Characterization of plasmid encoded efflux determinants from Staphylococcus epidermidis

publishe

Emergence of non-wild-type populations towards biocides in Staphylococcus epidermidis colonizing veterinary staff

[P269]Aims: To characterize biocide susceptibility of Staphylococcus epidermidis colonizing veterinary staff; propose epidemiological cut-off (ECOFF) values; assess relationships between biocide and antibiotic resistance phenotypes.Methods: The susceptibility profiles of 112 S. epidermidis isolates from nasal colonization of veter-inary staff towards six biocides (including benzalkonium chloride, chlorhexidine and triclosan) and ethidium bromide (EtBr), was determined by microdilution MIC determination. The MIC distribu-tions were analyzed by the normalized resistance interpretation method and the iterative statistical method to determine ECOFF values. Antibiotic susceptibility was determined by disc diffusion and antimicrobial resistance determinants screened by PCR.Results: Analysis ofMIC distributions enabled the detection of non-wild-type (NWT) populations towards most biocides and to the efflux marker EtBr and the proposal of tentative ECOFF values for the compounds tested. The NWT populations were correlated with carriage of the plasmid-en-coded efflux pump genes qacA/B and/or smr. NWT populations to triclosan were correlated with sh-fabI gene. We observed high frequencies of methicillin resistance(mecA+, 61 %) as well as of multidrug resistance phenotypes (50 %). Several determinants were associated with resistance phenotypes, including blaZ, erm, vga and fus genes. Carriage of qacA/B and/or smr was statistically associated with MDR phenotypes. Conclusions: This study discloses the first tentative ECOFF values of several biocides for S. epider-midis. It also reveals a high prevalence of biocide and antibiotic resistant S. epidermidis colonizing humans in close contact with animals, suggesting that these bacteria can be reservoirs for antimi-crobial resistance.publishe

Antibiotic and biocide resistance in Staphylococcus epidermidis colonizing humans in close contact with animals

Oral communicationpublishe

Characterization of antimicrobial resistance in Staphylococcus epidermidis colonizing veterinary staff and students

publishe

Perfil em alergénios do pólen de Platanus hybrida

Objetivos: O plátano (Platanus hybrida) é uma árvore frequentemente utilizada em ambiente urbano, com fins ornamentais. Sendo uma árvore de grande porte, produz pólen em grande quantidade. Embora seja responsável por níveis de exposição a pólen elevados no início da primavera, que são coincidentes com queixas da população, o seu potencial alergénico está pouco caracterizado. Este trabalho teve, assim, como objetivo caracterizar o perfil em alergénios do pólen de plátano na cidade de Évora, Alentejo. Métodos: Prepararam-se extratos de amostras de pólen de Platanus hybrida ou Dactylis glomerata utilizando tampão bicarbonato. Os extratos foram liofilizados e conservados a -80ºC. O conteúdo em proteínas foi determinado pelo método de Bradford. O perfil em alergénios foi avaliado por western blot utilizando soros humanos (obtidos mediante consentimento informado de doentes do Hospital do Espírito Santo de Évora – HESE). Resultados: Observou-se teste positivo a P. hybrida em metade dos soros testados. O perfil em proteínas de P. hybrida exibiu diversas bandas imunorreativas com massas moleculares compreendidas entre 10-90 kDa e com pI no intervalo 4,4-7,0. Foram encontradas imunorreativas comuns a Q. rotundifólia e/ou a D. glomerata. Duas bandas identificadas na gama de 50kDa e 60 kDa parecem específicas de P. hybrida. Também se registou reatividade cruzada com D. glomerata. Conclusões: Este trabalho evidencia alguns alergénios encontrados em pólen de P. hybrida. Para além disso mostra ainda a existência de reatividade cruzada com pólen de gramíneas. Estes resultados sugerem que o pólen de plátano, dada a sua grande abundância na cidade de Évora, poderá contribuir para o agravamento a sintomatologia da população que sofre de polinose, em particular no início da primavera. Agradecimentos: Este trabalho foi financiado por fundos do FEDER através do Programa Operacional Fatores de Competitividade – COMPETE”. Um agradecimento especial ao nosso colega, já falecido, Prof. Rui Brandão, pelo estímulo que deu a este trabalho e pela sua dedicação para a implementação e desenvolvimento da Aerobiologia na Universidade de Évora. Temos a honra de dedicar este trabalho à sua memória. Background and Aim: Although grasses and olive are the most relevant allergenic species in the Alentejo region, aggravation of allergic symptoms in the early spring, unrelated with those species pollen seasons, has been reported, particularly in urban environment. Plane trees, hence pollen, are highly abundant in the city of Évora, nonetheless allergen pollen profile has not yet been evaluated. The aim of this work was to characterize the allergen profile of pollen from Platanus hybrida, one of the most representative species in Evora showing pollination prior to the main pollen season in Alentejo. Methods: Pollen from Platanus hybrida, Quercus rotundifolia or Dactylis glomerata was extracted with ammonium bicarbonate buffer, lyophilized and stored at -80ºC until analysis. Protein content was determined by the Bradford method. SDS-PAGE followed by western blot, using allergic patient sera (obtained from the Hospital do Espírito Santo de Évora – HESE), were performed to evaluate the allergen profile of the pollen. Results: Protein profile of P. Hybrida has shown several bands in the Mr 10-90 kDa. Western blot have shown several immunoreactive bands. Protein profile according to the pI showed immunoreactive bands in the pI range 4.0-6.1. Cross-reactivity of P. hybrida with Q. rotundifolia and D. glomerata was found. Conclusion: These results evidenced allergens found in P. hybrida pollen. Moreover, cross–reactivity between P. hybrida and highly allergenic species such as D. glomerata was found which probably contributes for aggravation of pollinosis in the early spring. Acknowledgments: This work was supported by “FEDER - Programa Operacional Factores de Competitividade – COMPETE”. A special acknowledgment to our colleague Prof. Rui Brandão, deceased, for his dedication to the present work, to the implantation and development of Aerobiology in the University of Évora. We have the honour of dedicating this work to the memory of Prof. Rui Brandão