Introdução. A introdução dos antimicrobianos na prática clínica no século XX foi um grande avanço para a medicina. Entretanto, seu uso indiscriminado, tanto na medicina (humana e animal) quanto na agricultura e pecuária, possibilitou a seleção e disseminação de microrganismos resistentes. A transferência genética horizontal é um dos principais mecanismos responsáveis pela disseminação de genes que codificam resistência aos antimicrobianos, pois possibilita a transmissão da resistência de uma célula bacteriana (comensal ou patogênica) para outra. Genes codificadores de resistência a antimicrobianos de importância clínica são encontrados em microrganismos de origem ambiental, clínica e alimentar. Objetivo. O objetivo do presente estudo foi detectar genes que codificam resistência aos antibióticos -lactâmicos, Tetraciclinas e Quinolonas, em amostras de carne de frango, visando estudar a ocorrência da resistência antimicrobiana nesse produto considerado um alimento comum na dieta do homem. Materiais e Métodos. Foram utilizadas 30 amostras de carne de frango. Após a inoculação da carne de frango em caldo Luria 0,5 por cento , o DNA total das bactérias cultivadas nesse meio foi extraído por choque térmico e utilizado na pesquisa de genes de resistência pela técnica de PCR seguida de eletroforese em gel de agarose. Foi também realizada a pesquisa de Coliformes Termotolerantes por meio da técnica dos tubos múltiplos para estimar a qualidade higiênico sanitária das amostras. Resultados: Oito (26,7 por cento ) amostras apresentaram um ou mais genes codificadores de resistência à antimicrobianos -Lactâmicos, 28 (93,3 por cento ) amostras apresentaram um ou mais genes codificadores de resistência às Tetraciclinas e 28 (93,3 por cento ) amostras apresentaram um ou mais genes codificadores de resistência às Quinolonas. Conclusões: A realização deste estudo contribuiu com informações a respeito da circulação de genes de resistência na carne de frango e alerta as autoridades de Saúde Pública do Brasil quanto à disseminação da resistência bacteriana e a necessidade de mais estudos a respeito desse problema, já que esses são raros ou inexistentes no País. / Introduction. The introduction of antibiotics in clinical practice in the twentieth century was a breakthrough for medicine. However, their indiscriminate use in both medicine (human and animal) as in agriculture and livestock, enabled the selection and spread of resistant microorganisms. Horizontal gene transfer is a major mechanism responsible for the spread of genes encoding antimicrobial resistance, since it allows the transmission of resistance from one bacteria to another. Genes encoding resistance to antimicrobials of clinical importance are found in microorganisms present in food, environment and clinical sources. Objective. The aim of this study was to detect genes encoding resistance to -lactam antibiotics, tetracyclines and quinolones in meat samples from chicken samples, to study the occurrence of antimicrobial resistance in this product considered a common food in human diet. Materials and Methods. Thirty samples of chicken were used. After inoculation of chicken meat in Luria broth 0.5 per cent , the total DNA of the bacteria cultured was extracted by heat shock and used to search resistance genes by PCR followed by agarose gel electrophoresis. The search for thermotolerant coliforms was also conducted using the technique of multiple tubes in order to estimate the sanitary quality of the samples. Results: Eight (26,7 per cent ) of the samples had one or more genes encoding for resistance to -lactam antimicrobials, 28 (93,3 per cent ) had one or more genes encoding resistance to tetracyclines and 27 (93,3 per cent ) samples had one or more genes encoding resistance to quinolones. Conclusions: This study contributes to the scientific community and sanitary agencies, bringing information regarding the occurrence and distribution of resistance genes in chicken, alerting the Public Health authorities in Brazil about the spread of bacterial resistance and the need for more studies in this field, as these are rare or nonexistent in the country.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-03T19:19:19Z No. of bitstreams: 1 2015 - Marina Jorge de Lemos.pdf: 6290720 bytes, checksum: 466915088ab49af16fcd11435ccc2913 (MD5) / Made available in DSpace on 2017-05-03T19:19:19Z (GMT). No. of bitstreams: 1 2015 - Marina Jorge de Lemos.pdf: 6290720 bytes, checksum: 466915088ab49af16fcd11435ccc2913 (MD5) Previous issue date: 2015-12-08 / CAPES / An experiment was conducted in order to evaluate the intestinal morphology, performance, egg quality and analysis of the financial feasibility of including various additives in feed during the whole production period of Japanese quails. 