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Sanchez-Buso L.,University of Valencia | Sanchez-Buso L.,CIBER ISCIII | Olmos M.P.,Laboratorio Of Salud Publica Of Valencia | Camaro M.L.,Laboratorio Of Salud Publica Of Valencia | And 2 more authors.
Infection, Genetics and Evolution | Year: 2015

Environmental surveillance of Legionella pneumophila is a key component of the control measures established in urban settlements to ensure water safety and quality, with the aim of minimizing and limiting opportunistic infections in humans. In this work, we present results on the detection and genetic characterization of these bacteria in the outbreak-recurrent region of Alcoy (Comunidad Valenciana, Spain) using water and biofilm samples. We were particularly interested in studying the presence and distribution of L. pneumophila in the absence of outbreak or sporadic cases of legionellosis and in comparing the efficacy of culturing from water samples with a biofilm-based detection procedure using molecular amplification. To this end, water samples were taken from 120 sites distributed all around the city and its surroundings, as well as 60 biofilm swabs from half of the sampling sites. L. pneumophila could be isolated from water in just 4 of the locations. Touchdown PCR was applied to DNA extracted from water and also biofilm swabs, as a rapid method for both routine and outbreak investigations. L. pneumophila was detected by this method in 14 of the sites in which both water and biofilms were taken, although 13 of them tested positive using only the biofilm samples. These results show a ten-fold increase in the success rate of Legionella detection over water samples. The application of this method to study the presence of L. pneumophila in the water-supply system and risk facilities of Alcoy revealed different strains distributed in different areas of the city. Sequence Type ST578, endemic in the area and responsible for most clinical cases, was detected in one of the sampling sites. The number of positive samples correlated with water temperature but not with chlorine levels. The direct analysis of biofilm swabs improves the detection rate and genetic characterization of L. pneumophila and can complement analyses based on bacterial culture. © 2014 Elsevier B.V. Source

Roca M.,Polytechnic University of Valencia | Castillo M.,Laboratorio Of Salud Publica Of Valencia | Marti P.,Laboratorio Of Salud Publica Of Valencia | Althaus R.L.,National University of Costa Rica | Molina M.P.,Polytechnic University of Valencia
Journal of Agricultural and Food Chemistry | Year: 2010

Nowadays, the possible public health risk associated with the presence of quinolone residues and other antibiotics in milk is well-known, but there is a lack of information about the effect milk processing temperatures have on the presence of antimicrobial residues. The aim of this work was to determine the effect of different temperatures and heating times on the concentration of quinolones in milk by employing liquid chromatographic equipment analysis with fluorescence detection. In order to determine the thermo-stability of these compounds, the first-order kinetic model was applied, and the activation energies, half-lives, and percentages of degradation of each compound were calculated. Results showed that quinolones are very resistant to different heat treatments with maximum losses of concentration of 12.71% for ciprofloxacin and 12.01% for norfloxacin at 120 °C and 20 min. The high stability of quinolones represents a significant risk to human health because the residues of these antibiotics can remain in milk after heat treatment and, therefore, can reach the dairy industry and consumers. © 2010 American Chemical Society. Source

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