Browsing by Author "Pizarro, Cristina"
Now showing 1 - 10 of 14
Results Per Page
Sort Options
- Amostragem e Análise de Legionella em Sistemas de ÁguaPublication . Pizarro, Cristina; Rodrigues, Raquel
- Avaliação Microbiológica da Qualidade da ÁguaPublication . Pizarro, Cristina; Coelho, Carla
- Development of a Novel Peptide Nucleic Acid Probe for the Detection of Legionella spp. in Water SamplesPublication . Nácher-Vázquez, Montserrat; Barbosa, Ana; Armelim, Inês; Azevedo, Andreia Sofia; Almeida, Gonçalo Nieto; Pizarro, Cristina; Azevedo, Nuno Filipe; Almeida, Carina; Cerqueira, LauraLegionella are opportunistic intracellular pathogens that are found throughout the environment. The Legionella contamination of water systems represents a serious social problem that can lead to severe diseases, which can manifest as both Pontiac fever and Legionnaires' disease (LD) infections. Fluorescence in situ hybridization using nucleic acid mimic probes (NAM-FISH) is a powerful and versatile technique for bacterial detection. By optimizing a peptide nucleic acid (PNA) sequence based on fluorescently selective binding to specific bacterial rRNA sequences, we established a new PNA-FISH method that has been successfully designed for the specific detection of the genus Legionella. The LEG22 PNA probe has shown great theoretical performance, presenting 99.9% specificity and 96.9% sensitivity. We also demonstrated that the PNA-FISH approach presents a good signal-to-noise ratio when applied in artificially contaminated water samples directly on filtration membranes or after cells elution. For water samples with higher turbidity (from cooling tower water systems), there is still the need for further method optimization in order to detect cellular contents and to overcome interferents' autofluorescence, which hinders probe signal visualization. Nevertheless, this work shows that the PNA-FISH approach could be a promising alternative for the rapid (3-4 h) and accurate detection of Legionella.
- A Legionella como agente de infeção associada aos cuidados de saúde: casos práticosPublication . Pizarro, Cristina
- Legionella speciesPublication . Rodrigues, Raquel; Pizarro, Cristina
- Metodologias de Análise de Legionella em Sistemas de ÁguaPublication . Pizarro, Cristina; Rodrigues, RaquelIntrodução teórica; Amostragem: (Norma ISO 19458:2006, Water quality- Sampling for microbiological analysis;– Procedimentos internos); Método Cultural; Resultados INSA 2010-2012; Métodos de Biologia Molecular (Real – Time PCR).
- Métodos alternativos para a pesquisa de Salmonella sppPublication . Coelho, Carla; Pizarro, Cristina
- Microbiological monitoring of water for control of LegionellaPublication . Coelho, Carla; Pizarro, Cristina; Reinas, Alcina; Rebelo, HelenaLegionellosis is a collection of infections that are caused by Legionella pneumophila and related Legionella bacteria. The severity of legionellosis varies from mild febrile illness (Pontiac fever) to a potentially fatal form of pneumonia (Legionnaires’ disease) that can affect anyone, but principally affects those who are susceptible due to age, illness, immunosuppression or other risk factors, such as smoking. Legionella spp. are heterotrophic bacteria found in a wide range of water environments and proliferate at temperatures between 25°C and 45°C. These bacteria are members of the natural flora of many freshwater environments, such as rivers, streams and impoundments, where they occur in relatively low numbers. Bacteria of the genus Legionella are ubiquitous, they can proliferate in certain human-made water environments, such as water cooling devices associated with air conditioning systems, hot water, spas, distribution systems, on the inside surfaces of shower heads especially in warm waters. Legionellae can be ingested by certain amoebae which play an important role in their persistence in water environments. Devices that support multiplication of Legionella have been associated with outbreaks of Legionnaires’disease. Nosocomial cases usually make up a small proportion of reported cases of legionellosis. However, the proportion of cases that are fatal tends to be much higher with nosocomial infections than with community-acquired infections. Health-care facilities may include environments that support the proliferation and dissemination of Legionella and must be monitored. In Portugal only exists legislation for air conditioning systems and thermal waters. It is important to be aware of the need to develop specific rules for the detection of Legionella in water intended for human consumption in order to act more for the prevention of the disease than to act only in the monitoring of an outbreak. In recent years there has been an increasing incidence of disease caused by this bacterium, atypical pneumonia, and a large variety of water systems are different sources of contamination.
- Perspetiva de Legionella em Saúde Ocupacional e Saúde PúblicaPublication . Pizarro, CristinaA Doença dos Legionários é reconhecida como uma doença sub– notificada porque nem todos os casos diagnosticados são notificados através do sistema DDO. Além de sub–notificada, esta doença é também sub– diagnosticada.
- Pesquisa de Salmonella spp. em águas balnearesPublication . Pizarro, Cristina