360 quails were distributed in a completely randomized design in a time split plot scheme (9 to 23 weeks of age and 24 to 39 weeks old) with five treatments and eight repetitions of nine birds each. The used treatments were: control, antibiotic, prebiotic, probiotic and synbiotic. The intestinal morphology was evaluated by the height and width and width/height ratio of the villus, crypt depth and villus/crypt ratio; performance, by the feed intake, egg production, egg weight average, feed conversion (kg / kg and kg / dozen), egg mass and viability; egg quality, by the Haugh unit, yolk index, percentage of egg components, shell thickness measured by the micrometer and the scanning electron microscope (SEM); financial analysis was computed by the internal rate of return, net present value and cost benefit. The inclusion of additives in the feed increased the height and width of the villi, decreased crypt depth and increased villous / crypt ratio compared to the control. The inclusion of the additives reduced the feed intake in the two periods of production of the quails in comparison with the control. Throughout the production period, consumption was lower after inclusion of antibiotic and synbiotic in the feed. Egg production, egg weight average, egg mass and feed conversion (kg / kg and kg / dozen) were improved in the quails fed with additives in the two periods of production. The supply of additives within 24 to 39 weeks of age increased the Haugh unit of the eggs compared to the control. The inclusion of additives in the feed increased the yolk and shell percentage, and improved shell and membrane thickness measured by the micrometer compared to the control in both periods of production. The shell thickness (SEM) and the shell palisade layer were improved after inclusion of antibiotic and synbiotic in the feed within 24 to 39 weeks of age. The financial analysis showed best values in the treatments that used antibiotics and synbiotic. The inclusion of antibiotics, probiotic, prebiotic and synbiotic in the feed improves performance and egg quality throughout the production phase of Japanese quails, and these improvements increase effects when the birds receive the additives in the first productive period. The inclusion of antibiotics and synbiotic is more effective than the inclusion of the other additives in reducing food intake throughout the production period and improving shell thickness during the second production period. Intestinal integrity of Japanese quails improved after the inclusion of the tested additives. The financial analysis proved to be more viable to include antibiotic or synbiotic in the feed of Japanese quails in comparison to the other studied additives. / Foi conduzido um experimento com o objetivo de avaliar a morfologia intestinal, o desempenho, a qualidade dos ovos e an?lise da viabilidade financeira da inclus?o de diferentes aditivos na ra??o durante todo o per?odo produtivo de codornas japonesas. Foram utilizadas 360 codornas distribu?das em um delineamento inteiramente casualizado em esquema de parcela subdividida no tempo (de 9 at? 23 semanas de idade e de 24 at? 39 semanas de idade) com cinco tratamentos e oito repeti??es de nove aves cada. Os tratamentos utilizados foram: controle, antibi?tico, prebi?tico, probi?tico e simbi?tico. A morfologia intestinal foi avaliada atrav?s da altura e largura e propor??o largura/altura das vilosidades, profundidade de cripta e rela??o vilo: cripta; o desempenho pelo consumo de ra??o, produ??o de ovos, peso m?dio dos ovos, convers?o alimentar (kg/kg e kg/d?zia), massa dos ovos e viabilidade; a qualidade de ovos pela unidade Haugh, ?ndice de gema, percentagem dos componentes do ovo, espessura de casca medida pelo micr?metro e pelo microsc?pio eletr?nico de varredura (MEV); a an?lise financeira foi computada pela taxa interna de retorno, valor presente l?quido e benef?cio custo. A inclus?o dos aditivos na ra??o aumentou a altura e largura das vilosidades, diminuiu a profundidade de cripta e aumentou a rela??o vilo:cripta em compara??o com o controle. A inclus?o dos aditivos reduziu o consumo de ra??o nos dois per?odos de produ??o das codornas em compara??o com o controle. Durante todo o per?odo produtivo, o consumo foi menor ap?s inclus?o de antibi?tico e simbi?tico na ra??o. A produ??o de ovos, o peso m?dio dos ovos, a massa de ovos e a convers?o alimentar (kg/kg e kg/d?zia) foram melhores nas codornas alimentadas com os aditivos nos dois per?odos de produ??o. O fornecimento dos aditivos no per?odo de 24 at? 39 semanas de idade aumentou a unidade Haugh dos ovos em rela??o ao controle. A inclus?o dos aditivos na ra??o aumentou a porcentagem de gema e de casca, e melhorou a espessura da casca avaliada pelo micr?metro e das membranas da casca em compara??o com o controle nos dois per?odos de produ??o. A espessura da casca (MEV) e da camada pali?ada da casca foi melhor ap?s inclus?o de antibi?tico e simbi?tico na ra??o no per?odo de 24 at? 39 semanas de idade. A an?lise financeira mostrou os melhores valores nos tratamentos que utilizaram antibi?tico e simbi?tico. A inclus?o de antibi?tico, probi?tico, prebi?tico e simbi?tico na ra??o melhora o desempenho e a qualidade dos ovos durante toda a fase produtiva de codornas japonesas, sendo esse efeito potencializado quando as aves recebem os aditivos no primeiro per?odo produtivo. A inclus?o de antibi?tico e simbi?tico ? mais eficaz que a inclus?o dos outros aditivos na redu??o do consumo de ra??o em todo per?odo produtivo e em melhorar a espessura da casca durante o segundo per?odo produtivo. A integridade intestinal das codornas japonesas melhora ap?s a inclus?o dos aditivos testados. A an?lise financeira demonstrou ser mais vi?vel a inclus?o de antibi?tico ou de simbi?tico na ra??o das codornas japonesas em compara??o com os outros aditivos estudados.

