Evaluation of sodium hypochlorite efficiency on the elimination of Pseudomonas aeruginosa biofilm using two methods

Abstract

Aims — The purposes of the present work were to study the biofilm formation of Pseudomonas aeruginosa on stainless steel (316 and 304) and to investigate the effectiveness of sodium hypochlorite with different concentrations after 5 min of treatment, against P. aeruginosa biofilm formed on the same substrata. Methods — The methods used in this study were plate count method (PCM) and atomic force microscopy (AFM). Results — The results obtained using PCM showed that bacteria adhered more to stainless steel 316 than stainless steel 304. Furthermore, sodium hypochlorite was effective against cells of P. aeruginosa adhered to stainless steel 304 at the concentration of 0.5 %, but it was not effective against the ones adhered to stainless steel 316 until the concentration of 1%. The AFM results appeared that some bacteria still adhered to two types of stainless steel after sodium hypochlorite treatment at all concentrations. Conclusion — The type of surface and the disinfectant concentration have an effect on the efficiency of the disinfectant against biofilm. In addition the PCM and AFM do not give the same results.