Enterococcus and biocides: mechanisms of tolerance and selection for vancomycin resistance

Dissertation presented to obtain a Doctoral degree in Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa.

Biocides are chemical agents, generally with a broad-spectrum of activity, used to destroy, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism. Biocidal products comprise several chemical groups. Among the most commonly used are alcohols, aldehydes, biguanidines (e.g. chlorhexidine), phenols (e.g. triclosan) and quaternary ammonium compounds (e.g. benzalkonium chloride). Although some of the biocides were discovered many years ago, their generalised use began only some decades ago. They are used for cleaning and/or disinfecting in many different environments, such as in hospital facilities, veterinary facilities, food and pharmaceutical industry sites and in our homes. Biocides are also incorporated in several products as preservatives, such as deodorants, body creams and soaps. Some of the environments where biocides are applied are shared with enterococci.(...)

Financiall support by Fundação para a Ciência e Tecnologia (FCT), POCI 2010 and Fundo Social Europeu (FSE); BD nº SFRH/BD/41882/2007.