Antimicrobials are unique drugs in that they target "infectious" or "transferable" diseases. There is considerable evidence linking increasing antimicrobial use withincreasing resistance. Resistant bacteria do not know the boundaries, either between countries or within a society between hospital and primary care. Inappropriate prescribing of antimicrobials in hospitals therefore has consequences for whole communities and problems may spread both nationally and internationally. The gathering of reliable measurements of antibiotic use in hospitals employing standardised methods is essential to building an evidence base and highlighting inconsistencies at national and international levels. In this study, after data processing, validating and record linkage, a method forelectronic conversion of drug supply data to the ATC/DDD classification and forlongitudinal analysis was established for Tayside and then for a set of Europeanhospitals. Time series analysis and interrupted time series analysis were described and used for longitudinal surveillance and interventional study of antimicrobial use. This thesis explores issues concerning the evolution and management of hospital antimicrobial use using a wide range of methods. A series of drug utilisation research studies were implemented as the basis of research methods that, in combination of previously described methods, provided novel studies. No single measure can currently capture all of the aspects of hospital antibiotic use. However, a combination of detailed, point prevalence data from individual patients with longitudinal analysis of total consumption can provide meaningful data for comparison between hospitals and for analysis of the relationship between use and outcome. Additionally, there is a need to apply standard processes and novel methods to produce more meaningful surveillances. Longitudinal and point prevalence surveillances together with an explanation ofvariations in hospital characteristics are used to produce a set of coherent measurements of hospital antimicrobial use. Administrative data for longitudinal surveys requires continuous quality control.Whereas drug utilisation researchers and clinicians should target a set of indicators for interventional studies, large studies at national or international level need central data processing by country to identify targets for evaluation and for interventional studies. Support from experts in other fields is needed to address any shortcomings that may be experienced during continuous antibiotic drug utilisation monitoring at national and international levels.

