Master of Science / Department of Animal Sciences and Industry / Jim L. Nelssen / Piglet birth weight (BtW) is inextricably associated with preweaning survival. The non-linear antagonistic relationship between BtW and mortality risk is more severe in pigs <1.11 kg BtW than in pigs with BtW >1.11 kg. Thus, our research categorized fetal pigs as small (SM), median (MD), or large (LG) size depending on relative crown-rump length at d-60 gestation or BW within litter at d-95 gestation to evaluate differences in fetal myogenesis and development. At both d-60 and d-95, brain weights did not differ but brain weight:liver weight ratio was larger (P<0.05) for SM compared MD and LG. Cross-sectional area of the Longissimus muscle increased with increasing fetal size so that LG and MD had larger (P<0.05) whole muscle cross-sectional areas than SM although number of primary and relative secondary muscle fibers and their respective cross-sectional areas did not differ. Day-60 mRNA abundance of both IGF-1 and IGF-2 in SM was greater (P<0.05) than in MD and LG. Fetal size had a marginally significant effect (P=0.103) on gene expression of IGF-2 receptor with expression least in LG. Small fetuses had greater (P<0.05) d-60 MyoD gene expression and d-95 serum IGF-1 levels than MD and LG. Two experiments were conducted to determine the effects of feeding low or high doses of chlortetracycline (CTC) and antibiotic alternatives (pharmacologic Zn, Cu, and essential oil), alone or in combination, on nursery pig growth performance. Pharmacologic Cu (125 ppm from CuSO[subscript]4), Zn (2,000-3,000 ppm from ZnO), or increasing CTC level (0-441 ppm) improved growth performance additively while Origanum essential oil (0.005%) elicited no benefits and decreased G:F. Interactive effects of supplemental Cu (125 ppm), Zn (150 ppm), and ractopamine HCl (10 ppm for 28 d) on finishing pig growth performance, carcass characteristics, and antimicrobial susceptibility of enteric bacteria was evaluated. Ractopamine increased (P<0.001) ADG, G:F, HCW, percentage carcass yield, loin depth, percent fat-free lean, and decreased (P=0.014) backfat. Copper and/or Zn did not improve ADG, ADFI, or carcass traits. Fecal E. coli and Enterococcus bacterial resistance to most antibiotics decreased (P<0.05) over time or was stable for those that had a low baseline percentage of resistance.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-08-04T12:08:26Z No. of bitstreams: 1 PDF - Andreza Costa Miranda.pdf: 41222812 bytes, checksum: 456e1b5a9095a0dce0875807e9b2d2b1 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-08-29T15:43:37Z (GMT) No. of bitstreams: 1 PDF - Andreza Costa Miranda.pdf: 41222812 bytes, checksum: 456e1b5a9095a0dce0875807e9b2d2b1 (MD5) / Made available in DSpace on 2017-08-29T15:43:37Z (GMT). No. of bitstreams: 1 PDF - Andreza Costa Miranda.pdf: 41222812 bytes, checksum: 456e1b5a9095a0dce0875807e9b2d2b1 (MD5) Previous issue date: 2016-09-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Some micropollutants have been causing concern to health authorities with regard how they can be toxic to humans and if the conventional water treatment plants are effective for their removal. Among micropollutants currently present in the environment stand out microcystin-LR, organophosphorus pesticides (profenofos), veterinary drugs (Ivermectin) and antibiotic resistant bacteria. The low concentration of these micropollutants found in the environment requires efficient treatment and development of analytical techniques for the quantification and identification these compounds. This work was divided in two phase. In the first phase the Advanced Oxidation Processes (AOPs), namely H2O2/UV, TiO2 /UV and N-TiO2 /UV, have been compared with chlorination in the inactivation of an AR Escherichia coli (E. coli) strain in surface water.. Under the investigated conditions, chlorination (1.0 mg/L) was the faster process (2.5 min) to achieve total inactivation (6 Log). Among POA, H2O2/UV resulted in the best inactivation rate. Moreover, H2O2/UV and chlorination processes were evaluated in terms of cytotoxicity potential by means of MTT colorimetric test on a human-derived cell line and they similarly affected HepG2 cells viability. In the second phase, three fundamental aspects were evaluated: (1) degradation of micropollutants, profenofós (PFF), microcystin-LR (MC-LR) and ivermectin (IV) by H2O2/UV, H2O2 e UV; (2) validate the method for LC-MS/MS; (3) identification of oxidation by-products (OBPs) in finished water. The LC-MS/MS method for quantification of MC-LR and PFF showed good linearity with fitness coefficient (r) >0.99 and (r) >0.98, respectively. The precision, obtained was considered satisfactory. The limits of detection (LD) and quantification (LQ) were lower the Brazilian drinking water standard, suggesting the applicability of the method for the drinking water quality control .Among POA, H2O2/UV resulted in the best degradation of the micropollutants. / Alguns micropoluentes têm causado preocupações às autoridades no