Molecular analysis of resistance genes and virulence factors in clinical isolates of Pseudomonas aeruginosa
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2019-12-17
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“Análise molecular dos genes de resistência e fatores de virulência de isolados clínicos de Pseudomonas aeruginosa” Pseudomonas aeruginosa é considerada uma das principais causas de infeções hospitalares, denominadas de infeções nosocomiais, em todo o mundo entre pacientes hospitalizados. Este organismo possui uma grande versatilidade metabólica e capacidade de crescer em diferentes nichos ecológicos. É geralmente multirresistente e está associada a riscos de morbilidade e mortalidade. Neste estudo, foram avaliados os mecanismos de resistência a antibióticos e virulência de trinta e dois isolados clínicos de P. aeruginosa provenientes do CHTMAD, Vila Real, Portugal. O primeiro objetivo desta dissertação foi estudar a prevalência de P. aeruginosa em amostras clínicas e determinar seu fenótipo de resistência antimicrobiana utilizando agentes antipseudomonais: Amicacina, Gentamicina, Tobramicina, Ciprofloxacina, Aztreonam, Doripenemo, Meropenemo, Imipenemo, Cefepime, Ceftazidima, Piperacilina, Ticarcillina-ácido clavulânico e Colistina. Todos os isolados de P. aeruginosa apresentaram resistência ao antibiótico da classe dos carbapenemos, o Imipenemo. Além disso, esses isolados são multirresistentes, pois são resistentes a três ou mais classes de antimicrobianos (93,9%), como Cefalosporinas, Fluoroquinolonas e Penicilina. O segundo objetivo foi analisar os genes associados à resistência aos Carbapenemos (KPC, NDM, SPM e VIM-2) e fatores de virulência (toxA, algD, plcH, plcN e pilA) associados à patogenicidade de P. aeruginosa. Os resultados obtidos para os genes de produção de resistência aos Carbapenemos demonstram prevalência moderada (36,7%) em isolados de P. aeruginosa. Para os fatores de virulência foi também encontrada uma prevalência moderada (42,5%). O terceiro objetivo foi estudar a produção de biofilme, já que P. aeruginosa é uma bactéria com maior habilidade de formar biofilme. A produção de biofilme foi avaliada por três métodos distintos: método Congo Red, método do Tubo e método da Microplaca. Nos resultados obtidos neste estudo, o método da microplaca foi considerado o método mais eficaz na deteção da produção de biofilme. Conclui-se que o trabalho desenvolvido é de grande importância na epidemiologia, resistência antimicrobiana e virulência em isolados clínicos de P. aeruginosa. É ainda, importante detetar e controlar a disseminação de microrganismos multirresistentes.
“Molecular analysis of resistance genes and virulence factors in clinical isolates of Pseudomonas aeruginosa” Pseudomonas aeruginosa is one of the leading causes of hospital-acquired infections, also known as nosocomial infections, worldwide among hospitalized patients. This organism has a great metabolic versatility and ability to grow in different ecological niches. Is commonly multirresistant and are associated with high risks of morbidity and mortality. In this study, the antibiotic-resistance and virulence mechanisms of thirty-two clinical P. aeruginosa isolates from CHTMAD, Vila Real, Portugal were evaluated. The first objective of this dissertation was studying the P. aeruginosa prevalence in clinical samples and determine their antimicrobial resistance phenotype used antipseudomonal agents: Amikacin, Gentamicin, Tobramycin, Ciprofloxacin, Aztreonam, Doripenem, Meropenem, Imipenem, Cefepime, Ceftazidime, Piperacillin, Ticarcillin-clavulanic acid and Colistin. All P. aeruginosa isolates in this study presented resistant to carbapenem antibiotic imipenem. In addition, these isolates are multidrug resistant as they were resistant to three or more classes of antimicrobials (93.9%), such as Cephalosporin, Fluoroquinolones and Penicillin. The second objective was to analyse genotypically the resistance genes associated with carbapenem resistance (KPC, NDM, SPM and VIM-2) and virulence factors (toxA, algD, plcH, plcN and pilA) that are associated with the pathogenicity of P. aeruginosa. The results obtained for Carbapenem resistance production genes demonstrate a moderate prevalence (36.7%) in P. aeruginosa isolates. For the virulence factors also a moderate prevalence (42.5%) was found. The third objective was to study the biofilm production since P. aeruginosa is a bacterium with a greater hability to form biofilm. The biofilm production was evaluated by three distinct methods: Congo Red method, Tube method and Microtiter method. Based in our results microtiter plate method was found to be the most effective method in the detection of biofilm production. It is concluded that the work developed is of great importance in epidemiology, antimicrobial resistance and virulence in clinical isolates P. aeruginosa. It is also important to detect and control the spread of multidrug-resistance microorganisms.
“Molecular analysis of resistance genes and virulence factors in clinical isolates of Pseudomonas aeruginosa” Pseudomonas aeruginosa is one of the leading causes of hospital-acquired infections, also known as nosocomial infections, worldwide among hospitalized patients. This organism has a great metabolic versatility and ability to grow in different ecological niches. Is commonly multirresistant and are associated with high risks of morbidity and mortality. In this study, the antibiotic-resistance and virulence mechanisms of thirty-two clinical P. aeruginosa isolates from CHTMAD, Vila Real, Portugal were evaluated. The first objective of this dissertation was studying the P. aeruginosa prevalence in clinical samples and determine their antimicrobial resistance phenotype used antipseudomonal agents: Amikacin, Gentamicin, Tobramycin, Ciprofloxacin, Aztreonam, Doripenem, Meropenem, Imipenem, Cefepime, Ceftazidime, Piperacillin, Ticarcillin-clavulanic acid and Colistin. All P. aeruginosa isolates in this study presented resistant to carbapenem antibiotic imipenem. In addition, these isolates are multidrug resistant as they were resistant to three or more classes of antimicrobials (93.9%), such as Cephalosporin, Fluoroquinolones and Penicillin. The second objective was to analyse genotypically the resistance genes associated with carbapenem resistance (KPC, NDM, SPM and VIM-2) and virulence factors (toxA, algD, plcH, plcN and pilA) that are associated with the pathogenicity of P. aeruginosa. The results obtained for Carbapenem resistance production genes demonstrate a moderate prevalence (36.7%) in P. aeruginosa isolates. For the virulence factors also a moderate prevalence (42.5%) was found. The third objective was to study the biofilm production since P. aeruginosa is a bacterium with a greater hability to form biofilm. The biofilm production was evaluated by three distinct methods: Congo Red method, Tube method and Microtiter method. Based in our results microtiter plate method was found to be the most effective method in the detection of biofilm production. It is concluded that the work developed is of great importance in epidemiology, antimicrobial resistance and virulence in clinical isolates P. aeruginosa. It is also important to detect and control the spread of multidrug-resistance microorganisms.
Descrição
Dissertação de Mestrado em Bioquímica
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Pseudomonas aeruginosa , resistência a antibióticos