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Coagulase-Negative Staphylococci phages panorama: genomic diversity and in vitr...
Lopes, Maria Beatriz Afonso Sequeira; Silva, Maria Daniela Ferreira; Azeredo, Joana; Melo, Luís Daniel RodriguesCoagulase-negative staphylococci (CoNS) are commensal bacteria of the human skin and mucosal membranes. The incidence of nosocomial infections caused by these species is on the rise, leading to a potential increase in antibiotic tolerance and resistance. Phages are emerging as a promising alternative to combat CoNS infections. Scientists are isolating phages infecting CoNS with a particular interest in S. epide...
Phage-host interaction with cells in different metabolic states: A S. epidermid...
Melo, Luís Daniel Rodrigues; Silva, Maria Daniela Ferreira; Pinto, Graça; França, Ângela Maria Oliveira Sousa; Azeredo, JoanaIn nature, bacteria are not frequently found in the exponential state of growth. One particular issue is that the efficacy of antimicrobials, including phages, is always tested against bacterial cells at their highest growth rate. The majority of bacterial biomass occur in the form of a biofilm. Biofilms have a high tolerance to antimicrobial agents, mainly, due to the low metabolic activity of the biofilm cell...
Staphylococcus epidermidis phage activates metabolic and biosynthetic processes...
Silva, Maria Daniela Ferreira; Pinto, Graça; França, Ângela Maria Oliveira Sousa; Azeredo, Joana; Melo, Luís Daniel RodriguesBackground In nature, bacteria are frequently found in the stationary state of growth. The efficacy of antimicrobials, including phages, against these low-metabolic activity cells is usually limited. The Staphylococcus epidermidis SEP1 phage was previously shown to reduce the numbers of stationary cells. This study analysed for the first time how both exponential and stationary cells responded to phage infectio...
Bacteriophages effective against stationary cells: promising agents against ant...
Silva, Maria Daniela Ferreira; Pinto, Graça; França, Ângela Maria Oliveira Sousa; Azeredo, Joana; Melo, Luís Daniel RodriguesBacteriophages (phages), the viruses that specifically infect and kill bacteria, are ubiquitous in the environment. Most phage-host interaction studies are performed with exponentially growing cells. In nature, however, this is not the primary pattern of growth, with bacteria often surviving in the stationary phase. These bacterial cells are typically in a slower or non-dividing state, with low metabolic activi...
The unique ability of Staphylococcus epidermidis phage SEP1 activating dormant ...
Silva, Maria Daniela Ferreira; Pinto, Graça; França, Ângela Maria Oliveira Sousa; Azeredo, Joana; Melo, Luís Daniel RodriguesMost bacteriophages fail to replicate in dormant hosts. The lower metabolic activity of these cells, together with their thicker cell wall and the fewer adsorption sites available impair the action of phages against them. The SEP1 phage, isolated from Staphylococcus epidermidis, has the rare ability to reduce the number of cells in a stationary (dormant) state. To uncover how cells respond to SEP1 infection, bo...
Transtympanic delivery of the pneumococcal endolysin MSlys via PEGylated liposomes
Silva, Maria Daniela Ferreira; Ray, K.; Gama, F. M.; Remenschneider, A. K.; Sillankorva, Sanna[Excerpt] Introduction: Streptococcus pneumoniae is the most common pathogen that causes acute otitis media [1]. For decades, systemic antibiotic therapy has been the gold standard treatment for these infections. However, the increasing antibiotic resistance has prompted research for novel topical antibiotic alternatives. Endolysins, peptidoglycan hydrolases encoded by bacteriophages, have attracted a lot of at...
Development of a new approach to control otitis media pathogens
Silva, Maria Daniela FerreiraOtitis media is one of the most common illnesses in childhood and the leading cause for an antibiotic prescription. Endolysins, peptidoglycan hydrolases encoded by bacteriophages, are an attractive antibiotic alternative. Their transtympanic delivery directly to the middle ear would maximize bioavailability, reducing the probability of a recurrent or chronic infection. However, the tympanic membrane acts as a b...
Identification of the bacterial pathogens in children with otitis media: a stud...
Silva, Maria Daniela Ferreira; Lima, António; Marçal, Nuno; Dias, Luís; Gama, F. M.; Sillankorva, SannaUnderstanding the bacterial etiology of otitis media (OM) is important when designing and evaluating the best course of treatment. This study analyzed middle ear fluid (MEF) and nasopharynx (NP) samples collected from 49 children with OM undergoing myringotomy in the northwestern Portuguese district of Braga. A correlation between species in the NP and MEF was observed following pathogen detection by culture an...
Sustained release of a Streptococcus pneumoniae endolysin from liposomes for po...
Silva, Maria Daniela Ferreira; Paris, Juan L.; Gama, F. M.; Silva, Bruno F. B.; Sillankorva, SannaLocal delivery of antimicrobials for otitis media treatment would maximize therapeutic efficacy while minimizing side effects. However, drug transport across the tympanic membrane in the absence of a delivery system is challenging. In this study, the MSlys endolysin was encapsulated in deformable liposomes for a targeted treatment of S. pneumoniae, one of the most important causative agents of otitis media. MSl...
A relação entre a criatividade no trabalho e o afeto positivo no trabalho: o pa...
Silva, Maria Daniela FerreiraNo presente trabalho procuramos aprofundar o estudo das consequências da criatividade para o bem-estar dos colaboradores. Mais especificamente, analisar a relação entre a criatividade, o afeto positivo no trabalho e o papel moderador da perceção de clima de conformismo dos colaboradores. Recolhemos dados em dois momentos do tempo, numa organização portuguesa do setor dos transportes aéreos. Cada um dos particip...