Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-10-02T12:04:15Z No. of bitstreams: 2 Tese - Aline Pedrosa de Oliveira - 2016.pdf: 3128576 bytes, checksum: bbad449f3830d7359e905a2812b2a74e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-03T11:45:04Z (GMT) No. of bitstreams: 2 Tese - Aline Pedrosa de Oliveira - 2016.pdf: 3128576 bytes, checksum: bbad449f3830d7359e905a2812b2a74e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-03T11:45:04Z (GMT). No. of bitstreams: 2 Tese - Aline Pedrosa de Oliveira - 2016.pdf: 3128576 bytes, checksum: bbad449f3830d7359e905a2812b2a74e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-12-22 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Salmonella enterica is a foodborne pathogen with multifactorial and complex pathogenic mechanisms. Identification of the presence of virulence genes and antimicrobial resistance profiles in isolates of poultry origin provides relevant information on the risk attributed to the consumption of products contaminated by the agent. The objective of this study was to verify the susceptibility profile of Salmonella enterica for nalidixic acid (30μg), amicacin (30μg), ampicillin (10mg), ceftiofur (30μg), chloramphenicol (30μg), ciprofloxacin (5μg), enrofloxacin (5μg), streptomycin (10mg), gentamicin (10mg), tetracycline (30μg), tobramycin (10mg) and trimethoprim (5μg) used in both human and animal medicine, to investigate the presence of multiresistant isolates, to detect the presence of the variable region of the class 1 Integron, to analyze the association between the presence of Class 1 Integron and antimicrobial resistance and to evaluate the presence of virulence genes located in the islands of virulence 1 (invA) and 2 (sseD), gene encoding long polar fimbriae (lpfA) and plasmidial spvR, to identify the virulence profiles and pathogenicity potential of Salmonella enterica serovars isolated from carcasses, hearts, livers, gizzards and environment of slaughterhouses located in the State of Goiás and on chicken carcasses marketed in commercial establishments in Goiânia -GO. The highest resistance frequency was observed for ceftiofur, 19.12% (13/68), followed by streptomycin, gentamicin, tobramycin, tetracycline and trimetropic, 16.18% (11/68) both, nalidixic acid 14.71% (10/68), ampicillin 13.24% (9/68), and enrofloxacin 2,94% (2/68). No resistance was observed for ciprofloxacin, only intermediate, 45.59% (31/68), 100% (68/68) of the isolates were sensitive to amikacin and chloramphenicol. Of the 68 isolates 22 (32.35%) were resistant to one or more antimicrobial principles. Twelve profiles of antimicrobial resistance were identified, 54.54% (12/22) of the isolates presented multiresistance. The variable region of Class 1 Integron was detected in 63.23% (43/68) of the isolates. The presence of this region was not associated with antimicrobial resistance. All slaughterhouses and in most commercial establishments it was possible to identify Salmonella enterica carrying the Integron of class 1 demonstrating the ubiquity of the same. The invA gene was identified in 100% (59/59), sseD in 92.53% (54/59), lpfA in 86.51% (52/54) and spvR in 86.18% (49/59) of the serovars of Salmonella enterica. Six virulence profiles were identified, 77.97% of the isolates were grouped in profile A characterized by the presence of the four virulence genes simultaneously. The knowledge of the virulence profiles of the isolates allows to affirm that the serovars identified in the state of Goiás are potentially virulent and capable of triggering disease in poultry production systems and in humans. / Salmonella enterica é um patógeno de veiculação alimentar com mecanismos de patogenicidade multifatoriais e complexos. A identificação da presença de genes de virulência e de perfis de resistência a antimicrobianos em isolados de origem avícola fornece informações relevantes quanto ao risco atribuído ao consumo de produtos contaminados pelo agente. Pelo exposto, objetivou-se com este trabalho verificar o perfil de suscetibilidade de Salmonella enterica para ácido nalidíxico (30μg), amicacina (30μg), ampicilina (10mg), ceftiofur (30μg), cloranfenicol (30μg), ciprofloxacina (5μg), enrofloxacina (5μg), estreptomicina (10mg), gentamicina (10mg), tetraciclina (30μg), tobramicina (10mg) e trimetoprima (5μg), utilizados tanto na medicina humana quanto animal. Investigar a presença de isolados multirresistentes. Detectar a presença do Integron de classe e analisar a associação entre a presença deste e a resistência antimicrobiana. Ainda avaliar a presença de genes de virulência localizados nas ilhas de virulência 1 (invA) e 2 (sseD), gene codificador de fímbria polar longa (lpfA) e o plasmidial spvR em sorovares de Salmonella enterica isolados a partir de carcaças, corações, fígados, moelas e ambiente de abate de abatedouros localizados no estado de Goiás e em carcaças de frango comercializadas em estabelecimentos comerciais de Goiânia -GO. A maior frequência de resistência foi obervada para ceftiofur, 19,12% (13/68), seguido pelos antimicrobianos, estreptomicina, gentamicina, tobramicina, tetraciclina e trimetropima, 16,18% (11/68), ácido nalidíxico 14,71% (10/68), amplicilina 13,24% (9/68), e enrofloxacina 2,94% (2/68). Não foi observado resistência dos isolados para ciprofloxacina, sendo, 45,59% (31/68), considerados apenas intermediários. Entretanto, 100% (68/68) dos isolados foram sensíveis à amicacina e ao cloranfenicol. Dos 68 isolados, 22 (32,35%) foram resistentes a um ou mais princípios antimicrobianos. Foram identificados 12 perfis de resistência à antimicrobianos e 54,54% (12/22) dos isolados apresentaram multirresistência. A região variável do Integron de Classe 1 foi detectado em 63,23% (43/68) dos isolados. A presença desta região não apresentou associação com a resistência aos antimicrobianos. Em todos os abatedouros e na maioria dos estabelecimentos comerciais foi possível identificar Salmonella enterica transportando o Integron de classe 1, demonstrando a ubiquidade do mesmo. O gene invA foi identificado em 100% (59/59), sseD em 92,53% (54/59), lpfA em 86,51% (52/54) e spvR em 86,18% (49/59) dos sorovares de Salmonella enterica. Foram identificados seis perfis de virulência (A, B, C, D, E e F). Ao todo, 77,97 % dos isolados se agruparam no perfil A, caracterizado pela presença dos quatro genes de virulência simultaneamente. O conhecimento dos perfis de virulência dos isolados permite afirmar que os sorovares identificados no estado de Goiás são potencialmente virulentos e capazes de desencadear doença em sistemas de produção avícola e em humanos.

The objectives of this study were to investigate nutrient retention, intI1 prevalence, and compost maturity rates for poultry litter co-composted with 5, 10, and 20% southern yellow pine biochar and with or without 2% wood vinegar (WV). Samples were collected at 0, 57, and 112 days to measure nitrogen, phosphorus, and potassium (N, P, K) concentrations, microbial counts, pH, moisture content, carbon to nitrogen (C:N) ratio, and intI1 abundance. Composts were aerated once a week and the temperature was also recorded once a week. There was sufficient rainfall so no additional water was added. The results showed that N and P concentrations significantly increased over time in all treatments except 20% biochar and 20% biochar + wood vinegar, while K concentrations significantly decreased. In general, composting with wood vinegar significantly decreased nutrient concentrations; however, all nutrient concentrations were much higher than typical animal manure fertilizers. Increases in biochar level resulted in significantly lower bacteria counts and significantly higher fungi counts. Compost treatments containing wood vinegar had significantly lower bacteria and fungi counts, indicating that southern yellow pine wood vinegar had a biocide effect on microorganisms, and may be not suitable for composting at that application rate. intI1 prevalence was not significantly different among treatments, which may be due to insufficient thermophilic composting. Because thermophilic temperatures were not achieved, the compost was not mature by the end of the study; therefore, compost maturity rates could not be determined.