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- Detection of Staphylococcus aureus (MRSA/MSSA) in surfaces of dental medicine equipmentPublication . Gonçalves, Eva; Carvalhal, Rui; Mesquita, Rita; Azevedo, Joana; Coelho, Maria João; Magalhães, Ricardo; Ferraz, Maria Pia; Manso, M. Conceição; Gavinha, Sandra; Pina, Cristina Maria San Román Gomes de; Cardoso, Inês LopesMethicillin-Resistant Staphylococcus aureus (MRSA) represents one of the major causes of nosocomial infections, leading to high mortality. Surfaces in clinics, as well as the attending uniform and the hands of the dental doctor can be MRSA reservoirs. Having this in mind, the purpose of this study was to evaluate the presence of Methicillin-Sensitive Staphylococcus aureus (MSSA) and MRSA on dental medicine equipment surfaces. 354 Samples were collected from six equipment surfaces in six attendance areas before and after patient consultation and cultured in a selective medium. Polymerase Chain Reaction (PCR) was used to confirm the identity of bacterial strains as MRSA or MSSA. Data analysis was performed with chi-square tests with Bonferroni correction. It was observed 55.6% of uncontaminated samples. Contamination was: 17.5% MRSA (5.9% of samples collected before patient attendance and 11.6% after); 39.3% MSSA (14.1% collected before and 25.2% after). The prevalence of MRSA and MSSA was significantly higher after patient care. Integrated Clinic represented the most contaminated attendance area (MRSA 41.7%, MSSA 51.2%), the chair arm rest was the most contaminated surface for MRSA (29.7%) and the dental spittoon the most contaminated surface for MSSA (23.5%). Although a low level of contamination was observed, dental clinics, through patients possibly carrying bacteria, may be reservoirs for MRSA and MSSA transmission, and might contribute to potential nosocomial infections.
- Health monitoring and intervention plan on oil industry workers: results from a case-studyPublication . Oliveira, Gisela; Vidal, Diogo Guedes; Ferrari, Lilian; Costa, Andre; Ferraz, Maria PiaOil industry workers are particularly vulnerable to risks related to their especial working conditions like exposure to hazardous chemicals, explosions and fires, working in confined spaces and often in remote areas or in offshore platforms. Dedicated work health surveillance plans that take into consideration environmental risks are of the utmost importance to safeguard workers health and to communicate identified faults and gaps to other institutional departments to provide adequate intervention. This work presents an assessment case-study of an on-going health intervention and monitoring plan focused on oil industry workers and the quality of potable water distributed. In the assessment of risks to health, the quality of water for human use is case-sensitive as water is vital to life but may act as a transmission vector for several diseases whose symptoms may appear as acute (often as a consequence of water contamination by micro-organisms or toxic substances) or chronic, usually more related to the ingestion of chemically contaminated water. In the study timeline, six parameters were identified as critical in the water quality: Total Coliforms, Escherichia coli, iron, pH, turbidity and colour. A global graphical distribution of nonconformity anal-ysis by working service for each geographic location and for the entire period of the study highlighted the two worse water quality work sectors: ‘Oil Extractions Stations’ and ‘Baths & Changing Rooms’. Corrective measures arising from this case-study of the on-going health monitoring and intervention plan focus on sensibilization for improvement of workers hygiene and for cleaning and sanitization procedures.
- Staphylococcus aureusandEscherichia colidual-species biofilms on nanohydroxyapatite loaded with CHX or ZnO nanoparticlesPublication . Barros, Joana; Grenho, Liliana; Fontenente, Sílvia; Manuel, Cândida M.; Nunes, Olga C.; Melo, Luís F.; Monteiro, Fernando J.; Ferraz, Maria PiaImplant-associated infections are caused by surface-adhering microorganisms persisting as biofilms, resistant to host defense and antimicrobial agents. Given the limited efficacy of traditional antibiotics, novel strategies may rely on the prevention of such infections through the design of new biomaterials. In this work, two antimicrobial agents applied to nanohydroxyapatite materials-namely, chlorhexidine digluconate (CHX) and zinc oxide (ZnO) nanoparticles-were compared concerning their ability to avoid single- or dual-species biofilms of Staphylococcus aureus and Escherichia coli. The resulting biofilms were quantified by the enumeration of colony-forming units and examined by confocal microscopy using both Live/Dead staining and bacterial-specific fluorescent in situ hybridization. The sessile population arrangement was also observed by scanning electron microscopy. Both biomaterials showed to be effective in impairing bacterial adhesion and proliferation for either single- or dual-species biofilms. Furthermore, a competitive interaction was observed for dual-species biofilms wherein E. coli exhibited higher proliferative capacity than S. aureus, an inverse behavior from the one observed in single-species biofilms. Therefore, either nanoHA-CHX or nanoHA-ZnO surfaces appear as promising alternatives to antibiotics for the prevention of devices-related infections avoiding the critical risk of antibiotic-resistant strains emergence. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 491-497, 2017.
