Universiẗat, Diss., 2002--Osnabrück.

Made available in DSpace on 2014-06-11T19:32:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-23Bitstream added on 2014-06-13T21:03:19Z : No. of bitstreams: 1 marqueti_ac_dr_araca.pdf: 258633 bytes, checksum: 711d6e5f7bcc5a0600ade1c21b730a84 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este estudo avaliou a ocorrência de leveduras do gênero Candida sp além dos principais microrganismos periodontopatogênicos e enterobactérias na saliva, em mucosa e no biofilme aderido à prótese total, correlacionando com aspectos clínicos e condição de higiene bucal de 90 indivíduos edêntulos e portadores de prótese total, por meio de métodos moleculares (PCR). Espécimes clínicos intrabucais foram coletados desses indivíduos após avaliação das condições sócio-econômicas e comportamentais. A microbiota bucal dos pacientes foi caracterizada por meio da obtenção de amostras de biofilme aderido às próteses totais, mucosa e saliva, as quais foram processadas, por meio de PCR. As inter-relações entre os diferentes microrganismos foram determinadas por meio dos testes de Qui-quadrado e Mann- Whitney. Verificaram-se diferenças na ocorrência de Prevotella intermedia e Enterobacteriaceae na saliva dos pacientes edêntulos, o mesmo ocorrendo com Enterobacteriaceae, Camphylobacter rectus e gênero Pseudomonas no biofilme aderido às próteses totais. As condições de higiene bucal e estado de conservação da prótese total precários favoreceram a ocorrência de leveduras do tipo Candida sp, em especial Candida albicans, em níveis estatisticamente significante nas amostras de mucosa e biofilme aderido à prótese total, tornando este dispositivo protético um potencial reservatório de leveduras e bactérias entéricas que podem ser de relevância na patogênese das infecções oportunistas / The aim of this study was to evaluate the occurrence of major periodontopathogenic microorganisms and Enterobacteriaceae and biofilm adhered to the denture, mucosa and saliva in 90 edentulous subjects with complete dentures, using molecular methods (PCR). Clinical specimens were collected from these individuals after assessing the socio-economic circumstances and behavioral. The oral microbiota of patients was characterized by obtaining samples of the biofilm adhered to the dental prothesis and saliva, for detection of major pathogens using PCR. The possibility of inter-relationships between different microorganisms was determined using the chi-square test and Mann-Whitney test. There were differences in the occurrence of Prevotella intermedia and Enterobacteriaceae in the saliva of edentulous patients, likewise, Enterobacteriaceae, Pseudomonas, Camphylobacter rectus and the biofilm attached to denture patients. The conditions for oral hygiene and stat of preservation of prosthesis total precarious favored the occurrence of yeasts of the Candida sp, particularly Candida albicans, statistically significant levels in samples of mucosa and biofilm acceded to total prosthesis, prothetic device, making it a potential reservoir of enteric bacteria and yeasts that may be of relevance in the pathogenesis of opportunistic infections

The Enterobacter are often found in the feces of man and other warm blooded animals but have limited use as indicators of fecal contamination of foods and water since they are also often found as natural flora of non-fecal environments such as water and plants. This study proposes a method that may be useful for differentiating between fecal and non-fecal Enterobacter. Coliform bacteria associated with the human fecal environment often have a high incidence of multiple resistance to antibiotics. By determining multiple drug resistance and indexing Enterobacter in reference to their environmental source, it was discovered that isolates from human feces, raw sewage and certain foods demonstrated a higher index than isolates from rural soils, wild animal feces, cereal grains and other non-human environments. An index value greater than 0.2 indicated isolates from environments contaminated with human feces representing a high health risk while those isolates with an index of less than 0.2 came from relatively safe environments. Traditionally, the assessment of food borne health hazards is determined by measuring the quantity and kind of bacteria present. Drug resistance indexing will compliment these tests and aid in identifying serious bacterial contamination of foods. / Graduation date: 1981

