Susceptibilidade de amostras clínicas de pseudomonas aeruginosa a antibióticos e a Clorexidina.

Backgound and Objectives: Aimed to investigate whether there is a possible association between antibiotic resistance and susceptibility to chlorhexidine of 65 clinical strains of Pseudomonas aeruginosa isolated from patients in a Brazilian hospital. Methods: The samples were identified by the MicroScan system and the sensitivity to antibiotics was performed by the disk diffusion technique. The minimum inhibitory concentration (MIC) of chlorhexidine was evaluated by broth dilution method and bactericidal activity at concentrations of 0.2% and 2%, was evaluated by the test suspension, according to the European Standard 1040. Results: All strains tested showed sensitivity to polymyxin, followed by piperacillin / tazobactam (75.4%), ceftazidime and cefepime (41.5%), tobramycin (36.9%), aztreonam and amikacin (33.8%), levofloxacin (30.8%), ciprofloxacin (29.2%), ofloxacin (27.3%), gentamicin (26.2%) and ceftriaxone (7.7%). The MIC of chlorhexidine ranged from 2.5 to 40 micrograms / ml, with MIC50 and MIC90 of 10 and 20 mg / ml. In a suspension test, the concentration of chlorhexidine in 2% destroy any bacterial cell inoculum of 65 samples. At the concentration of 0.2% chlorhexidine removed 24.2% (15/65) of samples. A sample showed reduced susceptibility chlorhexidine, ie, in the test suspension, the reduction of viable bacteria in the inoculum was less than 5 log10. Three other samples were very close to a logarithmic reduction of 5. Conclusion: In our study, the results of in vitro tests with chlorhexidine were homogeneous, seeming to indicate an association of biocide with multiple antibiotic resistance of P aeruginosa samples tested. Noteworthy is the finding of a sample of P. aeruginosa with reduced susceptibility to chlorhexidine use in dilution of 0.2%. KEYWORDS: Pseudomonas aeruginosa. Chlorhexidine. Resistance.Justificativa e Objetivos: Pseudomonas aeruginosa é um importante patógeno hospitalar oportunista que apresenta diferentes mecanismos de resistência aos antibióticos constituindo um problema de grande importância em saúde pública Objetivou investigar se existe uma possível associação entre a resistência a antibióticos e a susceptibilidade a clorexidina de 65 amostras clínicas de Pseudomonas aeruginosa, isoladas de pacientes internados em um hospital brasileiro. Métodos: As amostras foram identificadas pelo sistema MicroScan e o perfil de sensibilidade aos antibióticos foi realizado pela técnica de disco-difusão. A concentração inibitória mínima (CIM) da clorexidina foi avaliada pelo método de diluição em caldo e a atividade bactericida, nas concentrações de 0,2% e de 2%, foi avaliada pelo teste de suspensão, de acordo com a Norma Européia 1040. Resultados: Todas as amostras testadas apresentaram sensibilidade a polimixina, seguida da piperacilina/tazobactam (75,4%). A CIM da clorexidina variou de 2,5 a 40 µg/ml, com CIM50 e CIM90 de 10 e 20 µg/ml. No teste de suspensão, a clorexidina na concentração de 0,2% eliminou 24,2% (15/65) das amostras. Uma amostra apresentou susceptibilidade qreduzida a clorexidina, i.e., no teste de suspensão, a redução de bactérias viáveis do inóculo foi inferior a 5 Log10. Outras três amostras sofreram uma redução logarítmica muito próxima de 5. Conclusão: Em nosso estudo, os resultados dos testes in vitro com a clorexidina foram homogêneos, parecendo não indicar uma associação deste biocida com a múltipla resistência aos antibióticos das amostras de P aeruginosa testadas. Destaca-se o achado de uma amostra de P. aeruginosa com reduzida susceptibilidade a clorexidina na diluição de uso de 0,2%. Palavras-chave: P. aeruginosa, clorexidina, resistência

Review of epidemiological and clinical characteristics and overall survival.

Backgound and Objectives: Aimed to investigate whether there is a possible association between antibiotic resistance and susceptibility to chlorhexidine of 65 clinical strains of Pseudomonas aeruginosa isolated from patients in a Brazilian hospital. Methods: The samples were identified by the MicroScan system and the sensitivity to antibiotics was performed by the disk diffusion technique. The minimum inhibitory concentration (MIC) of chlorhexidine was evaluated by broth dilution method and bactericidal activity at concentrations of 0.2% and 2%, was evaluated by the test suspension, according to the European Standard 1040. Results: All strains tested showed sensitivity to polymyxin, followed by piperacillin / tazobactam (75.4%), ceftazidime and cefepime (41.5%), tobramycin (36.9%), aztreonam and amikacin (33.8%), levofloxacin (30.8%), ciprofloxacin (29.2%), ofloxacin (27.3%), gentamicin (26.2%) and ceftriaxone (7.7%). The MIC of chlorhexidine ranged from 2.5 to 40 micrograms / ml, with MIC50 and MIC90 of 10 and 20 mg / ml. In a suspension test, the concentration of chlorhexidine in 2% destroy any bacterial cell inoculum of 65 samples. At the concentration of 0.2% chlorhexidine removed 24.2% (15/65) of samples. A sample showed reduced susceptibility chlorhexidine, ie, in the test suspension, the reduction of viable bacteria in the inoculum was less than 5 log10. Three other samples were very close to a logarithmic reduction of 5. Conclusion: In our study, the results of in vitro tests with chlorhexidine were homogeneous, seeming to indicate an association of biocide with multiple antibiotic resistance of P aeruginosa samples tested. Noteworthy is the finding of a sample of P. aeruginosa with reduced susceptibility to chlorhexidine use in dilution of 0.2%. KEYWORDS: Pseudomonas aeruginosa. Chlorhexidine. Resistance