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-03-27T12:00:11Z No. of bitstreams: 0 / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-03-27T13:49:39Z (GMT) No. of bitstreams: 0 / Made available in DSpace on 2018-03-27T13:49:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-03-02 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O queijo Minas Frescal (QMF) representa um dos queijos mais consumidos no Brasil. Diversos fatores do seu processamento influenciam suas características microbiológicas, e consequentemente, sua qualidade e propriedades organolépticas. Seu alto teor de umidade e os riscos de contaminação durante a cadeia produtiva favorecem a ocorrência de microrganismos contaminantes, muitas vezes apresentando resistência aos antimicrobianos. Dessa forma, do ponto de vista da segurança alimentar e frente ao crescente fenômeno da resistência bacteriana às drogas, torna-se importante a investigação sobre a estrutura da comunidade bacteriana em QMF, bem como a avaliação da ocorrência de marcadores genéticos microbianos relacionados à resistência a drogas e seu potencial de mobilização. Neste estudo foram obtidas 5 amostras de um mesmo lote de 7 marcas de QMF identificadas de A a G, totalizando 35 amostras. Após a extração de DNA total microbiano das amostras, foram utilizadas abordagens de DNA fingerprint, pela amplificação de sequências palindrômicas extragênicas repetitivas (rep-PCR) para avaliação comparativa da similaridade da estrutura global da comunidade bacteriana. Posteriormente, PCR-DGGE foi utilizada para avaliar o perfil e a riqueza das amostras com relação a grupos de bactérias láticas. Matrizes de similaridade foram obtidas utilizando o método de agrupamento UPGMA. Os resultados obtidos pela técnica de rep-PCR revelaram que as amostras de queijos foram claramente agrupadas de acordo com as suas respectivas marcas. Além disso, perfis semelhantes entre amostras de marcas diferentes foram observados, indicando a presença de um núcleo microbiano comum. As amostras avaliadas também foram agrupadas de acordo com suas respectivas marcas de fabricação de acordo com os padrões de DGGE obtidos para bactérias láticas. A elevada similaridade entre a maioria das amostras do mesmo lote obtida nas técnicas de fingerprint sugere a reprodutibilidade e aplicabilidade das técnicas, e controle no processamento dos queijos ao longo da cadeia produtiva. Para a avaliação do resistoma clínico, a presença de 40 marcadores de resistência a diferentes classes de antibióticos foi avaliada por reação de PCR. Um núcleo comum de marcadores genéticos em todas as marcas foi detectado, associado à resistência aos beta-lactâmicos, tetraciclinas, quinolonas e sulfonamidas. Outros marcadores, incluindo aqueles relacionados a bombas de efluxo e resistência aos aminoglicosídeos, também foram observados. Integrons de classes 1 e 2 foram detectados, respectivamente, em 77% e 97% das amostras. As diferentes amostras de QMF puderam ser agrupadas de acordo com seu perfil de marcadores genéticos de resistência aos antimicrobianos, o que sugere epidemiologia peculiar que pode estar relacionada a qualidade e aos níveis de contaminação dos queijos ao longo da cadeia produtiva. Em conjunto, os dados sugerem que embora a cadeia produtiva do QMF seja controlada na indústria, riscos sanitários são inerentes pela contaminação dos queijos por bactérias putativas resistentes a antimicrobianos. Como um todo, os dados apontam para a necessidade de discussão dos parâmetros de qualidade microbiológica na produção, armazenamento e distribuição de QMF. Além disso, a detecção de integrons de classe 1 e 2 levanta questões a respeito do potencial de transferência horizontal de genes de resistência para a microbiota humana através do consumo destes alimentos. / Minas Frescal cheese (QMF) represents one of the most consumed cheeses in the country. Several factors of its processing influence its microbiological characteristics, and, consequently, its quality and properties. Its high moisture content and the risks of contamination during the production chain favor the occurrence of contaminating microorganisms, often presenting antimicrobial