Browsing by Author "Fernandes, Ruben"
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- Antimicrobial resistance in bacterial strains isolated from different types of Portuguese cheesePublication . Amador, P.; Fernandes, Ruben; Tato-Costa, J.; Teles-Grilo, L.; Brito, L.; Prudêncio, CristinaThe present work aimed to study an eventual antimicrobial resistance and the presence of β-lactamases in enterobacteria isolated from cheese. β-lactams are among the most common antibiotics used for bacterial infections. Rates of bacterial resistance to antimicrobial agents are increasing world wide and the presence of β-lactamases is among one of the most common resistance mechanisms. In the present study we used twenty cheese samples, corresponding to six different types of Portuguese cheese, collected from local retail establishments. Samples were screened for the presence of β-lactams resistant Enterobacteriaceae in selective media with high concentration values of ampicilin. Colonies presumed to be resistant to ampicilin were further confirmed by antibiogram testing against other 13 different antibiotics, including six β-lactams. A total of 160 isolates were recovere from the selective media. The presence of β-lactamases on colonies was detected by adding nitrocefin to the cell biomass. After antibiogram testing about 40 isolates were confirmed to be resistant to, at least, one β -lactam subclass. The results obtained in this study point out to the presence, in different cheese samples, of Enterobacteriaceae resistant to β-lactams and the presence of β-lactamases. These results suggest that cheese may be a source of potential resistance transfer to the normal gastrointestinal flora of the consumer,which may be a cause of serious public health problems.
- Bloodstream infections caused by multidrugresistant Enterobacteriaceae: report from two portuguese hospitalsPublication . Fernandes, Ruben; Vieira, Mónica; Ferraz, Ricardo; Prudêncio, Cristina
- Cannabidiol and terpene formulation reducing SARS-CoV-2 infectivity tackling a therapeutic strategyPublication . Santos, Susana; Barata, Pedro; Charmier, Adilia; Lehmann, Inês; Rodrigues, Suzilaine; Melosini, Matteo M.; Pais, Patrick J.; Sousa, André P.; Teixeira, Catarina; Santos, Inês; Rocha, Ana Catarina; Baylina, Pilar; Fernandes, RubenIn late 2019, COVID-19 emerged in Wuhan, China. Currently, it is an ongoing global health threat stressing the need for therapeutic compounds. Linking the virus life cycle and its interaction with cell receptors and internal cellular machinery is key to developing therapies based on the control of infectivity and inflammation. In this framework, we evaluate the combination of cannabidiol (CBD), as an anti-inflammatory molecule, and terpenes, by their anti-microbiological properties, in reducing SARS-CoV-2 infectivity. Our group settled six formulations combining CBD and terpenes purified from Cannabis sativa L, Origanum vulgare, and Thymus mastichina. The formulations were analyzed by HPLC and GC-MS and evaluated for virucide and antiviral potential by in vitro studies in alveolar basal epithelial, colon, kidney, and keratinocyte human cell lines.
- Comparison of two methods for Streptococcus agalactiae clinical diagnosis: growth on Granada and polymerase chain reaction detectionPublication . Corrêa, K.; Fernandes, Ruben; Gomes, A.; Vieira, Mónica; Ferraz, Ricardo; Prudêncio, CristinaGroup B Streptococcus (GBS) or Streptococcus agalactiae is one of the most common causes of life-threatening infections in newborns suchd as sepsis, pneumonia or meningitis due to its vertical transmissi on mother-child mech-anism.
