis examines the influence of packaging on the microbial condition of beef for sale. The beef - Muscullus semimembranosus - was studied in an unpackaged state, and in the packaging of stretchable plastic wrap, in multilayer polyamide - polyethylene (PA / PE) wrap using a protective atmosphere and using 80% of vacuum into a bag from a multi-layered PA / PE wrap. The beef was stored at refrigerated temperature of +5 ° C. The total number of microorganisms (the number of colony forming units) were examined for 27 days. The compared samples show that the speed of increasing number of microorganisms is dependent on the type of packaging. According to the observed averages the best results are showed at meat packaged into a modified atmosphere and vacuum packaging, where there were no significant differences between these two types. Statistically there were no sigificant differences between the observed types of packaging. Packing in plastic wrap reduced microbial contamination of meat compared to unpackaged meat, but with vacuum packaging and modified atmosphere it could not be compared.

Bakgrund: Postoperativa sårinfektioner orsakar lidande för den drabbade patienten och kostnader för patienten, vården och samhället. Intraoperativ kontamination av operationsinstrumenten är en av källorna till dessa infektioner. Operationssjuksköterskan är ansvarig för aseptiken och operationsinstrumenten.   Syfte: Syftet med denna pilotstudie var att mäta graden av bakteriell kontamination över tid på operationsinstrument som används vid öppen neurokirurgi samt observera utvalda källor till kontamination under samma tid. Metod: Denna studie designades som en kvantitativ icke-experimentell observationsstudie. Datainsamlingen skedde under hösten 2015 och bestod av omhändertagandet av specifika instrument som använts av operatören under operationen efter förutbestämd åtgången knivtid. Bakterieodlingar på dessa instrument skedde sedan på laboratorium enligt en förutbestämd metod och graden av kontamination mättes genom observation av mängden colony forming units (CFU). Resultaten presenteras i form av förändringar av mängden CFU. Resultat: Fem operationer observerades och tio odlingar utfördes på tio instrument. Totalt tio CFU registrerades under samtliga observationer. Ingen signifikant ökning av antal CFU kunde observeras från en till två timmars knivtid (P=0,156). Antal dörröppningar ökade från 3,4 till 9,0 och antal personer på operationssalen ökade från 5,4 till 5,8. Slutsats: Trots det ringa antal observationer som ingick i denna studie tyder resultaten på god aseptik och minimal bakteriell kontamination på operationsinstrumenten under operationens två första timmar. Ytterligare forskning med längre observationer, fler observationer och observationer kring annan typ av kirurgi behövs. / Background: Post-operative surgical site infections (SSI) cause suffering for the afflicted patient and is a great cost for the patient, the health care system and society. Intra-operative contamination of surgical instruments is one of the sources of these infections. The operating room nurse is responsible for preventing infections. Purpose: The purpose of this pilot-study was to measure the degree of bacterial contamination over time on surgical instruments used in open neurosurgery as well as to observe specific sources of contamination during this time. Method: The design was a quantitative nonexperimental observational study. The data collection took place during autumn 2015 and consisted of the sampling of specific instruments used by the surgeon during surgery after preset elapsed operating times. Bacterial culturing on these instruments was then carried out at a laboratory according to a preset routine and the degree of contamination was measured by observing the amount of colony forming units (CFU). The results are presented as changes in CFU. Results: Five operations were observed and ten bacterial culturings were conducted on ten instruments. A total of ten CFU was registered during all observations. No significant increase in the number of CFU could be observed from one to two hours of elapsed surgery (P=0,156). The amount of door openings increased from 3,4 to 9,0 and the number of personnel in the operating room increased from 5,4 to 5,8. Conclusion: Despite the small number of observations included in this study the results indicate good aseptics and minimal bacterial contamination on the surgical instruments during the first two hours of surgery. Further research with longer observations, more observations and observations on other forms of surgery is needed.

