Disinfectant and antibiotic activities: a comparative analysis in brazilian hospital bacterial isolates

ABSTRACT

Nosocomial infections are an important cause of morbidity and mortality all over the world. It has been shown that appropriate enviromental 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 quartenary ammonium - formaldehyde - ethyl alcohol disinfectants. However, the susceptibility of strains to phenol and to one quartenary 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(per cent)) and eight (38(per cent)) 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(per cent)) showed resisance to these disinfectants. The results demosntrated the lack of correlation between antibiotic-susceptibility and susceptibility to disinfectants in hospital strains