The presence of Staphylococcus aureus in drinking water is a concern because of its potential to cause human infection and also because of its multiple antimicrobial resistance. This study evaluated the water quality of drinking water fountains and mist makers in four municipal parks of São Paulo for 13 months. Although all samples met bacteriological water quality criteria according to Brazilian regulations, the absence of residual chlorine (<0.1 mg/L) was observed. These data were significantly correlated with the frequency of S. aureus that was found in 25.2% of the samples. The mecA gene was detected in 36.7% of the isolates demonstrating its potential for resistance to several antimicrobials. Furthermore, 27.3% isolates carrying mecA gene had methicillin-resistant Staphylococcus aureus (MRSA) phenotypic potential. The presence of S. aureus with characteristics of microbial resistance in water for human consumption is an unprecedented finding. Hence, conducting surveillance for opportunistic bacteria, such as staphylococci in drinking water is reasonable to take control measures and to protect human health, especially in public places with high attendance.

The presence of opportunistic bacteria such as coagulase-negative Staphylococcus (CoNS) in drinking water poses public health concerns because of its potential to cause human infection and due to its antimicrobial resistance (AMR) diversity. This study evaluated the occurrence, virulence markers and AMR of CoNS in 468 drinking water samples from 15 public fountains located in four urban parks of São Paulo city (Brazil). Out of 104 samples positive for the presence of Staphylococcus genus, we detected CoNS in 75 of them (16%), which did not meet the Brazilian sanitary standards for residual chlorine. All isolates were of concern to public health for being responsible for infection in humans from low to high severity, nine of them are considered the most of concern due to 63.6% being multiresistant to antimicrobials. The results demonstrated that CoNS in drinking water must not be neglected. It is concluded that the presence of resistant staphylococci in drinking water is a potential health risk, which urges feasible and quick control measures to protect human health, especially in crowded public places.

La enfermedad de Parkinson es la segunda enfermedad neurodegenerativa del mundo, y la nanotecnología tiene un gran potencial para mejorar los tratamientos actuales. En este contexto, el presente trabajo tiene como objetivo estudiar la interacción de la nanopartícula de plata (AgNP) con la E3 UBIQUITIN-PROTEIN LIGASE PARKIN (PARK2 o Parkina), una proteína importante relacionada con la enfermedad de Parkinson. La proteína objetivo PARK2 (Parkina) fue seleccionada de la plataforma del Banco de Datos de Proteínas (PDB) con el ID PDB: 4BM9. El AgNP se obtuvo con un archivo CIF (Crystallographic Information File) de Ag cúbico cargado en la plataforma Nanocrystal para generar las coordenadas cristalográficas del archivo modelo 3D (archivo AgNP.pdb) con un total de 1865 átomos en su estructura. El acoplamiento molecular se realizó con la ayuda del servidor HDOCK, se configuró una caja de rejilla cúbica para abarcar toda la enzima, ajustada a 1,0 angstrom. HDOCK es un servidor utilizado para predecir los complejos de unión entre dos moléculas, como proteínas y ligandos, utilizando una estrategia de acoplamiento híbrido. El modelo de acoplamiento aplicado fue el algoritmo basado en un modelo geométrico. Para la evaluación de los resultados, se aplicó una distancia de 2,5 angstroms como zona de contacto entre la AgNP y los residuos de aminoácidos. Los resultados muestran que se observaron interacciones hidrofílicas e hidrofóbicas con valores de Potencial de Lipofilia Molecular de una media de -4,218 MLP. Las regiones cercanas al N-terminal de la enzima muestran un área mayor de interacción con el AgNP. Los residuos de aminoácidos cisteína, glutamina y glutamato presentan la mayor afinidad con la superficie de la AgNP evaluada en este estudio. Concluimos que los resultados del docking molecular de la interacción receptor-ligando del PARK2 (Parkina) pueden contribuir a la búsqueda de nuevos fármacos y terapias para inhibir la enfermedad de Parkinson.

Este trabalho dedico a todas as mulheres da família Cardoso, que com seus exemplos de vida foram combustíveis para minha jornada. Dedico em especial a minha mãe Teresa Cardoso por ser minha super-heroína, a minha irmã Jessica Janaina por seu apoio quando não tive forças para seguir e a minha querida avó Inês Soares Cardoso, que de alguma forma se manteve presente conosco. Sem vocês eu jamais chegaria até aqui! AGRADECIMENTOS A Deus e todos os seres de luz que me acompanham nesta vida. A minha orientadora, Profª. Drª. Tereza Pepe Razollini, pelo apoio e paciência.