Prevenção e controlo de bactérias do género Legionella em redes de água, sistemas e equipamentos. Implementação de um plano de caraterização e monitor

• Autor(a) principal: Costa, Susana Catarina Martins
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/17602
• topic: Legionella; Water and risk assesmennt

Legionella is problematic bacterium that deserves the attention of the public health, because it developed an almost unique way of adapting to the modern and industrial world that we build. This work had as main objectives: i) to implement three different methodologies used for research and quantification of Legionella spp. and Legionella pneumophila; ii) carry out a risk assessment in the reality of Águas do Douro e Paiva (ADP). To achieve the first objective, the following techniques were used: cultural method, using Buffered Charcoal Yeast Extract (BCYE) agar and Glycine Vancomycin Polymyxin Cycloheximide (GVPC) agar; Legiolert and Legipid. To achieve the second objective, a risk assessment methodology based on the global risk assessment was used. This made it possible to build a history about the reality of the ADP company and the risk of the proliferation of Legionella hitherto unknown. In the implementation of the three methodologies for the quantification of Legionella spp. and L. pneumophila 154 determinations were carried out between December 2019 and September 2020. Of these determinations, 16 were positive and in 138 the presence of Legionella was not detected. The studies showed that, in the context of the ADP company, the best method to adopt will be the cultural method. However, further studies are needed to see if this method will be the best option for all water matrices. From the risk analysis it was possible to notice that there are several systems that have some of the critical aspects for the growth of this bacterium, such as the water temperature above 20 °C during a long period of the year. The highest Global Index value found was 45.4 in a domestic hot water system. None of the evaluated points exceeded the limit value of 60. Considering the analysis carried out, it was possible to conclude that the risk of Legionella proliferation in Águas do Douro e Paiva is not serious. However, this risk must be monitored and reassessed whenever justified.