que diz respeito à quão tóxico podem ser a organismos humanos e os tratamentos convencionais utilizados nas estações de tratamento de água que não são eficientes em suas remoções. Dentre os micropoluentes, atualmente presentes no ambiente, destacam-se microcistina-LR, pesticidas organofosforados (profenofós), fármacos veterinários (Ivermectina) e bactérias resistentes a antibióticos. Os baixos níveis de concentração dos microcontaminantes encontrados no ambiente exigem etapas de tratamento eficientes e desenvolvimento de técnicas analíticos para quantificação e identificação segura desses compostos. Essa tese foi dividida em duas etapas. Na primeira etapa foi comparado os processos oxidativos avançados H2O2/UV, TiO2/UV e N-TiO2/UV com a cloração na inativação de cepas de Escherichia coli resistente a antibióticos presentes em água superficial. Sob estas condições, a cloração com concentração inicial de cloro em 1,0 mg/L foi o processo mais 6 eficiente a obter a inativação de uma população inicial de 10 UFC/100mL. Além disso, os processos de desinfecção com H2O2/UV e cloração foram avaliadas em termos de potencial de citotoxicidade por meio do teste colorimétrico MTT com linhagem de células derivadas dos seres humanos, os resultados mostraram que ambos os processos de desinfecção afetaram similarmente a viabilidade das células HepG2. Na segunda etapa do trabalho foram realizados estudos com três fases fundamentais: (1) Avaliar a degradação dos microcontaminantes (profenofós, microcistina-LR e ivermectina) por processo H2O2/UV, H2O2 e UV; (2) validar metodologia de técnicas analíticas para quantificação dos microcontaminantes em amostras de água por cromatografia líquida acoplada a espectrometria de massas (CLAE/MS) e; (3) Identificar os subprodutos formados com o auxílio do espectrômetro de massas com interface de ionização electrospray (ESI). A validação do método para identificação e quantificação dos microcontaminantes foi realizada por HPLC-ESI-MS/MS. Os resultados de validação calculados atenderam todas as exigências das normas consultadas e mostrou-se adequado para analisar amostras de água contendo os contaminantes estudados. Na etapa de degradação, dentre os processos utilizados, o processo H2O2/UV apresentou os melhores resultados de fotodegradação, seguido por radiação UV.

nÃo hà / HortaliÃas minimamente processadas (HMP) normalmente consistem de hortaliÃas frescas, cruas, lavadas, descascadas, cortadas, sanitizadas, centrifugadas, empacotadas e acondicionadas sob refrigeraÃÃo. HortaliÃas sÃo potenciais veÃculos de microrganismos que podem estar associadas à doenÃas transmitidas por alimentos. InÃmeras sÃo as causas para a presenÃa de elevada carga microbiana nesse tipo de produto, entre as quais estÃo: as tÃcnicas de cultivo, armazenamento, transporte e distribuiÃÃo para consumo, a prÃtica do uso de adubo orgÃnico, a utilizaÃÃo de Ãgua contaminada para rrigaÃÃo, o transporte realizado em engradados abertos e as condiÃÃes de higiene no manuseio e preparo de refeiÃÃes, principalmente quando tais alimentos sÃo consumidos crus. O objetivo desse estudo foi determinar a presenÃa de Enzimas Betalactamases de Espectro Expandido (ESBL) em cepas de Enterobacteriaceae isoladas de HMP comercializadas na cidade de Fortaleza e verificar se as hortaliÃas analisadas a atendem a RDC N 12 de 02 de janeiro de 2001, que rege o padrÃo microbiolÃgico dos alimentos no Brasil. Foram coletadas 80 amostras de HMP comercializadas em Fortaleza. As hortaliÃas estudadas foram: 8 amostras de acelga; 10 alface; 8 tomate cereja; 8 repolho roxo, repolho verde; 10 cenoura e vagem; 8 cenoura ralada; 10 cenoura ralada, repolho verde e repolho roxo; 10 saladas; 8 coentro, cebola e salsa picados. As anÃlises foram realizadas de abril de 2006 a maio de 2007. As contagens de microrganismos aerÃbios mesÃfilos variaram de 5,60 a 13,35 log UFC/ g de HMP. As contagens de bolores e leveduras variaram de 5,54 a 9,88 log UFC/ g de HMP. A contagem de coliformes totais e coliformes a 45ÂC foram bastante elevadas. O principal bolor isolado e identificado foi o enicillium spp. Todas as amostras de acelga, cenoura ralada, cenoura e vagem, cenoura ralada, repolho roxo e repolho verde, coentro e salsa picados encontravam-se imprÃprias para o consumo, pois apresentaram quantidades superiores a 100 coliformesa 45ÂC/g de amostra. Das amostras de alface 50% apresentavam contagem decoliformes a 45ÂC acima do permitido peÃa legislaÃÃo. Dos tomates cereja analisados 75% estavam dentro padrÃes microbiolÃgicos exigidos pela legislaÃÃo brasileira, para coliforme a 45ÂC. Das amostras de repolho roxo, repolho verde 87% estavam com contagem de coliformes acima do permitido. Das amostras de salada 80% estavam fora dos padrÃes. NÃo foram detectadas Salmonellas nas amostras de HMP analisadas. As principais cepas de Enterobacteriaceae isoladas foram E. coli, K. pneumoniae e E. aerogenes. Todas as cepas de K. pneumoniae e E. aerogenes foram resistentes à ampicilina. Foram detectadas cepas de E. coli, K pneumoniae e E aerogenes com