resistance. Thus, from the point of view of food safety and the growing phenomenon of bacterial resistance to drugs, it is important to investigate the structure of the bacterial community in Minas Frescal cheese, as well as the evaluation of the occurrence of microbial genetic markers related to drug resistance and its potential for mobilization. In this study 5 samples from the same batch of 7 brands of Minas Frescal cheeses were identified from A to G, totaling 35 samples. After the extraction of total DNA from the samples, DNA fingerprint approaches were used, by the amplification of repetitive extragenic palindromic sequences (rep-PCR) to evaluate the similarity of the global structure of the bacterial community. Afterwards, PCR-DGGE was used to evaluate the profile and richness of the samples in relation to groups of lactic bacteria. Similarity matrices were obtained using the UPGMA clustering method. The results obtained by the rep-PCR technique revealed that the cheese samples were clearly brand-clustered. In addition, similar profiles among samples of different brands were observed, indicating the presence of a common microbial nucleus. The evaluated samples were also separated according to their respective manufacturing brands by the DGGE for lactic acid bacteria. The high similarity among the majority of the samples from the same batch obtained in the fingeprint techniques suggests the reproducibility and applicability of the techniques, and control in the cheese processing along the production chain. For the evaluation of clinical resistance, the presence of resistance markers to different classes of antibiotics was evaluated by PCR reaction. A common core of genetic markers was detected, associated with resistance to beta-lactams, tetracyclines, quinolones and sulfonamides. Other markers, including those related to efflux pumps and aminoglycoside resistance, have also been observed, but not in all brands. Integrons of classes 1 and 2 were detected, respectively, in 77% and 97% of the samples. The different QMF samples could be grouped according to their profile of genetic markers of antimicrobial resistance, which suggests peculiar epidemiology that may be related to the quality and levels of contamination of the cheeses along the production chain. Taken together, the data suggest that although the productive chain of QMF is controlled in the industry, health risks are inherent in the contamination of cheeses by putative antimicrobial resistant bacteria. As a whole, the data point to the need to discuss the parameters of microbiological quality in the production, storage and distribution of QMF. In addition, the detection of class 1 and 2 integrons raises questions about the potential for horizontal transfer of resistance genes to the human microbiota through the consumption of these foods.

Les integrons sont des systèmes de recombinaison génétique bactériens qui jouent un rôle majeur dans la dissémination des gènes de résistances aux antibiotiques. Ces plateformes génétiques sont capables de capturer des cassettes de gène et de les réorganiser afin de trouver des solutions adaptatives à un environnement changeant. Le mécanisme de recombinaison des intégrons est original. Contrairement aux autres systèmes de recombinaison spécifique de site de la même famille (catalysés par les recombinases à tyrosine), le site de recombinaison associé aux cassettes est reconnu sous forme d'ADN simple brin replié. Une large part de mon travail de thèse a été dédiée à la compréhension des mécanismes qui permettent à ces sites de recombinaison de passer de la forme stable qu'est la double hélice d'ADN à la conformation leur permettant d'être reconnu par la recombinase des intégrons. L'autre partie de ma thèse a consisté au développement d'un outil génétique utilisant les remarquables propriétés de recombinaison des intégrons. Ce nouvel outil, nommé « intégron synthétique » permet de générer un grand nombre de combinaisons de séquences hétérologues in vivo. Il pourrait être d'une grande utilité aux ingénieurs tentant d'assembler des réseaux et voies génétiques d'intérêt, par évolution dirigée.

