As infecções nosocomiais têm se tornado uma importante causa de morbidade e mortalidade em todo o mundo. Práticas adequadas de higiene e desinfecção ambiental são fundamentais para o controle destas infecções. O objetivo deste trabalho foi avaliar a atividade bactericida de alguns desinfetantes em amostras hospitalares resistentes e sensíveis à antibióticos. A susceptibilidade aos desinfetantes e antibióticos de 27 amostras clínicas foi determinada pelo Método de Diluição de Uso (AOAC) e pelo Método de Kirby-Bauer, respectivamente. Os resultados mostraram que todas as amostras testadas foram susceptíveis ao hipoclorito de sódio, ao glutaraldeído e à associação de quaternário de amônio-formaldeído-álcool etílico. Contudo, a susceptibilidade das amostras ao fenol e ao quaternário de amônio se mostrou variável. Entre 21 amostras multirresistentes à antibióticos (Staphylococcus resistente à meticilina, Enterococcus spp, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Serratia marcescens e Escherichia coli) onze (52%) e oito (38%) foram resistentes ao composto quaternário de amônio e aos fenóis, respectivamente. Dentre as 6 amostras que demonstraram susceptibilidade aos antibióticos (estafilococos, Enterococcus spp, P. mirabilis, E. cloacae e E. coli), duas amostras (33%) mostraram resistência a estes desinfetantes. Os resultados observados neste estudo mostraram que não houve correlação entre susceptibiliadde à antibióticos e susceptibilidade à desinfetantes quando foram analisadas amostras clínicas hospitalares.

Nosocomial infections are an important cause of morbidity and mortality all over the world. It has been shown that appropriate environmental hygienic and disinfection practices can be very helpful to hospital infection control. The purpose of this study was to evaluate the bactericidal activity of some disinfectants against antibiotic-susceptible and antibiotic-resistant hospital bacterial isolates. The susceptibility of 27 clinical isolates to disinfectants and antibiotics was determined by the Association of Official Analytical Chemist’s (AOAC) Use-Dilution method and by the Kirby-Bauer method, respectively. All strains tested were susceptible to sodium hypochlorite, glutaraldehyde and to the association quaternary ammonium - formaldehyde - ethyl alcohol disinfectants. However, the susceptibility of strains to phenol and to one quaternary ammonium compound was variable. Among twenty-one antibiotic-multiresistant strains (methicillin-resistant staphylococci, Enterococcus spp, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Serratia marcescens and Escherichia coli) eleven (52%) and eight (38%) strains were resistant to the quaternary ammonium and phenol compounds, respectively. Among six isolates that demonstrated susceptibility to antibiotics (staphylococci, Enterococcus spp, P. mirabilis, E. cloacae and E. coli) two strains (33%) showed resistance to these disinfectants. The results demonstrated the lack of correlation between antibiotic-susceptibility and susceptibility to disinfectants in hospital strains.

Fresh and salt water samples analyzed in Rio de Janeiro city showed the presence of Plesiomonas shigelloides. Forty-six strains were isolated from both environments. A high incidence of P. shigelloides was achieved in polluted fresh and salt waters as well as in samples from non-polluted streams. P. shigelloides isolates had biochemical characteristics similar to those already described in the literature. None of the isolates analyzed produced enterotoxin in the suckling mouse assay. Hemolytic activity against sheep and human type A erythrocytes was detected in the strains tested. The results of the antibiotic susceptibility tests indicated that all the isolates were susceptible to the cephalosporins, penicillins combined with a beta-lactamase inhibitor, aminoglycosides, imipenem, norfloxacin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole. All the isolates were resistant to the penicillins.