Revisión por pares / joruiz@clinic.ub.es / Furazolidone-resistant mutants were obtained from four clinical isolates of diarrhoeagenic Escherichia coli. The stability of the resistance and the frequency of mutation were established. The minimal inhibitory concentration of furazolidone, nitrofurantoin, nalidixic acid, ampicillin, chloramphenicol and tetracycline was established both in the presence and absence of the efflux pump inhibitor Phe-Arg-β-Naphtylamyde. The presence of mutations in the nitroreductase genes nfsA and nfsB was analysed by PCR; sequencing and their enzymatic activity was assessed by a spectrophotometric assay. Alterations in outer membrane proteins were studied by SDS-PAGE. The frequency of mutation ranged from <9.6 × 10-10 to 9.59 × 10-7 . Neither an effect on efflux pumps inhibited by Phe-Arg-β-Naphtylamyde nor cross-resistance with the antibiotics studied was observed. Nineteen mutants (52.94%) presented mutations in the nitroreductase-encoding genes: 17 in the nfsA gene (15 mutants with an internal stop codon, 2 with amino acid changes), 2 in the nfsB (all amino acid changes). Alterations in the outer membrane proteins OmpA and OmpW were also observed. Although more studies are necessary to find other resistance mechanisms, present data showed the low potential of selecting furazolidone-resistant mutants, together with the lack of cross-resistance with unrelated antimicrobial agents.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Förekomsten av bakterier med olika typer av resistensmekanismer ökar globalt. De varianter som på engelska benämns ”Extended spectrum β-lactamases” (ESBL) är en heterogen grupp β- laktamaser som genom hydrolys inaktiverar β-laktamantibiotika och därigenom ger resistens mot bland annat β -laktamantibiotika som penicilliner och cefalosporiner. Resistensbestämning på kliniska laboratorier utförs huvudsakligen med lappdiffusion eller Minimum Inhibiting Concentration (MIC)-bestämning med gradienttester. Infektioner orsakade av ESBL-producerande organismer kan behandlas med β-laktamantibiotika kombinerat med en β-laktamasinhibitor. I Europa rekommenderas resistensbestämning med bestämd koncentration β-laktamasinhibitor, men produkter på marknaden saknas. Syftet med projektet var att utvärdera olika typer av gradienttester med amoxicillin- klavulansyra från två leverantörer (Etest och MIC Test Strip, MTS) och undersöka hur klavulansyra påverkar resistensbestämningen, samt att se hur resultat från lappdiffusion korrelerar med resultat från ovan nämnda tester. Lappdiffusion och MIC- bestämning med gradienttester med antingen bestämt förhållande av amoxicillin-klavulansyra (2:1) (Etest och MTS) eller bestämd koncentration klavulansyra (2mg/L) (MTS) utfördes med Escherichia coli (både med ESBL-positiva och ESBL-negativa stammar) samt med Proteus mirabilis. ESBL-detektion med cefpodoxim och cefpodoxim-klavulansyra utfördes parallellt. För P. mirabilis korrelerade lappdiffusionsresultat mycket bra med resultat från samtliga gradienttester. För E. coli korrelerade lappdiffusionsresultat mycket bra med MIC-värden vid användning av Etest 2:1 medan MTS 2:1 gav högre MIC-värden än referensdistributionen och resulterade i sämre korrelation. MIC-bestämning med MTS 2 mg/L resulterade i högre MIC-värden. Den nuvarande zonbrytpunkten behöver justeras för att korrelera med tolkningen från amoxicillin-klavulansyra med bestämd koncentration av klavulansyra 2 mg/L, framförallt för ESBL- producerande E. coli.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains ix, 111 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 104-110).

Thesis (M.S. - Soil, Water, and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves 119-122).

Thesis (M.Sc.)--University of Adelaide, Dept. of Microbiology, 1974.