<p>Bacterial resistance to antibiotics has become a serious problem. This is due to the remarkable ability of bacteria to respond and rapidly adapt to environmental changes. Integrons are elements with the capacity for gene capture by an integron-encoded site-specific recombinase called IntI. IntI binds and acts at the recombination sites, <i>attI </i>and<i> attC</i> resulting in excision and integration of short DNA elements called gene cassettes carrying an <i>attC</i> site in the 3’ end. Several families of antibiotic resistance genes are borne on gene cassettes in integrons connected to mobile elements. Other cassettes reside in the larger and ancestral superintegrons located on chromosomes in both pathogenic and environmental bacteria. Due to their close connection with lateral gene transfer systems, it is possible that integrons are functionally dependent on those networks. This work presents arguments for such connections. The<i> attC</i> of the <i>aadA1-qacE</i> cassette junction in Tn<i>21</i> was characterized in detail. Like other <i>attC</i> sites, it contains two pairs of inverted repeats and is almost palindromic. By using electrophoretic mobility shift assays, this study showed that IntI1 binds only to the bottom strand of <i>attC</i>. Upon folding the strand into a hairpin, a few chiral hairpin distortions define both the strand choice and also the appropriate orientation of the highly symmetrical site. Structural recognition also explains the wide sequence variation among <i>attC</i> sites. We have documented the initial cleavage step in recombination in IntI extracts and integrase levels in extracts were evaluated by a new method. Mutagenesis and homology modelling were performed to find amino acid residues in IntI1 that are important for recognition of <i>attC</i> hairpin-DNA. Comparisons were made with other tyrosine family members to explain how integron integrases differ in site-recognition and also in their mechanism of strand exchange.</p>

Bacterial resistance to antibiotics has become a serious problem. This is due to the remarkable ability of bacteria to respond and rapidly adapt to environmental changes. Integrons are elements with the capacity for gene capture by an integron-encoded site-specific recombinase called IntI. IntI binds and acts at the recombination sites, attI and attC resulting in excision and integration of short DNA elements called gene cassettes carrying an attC site in the 3’ end. Several families of antibiotic resistance genes are borne on gene cassettes in integrons connected to mobile elements. Other cassettes reside in the larger and ancestral superintegrons located on chromosomes in both pathogenic and environmental bacteria. Due to their close connection with lateral gene transfer systems, it is possible that integrons are functionally dependent on those networks. This work presents arguments for such connections. The attC of the aadA1-qacE cassette junction in Tn21 was characterized in detail. Like other attC sites, it contains two pairs of inverted repeats and is almost palindromic. By using electrophoretic mobility shift assays, this study showed that IntI1 binds only to the bottom strand of attC. Upon folding the strand into a hairpin, a few chiral hairpin distortions define both the strand choice and also the appropriate orientation of the highly symmetrical site. Structural recognition also explains the wide sequence variation among attC sites. We have documented the initial cleavage step in recombination in IntI extracts and integrase levels in extracts were evaluated by a new method. Mutagenesis and homology modelling were performed to find amino acid residues in IntI1 that are important for recognition of attC hairpin-DNA. Comparisons were made with other tyrosine family members to explain how integron integrases differ in site-recognition and also in their mechanism of strand exchange.

Floc-pathogen interactions are important determinants of the fate of pathogens in aquatic systems. The dissociation of bacteria from particles due to shear stress can significantly increase the presence of free-floating pathogenic bacteria in the aqueous phase. This has implications for pathogen transport and water quality. This study evaluated the interactions of water-borne pathogens with particles in selected aquatic ecosystems. Three experimental chapters and one concluding chapter is presented. Chapter 3 assesses the strength of the floc-microorganism association under different energy levels in relation to the physico-chemical properties and the bioorganic content of flocs from six different aquatic environments (SB, CSO, RF, AG, ML, MN); Chapter 4 evaluates how energy dissociates bacteria and affects microbial diversity in free-floating and particle-associated fractions in cohesive bed sediments (BedS) and suspended flocs (SusF) of three sites (SB, CSO, RF). Chapter 5 studies the diversity and succession among free-floating and particle-associated bacteria at different energy levels and the abundance of antibiotic resistance genes and Class 1 integrons (intI1) as a result of ecosystem perturbation in the six initial sites. Different strategies, such as standard laboratory analytical methods, as well as techniques based on analytical chemistry, biochemistry and molecular biology were used to accomplish these objectives. The bioorganic and physico-chemical properties of flocs and sediments, and the energy effects these structures are exposed to, play a role in the assessment of pathogen risk in water systems. Molecular approaches showed a significant difference in the composition of free-floating and particle-associated assemblages after simulated flow conditions and detected earlier differences in the dissociation of bacteria, compared to plating techniques. The analysis of integrons provided evidence for horizontal gene transfer events. Free-floating and particle-associated bacterial assemblages are potential genetic reservoirs for antibiotic resistance genes. This research shows that particles act as reservoirs for microorganisms, providing an early warning for potential indicators of human health risk in water systems and could determine the presence of future clinically relevant antibiotic resistance mechanisms and/or pathogenic microbial gene transfer in sediments, demonstrating the need to improve the existing protocols and methodologies that assess water quality. / Natural Sciences and Engineering Research Council of Canada (NSERC)