multiresistÃncia aos antibiÃticos testados. NÃo foi observada resistÃncia a ciprofloxacina, ceftazidima e imipenem. NÃo foram detectadas amostras de enterobactÃrias produtoras de ESBL. NÃo foram identificadas cepas de E. coli O15:H7 entre as cepas de E. coli isoladas de HMP. As condiÃÃes higiÃnico-sanitÃrias desses produtos podem ser melhoradas com a aplicaÃÃo de Boas PrÃticas em toda a cadeia produtiva. / Minimally processed vegetables (MPV) normally consist of fresh raw vegetables, washed, peeled, cut, disinfected, centrifugal dryed packed and kept under refrigeration. Vegetables are potential vehicle of microorganisms that can be associated to the outbreaks of foodborne. Countless are the causes for the presence high microbial load in that product type, among which are: the cultivation techniques, storage, transport and distribution for consumption, the practice of the use of organic fertilizer, the use of polluted water for irrigation, the transport accomplished in open crates and the hygiene conditions in the handling and preparation of meals, mainly when such foods are consumed raw. The objective of this study was to determine the presence of extendedspectrum &#946;-betalactamases (ESBL) in strains of Enterobacteriaceae isolated of MPV marketed in the city of Fortaleza and to verify if the analyzed vegetables assists the Brazilian Food Sanitation Standard, RDC N 12, 02 of january 2001. 80 samples of MPV were collected marketed in Fortaleza. Were collected vegetables studied: 8 samples beet; 10 lettuce; 8 of cherry-colored tomato; 8 purple cabbage, green cabbage; 10 carrot and green bean; 8 grated carrot; 10 grated carrot, green cabbage and purple cabbage; 10 salads; 8 cilantro, onion and parsley pricked. The analyses were accomplished of april from 2006 to may of 2007. The countings of mesophiles aerobic, varied from 5,60 to 13,35 log UFC / g of MPV. The countings of moulds and yeasts, varied from 5,54 to 9,88 log UFC / g MPV. The counting of total coliforms and fecal coliforms were quite high. The main isolated and identified mold was the Penicillium spp. All of the beet samples, grated carrot, carrot and green bean, grated carrot, purple cabbage and green cabbage, cilantro and parsley pricked met inappropriate for the consumption, because they presented amounts superior of 100 fecal coliforms / g samples. Of the samples of lettuce 50% they presented fecal coliforms counting above legislation. Of the tomatoes cherry analyzed 75% were inside patterns of the Brazilian legislation, for fecal coliforms. Of the samples of purple cabbage, green cabbage 87% were with fecal coliforms counting above. Of the samples of salad 80% were out of the patterns. Salmonellas were not detected in the samples of MPV analyzed. The main isolated Enterobacteriaceae were E. coli, K. pneumoniae and E. aerogenes. All of the strains of K. pneumoniae and E. aerogenes were resistant to the ampicillin. Strains of E. coli, K pneumoniae and E. aerogenes with multidrug resistance were detected. Resistance to ciprofloxacin, ceftazidime and imipenem was not observed. Enterobacteriaceae samples producing of ESBL were not detected. Were not identified strains of E. coli O15:H7 among the strains of E. coli isolated of MPV. The hygienicsanitary conditions of those products can be improved with the application of Good Practices in the whole productive chain.

La résistance bactérienne aux antibiotiques est devenue un problème majeur de santé publique impliquant des actions de surveillance et de lutte contre sa diffusion. L’épidémiologie de la résistance aux antibiotiques au sein des pathogènes cliniques est indispensable notamment à la prise en charge thérapeutique. Cependant, elle est également pertinente au sein des bactéries animales et environnementales afin d’en apprécier l’ampleur et d’en appréhender la diffusion. Alors que de nombreux travaux ont été conduits sur le microbiote des animaux de compagnie, les études portant sur la faune sauvage restent rares. Or, il apparaît opportun de l’intégrer dans l’étude de la dynamique des bactéries antibiorésistantes afin d’apprécier son rôle épidémiologique dans leur dissémination et d’évaluer les risques zoonotiques qui en découlent.Sur la base de notre revue de la littérature, nous avons mis en évidence un lien étroit existant entre les activités humaines et la présence de bactéries antibiorésistantes dans la faune sauvage. Ceci nous a conduits à discuter de l’existence probable de voies d’échanges entre le compartiment humain et animal.Sur la base d’une étude ayant démontré la présence dans le sud de la France d’un réservoir aviaire d’Escherichia coli producteurs de béta-lactamases à spectre élargi, nous avons exploré le microbiote cloacal de deux espèces de goélands, différentes par leurs niches écologiques et leur mode d’alimentation, en tant que réservoir potentiel de bactéries multirésistantes aux antibiotiques.Dans un premier temps nous nous sommes intéressés à la présence de Proteus mirabilis producteurs d'AmpC acquises dans le microbiote des goélands au cours