Resumen

GUIMARAES, José R.; FARAH, Carolina R. T.  y  FADINI, Pedro S.. Short-term toxicity test: monitoring Klebsiella oxytoca bacterium respiration using a flow injection analysis/conductometric system. J. Braz. Chem. Soc. [online]. 2012, vol.23, n.3, pp. 461-467. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532012000300012.

In this study, the Klebsiella oxytoca bacterium was used as a test organism in short-term toxicity evaluations, and Escherichia coli was used as reference. The inhibition of bacterial growth was quantified by flow injection analysis (FIA) via conductometric measurements of the CO₂ produced during respiration. The results were expressed as effective concentration (EC₅₀) values. K. oxytoca was more resistant than E. coli in respect to growth inhibition. The metal sensitivity order for K. oxytoca was found to be Hg²⁺ > Cd²⁺ > Cu²⁺ and Hg²⁺ > Cu²⁺ > Cd²⁺ for E. coli. The sensitivity to the Laborhex 2 detergent (active ingredient: chlorhexidine digluconate) was 1.55 ± 0.32 mg L^-1 and 0.32 ± 0.10 mg L^-1 for K. oxytoca and E. coli, respectively. The bacteria showed comparable sensitivities to the Riodeine Degermant detergent (active ingredient: polyvinyl pyrrolidone-iodine-PVP-I), of 11.0 ± 1.7 mg L^-1 and 12.0 ± 2.0 mg L^-1, for K. oxytoca and E. coli, respectively.

Palabras llave : short-term toxicity test; Klebsiella oxytoca; Escherichia coli; heavy metals; hospital detergents.