Thesis (PhD)--Macquarie University, Division of Environmental & Life Sciences, Department of Biological Sciences, 2008. / Bibliography: p. 257-274. / Literature review -- General materials and methods -- Characterisation of strain collection -- Distribution of integrons and gene cassettes in pseudomonas -- Genomic context of pseudomonas integrons -- Evolutionary analysis of pseudomonas spp. integrons 199 -- Final discussion -- Appendix -- References. / Integrons associated with mobile genetic elements have played a central role in the emergence and spread of multiple antibiotic resistance in many pathogenic bacteria. However, the discovery of integrons in the chromosomes of diverse, non-pathogenic bacteria suggests that integrons have a broader role in bacterial evolution. The Pseudomonas stutzeri species complex is a well studied model for bacterial diversity. Members of the complex are genetically closely related, but sub-taxa are not able to be defined by exclusively shared sets of phenotypic characters. Rather, on the basis of total DNA:DNA similarity, Ps. stutzeri strains have been divided into 17 different groups (termed genomovars). Two Ps. stutzeri strains have been found to contain Chromosomal Integrons (CIs). This thesis involved exploration of the hypothesis that a CI was present in the common ancestor of the Ps. stutzeri species complex and assessed the impact of integrons on diversity across all Pseudomonads. The history and significance of integrons is discussed in Chapter 1 as part of a literature review, and general materials and methods are provided in Chapter 2. Chapters 3 - 6 comprise the sections in which data generated during my PhD project are presented. A comprehensive analysis of the relationships between the strains being analysed is presented in Chapter 3. In Chapter 4, results of PCR and hybridisation screening for integrons across the strain collection are presented. In Chapter 5 the recovery of additional integrons and in depth sequence analysis of the recovered integrons are described. Finally, Chapter 6 contains statistical analyses of integron-associated genes and Chapter 7 contains a final discussion the most significant findings. Twenty-three Pseudomonas spp. strains were screened for the presence of integrons. All but three were found to contain integron-like sequences; however, most integron sequences recovered contained inactivated core integrons. viii Despite having a chromosomal locus, integrons in Pseudomonas were found to have properties indicative of frequent horizontal transfer. Evidence was also obtained which suggests that integrons have been acquired at the same locus on multiple independent occasions. This has not been observed in other families of chromosomal integrons and suggests that the loci at which integrons in Pseudomonas are found are hotspots for recombination. / Mode of access: World Wide Web. / xiii, 274 p. ill

Made available in DSpace on 2014-06-11T19:33:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-20Bitstream added on 2014-06-13T18:45:08Z : No. of bitstreams: 1 okamoto_as_dr_botfmvz.pdf: 316486 bytes, checksum: 9da72cf8a36b7e04e7b42adc80fe9b71 (MD5) / Universidade Estadual Paulista (UNESP) / Neste trabalho foram analisadas 100 cepas de Salmonella Enteritidis (SE) isoladas de material avícola, visando à detecção dos genes de virulência spvC e invA e resistência a antimicrobianos integron classe 1. Comparando-se com a possível expressão dos fatores de virulência para sobrevivência em condições impróprias de temperatura, pH e concentração de nutrientes e o teste de inibição em placa, respectivamente. Também a capacidade de transferência horizontal do gene integron classe 1 foi avaliada em SE. Das cepas analisadas, duas apresentaram os genes spvC e invA, simultaneamente, com uma provável expressão destes sendo verificada no crescimento com pH 10,0 ou temperatura de 25ºC. Porém em relação à concentração de nutriente, ambas as cepas não cresceram na menor concentração (0,5%). Não houve relação direta entre a presença do gene integron classe 1 com a multiresistência de SE aos 14 antimicrobianos testados, já que 80% das cepas pesquisadas foram resistentes a até três antimicrobianos e não apresentaram o referido gene. Entretanto, a transferência horizontal desse gene e da resistência antimicrobiana foi realizada in vitro, de um Escherichia coli para uma Salmonella Enteritidis, demonstrando a capacidade de disseminação do gene presente em integron classe 1. / In this work, 100 strains of Salmonella Enteritidis (SE) isolated from avian material were studied, aiming to detect the genes of virulence spvC and invA, as well as the antimicrobial resistance type 1 integron genes using the polymerase chain reaction (PCR), comparing it with the possible expression of the virulence factors to survive under inappropriate conditions of temperature, pH and nutrient concentration, and the plaque inhibition assay, respectively. Capacity of horizontal transfer of type 1 0,integron gene was also evaluated in SE. Two of the analyzed strains showed spvC and InvA genes simultaneously, with a probable expression verified through growing in pH 10.0 or 25°C temperature. However, regarding to nutrient concentration, the aforementioned strains did not grow at the lowest concentration (0.5%). There was no direct relation between type 1 integron gene and the multiresistance of SE to the 14 tested antibiotics, because 80% of the strains did not showed the gen, but was resistant till three antibiotics. However, horizontal transfer of this gene was performed in vitro, showing the capacity of dissemination of the type 1 integron gene between bacteria.