des deux années d’étude. Ces isolats étaient producteurs de céphalosporinases de type CMY-2 dont le support génétique était un élément intégratif et conjugatif (ICE) de la famille SXT/R391-like. Deux souches cliniques humaines avaient les mêmes enzymes, supports et fond génétiques que des souches aviaires. Ceci permet de supposer que ces goélands constituent un réservoir de P. mirabilis porteurs du gène blaCMY-2, et que les structures de type ICE SXT/R391-like joueraient un rôle important dans la dissémination et la persistance de ce gène de résistance.Nous avons également isolé des souches d’Escherichia coli productrices de carbapénèmases acquises, qui constituent actuellement l'une des menaces les plus préoccupantes pour la santé publique en termes d'antibiorésistance. Ces souches proviennent uniquement de goélands leucophées et sont porteuses du gène blaVIM-1. L’analyse de leur patrimoine génétique montre qu’elles sont liées à des souches humaines sensibles. Nous n’avons en effet pas isolé de souches humaines productrices de carbapénèmases de type VIM dans le même temps. Cette découverte pose la question d’un réservoir aviaire potentiel et d’une menace de diffusion.Lors du screening nous avons identifié une souche de Vibrio cholerae non-O1/non-O139 résistante aux carbapénèmes et provenant d’un goéland leucophée. Elle possédait des gènes blaVIM-1 et blaVIM-4 qui faisaient partie d’un integron de classe 1, situé sur un plasmide IncA/C. Il s’agit de la première description d’une souche de V. cholerae productrice de ce type de carbapénèmases. Ce travail démontre la complexité de la circulation de l’antibiorésistance au sein du microbiote étudié. Il ouvre de nombreuses perspectives d’un point de vue épidémiologique mais également fondamental sur les mécanismes et les supports génétique de cette antibiorésistance. En effet, il illustre bien les apports importants des outils d’épidémiologie moléculaire dans la surveillance de l’émergence et la compréhension de la dynamique de transmission et de diffusion des bactéries multirésistantes dans la faune sauvage. / Bacterial resistance has become a major public health problem leading to a strengthening of spread surveillance and control. The epidemiology of antimicrobial resistance (AMR) in clinical pathogens is essential for therapeutic management. It is also relevant in animal and environmental bacteria to determine and understand AMR existence and diffusion. While much work has been done on the microbiota of companion animals, studies involving wildlife are scarce. It is essential to consider wildlife when studying AMR dynamics to assess its epidemiological role in AMR spread and understand the zoonotic risk which ensues from it.With our literature review, we highlight the close link between human activities and the presence of AMR in wildlife. It led us to discuss the pathways between the human and animal compartments.A previous study reported the presence of an avian reservoir of extended spectrum beta-lactamases-producing Escherichia coli in the South of France. Based on this finding, we explored the microbiota of two gull species, differentiated by their ecological niches and diet, as a potential reservoir of AMR.First, we investigated the presence of acquired AmpC-producing Proteus mirabilis in the gulls’ microbiota over two years. The isolates produced CMY-2 cephalosporinases with the genetic support of an integrative and conjugative element (ICE) which belongs to the SXT/R391-like family. Two human strains had the same enzymes, genetic support and genetic background as the avian isolates. This suggests that these gulls may act as a reservoir of blaCMY-2-carrying P. mirabilis, and the SXT/R391-like ICEs may play an important role in this gene’s dissemination and persistence.We also isolated acquired carbapenemases-producing E. coli, which is currently one of the most serious AMR threats to public health. These strains, which carried the blaVIM-1 gene, were recovered from yellow-legged gulls. The phylogenetic analyses showed that the gulls are significantly linked with human susceptible isolates. However, VIM carbapenemase producing-human isolate was not isolated in the same time period. This discovery raises the question of a potential avian reservoir and the threat of diffusion.During the screening, we identified a carbapenem resistant non-O1/non-O139 Vibrio cholerae strain, recovered from a yellow-legged gull. It carried both blaVIM-1 and blaVIM-4 genes which were part of a class 1 integron structure located in an IncA/C plasmid. This is the first description of a V. cholera strain producing this type of carbapenemase.This work demonstrates the complexity of the AMR circulation in the microbiota studied. It opens many perspectives from an epidemiological and fundamental point of view on the mechanisms and genetic supports of AMR. It further illustrates the contribution of molecular epidemiology tools in the understanding of the dynamics of transmission and diffusion and the surveillance of the emergence of AMR in wildlife.

