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O envelhecimento populacional traz um número vasto de implicações que incluem, entre outras, condições de baixa imunidade. Esta situação implica maior risco de infecções no idoso, comparativamente ao jovem. Outras situações podem, também, contribuir para aumentar esse risco, nomeadamente má ventilação, aglomerado populacional, condições de humidade. Condições especiais, como o caso de indivíduos portadores, podem também contribuir para o risco de infecções no idoso.
O tratamento das infecções passa pela administração criteriosa de antibióticos. A identificação de espécies e estirpes é de grande importância, assim como a indicação adequada dos antibióticos. Nesse sentido, o Sistema Europeu de Vigilância da Resistência Antimicrobiana (EARSS) alerta para o desenvolvimento de bactérias multiresistentes aos antibióticos que deste modo representam uma ameaça crescente para a eficácia destes medicamentos.
O objectivo geral deste trabalho foi o de isolar e caracterizar estirpes bacterianas de Gram positivo provenientes de isolados ambientais em Lares de 3ª idade, bem como descrever o seu perfil de resistência a diversos grupos de antibióticos. Como complemento, estudou-se também a sua susceptibilidade a dois tipos de desinfectantes comummente utilizados.
As amostras foram recolhidas num único tempo de recolha e estas foram transportadas para laboratório no meio Cary Blair. Este estudo fará referência às amostras de zaragatoas de superfície provenientes de três lares de 3ª idade, localizados no distrito de Bragança.
No isolamento foi utilizado um meio selectivo (Ágar Chapman), de acordo com os géneros a estudar. Para a identificação preliminar dos isolados utilizaram-se métodos morfo-fisiológicos, nomeadamente a coloração de Gram e um conjunto de provas bioquímicas (oxidase, catalase e coagulase). Para a identificação dos géneros dos isolados de Gram positivo em estudo utilizou-se o sistema de identificação numérica API Staph (bioMérieux).
A susceptibilidade aos agentes antibacterianos foi determinada pela técnica de difusão em disco (método Kirby Bauer), avaliando-se o comportamento dos isolados estudados face a diversos grupos de antibióticos: β-lactâmicos, aminoglicosídicos, quinolonas, tetraciclinas, fenicóis, sulfonamidas, macrólidos, fosfomicinas, glicopéptidos, fluroquinonas e ansamicinas. A susceptibilidade das bactérias aos desinfectantes também foi determinada pela técnica de difusão em disco.
Da análise do perfil de susceptibilidade aos antibióticos verificou-se que dois dos três lares de 3ª idade estudados apresentaram multiresistência a antibióticos, nomeadamente ao ácido nalidíxico (quinolonas), sulfametoxazol (sulfonamidas) e eritromicina (macrólidos). Os resultados mostram que os isolados apresentaram maior resistência ao ácido nalidíxico e apresentaram maior sensibilidade, isto é, maior eficácia à vancomicina e teicoplanina (glicopeptídeos) e à rifampicina (ansamicinas).
Relativamente aos desinfectantes, verificou-se eficácia para ambos, no entanto em termos relativos o desinfectante à base de compostos clorados mostrou-se mais eficaz.
Das bactérias identificadas destaca-se Staphylococcus cohnii, Staphylococcus xylosus e Staphylococcus epidermidis, estas duas últimas espécies apresentaram um perfil de multi-resistência.
Staphylococcus epidermidis e Staphylococcus cohnii são espécies da microbiota normal dos humanos e geralmente poderão resultar de contaminação hospitalar (nosocomiais), enquanto que Staphylococcus xylosus normalmente é isolada de produtos lácteos e carne e é comummente usada para a fermentação de carnes, e a sua presença no Lar poderá ser devida a contaminação cruzada do ambiente das cozinhas.
Estes resultados vêem confirmar a importância de consciencializar utentes e funcionários para correctas práticas de higiene pessoal.