Submitted by ISAMERY AUXILIADORA MACHADO DE SARMIENTO null (isamerymachado@yahoo.com) on 2016-08-24T00:16:43Z No. of bitstreams: 1 Archivo combinado tese completa con link Isa.pdf: 3685365 bytes, checksum: 2df7162dfd0eb21c6e675c7966fce592 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-25T20:40:51Z (GMT) No. of bitstreams: 1 machadodesarmiento_ia_dr_bot.pdf: 3685365 bytes, checksum: 2df7162dfd0eb21c6e675c7966fce592 (MD5) / Made available in DSpace on 2016-08-25T20:40:51Z (GMT). No. of bitstreams: 1 machadodesarmiento_ia_dr_bot.pdf: 3685365 bytes, checksum: 2df7162dfd0eb21c6e675c7966fce592 (MD5) Previous issue date: 2016-06-30 / As doenças de transmissão alimentar (DTA) por bactérias constituem um problema de saúde pública no mundo. O objetivo do trabalho foi identificar por métodos microbiológicos e moleculares a presença de Campylobacter spp., Salmonella spp. e Escherichia coli em frangos de Botucatu-SP, Brasil. Sessenta (60) amostras de frangos resfriados de diferentes marcas foram coletadas aleatoriamente em diferentes estabelecimentos localizados tanto na periferia, quanto no centro da cidade de Botucatu, SP, no período de julho a outubro de 2015. Posteriormente, Campylobacter spp, Salmonella spp e E. coli foram isolados através de métodos microbiológicos convencionais. A confirmação das bactérias isoladas se realizou por provas bioquímicas e PCR. Além disso, as provas para determinar a resistência antimicrobiana e a existência de gene integron classe 1 foram realizadas. Os resultados demostraram a presença de três das principais bactérias que causam doenças de origem alimentar em carcaças de frango provenientes de supermercados e casas de carne de Botucatu. A prevalência de Campylobacter, Salmonella, e E. coli foi 38,3%, 13,3% e 60%, respectivamente. A resistência antimicrobiana dos isolados foi elevada e presença do gene íntegron classe 1 foi identificada em alguns agentes patogénicos. / The transmission of Foodborne Diseases (FBD) by bacteria constitutes a public health problem in the world. The objective of this study was to identify by microbiological and molecular methods the presence of Campylobacter spp., Salmonella spp. and Escherichia coli in broiler chickens at Botucatu, SP, Brazil. Sixty samples of chilled chickens of different brands were randomly collected from supermarkets and meat houses located in both the periphery and the center of the city, in the period from July to October 2015. Later, Campylobacter spp., Salmonella spp., and E. coli were isolated by conventional microbiological methods. Confirmation of the isolated bacteria was performed by biochemical and PCR tests. In addition, proofs to determine antimicrobial resistance and the existence of class 1 integron gene were carried out. Results confirmed the presence of the three assessed bacteria in poultry carcasses from selected establishments. The prevalence was 38.3%, 13.3% and 60% to Campylobacter, Salmonella and E. coli, respectively. Antimicrobial resistance of the isolates was high and the presence of integron class 1 gene has been identified in some pathogens.