Introdução: O leite pode ser considerado um dos alimentos mais completos por apresentar alto teor de proteínas e sais minerais, porém, também é considerado excelente meio de cultura para microrganismos. Objetivos: Identificar o número de UFC de Staphylococcus spp. e Klebsiella pneumoniae, cultivados isoladamente ou em associação, em leite integral estéril, a 6 oC, 27 oC e 37 oC e descrever a curva de morte térmica, quando submetidas ao processo de pasteurização lenta isoladamente ou em associação. Material e Métodos: Avaliação através da contagem das UFC, do comportamento de Staphylococcus spp. e K. pneumoniae, isoladas de tanque de refrigeração de leite, submetidas a temperaturas que simulam o leite em condições de refrigeração (6 °C), condições ambientais (25 °C) e na temperatura ideal de crescimento de patógenos mesófilos (36°C). Avaliação da sensibilidade de Staphylococcus spp. e K. pneumoniae isoladas e em associações ao processo de pasteurização lenta. Resultados: Na escala 1 de Mac Farland a média de UFC de K. pneumoniae foi maior que a de Staphylococcus spp. A 6 °C as bactérias no leite, isoladas ou em associação crescem na mesma velocidade. A 25 °C a K. pneumoniae cresce mais que o Staphylococcus spp. A 25 °C K. pneumoniae associada ao Staphylococcus spp. cresce mais do que quando encontra-se isolada. A 36 °C K. pneumoniae associada ao Staphylococcus spp. cresce mais do que quando encontra-se isolada e ainda mais que a 25 °C. A pasteurização lenta foi efetiva, pois reduziu em no mínimo 90% as UFC no leite após 30 minutos a 65 °C. Conclusão: a medida que aumenta a temperatura, até 36 °C, a Klebsiella pneumoniae apresenta crescimento superior ao Staphylococcus spp., a contaminação de leite por Klebsiella pneumoniae (contaminação ambiental) irá influenciar mais na qualidade do produto final, comparando-se à contaminação por Staphylococcus spp., oriundo de mastite e a interação de microrganismos altera a morte dos mesmos, recomendando-se que novos estudos sejam realizados para que se entenda melhor esse processo. / Introduction: The milk can be considered one of the most complete food for its high contents of protein and minerals, but also it is considered an excellent medium of culture for microorganisms. Objective: To identify the number of the Colony Forming Units of Staphylococcus spp. and Klebsiella pneumoniae, in integral sterile milk, at different temperatures (6ºC, 27ºC e 37ºC) and to describe a thermal curve death, when submitted to the process of slow pasteurization isolated or in association. Materials and methods: Evaluation by counting of the colony forming units and the behavior of the Staphylococcus spp. and Klebsiella pneumoniae, isolated and in association occurred in the cooling tank, submitted to temperatures that simulate the conditions of milk in cooling (6ºC), environmental condition (25ºC) and the optimal temperature for the growth of microorganisms (36ºC). Evaluation of the sensibility of Staphylococcus spp. and Klebsiella pneumoniae isolated and in association during the pasteurization process. Results: In Scale 1 of Mac Farland the average of the colony form units of the K. pneumoniae was greater than the colony of Staphylococcus spp. At 6ºC the microorganisms in the milk isolated or in association grew at the same speed. At 25ºC K. pneumoniae associated with Staphylococcus spp. grew more than when they were isolated. At 36ºC K. pneumoniae associated with Staphylococcus spp. grew more then when it was isolated and more than at 25ºC. So we can conclude that the slow pasteurization was effective, because it has reduced at least 90% of the colony form unity in the milk after 30 minutes at 65ºC. Conclusion: By raising the temperature up to 36ºC, a Klebsiella pneumoniae had a superior growth when compared with Staphylococcus spp.; the contamination of milk by Klebsiella pneumoniae (environmental contamination) influences the most the quality of the final product when compared to the contamination by Staphylococcus spp. from mastitis, we can also conclude that the interaction of microorganisms modify the death rate of them. New studies and researches are recommended to a deeper and better comprehension of this process.