Francisella tularensis est une bactérie à Gram négatif intracellulaire facultative, agent causal de la tularémie. Cette zoonose est induite principalement par deux sous espèces : F. tularensis subsp. tularensis (type A) et F. tularensis subsp. holarctica (type B) retrouvées respectivement en Amérique du Nord et dans tout l’hémisphère Nord. Cette seconde sous espèce, moins virulente que la première induit majoritairement des formes cliniques de sévérité moyenne à modérée dites ganglionnaires. Leur traitement est basé sur l’utilisation des antibiotiques de la classe des fluoroquinolones ou des tetracyclines, l’utilisation des aminosides étant réservée aux formes graves. Les adénopathies évoluent cependant souvent vers la suppuration et la chronicité (20 à 40% des cas), malgré l’administration d’un traitement antibiotique adapté.Les travaux réalisés visent à étudier l’hypothèse de l’émergence de la résistance bactérienne chez Francisella, expliquant ces échecs thérapeutiques. Ils sont basés sur le développement et l’étude d’un modèle d’évolution in vitro de la bactérie en présence de ciprofloxacine, une fluoroquinolone. Nos travaux ont confirmé la capacité de la bactérie à évoluer vers un haut niveau de résistance à ces antibiotiques, corrélée à l’accumulation de mutations dans les gènes codant pour les topoïsomérases de type II. De plus, nous avons observé la présence sur l’ensemble des souches de F. tularensis subsp. holarctica d’un niveau de résistance cliniquement significatif induit par des mutations modifiant la sous-unité GyrA de l’ADN gyrase sur les acides aminés en position 83 et 87. La recherche de ce marqueur dans des prélèvements de patient en échec thérapeutique suite à divers traitements antibiotiques s’est avérée infructueuse.Après avoir vérifié l’action de l’antibiotique sur les bactéries dans le compartiment intracellulaire (fibroblates), nous avons recherché les autres mutations induites lors de l’évolution de Francisella en présence de fluoroquinolones. Cette étude a permis l’implication de plusieurs systèmes de transports transmembranaires dans la résistance antibiotique. Nous avons également révélé l’existence d’une seconde cible majeure impliquée dans le métabolisme du fer de la bactérie. L’altération de cette cible (FupA/B) en plus d’être associée à une augmentation de la résistance aux fluoroquinolones est corrélée à une forte diminution de la capacité de la bactérie à se multiplier dans les cellules phagocytaires. / Francisella tularensis is a gram-negative facultative intracellular bacterium, causing tularemia. This zoonosis is mainly related to two subspecies: F. tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B) in North America and throughout the Northern Hemisphere, respectively. Infections with this second subspecies, less virulent than the first one, predominantly induce glandular clinical forms of mild to moderate severity. Their treatment is based on antibiotherapy using a fluoroquinolone or a tetracycline. The use of aminoglycosides is reserved for severe clinical forms. The lymph nodes infection, however, often become chronic (20 to 40% of cases), despite administration of an appropriate antibiotic treatment.The aim of this study was to verify the hypothesis of the emergence of bacterial resistance in Francisella, which could explain treatment failures. It is based on the development and study of an in vitro evolutionary experiment of the bacterium in the presence of ciprofloxacin, a fluoroquinolone. Our work confirmed the bacterium's ability to evolve towards a high-level of resistance to fluoroquinolones, this evolution being correlated with the accumulation of mutations in the genes encoding for type II topoisomerases. In addition, we observed in all strains of F. tularensis subsp. holarctica resistant to fluoroquinolones at a clinically significant level, the presence of mutations altering the GyrA subunit of DNA gyrase at amino acids positions 83 and 87. The research of this marker in clinical samples from patients with treatment failure following appropriate antibiotic treatment was however unsuccessful.After checking the action of antibiotics on bacteria internalized in the intracellular compartment in fibroblast cells, we looked for other mutations induced during the evolution of Francisella to resistance to fluoroquinolones. This study unveiled the involvement of several transmembrane transport systems in antibiotic resistance. We also revealed the existence of a second major target involved in Francisella iron metabolism. The alteration of this target (FupA/B), in addition to being associated with an increase in fluoroquinolone resistance, is correlated with a sharp decrease in the ability of the bacteria to multiply in phagocytic cells.

Bakgrund: Multiresistenta bakterier är ett globalt problem och ett hot mot folkhälsan. Smittförebyggande åtgärder som basala hygienrutiner är en central del i det preventiva arbetet mot multiresistenta bakterier. Patienter som är bärare av en multiresistent bakterie kan uppleva känslor av otrygghet och skam, därför är det av stor vikt att all hälso- och sjukvårdspersonal tillämpar en personcentrerad vård. Syfte: Att undersöka hälso- och sjukvårdspersonalens upplevelser av att vårda patienter med multiresistenta bakterier. Metod: Studien har genomförts som en litteraturöversikt baserad på 15 stycken artiklar. Artiklarna var av både kvalitativ, kvantitativ samt kombinerad kvalitativ och kvantitativ metod. Databaser som använts i sökningen är PubMed och CINAHL. Analysen resulterade i tre teman. Resultat: Resultatet presenteras under tre olika teman: Upplevelser av rädsla och osäkerhet, upplevd okunskap och behov av utbildning samt upplevelser av hinder för utförandet av infektions-preventiva åtgärder. Slutsats: Rädsla och osäkerhet hos vårdpersonalen framkom tydligt och ledde till brister i utförandet av omvårdnaden. Resultatet visade även en upplevd okunskap om multiresistenta bakterier och ett behov av utbildning efterfrågades. Kunskap genom utbildning skulle resultera i en större förståelse om multiresistenta bakterier och minska rädslan hos vårdpersonalen. / Background: Multiresistant bacteria is a global problem and a threat to public health. Infection prevention such as basic hygiene routines are a key part of preventive work against multiresistant bacteria. Patients who is a carrier of a multiresistant bacteria can experience feelings of insecurity and shame, therefore it is important that all healthcare professionals apply a person-centered care. Aim: To study the healthcare professionals' experience of caring for patients with multiresistant bacteria. Method: The study has been conducted as a literature review based on 15 articles. The articles were of both qualitative and quantitative method as well as mixed method with combined qualitative and quantitative method. Databases used in the search are PubMed and CINAHL. The analysis resulted in three themes. Result: The results are presented in three different themes: Experiences of fear and insecurity, experienced lack of knowledge and need for education and experiences of obstacles to the performance of infection prevention measures. Conclusion: Fear and insecurity in healthcare staff clearly emerged and led to shortcomings in the performance of nursing care. The result also showed an experienced ignorance of multiresistant bacteria and a need for education was requested. Knowledge through education would result in a greater understanding of multiresistant bacteria and reduce the fear among healthcare professionals ’.