- Cutibacterium acnes dysbiosis: Alternative therapeutics for clinical applicationPublication . Sá, Sara; Fernandes, Ruben; Gestoso, Álvaro; Macedo, José Mário; Martins-Mendes, Daniela; Pereira, Ana Cláudia; Baylina, PilarCutibacterium acnes (C. acnes) is a Gram-positive anaerobic facultative bacterium that is part of the human skin commensal microbiome. It colonizes various regions of the body, including the face, back, and chest. While typically a harmless commensal, under certain conditions, C. acnes can become pathogenic, leading to or promoting conditions such as acne vulgaris (AV), post-surgical infections, prostate cancer, and sarcoidosis. Current treatments for C. acnes infections often involve antibiotics, but the rise of antibiotic resistance has raised concerns. This review presents the virulence factors, clinical relevance, and current treatments of C. acnes, highlighting its association with AV, postsurgical infections, and other diseases. It also explores alternative innovative therapies such as phage therapy in development/research that are gaining prominence, with a growing focus on personalized medical approaches. To enhance C. acnes treatment while minimizing side effects and antibiotic prescription concerns, numerous clinical studies have been undertaken. These investigations span various pathological profiles and employ diverse strategies, such as utilizing bacterial extracts and compounds to restore healthy skin flora. The limitations and challenges of current and innovative treatments are also addressed, emphasizing the need for multidisciplinary strategies to combat C. acnes infections effectively.
- Dermic diffusion and stratum corneum: a state of the art review of mathematical modelsPublication . Couto, Ana; Fernandes, Ruben; Cordeiro, M. Natália D. S.; Reis, Sara S.; Ribeiro, Rogério T.; Pessoa, Ana S. MouraTransdermal biotechnologies are an ever increasing field of interest, due to the medical and pharmaceutical applications that they underlie. There are several mathematical models at use that permit a more inclusive vision of pure experimental data and even allow practical extrapolation for new dermal diffusion methodologies. However, they grasp a complex variety of theories and assumptions that allocate their use for specific situations. Models based on Fick's First Law found better use in contexts where scaled particle theory Models would be extensive in time-span but the reciprocal is also true, as context of transdermal diffusion of particular active compounds changes. This article reviews extensively the various theoretical methodologies for studying dermic diffusion in the rate limiting dermic barrier, the stratum corneum, and systematizes its characteristics, their proper context of application, advantages and limitations, as well as future perspectives.
- Effect of competitive exclusion in rabbits using an autochthonous probioticPublication . Cunha, Sara; Mendes, Ângelo; Rego, Dinis; Meireles, Diana; Fernandes, Ruben; Carvalho, André; Costa, Paulo Martins da; Fernandes, RúbenAnimal nutrition has been severely challenged by the ban on antimicrobials as growth promoters. This has fostered the study of alternative methods to avoid colonisation by pathogenic bacteria as well as to improve the growth of animals and feed conversion efficiency. These new options should not alter the normal intestinal microbiota, or affect it as little as possible. The use of probiotics, which are live microorganisms that beneficially affect the host by improving its intestinal microbial balance, can be seen as a promising way to achieve that goal. In this study, New Zealand White rabbits were fed diets containing an autochthonous probiotic of Enterococcus spp., with the strains EaI, EfaI and EfaD, and Escherichia coli, with the strains ECI 1, ECI 2 and ECD, during a 25-d trial, to evaluate the impact of the probiotic on the faecal microbiota, including population dynamics and antimicrobial resistance profiles. A control group of rabbits, which was fed a diet containing a commonly used mixture of antimicrobials (colistin, oxytetracycline, and valnemulin), was also studied. To assess the colonisation ability of the mentioned probiotic, the faecal microbiota of the rabbits was characterised up to 10 d after the administration had ended. Isolates of enterococci and E. coli were studied for phylogenetic relationships using enterobacterial repetitive intergenic consensus (ERIC-PCR) and pulse-field gel electrophoresis (PFGE), respectively. Although partially affected by an unexpected clinical impairment suffered by the rabbits in the experimental group, our results showed the following. The difference between the growth rate of the animals treated with antimicrobials and those fed the probiotic was not statistically significant (P> 0.05). The competitive exclusion product was present in the faecal samples in a large proportion, but stopped being recovered by culture as soon as the administration ended and the housing conditions were changed. Multidrug-resistant strains of enterococci and E. coli were more commonly recovered from faecal samples of animals fed diets containing antimicrobials, than from rabbits fed diets with our probiotic formula. The use of E. coli probiotics to prevent infection by enteropathogenic strains must be carefully considered due to the possible occurrence of gastrointestinal signs. On the other hand, enterococci strains may be more effective, but lack the long-term colonisation ability.