Introdução: O leite pode ser considerado um dos alimentos mais completos por apresentar alto teor de proteínas e sais minerais, porém, também é considerado excelente meio de cultura para microrganismos. Objetivos: Identificar o número de UFC de Staphylococcus spp. e Klebsiella pneumoniae, cultivados isoladamente ou em associação, em leite integral estéril, a 6 oC, 27 oC e 37 oC e descrever a curva de morte térmica, quando submetidas ao processo de pasteurização lenta isoladamente ou em associação. Material e Métodos: Avaliação através da contagem das UFC, do comportamento de Staphylococcus spp. e K. pneumoniae, isoladas de tanque de refrigeração de leite, submetidas a temperaturas que simulam o leite em condições de refrigeração (6 °C), condições ambientais (25 °C) e na temperatura ideal de crescimento de patógenos mesófilos (36°C). Avaliação da sensibilidade de Staphylococcus spp. e K. pneumoniae isoladas e em associações ao processo de pasteurização lenta. Resultados: Na escala 1 de Mac Farland a média de UFC de K. pneumoniae foi maior que a de Staphylococcus spp. A 6 °C as bactérias no leite, isoladas ou em associação crescem na mesma velocidade. A 25 °C a K. pneumoniae cresce mais que o Staphylococcus spp. A 25 °C K. pneumoniae associada ao Staphylococcus spp. cresce mais do que quando encontra-se isolada. A 36 °C K. pneumoniae associada ao Staphylococcus spp. cresce mais do que quando encontra-se isolada e ainda mais que a 25 °C. A pasteurização lenta foi efetiva, pois reduziu em no mínimo 90% as UFC no leite após 30 minutos a 65 °C. Conclusão: a medida que aumenta a temperatura, até 36 °C, a Klebsiella pneumoniae apresenta crescimento superior ao Staphylococcus spp., a contaminação de leite por Klebsiella pneumoniae (contaminação ambiental) irá influenciar mais na qualidade do produto final, comparando-se à contaminação por Staphylococcus spp., oriundo de mastite e a interação de microrganismos altera a morte dos mesmos, recomendando-se que novos estudos sejam realizados para que se entenda melhor esse processo. / Introduction: The milk can be considered one of the most complete food for its high contents of protein and minerals, but also it is considered an excellent medium of culture for microorganisms. Objective: To identify the number of the Colony Forming Units of Staphylococcus spp. and Klebsiella pneumoniae, in integral sterile milk, at different temperatures (6ºC, 27ºC e 37ºC) and to describe a thermal curve death, when submitted to the process of slow pasteurization isolated or in association. Materials and methods: Evaluation by counting of the colony forming units and the behavior of the Staphylococcus spp. and Klebsiella pneumoniae, isolated and in association occurred in the cooling tank, submitted to temperatures that simulate the conditions of milk in cooling (6ºC), environmental condition (25ºC) and the optimal temperature for the growth of microorganisms (36ºC). Evaluation of the sensibility of Staphylococcus spp. and Klebsiella pneumoniae isolated and in association during the pasteurization process. Results: In Scale 1 of Mac Farland the average of the colony form units of the K. pneumoniae was greater than the colony of Staphylococcus spp. At 6ºC the microorganisms in the milk isolated or in association grew at the same speed. At 25ºC K. pneumoniae associated with Staphylococcus spp. grew more than when they were isolated. At 36ºC K. pneumoniae associated with Staphylococcus spp. grew more then when it was isolated and more than at 25ºC. So we can conclude that the slow pasteurization was effective, because it has reduced at least 90% of the colony form unity in the milk after 30 minutes at 65ºC. Conclusion: By raising the temperature up to 36ºC, a Klebsiella pneumoniae had a superior growth when compared with Staphylococcus spp.; the contamination of milk by Klebsiella pneumoniae (environmental contamination) influences the most the quality of the final product when compared to the contamination by Staphylococcus spp. from mastitis, we can also conclude that the interaction of microorganisms modify the death rate of them. New studies and researches are recommended to a deeper and better comprehension of this process.