Les maladies infectieuses constituent un sérieux problème de santé publique aussi bien dans les pays en développement où elles sont la principale cause de taux de mortalité élevés, que dans les pays industrialisés où les résistances aux antibiotiques existants se développent de façon alarmante. Cette situation engendre un besoin sans cesse croissant de trouver de nouveaux composés antimicrobiens et/ou inhibiteurs de mécanismes de résistances aux antibiotiques. Les plantes médicinales, notamment celles utilisées de façon traditionnelle dans les pays en développement, constituent une source potentielle de ce type de composés. C’est dans ce cadre que l’espèce Cordia gilletii De Wild (Boraginaceae), une plante dont les écorces de racines et les feuilles sont traditionnellement utilisées en République Démocratique du Congo pour combattre les maladies infectieuses, a été étudiée sur le plan tant de ses activités biologiques que de sa composition chimique. Les extraits obtenus à partir des écorces de racines de cette plante ont montré d’intéressantes activités biologiques, (i) un effet antimicrobien direct (bactéricide pour les bactéries gram positif et bactériostatique pour les gram négatif) et indirect (augmentation ou restauration de l’activité des antibiotiques vis-à-vis des souches résistantes); (ii) un effet inhibiteur sur deux des gènes impliqués dans le quorum sensing de Pseudomonas aeruginosa, lasB and rhlA; (iii) un effet antiplasmodial sur une souche chloroquino-sensible de Plasmodium falciparum; (iv) un effet antioxydant mis en évidence par réaction avec le radical libre DPPH. Pour les extraits de feuilles, seule l’activité antiplasmodiale a été observée. <p>Les extraits d’écorces de racines, doués d’activité antimicrobienne directe (extrait méthanolique) et indirecte (extrait n-hexanique) ont été soumis à une série de fractionnements dans le but d’isoler et d’identifier les composés actifs. Pour suivre l’activité lors des fractionnements, le milieu de culture utilisé pour la détection des composés actifs sur une plaque chromatographique (CCM-bioautographie) a été optimisé. Le composé férulaldéhyde, isolé de l’extrait méthanolique, a montré des propriétés antimicrobiennes, antioxydantes et antiplasmodiales. De l’extrait n-hexanique ont été isolés deux composés, l’un actif, le lupéol et l’autre inactif, la friedéline. Le lupéol a montré un effet antimicrobien indirect en réduisant la CMI de certains antibiotiques vis-à-vis d’une souche de MRSA. Ces trois composés, s’ils ont déjà été identifiés dans d’autres plantes, sont décrits pour la première fois dans l’espèce Cordia gilletii ;et ce travail constitue le premier rapport de l’effet antimicrobien indirect du lupéol. <p>Dans le but de s’assurer de l’innocuité des extraits de C. gilletii, une recherche d’alcaloïdes pyrrolizidiniques (APs) a été réalisée par GC-MS. Ces alcaloïdes présentent en effet un réel danger pour la santé humaine et la famille des Boraginaceae, à laquelle appartient l’espèce C. gilletii, est connue comme une des principales sources de ces composés. Aucun AP n’a pu être mis en évidence dans les extraits d’écorces de racines et de feuilles de cette plante jusqu’à une limite de détection de 2 ppm, suggérant ainsi une absence de risque toxicologique en relation avec ces alcaloïdes. Ces résultats rassurants restent à confirmer sur d'autres échantillons obtenus dans des lieux de récolte différents.<p>Le présent travail montre que C. gilletii peut agir contre les microorganismes pathogènes par :(i) son action antimicrobienne directe (due entre autre au férulaldéhyde); (ii) son effet antimicrobien indirect (dû au lupéol), effet permettant d’augmenter ou de restaurer l’activité des antibiotiques vis-à-vis des souches résistantes ;et (iii) son effet inhibiteur de l’expression des gènes du quorum sensing, effet permettant d’atténuer la virulence d’agents infectieux. Ces actions peuvent permettent de faire face aux infections dues notamment à des microorganismes résistants.<p><p><p><p>Infectious diseases remain a serious public health problem both in developing countries, where they are the main cause of the high mortality rates recorded, and in industrialized countries where there is an alarming incidence of antibiotic resistance. There is thus an increasing need for new compounds that can act by a direct antimicrobial effect or by an indirect effect, inhibiting resistance mechanisms of microorganisms. Medicinal plants, particularly those traditionally used against infectious diseases in developing countries, are a probable source for these types of compounds. In this context, Cordia gilletii De Wild (Boraginaceae), a medicinal plant from which root barks and leaves are traditionally used against infectious diseases in Democratic Republic of Congo, was investigated for biological activities and phytochemical composition. Root bark extracts showed interesting biological activities: (i) antimicrobial properties, acting directly (bactericid and bacteriostatic effects against gram positive and gram negative bacteria, respectively) or indirectly (enhancement or restoration of antibiotic activity on resistant strains); (ii) inhibitory effect on the expression of two Pseudomonas aeruginosa QS genes, lasB and rhlA; (iii) antiplasmodial effect against a chloroquine sensitive strain of Plasmodium falciparum; (iv) antioxidant effect determined by the free radical DPPH quenching. Leaves extracts showed only antiplasmodial activity. <p>Root barks extracts with the highest direct (methanol extract) and indirect (n-hexane extract) antimicrobial properties were fractionated to isolate and to identify the active compounds. To bio-guide the fractionation, the culture medium for the detection of active compounds on chromatographic plates (TLC-bioautography) was optimized. The compound ferulaldehyde, isolated from the methanol extract, showed antimicrobial, antioxidant and antiplasmodial properties. From the n-hexane extract two compounds were isolated, lupeol and friedelin. Lupeol showed indirect antimicrobial effect by decreasing the MIC of some antibiotics against MRSA; whereas friedelin was inactive. Although these three compounds have already been described in other plant species, this is the first report of their occurence in Cordia gilletii; the indirect antimicrobial effect of lupeol is described for the first time in this work. <p>As it belongs to the family of Boraginaceae, a family well known as one of the most important sources of pyrrolizidine alkaloids (PAs), Cordia gilletii is susceptible to contain these toxic compounds that were consequently researched. A GC-MS analysis did not reveal the presence of PAs (detection limit, 2 ppm) in root barks and leaves extracts of C. gilletii, suggesting a lack of PA-related toxicity of this plant. This reassuring finding needs to be confirmed with samples harvested at different locations.<p>This work reveals that C. gilletii may act against pathogenic microorganisms by: (i) a direct antimicrobial effect (partly due to férulaldéhyde); (ii) the enhancement or restoration of antibiotic activity against resistant strains (effect of lupeol); and (iii) an inhibitory effect on the expression of quorum sensing regulator genes, decreasing the virulence of microorganisms. These actions could help to fight infections caused by resistant strains. <p><p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

The genus Streptomyces produces more than a half of the known bioactive substances, ranking it among the most important bacterial taxons. Streptomyces lincolnensis ATCC 25466 encodes a biosynthetic gene cluster for lincomycin biosynthesis in its genome. Apart from the biosynthetic and regulatory genes, the cluster also contains three resistance genes, lmr(A), lmr(B) a lmr(C), which could protect of the host from the toxicity of a synthesized antibiotic. The Lmr(C) protein belongs to ARE proteins which generaly confer resistance to clinically important classes of antibiotics: macrolides, streptogramins, lincosamides and pleuromutilins. In addition to antibiotic producers, ARE proteins are also present in pathogenic microorganisms. However, the resistance mechanism conferred by these protins which belong to ABC transporters, even though they lack the transmembrane domain, have not been characterized yet. This makes the ARE proteins an interesting subject of the research. Using deletion mutants in resistance genes lmr(A), lmr(B) a lmr(C) we studied their effect on the lincomycin production and resistance to lincosamides, lincomycin and clindamycin with special focus on the function of the lmr(C). We have found that deletion of lmr(C) does not significantly influence lincomycin production and...

Les systèmes de transduction du signal et les transporteurs ABC contribuent de façon conjointe à la réponse adaptative des bactéries aux changements d’environnement. Trois modules, associant un phosphorelais et un transporteur ABC, ont été répertoriés chez B. subtilis et sont impliqués dans la réponse à différents antibiotiques: BceRSAB, PsdRSAB et YxdJKLM. Ils sont caractérisés par une histidine kinase possédant une boucle extracytoplasmique courte et appartenant à la famille des Intramembrane Sensing - Histidine Kinase (IM-HK) et par un transporteur ABC possédant une Membrane Spanning Domain (MSD) à boucle extracytoplasmique exceptionnellement longue. En utilisant une approche phylogénomique, il a été établi que ce type de modules était restreint aux Firmicutes, où ils sont apparus et se sont largement répandus. De plus, cette analyse met en lumière une histoire évolutive très dynamique impliquant de nombreux transferts horizontaux, duplications et pertes de gènes, conduisant à un répertoire de modules Bce-like très varié chez ce phylum. Grâce à une analyse phylogénétique fine, il a été proposé une classification de ces modules en six sous-familles bien définies.Des études fonctionnelles ont été réalisées sur des membres de la sous-famille IV comprenant le module de résistance à la bacitracine BceRSAB de B. subtilis, dont l’expression des gènes codant pour le transporteur requiert, en présence de l’antibiotique, le système de transduction du signal aussi bien que le transporteur lui-même. Les résultats de ces études montrent que d’autres membres de la sous-famille IV, YtsCD de B. licheniformis et BceAB de B. halodurans, sont également impliqués dans la résistance à la bacitracine. Ils suggèrent aussi que dans ces modules le transporteur ABC est le premier senseur de la présence de l’antibiotique et qu'il active le système de transduction une interaction entre une sous unité du transporteur et la kinase du module. De plus, en présence de bacitracine, l’expression des gènes codant pour le transporteur BceAB ainsi que la résistance à cet antibiotique requièrent la présence de la boucle de la MSD BceB ce qui démontre l'importance de cette boucle aussi bien au niveau fonctionnel que structural.Par ailleurs, l’étude que nous avons réalisée suggère que le mécanisme original de