- Hábitos e comportamentos associados ao uso de antibióticos: A autonomia individual versus a saúde da comunidadePublication . Prudêncio, Cristina; Ferraz, Ricardo; Vieira, Mónica; Ribas, Cláudia; Ribas, Jorge; Fonte, Rosália; Fernandes, RubenA resistência a drogas é um dos graves problemas de saúde atual embora possa ser considerada uma resposta natural devida à pressão seletiva da droga. Esta resposta é no entanto exacerbada por vários fatores que incluem, abuso, subutilização ou má utilização, má adesão ao tratamento ou má qualidade das drogas disponíveis. Trata-se de um dos maiores desafios que enfrentam atualmente os profissionais de Saúde e a população em geral. A auto-medicação é um dos fatores que mais contribui para a resistência a antibióticos. No presente trabalho apresentamos um estudo preliminar onde foram avaliados os hábitos e comportamentos associados ao uso de antibióticos num grupo de Pais.
- High resistance to fourth-generation cephalosporins among clinical isolates of Enterobacteriaceae producing extended-spectrum β-lactamases isolated in PortugalPublication . Prudêncio, Cristina; Gestoso, Álvaro; Freitas, José Mota; Santos, Perpétua; Prudêncio, Cristina; Fernandes, Ruben; Fernandes, RúbenHere we report the molecular and antimicrobial susceptibility profile of extended-spectrum β-lactamase (ESBL)-producing strains found in the Portuguese northern occidental coast region (Minho). For this purpose, bacteria isolated from clinical hospitalised and non-hospitalised patients over a period of 2 years were identified and minimal inhibitory concentrations (MICs) were determined by microdilution methods according to the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) guidelines on Enterobacteriaceae. Additionally, ESBL phenotypic identification was confirmed by the Etest (AB BIODISK, Solna, Sweden). Various methods of molecular identification of the β-lactamase (bla) genes, involving polymerase chain reaction (PCR) and sequencing strategies, were used in this study. The ESBL-producing strains (n = 193) were isolated from urine (n = 127), sputum (n = 42), bronchoalveolar lavage (n = 14), blood (n = 7) and ascitic fluid (n = 3). The most frequent ESBL-producing organism isolated in the present study was Escherichia coli (67.9%; n = 131), followed by Klebsiella pneumoniae (30.6%; n = 59), Klebsiella oxytoca (0.5%; n = 1), Enterobacter aerogenes (0.5%; n = 1) and Citrobacter freundii (0.5%; n = 1). The ESBL detected in the present studywere the TEM type (40.4%), CTX-M type (36.8%) and SHV type (22.8%). TEM-52 and TEM-24 were the most frequent TEM types (20.2% and 12.9%, respectively). Members of TEM-10 (4.1%) and TEM-116 (2.1%) were also detected. Within the CTX-M family, CTX-M-9 group was represented by CTX-M-9 (13.5%) and CTX-M-14 (8.4%). In the CTX-M-1 group, CTXM-15 was the most frequent type (12.4 %), followed by CTX-M-1 (2.1%), CTX-M-3 (0.5%) and CTX-M-32 (0.5%). Regarding CTX-M types, it appears that CTX-M-14 is widespread among the northwestern Iberian Peninsula [1]. Klebsiella pneumoniae harbouring a CTX-M-15 enzyme was described for the first time in Portugal in 2005 [2] in the Lisbon area, but CTX-M-15 enzyme has also recently been found by us in the north of Portugal in another Enterobacteriaceae member, isolated from bloodstream infections [3] among seven patients in two different hospitals. Other ESBL-producing species (not E. coli or K. pneumoniae)were also found. This is the first time that C. freundii has been described as a producer of CTX-M-32 in this country. The SHV enzymes occurred only in 23.3% of all ESBL-producing organisms. Within this type, the most frequent type was SHV-12 (12.4%), followed by SHV-5 (8.8%) and finally SHV-2 (2.1%). Some isolates co-produced more than one ESBL type: TEM-52/CTX-M-14 (0.5%); TEM-116/CTX-M-14 (0.5%); and TEM-116/CTX-M-15 (0.5%). MIC testing showed that isolates producing ESBLs were mostly susceptible to carbapenems (100%) and amikacin (99.5%). In contrast, ESBL-producing strains presented low susceptibility rates to cefepime and quinolones. Indeed, 98.9% of the ESBL-producing strains were cefepime-resistant and 85.4% were resistant to quinolones (ciprofloxacin and norfloxacin). In the generality, these