- Prevalence of antibiotic (ß-lactams, tetracycline, metronidazole, erythromycin) resistance genes in periodontic infectionsPublication . Freitas, Daniel; Gonçalves, Lara; Coelho, Maria João; Ferraz, Maria Pia; Magalhães, Ricardo; Pina, Cristina Maria San Román Gomes de; Cardoso, Inês LopesObjective: Porphyromonas gingivalis and Prevotella intermedia are thought to be pathogens in adult periodontitis. Antibiotherapy is usually needed in the treatment of periodontitis being often prescribed empirically. To allow prescription of a specific antibiotic treatment, identification of resistance genes should be performed. The aim of this study was the identification of the presence of TetM, TetQ, TEM, cfxA, MefA, ErmB and Nim resistance genes in previously identified P. intermedia and P. gingivalis isolated from samples collected from periodontal infections. Method: PCR was used for the identification of TetM, TetQ, TEM, cfxA, MefA, ErmB and Nim resistance genes in strains isolated from samples collected from periodontal infections. Results: It was seen that 8% of isolates had one of the tested tetracycline resistance genes. A total of 32% of β-lactamases resistance genes was observed in isolated strains. It was also observed that 2% of isolates had one of the analysed erythromycin resistance genes. None of the isolates showed the presence of the metronidazole resistance gene. Conclusions: Most strains harboring β-lactamase resistance genes had been previously identified as P. intermedia. No tetracycline resistance gene and a very low percentage of β-lactamase resistance genes were observed in P. gingivalis strains.
- Lytic bacteriophages against multidrug-resistant Staphylococcus aureus, Enterococcus faecalis and Escherichia coli isolates from orthopaedic implant-associated infectionsPublication . Barros, Joana; Melo, Luís D.R.; Poeta, Patrícia; Igrejas, Gilberto; Ferraz, Maria Pia; Azeredo, Joana; Monteiro, Fernando J.Orthopaedic implant-associated infections are a devastating complication of orthopaedic surgery with a significant impact on patients and healthcare systems. The aims of this work were to describe the patterns of antimicrobial resistance, pathogenicity and virulence of clinical bacterial isolates from orthopaedic implant-associated infections and to further isolate and characterise bacteriophages that are efficient in controlling these bacteria. Staphylococcus aureus, Enterococcus faecalis and Escherichia coli isolated from orthopaedic infections showed multiresistance patterns to the most frequently used antibiotics in clinical settings. The presence of mobile genetic elements (mecA, Tn916/Tn1545 and intl1) and virulence determinants (icaB, cna, hlb, cylLs, cylM, agg, gelE, fsr and fimA) highlighted the pathogenicity of these isolates. Moreover, the isolates belonged to clonal complexes associated with the acquisition of pathogenicity islands and antimicrobial resistance genes by recombination and horizontal gene transfer. Bacteriophages vB_SauM_LM12, vB_EfaS_LM99 and vB_EcoM_JB75 were characterised and their ability to infect clinical isolates of S. aureus, E. faecalis and E. coli, respectively, was assessed. Morphological and genomic analyses revealed that vB_EfaS_LM99 and vB_EcoM_JB75 belong to the Siphoviridae and Myoviridae families, respectively, and no genes associated with lysogeny were found. The bacteriophages showed low latent periods, high burst sizes, broad host ranges and tolerance to several environmental conditions. Moreover, they showed high efficiency and specificity to infect and reduce clinical bacteria, including methicillin-resistant S. aureus and vancomycin-resistant enterococci. Therefore, the results obtained suggest that the bacteriophages used in this work are a promising approach to control these pathogens involved in orthopaedic implant-associated infections.
- Efeitos da vancomicina, tetraciclina, tigeciclina e metronidazol na proliferação/viabilidade de uma linha de células osteoblásticasPublication . Pacheco, Ana Paula; Ferraz, Maria Pia; Coelho, Maria João; Alegrete, Nuno; Fernandes, Maria HelenaNeste estudo foram avaliados mecanismos citotóxicos de alguns antibacterianos usados nos tratamentos de infecções ósseas, nomeadamente vancomicina, tetraciclina, tigeciclina e metronidazol numa gama de concentrações de 0,005 μg/mL a 100 μg/mL. Relativamente à vancomicina não foi encontrada nenhuma evidência de citotoxicidade sobre as células MG63. A tetraciclina tem um efeito tóxico a partir da concentração de 0,5 μg/mL, efeito igualmente verificado na tigeciclina, no entanto para concentrações inferiores a 0,01 μg/mL parece ter ocorrido uma estimulação da divisão celular para este último antibiótico. No caso do metronidazol parece ocorrer logo uma diminuição da proliferação nas concentrações inferiores a 0,05 μg/mL. In this study the citoxicity of some antibacterials commonly used in bone infections, namely vancomycin, tetracycline, tigecyclin and metronidazol in a concentration range of 0.005 μg/mL to 100 μg/mL was evaluated. Vancomycin did not present any evidence of causing citotoxic effects to MG63 cells. Tetracycline did present toxic effects in concentrations above 0.5 μg/mL. The same phenomena was observed with tigecycline, however in low concentrations (below to 0.01 μg/mL) proliferation of cells seemed to be increased. In the case of metronidazol proliferation was diminished in concentrations below to 0.05 μg/mL.