Magister Chirurgiae Dentium - MChD (Oral Medicine and Periodontics) / The aim of this study was to assess whether a mouthwash containing carbohydrate derived fulvic acid, is effective in reducing the salivary microbial count pre-operatively. Endeavours have been made to reduce the risk of infection, bacteraemia and cross-contamination during dental procedures by the application of topical antimicrobial agents. To date chlorhexidine is the most widely evaluated and efficacious agent against oral biofilms but there have been reports of adverse effects ranging from contact dermatitis to severe anaphylactic shock. A new mouth rinse containing carbohydrate derived fulvic acid are reported to have broad spectrum antimicrobial activity against specific oral microbes and Candida albicans with no side effects.

Bakgrund: Till operationssjuksköterskors ansvarsområden hör hygien och infektionsprevention. Vårdrelaterade infektioner (VRI) drabbar drygt 55 000 patienter i Sverige varje år. Av dessa VRI är runt 12 000 postoperativa sårinfektioner (SSI), varav hälften beräknas vara möjliga att undvika. En vanlig orsak till SSI är att bakteriebärande partiklar i luften, colony forming units (CFU), hamnar i operationssåret. Antalet personer i salen, personalens klädsel och antalet dörröppningar är några faktorer som antas påverka CFU-halten i operationssalens luft. Det råder osäkerhet kring vilka infektions-förebyggande åtgärder som bör prioriteras för att hålla CFU-halten nere och säkerställa en säker vård. Syfte: Att undersöka sambandet mellan CFU-halten i operationssalens sterila område och miljöfaktorer i salen.  Metod: En prospektiv icke-experimentell korrelationsstudie med kvantitativ ansats genomfördes. CFU-halten mättes med en aktiv luftprovtagare under 113 mätperioder fördelade på 17 operationer i en operationssal utrustad med LAF-ventilation. Samtidigt observerades antalet personer, antalet personer utan dok och antalet dörröppningar. Med hjälp av SPSS beräknades korrelationerna mellan de studerade variablerna. Resultat: Inget signifikant samband kunde påvisas mellan CFU-halten i operationsområdet och antalet personer i salen, antalet personer utan dok eller antalet dörröppningar. Slutsats: Luften i operationsområdet höll genomgående en ultraren nivå och CFU-halten påverkades inte av de studerade miljöfaktorerna. Detta är positivt ur perspektivet säker vård då det tyder på att risken för att drabbas av en postoperativ sårinfektion på grund av bakterier i luften är liten i salar med LAF-ventilation. Därigenom undviks onödigt lidande för patienter och kostnaderna för samhället hålls nere. Risken att drabbas av SSI påverkas av fler faktorer. Mer forskning behövs innan nuvarande rutiner kan ändras. / Background: Hygiene and infection prevention are two of the responsibilities of the operating room nurse. In Sweden, roughly 12,000 patients suffer from surgical site infections (SSI) each year, many of which could be avoided. A common cause of SSI is bacteria-laden particles (CFU) in the air of the operating room. The number of people in the room, the attire of the surgical staff and the number of door openings are thought to affect the CFU count. It remains unclear what preventive measures are most effective in reducing the CFU count to provide the safest care possible. Aim: To investigate the relationship between the CFU count in the sterile area of the operating room and various environmental factors. Method: A prospective, non-experimental correlational study was conducted. The CFU count was measured through active air sampling during 113 ten-minute periods, distributed over 17 operations, in an operating room equipped with a laminar air flow ventilation system. Simultaneously, observations were made of the number of people in the room, the number of people wearing a specific type of surgical cap called “dok” and the number of door openings. Correlations between variables were calculated using SPSS software. Results: No correlations between the CFU count within the sterile area and the studied variables were found. Conclusion: The air in the sterile area remained ultra-clean throughout the study, and the CFU count was not affected by the studied variables. This indicates that the risk of suffering from SSI caused by airborne bacteria is low, which benefits both patients and society. However, there is still a significant risk of suffering from SSI because of other risk factors. More research is needed before any new recommendations regarding hygiene routines in the operating room can be given.