high levels of resistance to quinolones were more conspicuous in members of the CTX-M family (98.1%) than TEM and SHV types (80.8% and 72.1%, respectively). In this study, cefepime presented a surprisingly low activity against ESBL-producing microorganisms. Recent literature refers to the inoculum effect exhibited by cefepime [4]. Nevertheless, we believe that this should not be pointed out as a single explanation once MIC determination is performed using inoculum concentrations of 0.5 McFarland standard. In our sample, only two K. pneumoniae harbouring SHV-2 ESBL were susceptible to cefepime. All the other clinical isolates (98.9%) expressing the ESBL phenotype were resistant to cefepime. It seems interesting that a recent study showed that cefepimewas successfully administered to three patients (two females and one male) aged between 47 years and 87 years carrying a Gram-negative ESBL-positive strain [5]. Nevertheless, other studies worldwide have begun to describe the emergence of high resistance to cefepime among Gram-negative ESBL-producers [6]. The present work showed a high diversity of ESBL enzymes occurring in the north of Portugal. In this country, the most prevalent type is still the TEM type, but CTX-M is growing rapidly [7]. The emergence of ESBL-producers resistant to cefepime in Portugal is a matter of concern. We believe that the uncontrolled use of cephalosporins may have an important role in the acquisition of resistance mechanisms, particularly the production of ESBL enzymes. Establishment of policies to monitor drug delivery in hospital and ambulatory pharmacies as well as implementation of public health defence strategies towards health promotion and drug resistance prevention appear to be urgent.
- Human salivary α-amylase (EC.3.2.1.1) activity and periodic acid and schiff reactive (PAS) staining: a useful tool to study polysaccharides at an undergraduate levelPublication . Fernandes, Ruben; Correia, Rossana; Fonte, Rosália; Prudêncio, CristinaHealth science education is presently in discussion throughout Europe due to the Bologna Declaration. Teaching basic sciences such as biochemistry in a health sciences context, namely in allied heath education, can be a challenging task since the students of preclinical health sciences are not often convinced that basic sciences are clinically valuable (J. R. Rudland, S. C. Rennie ( 2003) The determination of the relevance of basic sciences learning objectives to clinical practice using a questionnaire survey, Med. Educ. (Oxf.) 37, 962-965; E. C. Wragg ( 2003) How can we determine the relevance of basic sciences learning objectives to clinical practice?, Med. Educ. ( Oxf.) 37, 948-949). Thus, nowadays teachers are compelled to use their imagination to be able to elaborate laboratory sessions aiming for the understanding of theoretical concepts that are also clinically related: in other words, basic concepts and skills that underlie the competencies demanded of the future health professional. In the present work, we describe a set of laboratory sessions implemented in the discipline of biochemistry, belonging to the first year of several courses of allied health professionals, which can also be implemented in other health sciences courses. These sessions focus on the characteristics and properties of carbohydrates. The exercises we propose include two different laboratory practical sessions based on a histopathological routine technique known as periodic acid and Schiff reactive that is currently used to detect sugar metabolic and tumor diseases ( J. M. T. Rivera, C. T. Lopez, B. C. Segui ( 2001) Bioquimica Estructural: Conceptos y Tests, Tebar Flores, Madrid). The methodology described enables the demonstration of some biochemical properties of polysaccharides, namely animal and vegetable, and the catalytic activity of the human salivary alpha-amylase (EC.3.2.1.1) enzyme. A further comparison between alpha-amylase activity in vitro and in situ is also possible by the proposed methodology. Additionally, to this extent, a comparison between the results of the learning improvement that occurred after the implementation of this tool is presented.
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