- Equisetum arvense: avaliação das possibilidades de aplicação na regeneração ósseaPublication . Ferraz, Maria Pia; Pereira, Ana Catarina; Lopes, Maria Ascenção; Fernandes, Maria HelenaA procura de produtos naturais para o tratamento de doenças específicas tem aumentado muitos nos últimos anos, nomeadamente aquelas direccionadas para doenças do tecido ósseo como por exemplo a osteoporose. A utilização de fitoestrogéneos, dehydroepiandroesterona (DHEA) e vitamina K2 não só é segura como tem havido resultados clínicos preliminares estatisticamente controlados que suportam a vantagem da utilização de produtos naturais no tratamento da osteoporose. Há vários produtos de medicina tradicional Chinesa utilizados em ortopedia alegadamente com resultados satisfatórios. Neste trabalho extractos de Equisetum arvense, uma planta que cresce em solo português, foram estudados de forma a avaliar a possibilidade de serem usados como factores indutores de crescimento ósseo. Consumers are increasingly looking to natural health products to manage specific diseases like bone tissue diseases such as osteoporosis. The safety of phytoestrogens, dehydroepiandrosterone (DHEA) and vitamin K2 and the preliminary positive results from randomized controlled trials, provides some support for the use of Natural Health Products (NHP) in the prevention of osteoporosis. There are several traditional Chinese medicines commonly used to manage disorders of orthopaedics and were alleged to have obtained satisfactory results. Equisetum arvense a plant present in Potuguese soil was studied in order to evaluate the possibility of being used as an osteogenesis stimulator factor.
- Nasal carriage of Staphylococcus aureus among nursing students during curricular internshipPublication . Ferraz, Maria Pia; Magalhães, Ricardo; Pina, Cristina Maria San Román Gomes de; Coelho, Maria João; Cardoso, Inês Lopes
- Complexos catiónicos lipossoma-DNA: um veículo não viral alternativo para terapia genética em tecido ósseoPublication . Ferraz, Maria Pia; Cabral, AndreiaO desenvolvimento de vectores continua a ser um dos grandes problemas em terapia genética. Os diversos tipos de vectores são utilizados com o objectivo de transportar o DNA terapêutico ao núcleo das células-alvo, sendo os mais utilizados os vectores virais, dado a sua eficiência na libertação intracelular do material genético. No entanto, os lipossomas catiónicos, sendo vectores não virais, podem constituir um bom método para a libertação de genes em células do tecido ósseo, dado a sua versatilidade e segurança. The development of vectors is one of the biggest challenges in genetic therapy. The different types of vectors are used with the goal of transporting therapeutic DNA to the target cells nucleus. Viral vecteors are the most used due to their efficiency on intracelular release of genetic material. However, cathonic lipossomes can also be effective for delivering genes to bone tissue cells mainly due to their versatility and safety.
- Identification of nasal carriage of Staphylococcus aureus among nursing students during curricular clinical internships: an observational studyPublication . Coelho, Maria João; Magalhães, Ricardo; Cardoso, Inês Lopes; Pina, Cristina Maria San Román Gomes de; Ferraz, Maria PiaStaphylococcus aureusis considered one of the most frequently isolated bacteria in the community and in the hospital environment, beingassociated with several infections.Healthcare professionalsrepresent a group vulnerable to Staphylococcus aureus and MRSAcolonization, therefore being potential disseminators of these microorganisms during their care activities.The aim of this study was to evaluate the dynamics of S. aureusand MRSA nasal colonization among nursing students over the four years of university attendance, including pre-clinical exposure and at different moments during clinical rotations. Samples were collected from students from the 1st, 2nd, 3rdand 4thyear. The study identified 55.9% MSSA positive samples and 31.4% MRSA positive samplesfrom the total studied population. Simultaneous carriage of MRSA and MSSA was observed in students from all years of the nursing degree, but a highest MSSA colonization (61.5%) was linked to a lower MRSA colonization (30.8%). MRSA colonization seems to be dependent on the type of clinical internship, since the group attending internship in emergency rooms and surgery wards presented a significant increase in the amount of MRSA samples. Nursing students should be educated on the risks involved in carrying S.aureus and MRSA and informed about infection control measures.