Population aging brings a vast number of implications that include, among others, low immunity conditions. This implies a higher risk of infections in the elderly compared to young people. Some situations can increase this risk, including poor ventilation, crowded population and moist conditions. Special conditions, as the case of individuals with infections, may also contribute to the risk of contamination in the elderly. The treatment of infections involves the careful administration of antibiotics, knowing that the identification of species and strains is of great importance, as well as appropriate antibiotics indication. In this sense, the European System of Antimicrobial Resistance Surveillance (EARSS) alert to the development of antibiotic-resistant bacteria, which thus represent a growing threat to the effectiveness of these drugs. The overall objective of this study was to isolate and characterize gram-positive bacterial strains, derived from environmental isolates in nursing homes, and to describe the profile of resistance to several groups of antibiotics. In addition, we also studied their susceptibility to two types of commonly used disinfectants. Samples were collected on a single sampling time, and these were transported to the laboratory in a Cary Blair medium. This study refers to the surface swab samples from three nursing homes located in the district of Bragança. On insulation was used in a selective medium (Chapman agar), according to study gender. For preliminary identification of isolates were used morphological and physiological methods, including Gram stain and a set of biochemical tests (oxidase, catalase and coagulase), and for the identification of genera of the Gram-positive isolates, we used the numeric identification system API Staph (bioMérieux). Resistance to antibacterial agents was determined by disk diffusion technique (Kirby Bauer method), evaluating the behavior of the isolates against various groups of antibiotics: β-lactams, aminoglycosides, quinolones, tetracycline, fenicol, sulfonamides, macrolides, fosfomycin, glycopeptides, ansamycin and fluoroquinolones. The susceptibility of bacteria to disinfectants was also evaluated by the disk diffusion technique. From the profile analysis of antibiotic susceptibility tested in Gram positive bacteria, it was found that two of the three nursing homes studied showed multidrug resistance to antibiotics, including nalidixic acid (quinolones), sulfamethoxazole (sulfonamide) and erythromycin (macrolide). The results showed that the more resistant isolated was to nalidixic acid and that the higher sensitivity, ie, the most effectives were to vancomicin, teicoplanin (glycopeptide) and rifampicin (ansamicin). Regarding to disinfectants, we seen that both were effective, however, in relative terms, the disinfectant based on chlorine was more effective. From bacteria identified, stands out the Staphylococcus cohnii, Staphylococcus xylosus and Staphylococcus epidermidis, showing both of them a multi-resistance profile. Staphylococcus epidermidis and Staphylococcus cohnii are species of the normal microbiota of humans and can often result from hospital contamination (nosocomial), while Staphylococcus xylosus is usually isolated from dairy products and meat. It is usually used for fermentation of meat and its presence in the home, may be due to cross contamination of the environment of the kitchen. These results confirm the importance of user and staff awareness to correct personal hygiene practices.
Population aging brings a vast number of implications that include, among others, low immunity conditions. This implies a higher risk of infections in the elderly compared to young people. Some situations can increase this risk, including poor ventilation, crowded population and moist conditions. Special conditions, as the case of individuals with infections, may also contribute to the risk of contamination in the elderly. The treatment of infections involves the careful administration of antibiotics, knowing that the identification of species and strains is of great importance, as well as appropriate antibiotics indication. In this sense, the European System of Antimicrobial Resistance Surveillance (EARSS) alert to the development of antibiotic-resistant bacteria, which thus represent a growing threat to the effectiveness of these drugs. The overall objective of this study was to isolate and characterize gram-positive bacterial strains, derived from environmental isolates in nursing homes, and to describe the profile of resistance to several groups of antibiotics. In addition, we also studied their susceptibility to two types of commonly used disinfectants. Samples were collected on a single sampling time, and these were transported to the laboratory in a Cary Blair medium. This study refers to the surface swab samples from three nursing homes located in the district of Bragança. On insulation was used in a selective medium (Chapman agar), according to study gender. For preliminary identification of isolates were used morphological and physiological methods, including Gram stain and a set of biochemical tests (oxidase, catalase and coagulase), and for the identification of genera of the Gram-positive isolates, we used the numeric identification system API Staph (bioMérieux). Resistance to antibacterial agents was determined by disk diffusion technique (Kirby Bauer method), evaluating the behavior of the isolates against various groups of antibiotics: β-lactams, aminoglycosides, quinolones, tetracycline, fenicol, sulfonamides, macrolides, fosfomycin, glycopeptides, ansamycin and fluoroquinolones. The susceptibility of bacteria to disinfectants was also evaluated by the disk diffusion technique. From the profile analysis of antibiotic susceptibility tested in Gram positive bacteria, it was found that two of the three nursing homes studied showed multidrug resistance to antibiotics, including nalidixic acid (quinolones), sulfamethoxazole (sulfonamide) and erythromycin (macrolide). The results showed that the more resistant isolated was to nalidixic acid and that the higher sensitivity, ie, the most effectives were to vancomicin, teicoplanin (glycopeptide) and rifampicin (ansamicin). Regarding to disinfectants, we seen that both were effective, however, in relative terms, the disinfectant based on chlorine was more effective. From bacteria identified, stands out the Staphylococcus cohnii, Staphylococcus xylosus and Staphylococcus epidermidis, showing both of them a multi-resistance profile. Staphylococcus epidermidis and Staphylococcus cohnii are species of the normal microbiota of humans and can often result from hospital contamination (nosocomial), while Staphylococcus xylosus is usually isolated from dairy products and meat. It is usually used for fermentation of meat and its presence in the home, may be due to cross contamination of the environment of the kitchen. These results confirm the importance of user and staff awareness to correct personal hygiene practices.
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Citation
Amaro, Andreia Inês Alves (2011). Susceptibilidade a antibióticos em isolados bacterianos do ambiente em lares de 3ª idade. Bragança: Escola Superior Agrária. Dissertação de Mestrado em Biotecnologia
Publisher
Instituto Politécnico de Bragança, Escola Superior Agrária