régulation des gènes du transporteur BceAB de B. subtilis pourrait être généralisé à tous les modules équivalents présents chez les Firmicutes. Ces modules constitueraient ainsi un mécanisme important de résistance aux antibiotiques peptidiques chez les bactéries de ce phylum qui comprend de nombreux pathogènes. / Signal transduction systems and ABC transporters often contribute jointly to adaptive bacterial responses to environmental changes. In Bacillus subtilis, three such pairs, thereafter called modules, are involved in responses to antibiotics: BceRSAB, PsdRSAB and YxdJKLM. They are characterized by a histidine kinase belonging to the Intramembrane Sensing – Histine Kinase family (IM-HK) and by a Membrane Spanning Domain (MSD) possessing an unusually large extracytoplasmic loop. Using a phylogenomic approach we were able to demonstrate that such modules, associating a phosphorelay and an ABC transporter, are specific but widespread in Firmicutes where they originated. This analyse highlight a highly dynamic evolutionary history involving numerous horizontal gene transfers, duplications and lost events, leading to a great variety of Bce-like module repertories in members of this bacterial phylum. Based on fine phylogenetic analyses, the Bce-like modules were divided into six well-defined subfamilies. Functional studies were performed on some members of subfamily IV comprising the bacitracin resistance module BceRSAB of B. subtilis, the expression of which being found to require, in the presence of bacitracin, the signal transduction system as well as the ABC transporter itself. The present results indicate that two other members of subfamily IV, YtsCD of B. licheniformis and BceAB of B. halodurans, were also found to participate in bacitracin resistance processes. The results also suggest that in these modules the ABC transporter works as the first sensor of the antibiotic and that it then activates the signal transduction system through an interaction between one of the two ABC transporter domains and the module kinase.Bacitracin dependent expression of bceAB and bacitracin resistance processes were shown to require the presence of the BceB translocator loop suggesting a crucial role for this loop as well at a functional level, as at a structural level.This study suggests that the original BceRSAB module regulatory mechanism might be generalised to other modules and would constitute an important common antibiotic resistance mechanism in Firmicutes which comprise many human pathogens.

Uropathogenic E. coli (UPEC) is the most frequent cause of urinary tract infection (UTI), being responsible for up to 85% of community acquired and 40% of nosocomial cases. UPEC strains harbour various virulence factors that contribute to their ability to cause disease. The high prevalence across the globe of multidrug resistant UPEC is a significant threat to therapy. Virulent and resistant UPEC strains have been recognised as belonging to major lineages and we have only recently begun to understand the factors contributing to their successful global dissemination. Work in this thesis was carried out to identify the population structure of E. coli isolates recovered from urosepsis and biliary sepsis, to reveal any differences in genetic background. A total of 100 isolates from the blood and urine of 50 patients presenting with urosepsis and 27 isolates from cases of biliary sepsis were subjected to genotypic and phenotypic analysis, including MLST, virulence gene detection and antibiogram and metabolic profiling. Urosepsis paired isolates showed identical genotypes and antimicrobial resistance profiles. However, several pairs of isolates showed discrepant metabolic activity profiles suggesting niche specific regulation of metabolism. Members of the ST131 clone were significantly associated with antibiotic resistance and ST38 isolates were associated with the highest level of metabolic activity. An in vivo infection model was used to investigate the virulence potential of isolates from the major UPEC lineages. Galleria mellonella larvae inoculated with ST69 and ST127 isolates showed significantly higher mortality rates than those infected with other strains. However, one isolate of ST127 (strain EC18) was avirulent and comparative genomic analyses with a single virulent ST127 strain revealed an IS1 mediated deletion in the O-antigen cluster in strain EC18, which is likely to explain the lack of virulence in the larvae and demonstrates the importance of this cell surface molecule in the model system. Finally, a total of 202 UPEC isolates were recovered from community and hospital urine samples from a tertiary care hospital in Riyadh, Saudi Arabia. Molecular epidemiological investigation of the strains was carried out to examine the overall UPEC population structure, for the first time in any part of Saudi Arabia. The most common lineages were ST131 (17.3%), ST73 (11.4%), ST38 (7.4%), ST69 (7.4%) and ST10 (6.4%). The findings highlight the successful spread of multidrug resistant, CTX-M positive ST38, ST131 and ST405 UPEC in Saudi Arabia. The high proportion (35%) of ESBL producing E. coli isolates is a particular concern and is driving frequent prescription of carbapenem antibiotics. A total of four isolates of ST38 were positive for aggR, which is a virulence marker of enteroaggregative E. coli (EAEC); ST38 strains that cause UTI but have an EAEC genetic background are becoming recognised as novel UPEC and this clonal group warrants further study.