Dois experimentos foram conduzidos com o objetivo de avaliar os efeitos do uso combinado de salinomicina e virginiamicina sobre o metabolismo ruminal, a digestibilidade, o comportamento ingestivo e as características sanguíneas de novilhos Nelore alimentados com dietas de alto concentrado. No experimento I, oito novilhos Nelore com 322 ± 26 kg de peso vivo (PV) inicial foram alocados no delineamento em quadrado latino 4 x 4 replicado, com quatro tratamentos em quatro períodos de 16 dias. Os tratamentos foram arranjados em esquema fatorial 2 x 2, com dois níveis de salinomicina (0 e 13 ppm) e dois níveis de virginiamicina (0 e 15 ppm) na matéria seca (MS) das dietas, que continham 80% de concentrado na MS. No experimento II, oito novilhos Nelore com 434 ± 35 kg de PV inicial foram alocados no mesmo delineamento, mas com períodos de 21 dias. Os tratamentos foram arranjados em esquema fatorial 2 x 2, com dois níveis de concentrado (70 e 90%) e dois níveis de virginiamicina (0 e 15 ppm) na MS das dietas. A salinomicina foi incluída em todas as dietas (13 ppm). Em ambos os experimentos, foram avaliados o consumo individual, a degradabilidade ruminal in situ, a digestibilidade aparente, a fermentação ruminal, o comportamento ingestivo, a população de protozoários ciliados ruminais e as características sanguíneas. As análises estatísticas foram realizadas pelo procedimento MIXED do SAS. No experimento I, houve efeito de nível de salinomicina e virginiamicina sobre as degradabilidades efetiva (DE) e potencial (DP) da fibra insolúvel em detergente neutro (FDN), sendo que os menores valores (P ≤ 0,05) foram observados para os animais tratados com os aditivos. A digestibilidade da proteína bruta (PB) foi maior (P = 0,01) para os novilhos que receberam salinomicina. Animais tratados com virginiamicina apresentaram maior (P = 0,01) concentração ruminal de propionato e menores (P ≤ 0,05) concentrações de acetato, butirato e lactato. Esses animais também apresentaram maior (P ≤ 0,03) tempo total de ruminação (TTR) e mastigação (TTM) e maior (P = 0,05) concentração de lactato no sangue. No experimento II, o aumento no teor de concentrado das dietas promoveu aumento (P = 0,01) no consumo de MS e nas digestibilidades aparentes da MS e PB, bem como redução (P < 0,01) na DE da FDN e PB. Animais tratados com ambos os aditivos apresentaram menor (P = 0,03) DE da FDN. As concentrações ruminais de acetato foram reduzidas (P < 0,01) com a inclusão de virginimicina, mas novilhos tratados com ambos os aditivos e alimentados com dieta contendo 90% de concentrado apresentaram aumento (P < 0,01) nas concentrações de propionato. O aumento no teor de concentrado promoveu redução (P < 0,01) no TTR e TTM dos animais, bem como na população de protozoários ciliados do rúmen e no pH sanguíneo. O uso combinado de salinomicina e virginiamicina apresentou efeitos positivos sobre a fermentação ruminal, especialmente quando a dieta com maior proporção de concentrado foi utilizada. / Two experiments were conducted to evaluate the effects of the combined use of salinomycin and virginiamycin on ruminal metabolism, digestibility, feeding behavior, and blood characteristics of Nellore steers fed high concentrate diets. In experiment I, eight Nellore steers with 322 ± 26 kg of initial body weight (BW) were allotted to a replicated 4 x 4 Latin square, with four treatments and four 16-day periods. Treatments were arranged in a 2 x 2 factorial design, with two salinomycin levels (0 and 13 ppm) and two virginiamycin levels (0 and 15 ppm) in the diet dry matter (DM), which contained 80% concentrate on a DM basis. In experiment II, eight Nellore steers with 434 ± 35 kg of initial BW were allotted to the same experimental design, but with 21-day periods, in a 2 x 2 factorial arrangement of treatments, with two concentrate levels (70 and 90%) and two virginiamycin levels (0 and 15 ppm) in the diet DM. Salinomycin was included in all diets (13 ppm). In both experiments, individual intake, in situ ruminal degradability, apparent digestibility, ruminal fermentation, feeding behavior, ciliated protozoa counts, and blood characteristics were evaluated. Statistical analyses were conducted using the MIXED procedure of SAS. In experiment I, there were effects of salinomycin and virginiamycin on effective and potential degradabilities (ED and PD, respectively) of the neutral detergent fiber (NDF), with lower values (P ≤ 0.05) observed for animals receiving the additives. Crude protein (CP) digestibility was higher (P = 0.01) for salinomycin-treated steers. Animals receiving virginiamycin showed higher (P = 0.01) ruminal concentrations of propionate and lower (P ≤ 0.05) ruminal concentrations of acetate, butyrate, and lactate. These animals also showed higher (P ≤ 0.03) total time spent ruminating (TTSR) and total time spent chewing (TTSC), as well as higher (P = 0.05) blood lactate concentrations. In experiment II, increasing concentrate levels increased (P = 0.01) DM intake and DM and CP digestibilities, but also decreased (P < 0.01) ED of the NDF and CP. Ruminal concentrations of acetate were reduced (P < 0.01) due to the inclusion of virginiamycin, but steers receiving both feed additives within the 90% concentrate group showed increased (P < 0.01) ruminal concentrations of propionate. Increasing concentrate levels decreased (P < 0.01) TTSR and TTSC, as well as ciliated protozoa counts and blood pH. The combined use of salinomycin and virginiamycin showed positive effects on ruminal fermentation, especially when animals were fed the higher concentrate diet.

Rhodococci are notable for their ability to degrade a variety of natural and xenobiotic compounds. Recently, interest in Rhodococcus has increased due to the discovery of a large number of genes for secondary metabolism. Only a few secondary metabolites have been characterized from the rhodococci (including 3 recently described antibiotics). Twenty-four new Rhodococcus strains were isolated from soils in East Tennessee using acetonitrile enrichment culturing and identified using 16S rRNA analysis. Forty-seven Rhodococcus strains were screened for antibiotic production using a growth inhibition assay. One strain, MTM3W5.2, had 90% similarity to the Rhodococcus opacus 16S rRNA gene sequence and produced a large zone of inhibition against R. erythropolis and a large number of closely related species. The antimicrobial compound produced by MTM3W5.2 had a large MW of 911.5452 Da and acts much like a bacteriocin but no amino acids were detected in this molecule based on TLC analysis.

In this thesis we modify an existing model for the spread of resistant bacteria in a hospital. The existing model does not account for some of the trends seen in the data found in literature. The new model takes some of these trends into account. For the new model, we examine issues relating to identifiability, sensitivity analysis, parameter estimation, uncertainty analysis, and equilibrium stability.

Sciadopitys verticillata was subjected to three propagation treatments designed to inhibit coagulation of its latex-like sap at the cut ends of the stem cuttings. Twenty-four hour soaking in water prior to rooting hormone application significantly enhanced production of adventitious roots. Old wood stem cuttings from shade-grown trees rooted at higher proportions than stem cuttings collected from sun-grown trees. Height, age, and place of origin of the source trees were not important factors in successful rooting. Antibacterial activity against some human pathogens and soil bacterial species was detected in latex application trials but the antibiotic activity was not related to the bacterial Gram reaction. The latex-like sap inhibited none of four plant pathogens tested. A suspension of the water insoluble latex-like sap of S. verticillata had a pH of 5.8. Antibacterial activity of S. verticillata sap was heat stable, which indicates the activity was not protein-based.

Antibiotic-resistant bacteria(ARB) is causing increased health risk and cost to society. Mathematical models have been developed to study the transmission of resistant bacteria and the efficacy of preventive measures to slow its spread within a hospital setting. The majority of these models have assumed a constant total hospital population with the admission and discharge rates being equal throughout the duration. But a typical hospital population varies from day to day and season to season. In this thesis, we apply variable admission and discharge daily rates to existing deterministic and stochastic models which examine the transmission of single and dual resistant bacteria. We perform stability and equilibrium analyses as well as a sensitivity analysis on the resulting model..

The soil bacterium Rhodococcus is a member of the phylum Actinobacteria and is related to Streptomyces, which is known for its production of many secondary metabolites. Recent genomic investigation of Rhodococcus has uncovered many silent gene clusters that appear to code for nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKS) of unknown function. Previous work, showed that Rhodococcus species strain KCHXC3 produces an inhibitory compound in agar culture extracts that displays prominent activity against several Gram positive and Gram negative species including the pathogens Rhodococcus equi, Shigella dysenteriae and Pseudomonas aeruginosa. Using the engineered Rhodococcus transposon vector, pTNR, the goal of this investigation is to screen random mutants of KCHXC3 for strains that no longer produce the inhibitory molecule. A library of 1825 random insertion mutants was produced via electroporation then screened for production of the inhibitory molecule by a disk diffusion assay against Shigella dysenteriae. From this screening, 7 mutants which no longer produce the compound of interest were identified.

The bacterium Rhodococcus is a potential source for novel antimicrobial metabolites. Recently, the Rhodococcus strain MTM3W5.2 was isolated from a soil sample collected from Morristown, East Tennessee and was found to produce an inhibitor molecule that is active against similar Rhodococcus species. The aim of this research is to extract, purify, and characterize the active compound. The compound was obtained from both agar and broth cultures of strain MTM3W5.2 and purified by primary fractionation of crude extract on a Sephadex LH-20 column, followed by semi-preparative reversed phase column chromatography. Final purification was achieved using multiple rounds of an analytical C18 HPLC column. Based on the results obtained from UV-Vis, FT-IR, and HR-MS, the molecule is a polyketide with a molecular formula of C52H78O13 and an exact mass of 911.5490 amu. The partial structure of this compound has been determined using 1D and 2D NMR spectroscopy.